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234 Cards in this Set
- Front
- Back
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What are the 6 classic gram-positive bacteria that cause most of the disease in humans?
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Coccus:
1) Streptococcus 2) Staphylococcus Spore producing: 3) Bacillus 4) Clostridium Non-spore producing: 5) Corynebacterium 6) Listeria |
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How does the appearance of streptococcus and staphylococcus differ? Which is catalase positive?
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Strep - strip
Staph - grape clusters; catalase positive |
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What is the other name for group A Beta-Hemolytic Strep?
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Streptococcus pyogenes
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What are the 4 diseases that Strep pyogenes cause by local invasion or exotoxin release? What 2 diseases does it cause through delayed antibody mediated?
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1) Streptococcal pharyngitis
2) Streptococcal skin infection (necrotizing fasciitis) 3) Scarlet fever 4) Streptococcal toxic shock syndrome 1) Rheumatic fever 2) Glomerulonephritis |
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If a bright red rash begins on the trunk and neck and then spreads to the extremities, sparing the face, what is the probable disease and cause?
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Scarlet fever, caused by Strep pyogenes (Group A Beta-hemolytic Streptococci)
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What diplococcus causes the 2nd most common STD? Is it gram positive or negative?
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Neisseria gonorrhoeae
Gram negative |
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What's the difference between endotoxins and exotoxins? What is the only gram positive bacteria to produce endotoxin?
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Endotoxin is lipid A, which is a piece of the outer membrane LPS of gram-negative bacteria. Listeria monocytogenes is the only gram-positive bacteria to excrete.
Exotoxin is a protein released by both gram-positive and gram-negative bacteria. Listeria monocytogenes is the only gram-positive bacteria to not release exotoxin. |
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What are the 2 major STD's that cause PID (Pelvic Inflammatory Disease)?
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Neisseria gonorrhoeae and Chlamydia trachomatis
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E. coli takes on a green sheen in this medium.
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EMB agar (Eosine Methylene Blue)
E coli in this Medium Becomes shiny green |
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What property does the MacConkey agar test for? What is a positive sign? Of the enterics, which of the 2 main ones will show positive on this test?
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Fermentation of lactose.
Turns pink-purple. Escherichia coli and Klebsiella pneumoniae The MacConKEy donKEy went wonKEy and turned pink after he drank some milk (lactose) and it started to ferment. K= Klebsiella pneumoniae E=E. coli |
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What 2 bacteria typically cause diarrhea that looks like rice water without fever and without actual invasion of the epithelium cells?
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Enterotoxigenic Escherichia coli (ETEC)
Vibrio cholera They're both spread by fecal-oral transmission |
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Which bacterium is the most common cause of UTI's?
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Escherichia coli
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What bacterium is a common cause of pneumonia in hospitalized or debilitated patients and causes a thick sputum like red currant jelly? What causes the colored sputum? Is this bacterium gram-positive or gram-negative? Is it motile?
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Klebsiella pneumoniae - gram-negative
The red sputum is the color of the O antigen capsule. This bacteria is non-motile. Remember: Klebsiella Kauses Kurrant Kolored jelly and Kan't move. |
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Which 2 bacteria cause fever and bloody diarrhea by invading the cell and releasing the shiga toxin? How would you differentiate them?
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Enteroinvasive Eschericia coli (EIEC)
Shigella dysenteriae Shigella does not ferment lactose. E. coli ferments lactose. |
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This bacterium is one of the 3 leading causes of diarrhea in the world, often affects children, and can be spread through fecal-oral transmission or by drinking unpasteurized milk. It has a flagellum.
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Campylobacter jejuni
Remember: Les JEUNES (the young) get this from going to CAMP and getting BACTERIA from the milk. Kids swim at camp (FLAGELLUM) |
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What are some of the important infections that Pseudomonas aeruginosa can cause?
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This obligate aerobic, gram-negative rod can infect through: (Remember: BE a PSEUDO Fool)
B - Burns/wounds with eventual sepsis E - Endocarditis (common cause of right heart valve endocarditis in IV drug users as well as Staph aureus) P - Pneumonia (people with cystic fibrosis) S - Sepsis E - External malignant otitis media U - UTI D - Diabetic osteomyelitis O - Optic corneal infection (from contacts) F: Folliculitis ("Hot tub folliculitis") |
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This bacterium is one of the few gram-negative bacteria that doesn't contain Lipid A (no endotoxin). It is usually part of the normal flora, but after abdominal surgery it can get into the peritoneal cavity and form abscesses.
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Bacteroides fragilis
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What is the gram-negative bacterium that is a diplococcus?
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Neisseria.
"My niece dated two cocks. One gave her meningitis and the other gave her gonorrhea" |
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What is the other name for meningococcus?
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Neisseria meningitidis
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What are the 2 pathogenic species of Bacillus? Aerobic or anaerobic?
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Bacillus anthracis - causes anthrax (cutaneous, pulmonary, gastrointestinal)
Bacillus cereus - causes food poisoning ("Be serious" is what you tell the doctor when he says to treat this with antibiotics, since it's the exotoxin (enterotoxin) that causes the food poisoning) Bacillus is aerobic. |
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What bacterium causes flaccid paralysis? What causes tetanic paralysis? How do they work?
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Clostridium botulinum produces a lethal neurotoxin that blocks the release of ACh from presynaptic nerve terminals in the autonomic nervous system and motor endplates causing a FLACCID paralysis.
Clostridium tetani produces a toxin that is taken up through retrograde transport from the endplate to the neuron and blocks inhibitory interneurons. |
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What bacterium causes gangrene? What are its characteristics?
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Clostridium perfringens
Gram-positive, spore-forming, anaerobic |
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What bacterium causes Pseudomembranous Enterocolitis? What are the bacterium's characteristics? What is the preferred treatment?
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Clostridium difficile
Gram-positive, spore-forming, anaerobic Tx: Oral or IV metronidazole or oral vancomycin |
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This gram-positive bacterium causes a serious disease when it colonizes the pharynx, forming a grayish pseudomembrane. From there it can release an exotoxin into the bloodstream which damages heart and neural cells.
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Corynebacterium diphtheriae
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This bacterium can cause problems in pregnant women, neonates and can cause meningitis in the elderly and immunocompromised. It is one of the main causes of meningitis in neonates.
What is it and what are its characteristics? |
Listeria monocytogenes
It is a falcutative, motile, gram-positive rod that is usually traced to unpasteurized dairy and deli meats. |
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What 2 bacteria are the most responsible for meningitis in infants after the mother's antibodies have waned?
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Neisseria meningitidis
Haemophilus influenzae |
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Name 4 bacteria that induce cAMP and what they cause.
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1) Vibrio cholerae - causes rice-water diarrhea
2) Bordetella pertussis - causes whooping cough 3) E. coli (ETEC) - causes watery diarrhea like cholera 4) Bacillus anthracis toxin is itself an adenylate cyclase and causes anthrax c = Cholera A = Anthrax M = Montezuma's revenge (ETEC) P = Pertussis |
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The diarrhea that E. coli causes can closely resemble that caused by what 2 other bacteria?
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E. coli ETEC resembles Vibrio cholerae with similar watery diarrhea
E. coli EHEC and EIEC resemble Shigella with bloody diarrhea w/ white cells. EIEC has fever, like the dysentery that shigella causes. |
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What bacterium is the most common cause of gram-negative sepsis?
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E. coli
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What's the difference between transformation and transduction?
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Transformation occurs when a COMPETENT bacterium binds naked DNA fragments.
Transduction occurs when bacteriophages carry a piece of bacterial DNA from one bacterium to another. Transformation can occur without a 3rd party; transduction requires a bacteriophage. |
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Which species of strep are alpha-hemolytic and how do the colonies look on blood agar?
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Streptococcus pneumoniae and the viridans strep (eg S. mutans)
They leave a greenish discoloration in the agar. |
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What do Staph aureus, Strep pyogenes, Strep agalactiae (group B strep), E. coli and Listeria monocytogenes have in common?
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They are all beta hemolytic and show a clear area of hemolysis on blood agar.
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This bacterial group is normal human GI tract flora that is frequently found in the nasopharynx and gingival crevices.
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Viridans Group Streptococci
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What 3 types of infections do the viridans group of strep cause?
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1) Dental infection
2) Endocarditis (subacute bacterial endocarditis) 3) Abscesses ("Streptococcus intermedius and anginosus, immediately assess for ABSCESS!") |
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What are the symptoms of rheumatic fever?
Morphologically, what is seen? |
FEVER, of course.
No "rheum" for SPECCulation: Subcutaneous plaques/nodules Polyarthritis Erythema marginatum (rash) Carditis Chorea (St. Vitus dance) Morphologically, there are Aschoff bodies [central area of fibrinoid necrosis surrounded by Anitschkow cells (reactive histiocytes)] |
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What does Streptococcus agalactiae (group B strep) cause?
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B is for Babies and Bacitracin-resistant!
Causes pneumonia, meningitis and sepsis (mainly in BABIES!) |
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These 2 bacteria used to be part of the Group D Strep until they were given their own genus. They're part of the normal colonic flora. What are they and what do they cause?
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Enterococcus faecalis and Enterococcus faecium.
They cause UTI's, subacute bacterial endocarditis, wound infections, etc. Usually nosocomial. |
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This Strep has a strong relationship with colon cancer - many people who have colon cancer have bacteremia with it. It also can cause SBE (subacute bacterial endocarditis) in colon cancer patients.
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Streptococcus bovis
BOVIS in the BLOOD: BETTER BEWARE, CANCER in the BOWEL! |
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Name 7 facultative intracellular organisms.
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My Love, Bruce, Sailed to Nice, France Years ago to join the Legion.
Mycobacterium Listeria monocytogenes Brucella Salmonella typhi Neisseria gonorrhoeae Francisella tularensis Yersinia Legionella |
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What antibiotics are gram-negative bacteria resistant to?
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Penicillin G and vancomycin
The gram-negative outer membrane layer inhibits entry. |
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Between Neisseria menigitidis and Neisseria gonorrhoeae, which one ferments glucose and which one ferments both glucose and maltose?
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Neisseria MeninGitidis ferments both Maltose and Glucose
Neisseria Gonorrhoeae ferments Glucose |
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What is Fitz-Hugh-Curtis syndrome? What can cause it?
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Peri-hepatitis which is an infection caused by N. gonorrhoeae of the capsule that surrounds the liver. It may also follow chlamydial PID. A patient will complain of right upper quadrant pain and tenderness.
Fitz-Hugh-Curtis = Fu*k*d Hepatic Capsule |
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Besides gonorrhea, what does Neisseria gonorrhoeae cause?
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Fitz-Hugh-Curtis syndrome
Septic Arthritis Neonatal conjunctivitis PID "Fitz, Hugh, and Curtis all had gonorrhea and SAw a NEONATE PIDdle." |
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Who is most at risk for Klebsiella pneumonia?
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Alcoholics and Diabetics.
Remember the 4 A's for Klebsiell-A: Aspiration pneumonia Abscess in lungs Alcoholics di-A-betics |
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What are the differences between Salmonella and Shigella?
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Salmonella is motile (salmon can swim).
Salmonella produces H2S Shigella is more virulent (10 organisms vs 10E5 organisms) Neither one is part of normal flora! |
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What causes Typhoid fever and how?
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Salmonella typhi
Not zoonotic! After invading the intestinal epithelial cells, it invades the regional lymph nodes, finally seeding multiple organs. The bacteria is phagocytosed by monocytes and can survive intracellularly. "TYPHOID Mary was quarantined on an island and spent her days watching the SALMON swim by" |
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What are the typical symptoms of Typhoid fever?
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Salmonellosis starts 1-3 weeks after exposure and includes fever, headache and abdominal pain that can mimic appendicitis. The spleen may enlarge and the patient may develop diarrhea and rose spots on the abdomen (think salmon-colored spots). Dx through blood, stool or urine culture.
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Who are more susceptible to Salmonella infections? (Remember, Salmonella is encapsulated.)
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Patients who have lost their spleen or their spleen has atrophied (Sickle Cell patients are particularly prone to Salmonella osteomyelitis).
This is because the immune system clears encapsulated bacteria by opsonizing them and then the macrophages and neutrophils in the spleen phagocytose them. |
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Do antibiotics help in Salmonella-caused diarrhea?
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No. They do not shorten the course of the disease and do cause prolonged bacterial shedding in the stool.
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What bacteria can cause fever, diarrhea and abdominal pain in the right lower quadrant and can mimic Crohn's or appendicitis?
How is it spread? |
Yersinia enterocolitica
Animals are a major source. It is spread from contaminated foods (milk, pork), or fecally contaminated water. Note that Typhoid fever, caused by Salmonella typhi, can also start with fever, headache and abdominal pain in RLQ. "YEaRS ago, when I was eating a lot of pork and drinking unpasteurized milk, I thought I had appendicitis." |
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What are the 3 common spirochetes?
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Borrelia (B is for BIG)
Leptospira Treponema "Spiro got a hero BLT sandwich." Only Borrelia can be visualized using stain in light microscopy. Treponema is visualized by dark-field |
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What bacterium causes the same disease as ETEC, but more severe? (Common in travelers and children in endemic areas.)
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Vibrio cholera
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What does Vibrio cholera look like?
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It's a curved gram-negative rod with a single polar flagellum.
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Which organisms are encapsulated?
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Strep pneumoniae
Neisseria meningitidis Klebsiella pneumoniae Haemophilus influenzae Salmonella typhi Cryptococcus neoformans Pseudomonas aeruginosa "Some Nasty Killers Have Some Capsule Protection" |
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What symptoms does Clostridium difficile cause?
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Explosive, foul-smelling diarrhea
DIFFICult to be in a CLOSet with someone having explosive, foul-smelling diarrhea because there would be NO AIR to breathe. Clostridium difficile is an anaerobe. |
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What are 4 serious diseases that Haemophilus influenzae B can cause?
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1) Meningitis
2) Sepsis 3) Acute epiglottitis 4) Septic arthritis |
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Who is most at risk of Haemophilus influenzae B infection?
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Children between the ages of 6 months to 3-5 years (after mother's antibodies have worn off and child's have not yet developed).
Also, patients with COPD get frequent infections with nonencapsulated strains, as well as people debilitated from viral flu. |
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What was the leading cause of meningitis in children ages 6 months to 3 years before the vaccine was developed?
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Haemophilus influenzae B
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If a child has contracted meningitis from an H. influenzae infection, what can be done to minimize the risk of developing neurologic deficits from the endotoxin that is released from IV antibiotics being administered?
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Steroids 15-20 minutes before giving the IV may minimize the risk of neurologic deficits.
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What causes the STD chancroid?
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Haemophilus ducreyi
"HA! Do cry if you get this, it's a painful genital ulcer" |
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How would you differentiate chancroid from syphilis, herpes and lymphogranuloma venereum?
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Chancroid: PAINFUL, unilateral swollen inguinal lymph node
Syphilis: PAINLESS, no pus, bilateral adenopathy Herpes: PAINFUL, but usually accompanied by systemic symptoms Lymphogranuloma venereum: PAINLESS |
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What is the major virulence factor of Bordetella pertussis? How does it work?
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Pertussis toxin (exotoxin). B unit binds, A unit activates adenlyate cyclase, stimulating cAMP production.
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What are the stages of whooping cough?
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A week-long incubation period followed by:
1) Catarrhal stage that lasts 1-2 weeks and is similar to an upper resp tract infection with low-grade fever, runny nose and mild cough. This is the stage where it's most contagious. 2) Paroxysmal stage where the fever subsides and the person develops characteristic bursts of nonproductive cough. This can last a month. 3) Convalescent stage where the attacks become less frequent and the patient is no longer contagious. |
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For what bacterial infection is a calcium alginate swab necessary to culture the throat?
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Bordetella pertussis because it does not grow on cotton.
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What do Clue cells from a vaginal swab of a patient with vaginitis/vaginosis usually indicate?
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Gardnerella vaginalis
This is not sexually transmitted. It usually results in increased malodorous discharge without obvious vulvitis or vaginitis. I don't have a CLUE why the gardener smells fishy. |
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This organism is ubiquitous in natural and man-made water environments. Aerosolized contaminated water is inhaled, resulting in infection. What is it and what are its characteristics?
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Legionella pneumophila
Gram-negative rod Facultative intracellular organism that settles in the lower respiratory tract and is consumed by macrophages where it inhibits phagosome-lysosome fusion. |
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What are the 2 ways that Legionella can protect itself in the face of environmental hardship?
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1) It can live in amoabas and when the amoeba encysts, Legionella is protected.
2) It can enter a low metabolic state and can survive in a biofilm. |
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What are the 2 main diseases caused by Legionella pneumophila and what are their clinical pictures?
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Pontiac fever: headache, fever, muscle aches and fatigue. Self-limiting; recovery in usually a week.
Legionnairres' Disease: pneumonia with fever and non-productive cough. May have many other symptoms like confusion, diarrhea and muscle aches. |
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How does one get infected with Yersinia pestis? What does Yersinia pestis cause?
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Rodents are the reservoir, fleas are the vector to humans. Causes bubonic plague and pneumonic plague. Pneumonic can be spread human to human.
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This can cause infection from a cat or dog bite because the bacteria colonizes the mouth of these animals much like Streptococcus viridans colonizes the human nasopharynx.
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Pasteurella multocida
Picture MULTiple cats and dogs in a PASTURE. |
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What disease resembles bubonic plague except that it starts with a skin ulcer? What bacterium causes it?
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Tularemia.
Francisella tularensis |
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How does one get infected with Francisella tularensis?
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By handling infected rabbits and from the bites of ticks and deerflies.
Picture FRANCIS the RABBIT in a field of TULips with a TICK on one ear and a DEERFLY on the other. |
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Patient presents with fever, headache and hot, red, painful inguinal nodes. What is a possible diagnosis and what causes it?
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Bubonic plague (Yersinia pestis)
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Patient works in a meat packing plant and presents with fever, sweats, backache, and lymphadenopathy. The symptoms are undulant in nature. What is a possible diagnosis and what causes it?
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Brucellosis
Brucella abortus - gram-negative, facultative intracellular organism. |
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What are the characteristics of Yersinia pestis?
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Gram-negative with a bipolar staining pattern. Facultative intracellular organism.
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What are 2 obligate intracellular parasites that steal ATP from the host cells and spit out ADP? Which one does not have any mechanism for making ATP?
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Chlamydia and Rickettsia.
Chlamydia cannot make ATP at all. "Like a CLAM that must be inside a shell, Chlamydia must be inside a cell." |
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How must Chlamydia and Rickettsia be cultured?
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Living cells, usually chick embryo yolk sacs or cell cultures, are inoculated with Chlamydia and Rickettsia, since they're both obligate intracellular organisms.
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What type of cells does Chlamydia most often attack? Where are these located?
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Chlamydia is fond of columnar epithelial cells that line mucous membranes. Conjunctiva, cervix, lung.
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Describe the 2 forms of Chlamydia during its life cycle.
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1) Elementary Body - Enters cell through Endocytosis
2) Reticulate Body - Inhibits phagosome-lysosome fusion and Replicates by fission |
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Chlamydia trachomatis infects primarily what 2 areas of the body?
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Eyes and genitals
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What is the leading cause of preventable blindness in the world? How does it cause it?
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Trachoma caused by Chlamydia trachomatis, serotypes A, B and C.
The conjunctival infection causes inflammation and scarring. Scar TRACtion pulls and folds the eyelid inward so the eyelashes rub against the conjunctiva and cornea, causing scarring, infections and blindness. |
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What do the different types of Chlamydia cause?
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Chlamydia trachomatis, serotypes A, B, C cause trachoma (Remember: A=Africa/B=Blindness/C=Chronic)
Serotypes L1, L2, and L3 cause lymphogranuloma venereum (LGV) Serotypes D-K is everything else: Inclusion conjunctivitis (usually in newborns) Infant pneumonia Cervicitis Nongonococcal urethritis in men Chlamydophila psittaci - atypical pneumonia Chlamydophila pneumoniae (TWAR) - atypical pneumonia |
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Why are all newborns in the US given erythromycin eye drops?
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To prevent inclusion conjunctivitis from Chlamydia trachomatis
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What is Lymphogranuloma Venereum, what causes it, and how does it develop?
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Lymphogranuloma venereum is an STD caused by Chlamydia trachomatis, serotypes L1, L2 and L3. It starts with a painless papule or ulceration on the genitals that heals spontaneously. The bacteria migrate to regional lymph nodes which enlarge in the next 2 months, become tender and may break open.
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What causes the atypical pneumonia 1-3 weeks after inhalation of dust from bird feathers or dried-out feces?
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Chlamydia psittaci causes psittacosis.
Picture a coughing person with a bird on his arm that's eating a clam. |
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What types of cells does Rickettsia favor?
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Endothelial cells that line blood vessels. (This is what causes the conjunctival redness and skin rash, maybe even the headache. The fever is due to the immune reaction.)
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What causes Rocky Mountain Fever and what are the symptoms? What type of bacteria is it? Where does it proliferate?
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Rickettsia rickettsii
It presents within a week after a person is bitten by a tick and is characterized by fever, conjunctival redness, severe headache and a rash that initially appears on the wrists, ankles, soles and palms and later spreads to the trunk. It's a gram-negative obligate intracellular parasite. It proliferates in the endothelial lining of the blood vessels. "Rickettsii on the wRists, Typhus on the Trunk". |
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What causes epidemic typhus? What causes endemic typhus?
Does infection with one confer immunity to the other? |
Rickettsia Prowazekii causes ePidemic typhus.
Rickettsia typhi causes endemic typhus. These are similar and infection with one confers immunity to the other. |
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What's the difference in the rash caused by Rickettsia rickettsii and Rickettsia prowazekii?
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Rocky mountain spotted fever (rickettsii) causes a rash that starts on the wrists, ankles, palms and soles.
Epidemic typhus (prowazekii) causes a rash on the trunk that spares the palms, soles and face. Rickettsii on the wRists, Typhus on the Trunk |
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What causes Syphilis and what are the stages?
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Treponema pallidum
Primary: Painless chancre that appears 3-6 weeks after initial contact. Secondary: Systemic symptoms up to 6 weeks after primary chancre has healed including a rash (small, red macular lesions over the body, particularly the palms, soles, and mucous membranes of the oral cavity), lymphadenopathy, maybe fever, weight loss and hair loss. Tertiary: 6-40 years later. Can be grouped into 1) Gummatous syphilis 2) Cardiovascular syphilis 3) Neurosyphilis |
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What is the "prostitute's pupil" called that can be seen in some forms of neurosyphilis?
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Argyll-Robertson pupil.
"It accommodates but does not react (to light)" "An ARGYLE sweater was ROBERT'S favorite thing to wear when he went to the PROSTITUTE." |
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What is the condyloma latum and when does it appear in syphilis?
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A painless, wartlike lesion that often occurs in warm, moist sites like the vulva or scrotum. It can appear during secondary syphilis.
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What are the main symptoms of congenital syphilis?
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Saber shins, saddle nose, CN VIII deafness, Hutchinson's teeth (upper central incisors are widely spaced with a central notch in each tooth), mulberry molars (molars have too many cusps).
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What causes Lyme disease?
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Borrelia burgdorferi, a spirochete.
"Borrelia burgdorferi, A tick bites you like a key LYME pie" |
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What are the 4 organ systems that can be attacked in the early disseminated stage of Lyme disease (2nd stage)?
What are the typical symptoms? |
Nervous system, joints, heart and skin.
BAKE a Key LYME pie: Bell's palsy, Arthritis, Kardiac block, Erythema migrans |
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What is Weil's disease and what causes it?
How does one get it? |
Infectious jaundice caused by Leptospira interrogans, a spirochete.
It's caused by swimming in water contaminated with animals' urine. "WEIL I was swimming and doing my pirouettes, I LEPT into a pool of urine, after which, my doctor INTERROGATED me" |
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What stain is used to detect Mycobacterium tuberculosis and what color does it stain? What else stains this way?
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Acid fast stain.
It stains red. Mycobacterium tuberculosis, Mycobacterium leprae and Nocardia all are acid fast. |
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There is one class of lipid that only acid fast organisms have and that is involved in mycobacterial virulence. What is it?
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Mycoside - a mycolic acid bound to a carbohydrate
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Is Mycobacterium tuberculosis and leprae obligate aerobes, facultative anaerobes, or obligate anaerobes?
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Obligate aerobes
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T/F: Mycobacterium is a facultative intracellular organism.
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True
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How does Mycobacterium tuberculosis and the immune system interact?
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1) With the first exposure (usually be inhalation of the lungs), the host has no specific immunity. The inhaled bacteria cause a local infiltration of neutrophils and macrophages. Due to the various virulence factors, the phagocytosed bacteria are not destroyed. However, the host rapidly acquires its prime defense: cell-mediated immunity.
2) T-cells are activated and release lymphokines that attract macrophages. The macrophages attack the bacteria and the lung tissue, causing caseous necrosis that's surrounded by macrophages, multinucleated giant cells, fibroblasts and collagen deposits. |
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What are the 2 ways to test for exposure to TB?
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PPD (Purified Protein Derivative) skin test which will result in an area of induration bigger than 10 mm after 48 hours due to a type IV delayed hypersensitivity reaction.
Quantiferon TB that measures interferon gamma levels produced in whole blood in response to addition of specific tuberculosis antigens. This test is more specific. |
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Describe primary and secondary TB.
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PRIMARY: Majority of cases are asymptomatic. Lesions near the middle of the lung are formed (Ghon focus). A ghon complex includes this and calcified granulomas in the perihilar lymph node. Infection is walled off. Early on, the necrosis is caseous.
SECONDARY: Only 5% of infected people develop this at a later date. Initial symptoms include malaise, weight loss, tidal fevers and night sweats. As it progresses, they may have chest pain, sputum and/or hemoptysis. HIV patients have a much higher risk of developing. |
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What are the ways to diagnosis secondary TB?
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Chest X-ray
Sputum acid-fast stain and culture |
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What is scrofula?
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Lymph node TB
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What are the 2 major forms of leprosy and which is more severe?
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1) Lepromatous leprosy (LL): This is most severe because patients cannot mount a cell-mediated immune response. There are many skin lesions. Remember: "L" is for lethal.
2) Tuberculoid leprosy (TL): This is a milder and self-limiting disease because patients can mount a cell-mediated response. Often there are only 1 or 2 skin lesions. Both are caused by Mycobacterium leprae. |
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Between Staph aureus, Staph epidermidis and Staph saprophyticus, which one(s) are catalase positive? Which are coagulase positive?
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All 3 are catalase positive.
Staphylococcus aureus is coagulase positive, the other 2 are negative. |
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What is the common infection caused by Staphylococcus saprophyticus?
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UTI's in sexually active women. It is the 2nd leading cause (E. coli is first)
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What is the most common infections caused by Staph epidermidis?
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Nosocomial infections: prosthetic joints, prosthetic heart valves, sepsis from intravenous lines, UTI's.
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What bacterium is a component of normal skin flora and causes many nosocomial infections as well as contaminating many blood cultures?
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Staphylococcus epidermidis
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Which E. coli invades intestinal mucosa?
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EIEC
Entero INVASIVE E coli |
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Which bacteria commonly cause UTI's?
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SSEEK Citrus PP
S: Serratia marcescens - often nosocomial S: Staph saprophyticus - 2nd leading cause in sexually active women E: E. coli - leading cause E: Enterobacter - often nosocomial & drug resistant K: Klebsiella pneumoniae - large Kapsule Citrus: Citrobacter freundii P: Proteus mirabilis - associated with struvite stones P: Pseudomonas aeruginosa - blue-green pigment & fruity odor; usually nosocomial and drug resistant |
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This organism is a marine bacterium that causes gastroenteritis after ingestion of uncooked seafood (sushi). It is the leading cause of diarrhea in Japan. What is it and what are its characteristics?
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Vibrio parahaemolyticus
Curved gram-negative rod "The VIrile PARAtroopers had to heave after eating sushi" |
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What are the characteristics of Helicobacter pylori and what does it cause?
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Curved gram-negative rod
Gastric ulcers, duodenal ulcers (most common cause), gastric adenocarcarcinomas, gastritis |
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How do you test for H. pylori?
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Since it's urease positive, you can test with a urease breath test.
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What's unique to the mycoplasma bacteria? What is the treatment?
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They lack a cell wall and instead have a cell membrane which is packed with sterols like cholesterol.
Penicillin does not work, but macrolides, tetracyclines and quinolones do. |
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What are the symptoms of a Mycoplasma pneumoniae infection?
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After a 2-3 week incubation period, infected patients will have a gradual onset of fever, sore throat, malaise and a persistent dry hacking cough (walking pneumonia).
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What are 4 diagnostic tests for Mycoplasma pneumoniae?
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1) Cold agglutins - put test tube of blood on ice and blood will clump
2) Complement fixation test - patient's serum is mixed with glycolipid antigens prepared from Mycoplasma 3) Sputum culture - Mycoplasma can be grown on artificial media if it's rich in cholesterol and nucleic acids 4) DNA probe - DNA can be detected in sputum samples through PCR |
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What are three organisms that cause atypical pneumonia (pneumonia that can't be treated with penicillin)?
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Mycoplasma, Chlamydia, Legionella
My Cough Lasts (when it's treated with penicillin) |
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What are the different Tineas and what causes them?
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All are caused by a fungus (Microsporum, Trichophyton and Epidermophyton); Tinea Versicolor is caused by Malassezia furfur.
Tinea corporis - ringworm Tinea cruris - jock itch Tinea pedis - athlete's foot Tinea capitis - scaly lesions of the scalp with loss of hair Tinea unguium - onychomycosis (nails) Tinea versicolor (AKA Pityriasis versicolor) - hypopigmentation of the skin |
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What are the three systemic fungi that are all inhaled as spores and can cause infection primarily in the lung, but also in the skin, bones and meninges?
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Histoplasma capsulatum
Blastomyces dermatitidis Coccidiodes immitis "The fungus COCKS his gun, BLASTS away, and HITS the lung, skin, bones and meninges" |
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What is the dimorphic nature of the systemic fungi Histoplasma, Blastomyces and Coccidiodes?
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At room temperature, they have spores. Once inhaled and at body temperature, they grow as yeast.
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What region of the country is Histoplasma common? Blastomyces? Coccidiodes?
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Histoplasma is common in areas surrounding the Mississippi.
Blastomyces is common in areas east of the Mississippi. Coccidiodes is endemic to the US Southwest. |
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Compare Histoplasma, Blastomyces and Coccidiodes.
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Histoplasma is present in bird and bat droppings. It generally causes lung and skin infections.
Blastomyces is present in soil and rotten wood. It is the most rare, but it is the most serious. Generally causes weight loss, night sweats, lung involvement and skin ulcers. "The LAST to get, the LAST to leave, no BLAST to have" Coccidiodes is a spore in the soil and causes "Valley Fever". |
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Name the 3 common types of infections that Candida albicans can cause in normal individuals.
Name the 2 types of systemic infections that Candida albicans can cause in immunocompromised individuals. |
In normal hosts:
1) Oral thrush 2) Vaginitis 3) Diaper rash In immunocompromised hosts: 1) Esophagitis - Extension of thrush into the esophagus 2) Disseminated - Candida invades the bloodstream |
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What are the clinical manifestations of Cryptococcus neoformans? Who does it affect?
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It causes meningoencephalitis and is fatal if not treated (though it can cause pneumonia, skin ulcers, and bone lesions like the other systemic fungi). 75% of cases present in immunocompromised persons. Almost 10% of AIDS patients develop cryptococcosis.
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This fungus is inhaled and can cause both a Type I and Type IV allergic reaction. It is not dimorphic. It has V-shaped angles.
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Aspergillus spp
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What are the pathologies caused by Aspergillus?
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The 4 A's:
ABPA (Allergic Broncho-Pulmonary Aspergillosis) Invasive Aspergillosis (in immunocompromised patients; characterized by pneumonia and nodular infiltrates) Aspergilloma (fungal ball in persons with lung cavitations, from TB, for example) Aflatoxin-caused liver damage |
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What fungus can be part of the normal flora but cause pneunomia in advanced HIV patients?
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Pneumocystis carinii (now called jiroveci)
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What must negative RNA viruses carry with them in order to replicate?
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RNA-dependent RNA polymerase
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Which of the DNA viruses are naked?
Which of the RNA viruses are naked? |
Naked DNA: PAPova, Adeno and PArvo
Naked RNA: Calici, Picorna, Reo "A woman must be naked to have a PAP smear, and giving CPR is easier with a naked person" |
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Which viruses are DNA viruses?
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HHAPPPy Viruses because they have DNA!
H: Herpes H: Hepadna (Hep B) A: Adeno P: Papova (Papilloma and Polyoma) P: Parvo P: Pox |
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Most DNA viruses are double-stranded. Which one isn't?
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Parvo
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What causes 5th disease, what's the other name for 5th disease, and what are the symptoms?
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Parvovirus (B19 strain) causes 5th disease, AKA erythema infectiosum.
Symptoms are "slapped cheek" rash and a fever in children. In adults, it presents with symmetric polyarthritis usually in the wrists and knees. "I take the 5TH even if my WRISTS are tied, no matter how much you SLAP me! This is just PAR for the course" |
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What virus migrates up the nerves to the sensory ganglia (dorsal root) and resides there until reactivation through some stress?
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Herpesvirus
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What subgroup of Herpes causes cell destruction (cytopathic effect)? Which ones are included in this subgroup? Histologically, what do you see?
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Alpha subgroup
It includes HSV 1 and 2, CMV and Varicella-Zoster. Scapings will reveal multinucleated giant syncytial cells and intranuclear inclusion bodies. |
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What mechanism causes the multinucleated giant cells and intranuclear inclusion bodies in the alpha subgroup of Herpesvirus?
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Viral proteins are inserted into the host cell plasma membranes, resulting in cell fusion to form multinucleated giant cells.
Intranuclear inclusions are considered to be areas of viral assembly. |
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What is the number one cause of sporadic viral encephalitis in the US? What are the symptoms?
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HSV-1
Sudden onset of fever and focal neurological abnormalities. |
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What are the organisms that can cross the blood-placenta barrier during pregnancy?
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TORCHES:
TO: Toxoplasma R: Rubella C: Cytomegalovirus HE: HErpes simplex, HIV S: Syphilis |
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What causes oral herpes and what causes genital herpes?
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HSV 1 and HSV 2 can both cause either, though HSV 1 tends to be oral and HSV 2 tends to be genital.
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What causes chicken pox?
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Varicella-Zoster Virus, a Herpes virus
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What causes shingles?
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Varicella-Zoster Virus (previous exposure required).
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Describe the differences in the outbreak of vesicles in Chicken Pox vs Shingles.
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Varicella (Chicken Pox):
Fever, malaise and headache are followed by a rash that starts on the face and trunk, spreading to the rest of the body. Lesions can be in different stages. Zoster (Shingles): Following a stressed state or lowered cell-mediated immunity, burning, painful lesions develop over the area supplied by the sensory nerves where the virus was lying dormant. Lesions are almost always unilateral. |
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Which virus is a common cause of congenital abnormalities in the US and can cause extensive hepatic and brain damage leading to abortion, stillbirth, or postnatal death?
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Cytomegalovirus - a Herpes virus
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Which virus has a strong association with Kaposi's sarcoma?
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HHV 8, a Herpes virus
"HHV8 is bad for HIV, mate!" |
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What does CMV cause in AIDS patients? What does it cause in bone marrow transplant patients?
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AIDS Patients:
CMV retinitis CMV colitis Bone Marrow Transplant Patients: CMV pneumonitis (severe pneumonia often leading to death in these patients) |
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What does HHV 6 cause?
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Roseola infantum ("sixth disease"): a common eruption on the skin seen in children age 6 months to 3 years (but peak incidence is 6 months to 1.5 years). Abrupt onset of high fever for 3-5 days followed about 24 hours later by a faint macular rash, including a "slapped cheeks" appearance.
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What causes mononucleosis?
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Epstein-Barr Virus, a Herpes virus
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What virus has a strong association with Burkitt's lymphoma?
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Epstein-Barr (EBV)
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What cells are infected in Epstein-Barr and how?
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EBV binds to C3d on B cells
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Where in the cell do DNA viruses replicate? What's the exception?
Where in the cell do RNA viruses replicate? What are the exceptions? |
DNA viruses replicate in the nucleus except for poxvirus. "Pox in a box, doesn't need the nucleus". It carries its own DNA-dependent RNA polymerase.
RNA viruses replicate in the cytoplasm except influenza and retroviruses. |
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What are the most common symptoms of Adenovirus?
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Pharyngitis
Conjunctivitis Pneumonia Picture A DEN full of coughing, hoarse children with red eyes. |
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What causes warts?
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HPV - Human Papilloma Virus
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What are condyloma acuminata and what causes them?
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Genital warts. HPV
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Which 2 types of HPV cause over 70% of cervical cancers?
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HPV 16 and 18
Generally these higher numbers are associated with cancer. |
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What causes smallpox?
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Poxvirus
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What causes Molluscum Contagiosum? What are the clinical manifestations? Who is most at risk?
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Poxvirus
There are small, white bumps that have a central dimple; similar to warts with benign hyperproliferation of epithelial cells. AIDS patients frequently develop them. |
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Which DNA virus causes aplastic crisis in patients with chronic hemolytic anemia and is associated with acute polyarthritis in adults?
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B19 - Parvovirus
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Which family of viruses carry a unique enzyme called reverse transcriptase? What does it do?
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Retrovirus
It is an RNA-dependent DNA polymerase that converts the viral RNA into DNA. |
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Which family of viruses can cause cancer in the cells they infect by turning proto-oncogenes into oncogenes?
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Retrovirus
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What are the 2 most well-known retroviruses that infect humans?
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HTLV-1 (Human T-cell Leukemia Virus)
HIV (Human Immunodeficiency Virus) |
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What causes influenza? Is it RNA or DNA?
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Orthomyxovirus, an RNA virus
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What's unique about the RNA structure of orthomyxovirus? HINT: It's what allows it to mutate so quickly.
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It has 8 genomic segments that promote reassortment of segments upon infection with two different strains.
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What does HA (hemagglutinin) and NA (neuraminidase) do for the influenza virus (orthomyxovirus) and paramyxoviruses (except RSV)?
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HA is the viral attachment protein that binds to sialic acid on epithelial cell surface receptors allowing the virus to be adsorbed into the cell.
NA does 2 things: it cleaves neuraminic acid (disrupting the mucin barrier and exposing the sialic acid binding sites) and it cleaves the sialic acid, facilitating release of the virus from infected cells. It is the target for the antiviral drugs zanamivir (Relenza) and oseltamivir (Tamiflu) |
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What cells does orthomyxovirus target?
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Mucus-secreting, ciliated and other epithelial cells in the upper respiratory tract.
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What are the different types of influenza? Which one(s) affect humans?
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A, B, and C.
Only A and B affect humans. |
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What are all the diseases caused by paramyxovirus?
|
PaRaMyxovirus
P: Parainfluenza (Croup in Children; rhinitis, pharyngitis, bronchitis in adults, pneumonia in children, elderly and immunocompromised) R: RSV (Respiratory Syncytial Virus) M: Mumps and Measles (Rubeola) |
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What virus is the number one cause of pneumonia in infants less than 6 months of age?
What virulence factor does it have? What virulence factor is it missing that others in the same family and one other family have? |
RSV, a paramyxovirus
It has a fusion (F) protein that causes the infected cells to fuse together into multinucleated giant cells similar to those caused by the herpes virus family. It lacks the HA and NA glycoproteins that are in the other paramyxo viruses as well as the orthomyxo virus family. |
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Which viruses are negative-stranded RNA and must always bring their own RNA-dependent RNA polymerase?
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"Always Bring Polymerase Or Fail Replication"
or "Rabid Bunnies Fight Or Perish in the Arena" A: Arenavirus B: Bunyavirus P: Paramyxovirus O: Orthomyxovirus F: Filovirus R: Rhabdovirus |
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What family of viruses does Rubeola (measles) belong to? What are the symptoms?
|
Rubeola is a paramyxovirus.
Symptoms are: Prodrome - conjunctivitis, swelling of the eyelids, photophobia, high fever, cough, rhinitis and malaise Koplik's Spots - Small red-based lesions with blue-white centers in the mouth Rash - Red, flat to slightly bumpy spreading from the forehead to the face, neck and downwards hitting the feet by the 3rd day. |
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What are the possible complications from measles?
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Pneumonia, eye damage, myocarditis and encephalitis (subacute sclerosing panencephalitis).
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How are the different types of viral hepatitis caused?
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Types: A, B, C, D, E
A and E are at the ends so they transmit through fecal-oral route. BCD are transmitted through BlooD |
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Which type of viral hepatitis is a DNA virus?
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Hep B
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Which types of viral hepatitis can be chronic?
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B, C and D
Remember, A and E for AcutE |
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What do the serologic tests look like for Hep A at 1 month after exposure and 4 months after exposure?
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1 month:
Anti-HAV IgM high Anti-HAV IgG low 4 months: Anti-HAV IgM low Anti-HAV IgG high |
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Is Anti-HAV IgG protective against future infection with Hep A?
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Yes.
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What family does Hep A virus belong to?
|
Picornavirus
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What diseases are caused by Picornavirus?
|
Remember: PERCH on A peak (pico)
P: Polio E: Echovirus R: Rhinovirus C: Coxsackievirus H: Hep A |
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What causes hand, foot and mouth disease?
|
Coxsackievirus, a Picornavirus (though other Picornaviruses like Echovirus and the Enteroviruses can also cause it)
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What 2 viruses cause the common cold and what family or families are they from?
|
Rhinovirus - a Picornavirus
Coronavirus - a Coronavirus ("A beer is just a beer, but a Corona is a Corona") Picture a Rhino with a runny nose holding a Corona. |
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What deadly virus is fairly new and is a member of Coronavirus?
|
SARS - (Severe Acute Respiratory Syndrome)
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|
What virus causes Hep C?
|
Flavivirus
"FLAVonoids have vitamin C" |
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|
What causes yellow fever?
|
Flavivirus
Remember: "Flav" means yellow |
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What are the 2 main members of togavirus and what do they cause? What is the reservoir?
|
Rubivirus:
Rubella (German measles) Alphavirus: Eastern equine encephalitis Western equine encephalitis Think of ancient Romans wearing TOGAS and riding horses (EQUINES), conquering the GERMANS through MEASLES and the Greeks (the originators of our modern ALPHAbet) through ENCEPHALITIS. Birds are the reservoir. |
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What does flavivirus cause?
|
Hep C
and the following ARthropod BOrne viruses (arboviruses): Dengue Fever St. Louis Encephalitis West Nile Virus Yellow Fever "DENny traveled the world from ST. LOUIS to the WEST NILE, picking up YELLOW FEVER in Africa (where 90% of cases now occur)" |
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|
What are the 4 viruses that are passed from mother to fetus?
|
Rubella
CMV HIV HSV Remember ToRCHeS: To: Toxoplasma gondii R: Rubella C: CMV He: Herpes Simplex, HIV S: Syphilis |
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|
What are the main symptoms of Dengue Fever and where does one contract it?
|
It's called break-bone fever because of the severe painful backache, muscle and joint pain and severe headache.
It's a mosquito-borne disease (arbovirus) that occurs mainly in the tropics, but there are periodic cases in the Southwest US It's a flavi virus |
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What are the main symptoms of yellow fever and where does one contract it?
|
Symptoms: High fever, black vomitus and jaundice.
90% of cases today are in Africa, though it was made famous by the Panama Canal project. |
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What can mumps cause?
|
Parotitis, Orchitis and aseptic Meningitis
"Mumps makes your parotid glands and testes as big as POM-poms." |
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|
What are the 3 disease manifestations of polio?
|
1) Mild illness: An asymptomatic infection or a mild febrile viral illness is the most common form. This especially occurs in infants in less-developed nations.
2) Aseptic meningitis: Fever and meningismus can develop as the poliovirus infects the meninges. Recovery is complete in 1 week. 3) Paralytic poliomyelitis: The viral infection destroys presynaptic motor neurons in the anterior horn of the spinal cord as well as the postsynaptic neurons leaving the horn. Usually occurs in persons older than 15 years old. |
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|
Which cells does polio attack?
|
Tonsils, Peyer's patches in intestines, and Motor neurons
Think fecal-oral spread and paralysis. |
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|
What is the only virus in the Rhabdovirus family that infects humans?
|
Rabies
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|
|
What is the clinical course of infection for rabies virus?
|
When a human is bitten, the virus replicates locally at the wound site for a few days, then migrates slowly over weeks to a year up nerve axons to the central nervous system causing a fatal encephalitis.
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|
What virus is a major cause of fatal diarrhea in infants worldwide and what family does it belong to?
|
Rotavirus - a Reovirus
Symptoms include vomiting, diarrhea, fever and dehydration. Fatalities usually occur in individuals who live in developing countries and who are malnourished and dehydrated before the infection. "ROTA = Right Out The Anus" |
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|
Which of the following virus families has double stranded RNA?
A) Paramyxo B) Reo C) Orthomyxo D) All of the above |
B: Reo is double stranded, which is an exception since most RNA viruses are single stranded.
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|
What protozoa causes malaria?
|
4 types of Plasmodium:
Plasmodium ovale Plasmodium vivax Plasmodium falciparum Plasmodium malariae "Malaria typically occurs in countries that don't have PLASMa tv's in the home" |
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|
What are the clinical symptoms of malaria?
|
Periodic episodes of severe chills and high fevers associated with the rupture of red blood cells.
Also: anemia, headache and splenomegaly |
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|
Name 3 protozoa whose transmission is through cysts in water that cause diarrhea. What type of diarrhea does each one cause?
|
Giardia lamblia - foul-smelling, fatty diarrhea (often seen in campers/hikers); think fat-rich Ghirardelli chocolate.
Entamoeba histolytica - bloody diarrhea (dysentery) in some people - incidence is highest in tropical and subtropical regions that have poor sanitation Cryptosporidium - mild, watery diarrhea in non-immunocompromised patients, but severe diarrhea in AIDS Picture an AMOEBA crawling through the CRYPTs of the intestine, making the person's poop look like melted Ghirardelli chocolate. |
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Normally, Entamoeba histolytica can be asymptomatic, but what are some of the more severe complications?
|
The trophozoites may invade the intestinal mucosa causing erosions resulting in abdominal pain, loose stools and flecks of blood and mucus in the stool. Also, they may penetrate the portal blood circulation, forming abscesses in the liver followed by spread through the diaphragm into the lung.
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|
Microscopic examination of vaginal discharge on a wet mount reveals a highly motile parasite. What is the likely protozoan, how is it transmitted and what does it cause?
|
Trichomonas vaginalis (Picture a prostitute asking a John: "How 'bout a TRICK and a MOAN baby?")
Sexually transmitted It causes vaginitis. Symptoms can include itching, burning on urination and copious vaginal secretions. Speculum exam reveals a thin, watery, frothy, malodorous discharge and a strawberry cervix ("Watch this TRICK; I'll make my cervix look like a STRAWBERRY") |
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|
What protozoa can pass from mother to fetus and is found in meat or cat feces?
|
Toxoplasma gondii
Remember ToRCHeS: To: Toxoplasma gondii R: Rubella C: CMV He: Herpes Simplex Virus, HIV S: Syphilis |
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|
What does Toxoplasma gondii cause in AIDS patients? What does it cause in neonates if congenitally acquired?
|
AIDS patients: brain abscess is common (Toxoplasma encephalitis is the most common CNS infection in AIDS patients), but can also present with fever, lymphadenopathy, hepatosplenomegaly or pneumonia.
Neonates: Classic triad of chorioretinitis, hydrocephalus and intracranial calcifications Bottom line: In AIDS patients and fetuses, "Toxoplasma gondii's bad for the BRAIN, bad for the EYES!" |
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|
What protozoan can cause an infection with general malaise, fever without periodicity, headache, chills, sweating, fatigue and weakness along with hemolytic anemia? HINT: Infection follows contact with an infected tick and is predominantly in northeastern US. It appears as a "Maltese cross" in the blood smear.
|
Babesia microti; causes babesiosis
Transmitted by Ixodes tick (same as Borrelia burgdorferi) "Look at the BABE with the CROSSed eyes carrying a MICROTIck" |
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|
What protozoan causes African sleeping sickness and Chagas disease?
|
Trrypanosoma rhodesiense and gambiense - African Sleeping Sickness
Trypanosoma cruzi - Chagas Disease |
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|
What disease is found mostly in Central and South America, and can cause fever, weakness, splenomegaly in its acute phase and cardiomyopathy, megacolon and megaesophagus in its chronic phase? What is the organism that causes it? HINT: It's transmitted through the feces of the "Kissing Bug" (Reduviid bug).
|
Chagas Disease, caused by the protozoan Trypanosoma cruzi.
Picture the body (SOMA) of Tom CRUISE taking a TRIP to PANama and getting KISSED. |
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|
What disease starts with a hard, red, painful skin ulcer and progresses to systemic symptoms of enlarged lymph nodes, recurring fever, somnolence and coma? What organism causes it?
|
African sleeping sickness, caused by the protozoa Trypanosoma gambiense and rhodesiense. It's transmitted by the bite of a Tsetse fly.
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|
What organism causes visceral leishmaniasis? What are the symptoms? How is it transmitted?
|
The protozoan Leishmania donovani.
Symptoms can include spiking fevers, hepatosplenomegaly, pancytopenia and hyperpigmentation of the skin. It's transmitted through a sandfly. Picture a tan sandfly named DON OVANI on a LEASH displaying MANIA |
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|
What causes an "oriental sore" - a skin ulcer at the site of a sandfly bite?
|
The protozoan Leishmania donavani.
Picture a sandfly on a leash acting like a maniac. He can cause skin ulcers or Visceral Leishmaniasis (aka: Kala-azar w/ symptoms of spiking fevers, hepatosplenomegaly, pancytopenia). Found in Africa, Asia and Europe. Another species is found in South America. |
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|
Which hepatitis is dependent on HBV?
|
Hep D
It's a defective virus that requires HBsAg as its envelope. Coinfections with HBV and HDV can become much more serious. D: Defective, Dependent on HBV |
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|
What helminth is often found in raw pork and causes myositis (inflammation of the muscle)? How does it attack the body?
|
Trichinella spiralis
It penetrates into the intestinal mucosa. The larvae then enter the bloodstream and spread to organs and skeletal muscle producing fevers and muscular aches. "It's TS (tough sh!t) if you get this TS (Trichinella spiralis) because the meds only work on the enteric stages and have little effect on muscle larvae" |
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|
What's the scientific name for pinworms and what is the most common symptom?
|
Enterobius vermicularis
Anal pruritis (itching) "Enterobius vermicularis Is no trip to Paris It will itch like a bitch And when you scratch, you're embarrased!" |
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|
What are the two pathogenic hookworms and what do they cause? What is the mode of transmission?
|
Necator americanus
Ancyclostoma duodenale Symptoms can include diarrhea, abdominal pain, fatigue, weight loss and nutritional deficiencies. Also, since the hookworm sucks blood from the intestinal wall, the infection may cause anemia. Ancylostoma duodenale and Necator americanus are contracted when the filariform larva penetrates between the toes. "When your feet and ANKLES are NAKED as a gator Watch out for ANCYLOSTOMA and NECATOR" |
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|
This roundworm is consumed in egg form, then the larvae emerge in the small intestine, penetrate through the intestinal wall and travel in the bloodstream to the lungs. The larvae grow in lung alveoli until they are coughed up and swallowed. These larvae again reach the small intestine and mature into adults.
|
Ascaris lumbricoides
"Ask Cari how scary is Ascaris lumbricoides. She ate eggs of this giant roundworm and it gave her an intestinal infection." |
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|
What organism causes elephantiasis? What type of organism is it? How does it cause elephantiasis?
|
Wuchereria bancrofti, a nematode (roundworm)
It is transmitted through the bite of a mosquito and infects the lymph vessels and nodes of the genitals and lower extremities. "WU! Would you look at the size his leg? It's the size of a big ROUND BANyan tree!" |
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|
This organism needs snails to mature before it can penetrate the skin of humans, which happens when they're swimming in fresh water. What is it and what type of organism? How does it mature and what are the symptoms of infection?
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Schistosoma - fluke; causes schistosomiasis
On contact with humans, the parasite burrows into the skin, matures into another larval stage (schistosomula), then migrates to the lungs and liver, where it matures into the adult form. The adult worm then migrates to its preferred body part, depending on its species. These areas include the bladder, rectum, intestines, liver, portal venous system (the veins that carry blood from the intestines to liver), spleen, and lungs. Symptoms vary with the species of worm and the phase of infection. * Heavy infestation (many parasites) may cause fever, chills, lymph node enlargement, and liver and spleen enlargement. * Initial invasion of the skin may cause itching and a rash (swimmer's itch). In this condition, the schistosome is destroyed within the skin. * Intestinal symptoms include abdominal pain and diarrhea (which may be bloody). * Urinary symptoms may include frequent urination, painful urination (dysuria), and blood in the urine (hematuria). Complications include squamous cell carcinoma of the bladder. |
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What are the 3 major disease syndromes that occur sequentially after an infection with Schistosoma?
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1) Dermatitis as the cercariae pentrate a swimmer's skin
2) Katayama fever - this starts 1-2 months after infection and can last 3 months with fever, headache, weight loss and cough. 3) Granuloma formation - as the eggs are released into the body and get into tissues, granulomas, fibrosis and inflammation of the spleen and liver occur. Chronic infection can lead to squamous cell carcinoma of the bladder. |
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What is the tapeworm whose larvae is found in undercooked pork? What is the tapeworm whose larvae is found in undercooked beef? What is the tapeworm whose larvae is found in raw, freshwater fish? What do each of these cause?
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Taenia solium - pork tapeworm
Causes tapeworms when larvae are ingested. Causes Cysticercosis when eggs are ingested. Theses cysts are usually in the brain or skeletal muscles. Taenia saginata - beef tapeworm Causes tapeworm when larvae are ingested. Diphyllobothrium latum - fish tapeworm Causes B12 deficiency. (Di-Phyllo-Bothrium: Di means 2. Phillo means leaf. 2 l B looks like B 1 2 backwards.) |
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What are the symptoms of the rare, but severe, pneumonia that can be caused by Staph aureus?
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It usually follows a viral upper respiratory illness with abrupt onset of fever, chills and lobar consolidation of the lung. Purulent lung abscesses are common.
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What's the difference between endocarditis caused by Staph aureus and endocarditis caused by Strep viridans or Group D strep?
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Staph aureus will cause an acute endocarditis with sudden onset of high fever, chills and myalgias. Patient may or may not have a murmur.
Strep viridans and Group D strep cause a subacute endocarditis that has a more gradual onset. Sx include murmur, splinter hemorrhages, Osler nodes (tender subQ nodules) and Janeway lesions (small, non-tender, erythematous or hemorrhagic macules on the palms or soles). |
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Describe the differences between the yeast and mold form of a fungus.
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Yeast:
1) Reproduces by budding - a mother cell pinches off a portion of itself to produce a daughter cell 2) Daughter cell can elongate into a PSEUDOHYPHAE Mold: 1) Consist of threadlike tubular structures called HYPHAE 2) Hyphae are either hollow and multinucleate (COENOCYTIC), or divided by partitions or cross-walls (SEPTATE) 3) Hyphae form together to produce a matllike structure called a MYCELIUM |
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What is Whipple's disease and what causes it?
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Whipple's disease is a rare systemic illness caused by the gram-positive bacterium Tropheryma whippelii. Main symptoms are arthritis, weight loss, and diarrhea. Diagnosis is by small-bowel biopsy. Mostly affects men 30-60 years old.
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What is special about Bacillus anthracis that gives it such virulence? (3 things)
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1) Exotoxin is encoded on a plasmid called pXO1. The exotoxin contains 3 separate proteins: Edema factor (EF) that increases cAMP; Protective antigen (PA) that promotes entry into phagocytic cells; and Lethal factor (LF) - a zinc metalloprotease that inactivates protein kinase
2) Capsule - Bacillus anthracis is the only bacterium with a capsule composed of protein. This prevents phagocytosis. 3) Spore - very stable; can survive dormant in the soil for decades |
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What are the bacterial, viral and fungal causes of meningitis and what populations are at risk for each?
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Neonatal: Group B strep, E. coli, Listeria monocytogenes
6 months - 6 years: Neisseria meningitidis, Haemophilus influenzae, enteroviruses (esp coxsackievirus) 6 - 60: Neisseria meningitidis, Strep pneumoniae, enteroviruses, HSV 60+ years: Listeria, Strep pneumoniae, gram negative rods |
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What are the catalase positive organisms?
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CATs need their own SPACE
S=Staph aureus P=Pseudomonas A=Aspergillus C=Candida E=Enterobacter (E. coli) |
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What are the properties of the Diphtheria toxin?
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ABCDEF
AB = A/B type toxin C = Corynebacterium D = diphtheriae E = EF-2 (binds to elongation factor 2) |
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What are 4 diseases that E. coli can cause?
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You get E. coli from DUNG:
D = Diarrhea U = UTI N = Neonatal meningitis G = Gram-negative sepsis |
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What bacteria are obligate anaerobes?
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The ones that are Choked By Air:
C = Clostridium B = Bacteriodes A = Actinomyces |
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What are the urease positive organisms?
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UREASE +'s are PROs at putting you through HELL, but NO CRYing
Ureaplasma Proteus Helicobacter pylori Nocardia Cryptococcus (fungus) |
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What cytokine stimulates the production of TH1? What inhibits it?
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IL-12 (produced by macrophages) stimulates the production of TH1.
IL-10 (made by TH2 cells) inhibit the production of TH1. |
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What cytokine stimulates the production of TH2? What inhibits it?
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IL-4 (made by TH2 cells - so it's self perpetuating) stimulates the production of TH2 cells.
IFN-gamma (made by TH1 cells) inhibit the production of TH2 cells. |
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Is TH1 better at dealing with intracellular or extracelluar infections?
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Intracellular.
TH1 usually occurs first and is important in eliminating intracellular infections (viruses, bacteria, and parasites) |
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What is the Fab fragment on an antibody?
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The Antigen Binding fragment
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Which interleukin acts on the hypothalamus to increase temperature and create a fever?
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IL-1
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What surface proteins does HIV require to infect a cell? Which cells have these?
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HIV binds to CD4, but it needs a co-receptor: CCR5 which is on macrophages, and CXCR4, which is on T-cells.
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