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65 Cards in this Set
- Front
- Back
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Features of Spirochetes
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Helical in shape
Long and thin Axial Filaments Cannot be seen by compound microscope Must use Darkfield microscope Fragile, easy to kill with antibiotics Hard to grow in culture |
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Treponema pallidum
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Disease: syphilis
Route of Transmission: sexually or congenitally (acquired at birth) transmitted Features: Can't be seen by light microscopy Cannot be grown in vitro very susceptible to heat and drying 2-3 week incubation Primary syphilis infection small hard based chancre (ulceration or sore) for a few days Painless, many patients do not even know it is there. Secondary Syphilis 1-3 months later secondary syphilis appears as wide spread skin rash even on palms mild fever flu-like symptoms - sore throat, lymphadenopathy (swollen lymph nodes), myalgia (sore muscles) highly infectious |
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Treponema pallidum
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Primary - chancre
Secondary - rash including palms and soles Tertiary - neurological symptoms |
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Treponema pallidum
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Tertiary syphilis
may occur decades later neurological symptoms circulatory involvement and gummas (large lesions) Accommodation of pupils but no reaction to light is known as Argyll Robertson pupils. Dorsal root column demyelination causes tabes dorsalis which causes abnormalities of sensation, sharp pains, incoordination and incontinence. Also called "slapped foot walking" because of the loss of feeling in the feet. It causes a distinctive way of walking. Congenital syphilis transmission usually occurs after first trimester, outcome may range from intrauterine death congenital abnormalities or silent infections which do not show up until about 2 years of age as facial and tooth deformities. Diagnosis usually by dark field microscopy and serology. Vaccine: no vaccine, Penicillin for treatment |
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Secondary syphilis
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Secondary Syphilis
1-3 months later secondary syphilis appears as wide spread skin rash even on palms mild fever flu-like symptoms - sore throat, lymphadenopathy (swollen lymph nodes), myalgia (sore muscles) highly infectious |
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Borrelia recurrentis
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Disease: relapsing fever
Route of Transmission: soft tick bite and body lice Features: This spirochete is endemic (indigenous) in rodents and is transmitted to humans by tick bite and body lice. After a 3-10 day incubation, an individual will develop sudden chills and fever which will last for 3-5 days. The fever will lapse for ~1 week before the next bout. 3-10 fever episodes will usually be seen. Relapses are due to antigenic variation of the spirochetes. Diagnosis is by blood smear. Vaccine: Tetracycline for treatment Recurring bouts of fever about 1 week apart. |
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Borrelia burgdorferi
Disease: Lyme disease |
Route of Transmission: transmission by hard ticks
Symptoms: diagnosis usually serology difficult to see Lyme disease slowly progressing characteristic bull's eye skin lesions in 50% of cases organisms are harbored in mice and deer 1 week incubation fever, headache, myalgia (muscle pain), lymphadenopathy (swelling of lymph nodes), joint pain, fatigue later neurological and cardiac problems pets also susceptible Vaccine: No vaccine, Tetracycline, erythromycin and penicillin Bull's eye lesion in 50% of cases, arthritic symptoms otherwise. |
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Helical organisms with flagella
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Campylobacter jejune
Helicobacter pylori |
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Campylobacter jejune
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Disease: outbreaks of food borne intestinal disease
Route of Transmission: food borne Features: associated with poultry, milk and water. Household pets may serve as a reservoir invades GI epithelium produces cytotoxin (bacterial toxins that kill host cells) Incubation 2-11 days Duration 3 days- 3 wks Diarrhea, abdominal cramps and fever no vomiting Vaccine: No vaccine, self-limiting disease |
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Helicobacter pylori
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Disease: Gastritis (inflammation of the stomach) and gastric ulcers
Route of Transmission: Unknown Features: produce cytotoxins as well as ammonia as a result of urease (an enzyme that changes urea into ammonium carbonate) to neutralize stomach acid in the localized regions of the colony. As the colony grows, the cytotoxins form the ulceration. Responsible for 100% of all duodenal ulcers and 80% of peptic ulcers. Where do you think the other 20% come from? It is not stress or spicy foods. The rest come from over the counter drugs like NSAIDS, aspirin, and even alcohol abuse. also strongly associated with stomach cancer Vaccine: No vaccine , treat with antibiotics. Ulcers should not be treated with anti-acids as this will only exacerbate the growth of the organism. Responsible for almost all ulcers. Have been proven using Koch's postulates. |
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Gram-negative aerobic
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The Pseudomonads are the first group we will cover.
Pseudomonas species belong to this group. These organisms are rod shaped with polar flagella and often produce diffusible pigments. Pseudomonas is very proficient as an opportunistic pathogen. The Pseudomonads grow ubiquitously in the ecosystem. Many are capable of growing at refrigerator temperatures and decomposing chemicals which kill most microbes. They can grow in soaps, adhesives and even in some antiseptics. They carry resistances to a wide variety of antibiotics. Although these organisms are aerobic, they are often capable of anaerobic respiration using nitrate as the terminal electron acceptor. Because of this ability, they contribute to the conversion of nitrates from the soil into a form useable by plants. |
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Pseudomonas aeruginosa
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Disease: Dermatitis (inflammation of the skin), Outer ear infections, infections of burn and Cystic Fibrosis patients
Route of Transmission: Water borne, direct contact, nosocomial infections Features: opportunistic pathogen can colonize hair follicles and cause self limiting rash Can be transmitted in pools, hot tubs, loofa sponges Infected areas may exhibit blue-green pus due to pigment Very distinctive putrid, grape-like odor Vaccine: None Known for its flourescent green pigment, heavy pigment and very characteristic odor. |
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Legionella pneumophila
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Disease: Legionnaire's disease or legionellosis
Route of Transmission: Respiratory route Features: These microbes colonize streams, water lines in hospitals, showers and cooling towers of air conditioning systems grows in macrophages Legionnaire's disease is an atypical pneumonia which means it is a pneumonia not caused by the 3 leading bacterial agents. It is a severe, quickly fatal disease in older people particularly if they are smokers and heavy drinkers. Also causes Pontiac fever (flu-like illness) in young previously healthy individuals Vaccine: None |
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Bordetella pertussis
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Disease: Whooping cough
Route of Transmission: Respiratory route Features: Three stages of disease in children: Initial phase called catarrhal stage resembles a cold. Paroxysmal phase is caused by destruction of mucociliary escalator. Accumulation of mucus in trachea and lungs causes characteristic whooping cough. Convalescence phase may last months. Adults can also contract whooping cough especially if childhood vaccines are withheld. The complications can be serious. |
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Bordetella pertussis
Known for the destruction of the mucociliary escalator |
Bronchopneumonia, which may be a 2ndry infection by Haemophilus influenzae, atelectasis (collapse of the lung) resulting in bronchiectasis.
Bronchiectasis is distortion and stretching of one or more bronchi resulting in chronic lung infections . Convulsions may also occur after a serve paroxysm of coughing may lead to intracerebral hemorrhage. Bronchopneumonia is a leading type or pneumonia in which the inflammations is spread throughout the lungs in small patches rather than confined to one lobe as in pneumococcal pneumonia. The pressure of paroxysmal coughing may cause conjunctival hemorrhage and epistaxis (nose bleed). A frenal ulcer may also appear on the tongue in the early stages of disease. The frenum is the fold of skin on the underside of the tongue. Vaccine: DTaP vaccine (diphtheria, tetanus and acellular pertussis). Acellular boosters may be given Immunization is recomm for all children unless the pt shows evidence of progressive neurological deficit of fam history |
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Moraxella lacunata
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Disease: conjunctivitis (pink eye). This is one of the most common bacterial causes of pink eye.
Route of Transmission: Direct contact Features: strictly aerobic coccobacillus, an inflammation of the membrane that covers the eye and lines the eyelids. Vaccine: None |
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Brucella melitensis
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Disease: brucellosis or undulant fever
Route of Transmission: Direct handling of infected animals Symptoms: nonmotile coccobacillus which is an obligate intracellular bacterium Undulate fever is a zoonotic disease (where a non-human vertebrate serves as reservoir of infection, and humans are only accidental hosts). The reservoir is domesticated animals:cows, pigs, goats; bacteria enter through skin or mucosa, capable of surviving phagocytosis by macrophages. spread via lymph to liver, spleen or bone marrow, signs are malaise (general weakness and tiredness) swollen lymph nodes and fever that undulates or spikes every evening Also called Bang's Disease, Malta Fever,rock fever of Gibraltar and undulant fever. Vaccine: vaccine is available for cattle and high risk groups; Farmers, ranchers, vets, meat packers are risk groups, Erythromycin and tetracycline Known for abortion storms in pregnant cows. |
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Francisella tularensis
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Disease: tularemia (rabbit fever)
Route of Transmission: Spread to humans by handling infected meat, eating undercooked meat or deer fly bites, Respiratory route is less common Features: plague-like disease in animals, reservoir in small animals, Highly infectious ulceration at site of entry then septicemia (bacteria in blood), swollen painful lymph nodes and pneumonia, organisms resist phagocytosis Vaccine: Streptomycin is drug of choice, Cannot be treated with penicillins or cephalosporins, Live attenuated vaccine is available for people at high risk such as trappers; ticks should be avoided Known for being a zoonotic disease. |
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Gram Negative, Microaerophilic Cocci
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A microaerophile is an organism which requires reduced oxygen levels and carbon dioxide for growth. They are a subtype of aerobe and absolutely require oxygen, but just in small amounts. The best way to grow a microaerophile in the lab is in a candle jar. The growth requirement must also be addressed in a clinical lab were patient samples must be grown in reduced oxygen levels in order to confirm one of these organisms.
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Neisseria gonorrhoeae
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Disease: Ophthalmia neonatorum, Gonorrhea and PID
Route of Transmission: Via birth canal or sexually Symptoms: Organism susceptible to drying and survives poorly outside human host Transmission occurs more readily male to female than female to male. Transmission from female to infant during childbirth is seen as an eye infection (ophthalmia neonatorum) in newborns |
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Neisseria gonorrhoeae
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Symptoms:
Organism susceptible to drying and survives poorly outside human host Transmission occurs more readily male to female than female to male. Transmission from female to infant during childbirth is seen as an eye infection (ophthalmia neonatorum) in newborns Pelvic Inflammatory Disease (infection of uterus and uterine tubes) Incubation period 2-7 days more than 70,000 cases per year bind to cells by fimbriae in males painful urination and pus discharge females may be asymptomatic unless spreads to PID may include abdominal/pelvic pain, discharge, salpingitis (uterine tube infection) and cervix infection Diagnosis rests on microscopy and culture of discharge Samples should be collected in the clinic or at the bedside and transferred to warmed media immediately, Endocarditis (inflammation of the lining of the heart), meningitis (inflammation of the membranes covering the spinal cord) and arthritis can develop if untreated. Vaccine: drug of choice is beta-lactamase-stable cephalos |
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Neisseria gonorrhoeae
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As STD, known for what is called the "drip" or the "clap".
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Bacterial meningitis:
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progressive impairment of CNS (central nervous system) leading to coma and death, Intense headaches, photophobia (light sensitivity), fever and stiff neck. How do these symptoms differ from viral, fungal or protozoan meningitis? They do not; however, remember viral meningitis will not cause turbidity in CSF, where "cellular" meningitis of any kind can. Since bacterial meningitis is more common that protozoan or fungal, it is test for first. Bacterial meningitis is also a faster killer and should be evaluated right away.
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Gram stain and culture must be performed on CSF (cerebral spinal fluid), Neisseria meningitidis (1), Streptococcus pneumoniae (2), and Haemophilus influenzae (3)
ALL THREE ARE |
microaerophilic and Haemophilus influenzae requires blood. So proper growth conditions are necessary to identify one of the top three.
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Neisseria meningitidis
Known for the rash associated with the meningitis. |
Disease: Meningococcal meningitis
Route of Transmission: grows in throats of healthy carriers, spread by respiratory droplets Symptoms: once in blood, the organism crosses the blood-brain barrier symptoms due to endotoxin diagnosis of meningitis is based on cultures made on blood agar which are incubated at reduced oxygen tension Cells look like coffee-beans microscopically causes most of meningitis cases 10-15% mortality 10-15% of infected individuals have long term complications such as deafness, mental retardation, etc. The Rash of this disease differentiates it from other menigitis causes. Vaccine: purified capsular polysaccharide is used as vaccine for some strains (type A and C; Not B), Penicillin or cephalosporin first treatment, maybe along with chloramphenicol, Rifampicin for prophylaxis |
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The facultative anaerobic, Gram negative rods
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Enterobacteriaceae, Vibrionaceae and Pasteurellaceae.
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Enterobacteriaceae
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The Enterobacteriaceae or enterics inhabit the intestinal tracts of animals and are usually active glucose fermenters.
Many enterics are motile with peritrichous flagella and have fimbriae allowing them to attach to mucous membranes. Endotoxin is found in the outer membrane of all members of this group. Endotoxin causes high fever and shock, activation of complement, blood clotting, inflammation and stimulation of immune cells through the release of cytokines. Most have sex pili which are involved in genetic exchange particularly antibiotic resistances. Bacteriocins (proteins causing lysis of related species of bacteria) are also produced. Common cause of Septicemia (presence of pathogenic bacteria in the bloodstream): |
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Enterobacteriaceae
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microbes actively reproducing in blood or lymphatic system
Red streaks extending up from the affected area, fever toxemia (presence of bacterial toxins in the blood) and septic shock (collapse of circulatory function due to infection) are complications Some of the most important genera of enterics are Escherichia, Salmonella, Shigella, Klebsiella, Serratia, Proteus, Yersinia, Erwinia and Enterobacter. Antibiotics usually work well, aseptic techniques are prophylactic. |
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Escherichia coli
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Disease: Urinary tract infection and Traveler's diarrhea
Route of Transmission: Fecal/oral route Symptoms: the most well known enteric. It is a common inhabitant of the intestinal tract and is a workhorse in molecular biology/biotechnology. The presence of E. coli in water and foods is often an indication of fecal contamination. Although it is not usually pathogenic, many pathogenic strains exist, and the organism is very opportunistic as are most microbes. E. coli is a major contributor to UTI (urinary tract infections) UTI: frequent painful/burning urination, difficulty voiding bladder, cloudy foul-smelling urine, blood in urine, abdominal pain, fever Diagnosed by urine culture Caused by a number of organisms from this group and others many strains produce an enterotoxin (a bacterial toxin that causes inflammation of the stomach and intestine) which is associated with traveler's diarrhea. |
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some of the most commonly produced toxins or virulence factors
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1. endotoxin , LPS (found in all E. coli becase they are Gram Neg)
2. Adhesins , associated with UTI 3. Capsule (Strains with capsule are more virulent) 4. Enterotoxin (cholera or shiga-like toxin found in diarrhea causing strains) 5. Verotoxin (only found in 0157:H7 which is the Jack-In-The-Box E. coli) causes inflammation and bleeding of the colon and kidney damage. Can shut down the kidneys in children in 24 hours. Vaccine: None "Travel tip: Economy-section farts on an inbound flight from the Third World are the deadliest a traveler will ever encounter." – George Carlin The Jack-in-the-Box E. coli (O157:H7) is the deadliest strain. |
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Salmonella species
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Disease: salmonellosis
Route of Transmission: fecal/oral route Symptoms: all species are potential pathogens Salmonella are also involved in many severe, food-borne gastrointestinal diseases called salmonellosis causes 70% of all food borne diarrheal diseases in the United States Source is often uncooked eggs, nausea, abdominal pain diarrhea 12-36 hours after ingestion fever from endotoxin a variety of species cause this syndrome salmonella may be harbored in the human body Vaccine: rehydration therapy may be needed Causes 70% of the diarrheal disease in the United States. It requires a large dose of Salmonella to make you sick. You only have to swallow one shigella to get extremely sick. |
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Salmonella typhi
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Disease: typhoid fever
Route of Transmission: fecal/oral route Symptoms: 2 week incubation, high fever, headache, diarrhea and malaise for 1-2 weeks Harbored in gall bladder of carriers, Carriers are treated by gall bladder removal 10% mortality if untreated Vaccine: Killed vaccine, Ampicillin, chloramphenicol, cotrimoxazole, ciprofloxacin |
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Salmonella typhi
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Known for the formatin of carriers with the organism harbored in their gall bladders.
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Shigella dysenteriae
It requires a large dose of Salmonella to make you sick. You only have to swallow one shigella to get extremely sick. |
Disease: bacillary dysentery or shigellosis and traveler's diarrhea
Route of Transmission: fecal/oral route Symptoms: small dose required invasion of ileum and colon causes bloody mucoid diarrhea abdominal cramps, fever, intense inflammation also produces a neurotoxin (bacterial toxin that affects the nervous system) Mortality 20% if untreated Vaccine: No vaccine, antibiotics should be avoided because of high degree of resistance, Hand washing is prophylactic |
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Klebsiella pneumoniae
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Disease: Urinary and respiratory tract infections
Route of Transmission: Normal flora or by direct contact Symptoms: survives very well on hands a major cause of septicemia in children and pneumonia in alcoholics On the rise, may replace current as #1 bacterial pneumonia cause Vaccine: No vaccine, very resistant to antibiotics, aseptic technique and handwashing are prophylactic Many Klebsiella infections are nosocomial and originated from objects like stethoscopes which are shared between patients without being sanitized. |
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Yersinia pestis
In the pneumonic form, inhaling one cell results in death in 24 hours. Is a zoonotic disease. |
Disease: bubonic plague and pneumonic plague
Route of Transmission: Flea bite in bubonic form, respiratory route for pneumonic form Symptoms: With human to human transmission the LD50 is less than 1 symptoms may include bruising and buboes (enlarged lymph nodes) Childhood poem, Ring around the Rosie, dedicated to the bubonic plague rash Tet and streptomycin are effective if administered promptly after exposure endemic in rodent populations Vaccine: Killed vaccine gives partial protection, Prophylaxis by strict quarantine, rodent control, strict isolation of patients, prophylactic antibiotics |
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Yersinia enterocolitica
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Disease: childhood diarrheal disease
Route of Transmission: Contaminated water or foods, from dogs also possible Symptoms: infect intestinal lining causing ulcerations spreads to lymph system where ulcerations also develop fever, diarrhea and abdominal pain which may be mistaken for appendicitis arthritic symptoms may develop Vaccine: self-limits in 1-3 weeks, antibiotics may speed recovery |
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Vibrio cholerae
Known for the large volume of diarrhea produced per day and death due to the secondary effects of dehydration. |
Disease: cholera
Route of Transmission: Contaminated water or foods Symptoms: causes profuse, watery diarrhea produces exotoxin (toxin secreted by bacteria) which alters membrane permeability of intestinal mucosa and causes massive watery diarrhea (rice water stool; 3-5 gallons/day) and vomiting fever usually absent, incubation 3 days, symptoms last several days 50% mortality if untreated, death as a result of severe dehydration 300,000 people died of cholera in Rwanda in 1995 Vaccine: Tetracycline shortens the symptoms, a whole cell vaccine is available but of limited use |
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Vibrio parahaemolyticus
Cooking completely eliminates the risk of this disease. |
Disease: gastroenteritis (inflammation of stomach and intestine)
Route of Transmission: raw or undercooked shellfish Symptoms: produces a cytotoxin and hemolysin diarrheal disease with abdominal pain burning sensation, nausea, vomiting and watery stool prevented by cooking fish symptoms after 24 hours Vaccine: No vaccine, Without treatment recovery in few days, rehydration therapy rarely |
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Haemophilus influenzae capsular type b (Hib)
Pasteurellaceae |
Disease: Meningitis, earaches, epiglottitis, septic arthritis, bronchitis and pneumonia
Route of Transmission: airborne transmission Vaccine: a vaccine directed against the capsular polysaccharide is available, HibTITER given to infants, may also be given as TETRAIMMUNE vaccine which is Hib, diphtheria, pertussis and tetanus combined, Ampicillin for non-beta-lactamase producers, Cephalosporin or chloramphenicol as alternatives. Rifampicin recommended as prophylactic. New Comvax vaccine provides children with protection against Hib and Hepatitis B Virus combined. |
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Haemophilus influenzae capsular type b (Hib)
Until recently, this was the #1 cause of meningitis in children. Because of the HIB vaccine, it has dropped to three; but it is still a very common cause of childhood ear aches and other more minor infections. |
Features:
Haemophilus species commonly inhabit the mucous membranes of the upper respiratory tract, mouth, vagina and intestinal tract of humans. Acute otitis media caused by the organism often follows viral upper respiratory tract infections. Congestion of the eustachian tubes results in fluid buildup in the middle ear and allows H. influenzae to colonize. The pressure building up within the area of the middle ear results in pain, and may lead to bulging and perforation of the tympanic membrane with discharge of pus. This organism is also a leading cause of epiglottitis in children who are not vaccinated. The epiglottis may swell and cause airway obstruction. X ray is preferred at all times in a suspected case of epiglottitis because physical examination of the throat and pharynx may cause the epiglottis to obstruct the trachea. It may be necessary to intubate and ventilate the patient if there is severe respiratory distress. Anesthetic will probably be necessary for intubation. H. influenzae is now the third most common bacterial meningitis in children. Progressive CNS infection leading to blindness, deafness, paralysis, coma and sometimes death Begins with intense headache, light sensitivity, fever and neck stiffness. This organism is the leading cause of contracted mental retardation in the U.S. This organism also causes earaches, epiglottitis, septic arthritis, bronchitis and pneumonia. (This organism does not cause influenza) Haemophilus species lack the cytochrome system necessary for respiration and must be supplied with blood hemoglobin in order to grow. In addition the cofactor (electron acceptor), NAD, must be provided. H. influenzae type B is most common (six types total), CSF may be used to culture or Gram stain Mortality rate 5% 35% of survivors develop permanent neurological problems such as seizures, deafness and mental retardation |
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Gardnerella vaginalis
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Disease: vaginitis (inflammation of the vagina)
Route of Transmission: normal flora in most women or their sexual partners Symptoms: sensitive to pH changes, foul odor and discharge It along with several other genera is classified as a Gram variable organism and may be found in either the Gram positive or Gram negative facultatively anaerobic rod grouping Also classified with Gram Negative, Facultative anaerobes in text Considered a Gram variable organism) Vaccine: None This is not a classical STD. Although some doctors will call it an STD because it can be transferred between partners during sex. |
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Coxiella burnetii
Only known Gram negative endospore producer. obligate intracellular bacteria |
Disease: Q fever
Route of Transmission: transmitted by aerosols from animals or by contaminated milk from cows Symptoms: This organism is also the only known Gram-negative endospore producer Not transmitted by insects like the other Rickettsias resistant to drying, heat and sunlight main site of action is the lung fever, severe headache, atypical pneumonia can develop into hepatitis and endocarditis disease may self-limit in 1-2 weeks May also become chronic and fatal if untreated Vaccine: Killed vaccine available for high risk groups, Killed by pasteurization, Antibiotic therapy available |
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Rickettsia prowazekii
obligate intracellular bacteria |
Disease: epidemic typhus
Route of Transmission: transmitted in the feces of human lice Symptoms: rash, prolonged high fever, and stupor Vaccine: treatable with antibiotics |
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Rickettsia typhi
obligate intracellular bacteria |
Disease: endemic murine typhus (not the same as typhoid fever caused by Salmonella)
Route of Transmission: rat fleas Symptoms: less severe Vaccine: None, usually self-limiting |
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Rickettsia rickettsii
obligate intracellular bacteria |
Disease: Rocky mountain spotted fever
Route of Transmission: tick bite Symptoms: Rickettsias multiply inside the host cell cytoplasm. Rickettsial disease in humans results in damage to the permeability of capillaries, and potential collapse of the cardiovascular system causes a rash similar to measles but also on the soles and palms (viral infections do not produce rashes here). also have a fever and headache death often as a result of kidney and heart failure Vaccine: Tet and chloramphenicol very effective early, no vaccine * Remember there are only two diseases causing a rash on the palms and soles. Both are bacterial. Rocky mountain spotted fever and syphilis are both indicated by this rash. |
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Chlamydia trachomatis
obligate intracellular bacteria |
Disease: trachoma (infection of the conjunctiva of the eye), nongonococcal urethritis, PID and lymphogranuloma venereum
Route of Transmission: STD (sexually transmitted disease) or transmitted by direct contact Symptoms: scar tissue forms on cornea the leading infectious cause of blindness in the world most common sexually transmitted disease and leading cause of infertility 75% of females often asymptomatic bacteria easily infect warm, moist cervix and can cause permanent reproductive organ damage, infection of lymph nodes and inflammation of the genitalia, spreads to fallopian tubes resulting in PID In women symptoms include: unusual vaginal discharge, burning when urinating, lower abdominal pain or pain during intercourse, and bleeding between menstrual periods. In men: discharge from the penis, burning when urinating, burning and itching around penis opening, pain and swelling of testicles Serology inefficient in diagnosis because organisms are intracellular Advanced infections become LGV with buboes, often ruptured, strictures and fistulas Vaccine: None, Tetracycline and Erythromycin used, Fluoroquinolones useful. Trachoma is the leading infectious cause of blindness worldwide. It can infect the eyes of newborns also. |
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Chlamydia trachomatis
obligate intracellular bacteria |
LGV, This figure (right) shows a stricture, which is a pinching due to scar tissue. This one is an esophageal stricture. However, rectal strictures are common in advanced LGV, resulting in the buildup of waste.
It is common for fistulas to form in the rectum resulting in peritonititis. In LGV, buboe are common in males and females. These buboe often rupture to the outside as these have. Remember, bubonic plague is not the only bacterial diseases associated with buboes. |
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Chlamydia pneumoniae
obligate intracellular bacteria |
Disease: Pneumonia, Atherosclerosis?
Route of Transmission: Respiratory route Symptoms: Typical symptoms of pneumonia. Organism found in 90% of coronary arteries with atherosclerotic plaque and only 4% of patients with no atherosclerosis. Vaccine: None Heart disease linked to this organism is a hot area of research. It is thought that the organism changes the surface of artery linings resulting in the pre-disposition to the deposition of plaque. Wouldn't it be neat is we could develop a vaccine against this organism which would serve the dual role as an anti-plaque vaccine? |
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Mycoplasma pneumonia
Bacteria Without Cell Walls |
Disease: primary atypical pneumonia
Route of Transmission: Respiratory route Symptoms: also known as "walking pneumonia", contains no peptidoglycan, but does have outer membrane, cells attach to ciliated respiratory epithelium in the respiratory tract, lasts for weeks but is usually not severe enough to require hospitalization, a very common cause of pneumonia in previously healthy middle aged individuals. Vaccine: None, Tet and erythromycin Remember, walking pneumonia is hard to treat because all antibiotics which target peptidoglycan will not work. |
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Staphylococcus aureus
Bacteria Without Cell Walls Gram positive Cocci |
Disease:
Folliculitis (pimples) Impetigo in neonates Sty (follicle of lash) Boils (furuncle) Carbuncles (progressively expanding infections, hard, round deep inflamed regions) postoperative infections catheter infections scalded skin syndrome TSS Staphylococcal food poisoning Route of Transmission: Normal flora and post-operative infections Symptoms: Most common species Neonates particularly susceptible because of naive immune system A variety of toxins can be produced causing, other exfoliative conditions TSS, and food poisoning typical skin lesions are pus-filled with red margins bugs may be cultured and Gram stained from the discharge Positive coagulase test confirms the presence of the organism. Antibiotics usually work well, Lesions may require lancing. Food poisoning occurs by enterotoxin which remains active after boiling, symptoms of nausea, vomiting and diarrhea begin 1-24 hours after eating Vaccine: None, IV rehydration may be necessary Impetigo in newborns if most commonly caused by Staphylococcus. In older children and adults, it is usually caused by Streptococcus. Honey colored fluid (above) and honey colored crusting (below) is indicative of impetigo. * Don't forget that methicillin resistant Staphylococcus aureus is a common nosocomial infection as well as a disease associated with unsanitized surfaces, like high school gyms and athletic equipment. It is spread by contact and often starts out looking like a spider bite. It will continue to spread if not treated. |
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Streptococcus pyogenes
Bacteria Without Cell Walls Gram positive Cocci |
Disease:
strep throat ear, sinus and tonsil infections Puerperal sepsis Impetigo in older children and adults erysipelas **Scarlet fever **Rheumatic fever Route of Transmission: Respiratory or direct contact Symptoms: Beta hemolytic Alpha-hemolytic species produce alpha-hemolysin which reduces hemoglobin( red) to methemoglobin (green) resulting in a greenish zone around the colonies. Beta-hemolytic species produce hemolysin which forms a clear zone when blood cells are lysed. Some species have no apparent hemolysis and are classified as gamma-hemolytic. produce a variety of toxins Impetigo, Purulent (pus-filled) lesions with honey-colored crusts, lesions near mucous membranes Red skin discolorations (erysipelas) may result from strep producing erythrogenic toxin (toxin that causes abnormal redness due to inflammation) spread by direct contact or overgrowth of flora responds well to antibiotic therapy Scarlet fever- toxin gene carried on a prophage, causes rash (not on soles or palms) which is pin-point and rough (sand paper) to the touch, "Strawberry tongue" is red, enlarged and raw, followed by desquamation Rheumatic fever caused by cross reactive antibodies between strep and heart. Endocarditis is infection of inner lining of the heart, tissue, acute glomerulonephritis (inflammation of the kidney) and inflammation Streptococci are usually absent by this point, so anti-inflammatory drugs are given Vaccine: No vaccine, Antibiotic therapy Be sure you can differentiate between scarlet fever and rheumatic fever! |
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Streps
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This figure shows the classic way of differentiating between the three types of streps. Alpha hemolysis results in modification of the hemoglobin in blood causing the opaque greenish/yellow color of the agar. Beta hemolysis results in lysis of red blood cells which is seen here as a clearing of the agar. You can now see through it. Gamma hemolysis results in no apparent change to the blood. The most dangerous streps are beta hemolytic.
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Streptococcus pneumoniae
Bacterial Pneumonias: fluid accumulation, fever, chest pain and impairment of respiratory function |
Disease: Pneumococcal pneumonia
Route of Transmission: Respiratory droplet transmission Symptoms: normal flora at some times, 4% of population are carriers Capsulated symptoms are fever, fluid accumulation, difficulty breathing, chest pain and rust colored sputum Sickle cell patients are more susceptible to pneumococcal pneumonia and should be vaccinated, increased susceptibility is due to atrophy of the spleen Vaccine for pneumonia may provide some protection against Pneumococcal meningitis, relatively rare but causes high mortality rate 15% mortality Second most common cause of bacterial meningitis in children and young people, but one of the fastest to kill. Can kill within 24 hours. The most common cause of meningitis in adults. Vaccine: Capsular polysaccharide vaccine, Penicillin treatment of choice for sensitive strains |
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Enterococcus faecium and faecalis
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Disease: urinary tract infection, endocarditis, post operative infections
Route of Transmission: Normal flora or nosocomial Symptoms: frequent painful/burning urination, difficulty voiding bladder, cloudy foul-smelling urine, blood in urine, abdominal pain, fever, Diagnosed by urine culture, inflammation of heart lining Vaccine: No vaccine, Antibiotic therapy, Many strains resistant to vancomycin (VRE These organisms are used in the lab. Just a friendly reminder to wash your hands frequently!! |
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Bacillus anthracis
Endospore-forming Gram-positive rods |
Disease: anthrax
Route of Transmission: respiratory route or spore entrance through abrasions Symptoms: endospores can survive up to 60 years cattle acquire spores by grazing, humans get disease by handling cow products or respiratory site of entry often develops black necrotic pustule (eschar) followed by septicemia results in pneumonia Vaccine: Penicillin is drug of choice, vaccine is available These are black eschars. Although they look horrible, cutaneous anthrax (also called wool sorter's disease) is easily curable with antibiotics. If it is left untreated, it will progress into pnemonia which is more deadly. Acquisition of the disease by respiratory route, by inhaling the endospores, causes a rapid pneumonia, which is still treatable with antibiotics, but must be treated quickly. Because it is not as efficient to spread, it is not the best choice as a biological weapon. |
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B. cereus
Endospore-forming Gram-positive rods |
Disease: Food poisoning
Route of Transmission: associated with ingestion of reheated rice Symptoms: Produces two toxins heat stable toxin associated with germination of spores and causes food poisoning 1-5 hours after ingestion (intoxication) heat labile enterotoxin produced by vegetative cells causes diarrhea 10-15 hours later (infection). most commonly associated with reheated rice dishes Vaccine: No Vaccine, most illness is self-limiting |
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Clostridium tetani
Endospore-forming Gram-positive rods |
Disease: Tetanus or lockjaw
Route of Transmission: Puncture wound Remember this disease has nothing to do with rust or rusty nails. Symptoms: the organism reaches the anaerobic environment it prefers after puncture wound 72 hours with headaches, fever, irritability and paralysis of face and neck severe disease noted by muscle spasms and convulsions endospores widespread in soil, produces a neurotoxin called tetanospasmin (LD50 = 20ng) which causes spastic paralysis convulsive contractions of voluntary muscles death results from spasms of respiratory muscles Vaccine: Immunization by DPT (Diphtheria, Pertussis and Tetanus) includestetanus toxoid (inactivated toxin), booster is often given, if you have never been immunized before, tetanus immune globulin is given, Debridement (removal of tissue) and antibiotics may be necessary to clear the organisms |
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Clostridium botulinum
Endospore-forming Gram-positive rods |
Disease: botulism
Route of Transmission: Ingestion of toxin or bacilli Symptoms: caused by ingesting preformed exotoxin which is destroyed by proper boiling ( an intoxication, not a true infection) Symptoms include nausea, diplopia (double vision) and dysphagia (difficulty in swallowing) toxin is acid stable and survives stomach, Toxin is heat labile acts at neuromuscular junctions by inhibiting acetylcholine release so nerve impulses are blocked blurred vision occurs within the first 1-2 days followed by flaccid paralysis and often death due to respiratory failure as a result of paralysis of the diaphragm. Wound botulism may also occur when the organism grows anaerobically in deep wounds. Vaccine: Treatment is antitoxin, Supportive therapy essential, Until 1993, the U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID) kept one horse named First Flight and injected him with 7 serotypes of botulism toxoid. He was the United States only source of heptavalent botulinum antitoxin and donated more than 1,600 liters of blood during his duty. He was the only source of antitoxin for our troops during the Gulf War when Saddam Hussein had botulism in his germ warfare arsenal. First Flight has now been retired. Remember it is the bulging cans you have to worry about, not the dented cans. |
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Clostridium perfringens
Endospore-forming Gram-positive rods |
Disease: Gas gangrene and food poisoning
Route of Transmission: wound Symptoms: progressive necrotizing infection Produces at least 12 toxins and tissue-destroying enzymes in wounds organisms then use nutrients released Bacterial fermentation may produce gas pockets in tissue Food poisoning occurs when cells are ingested and sporulate in the gut releasing toxin. Does not usually require treatment Vaccine: No vaccine, Treatment includes penicillin, Metronidazole, antitoxin, Debridement, hyperbaric chambers and amputation used to treat gas gangrene |
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Clostridium difficile
Endospore-forming Gram-positive rods |
Disease: Pseudomembranous Colitis (antibiotic associated diarrhea)
Route of Transmission: normal gut flora or fecal/oral route Symptoms: Thrives under antibiotic selection rapidly fatal in compromised hosts produces several toxins which damage gut wall Vaccine: No vaccine, Antibiotic therapy, Prevention in hospital setting depends on hygiene This is a common nosocomial infection. |
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Listeria monocytogenes
Regular nonsporing gram-positive rods |
Disease: Listeriosis (meningitis in neonates and immunocompromised)
Route of Transmission: Food-borne or in utero Symptoms: contaminant of dairy foods which can be very damaging to pregnant women resulting in stillbirth or meningitis and sepsis in newborns infects immunocompromised, cancer patients can cross placenta causing spontaneous abortion or stillbirth Found in cow's milk and infected foods such as cheese may be asymptomatic in healthy people Pregnant women advised against eating any uncooked foods. Vaccine: No Vaccine, Antibiotic therapy To avoid this disease, always check for pasteurization. |
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Corynebacterium diphtheriae
Irregular nonsporing gram-positive rods |
Disease: diphtheria
Route of Transmission: spread by respiratory aerosol Symptoms: Infects throat or skin iron regulated toxin production from lysogenic phage symptoms are sore throat, fever, malaise and swelling of the neck, all are directly related to the toxin produced. Pseudomembrane: fibrous membrane containing dead host and bacterial cells can form leathery blockage of trachea The exotoxin inhibits host protein synthesis and can result in heart, kidney or nerve damage The disease is uncommon in industrialized countries because of vaccine use. Vaccine: antitoxin and penicillin or erythromycin are given, part of DPT vaccine as toxoid (inactivated toxin) The pseudomembrane, a tough leathery flap of white blood cells and dead macrophges, is not the same thing as phlegm. It cannot be coughed loose. It may have to be surgically removed to restore the air way. |
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Mycobacterium leprae
Acid-fast, aerobic, non-spore-forming, nonmotile, rod-shaped bacteria |
Disease: Leprosy
Route of Transmission: close, prolonged contact Symptoms: chronic degenerative infection that leads to gradual tissue destruction Leprosy also called Hansen's disease pathogenesis mostly due to host's immune response rather than bacterial toxicity M. leprae only bacterium that grows in peripheral nervous system and also grows in skin cells. prefers cooler temps of the extremities. Two forms of leprosy. Tuberculoid (neural) form results in loss of nerve sensation in an area surrounded with nodules. Organisms can be detected in cool areas such as earlobes. Usually this form is self limiting because of immune system effectively clears the infection. The lepromatous (progressive) form results when the person's immune system does not respond effectively to the disease and nodules spread to all parts of the body. Necrosis of tissue also occurs. Vaccine: Antibiotics can render victims noncommunicable in a few days (Dapsone, Rifampicin, Clofazimine), there is a vaccine in trials, BCG vaccine is 50% effective Note the deformity of the skin by tubercles in the skin. However, you should also note that this disease is very hard to spread. |
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Mycobacterium tuberculosis
Acid-fast, aerobic, non-spore-forming, nonmotile, rod-shaped bacteria |
Disease: tuberculosis
Route of Transmission: respiratory droplet transmission Symptoms: chronic progressive lung infection weight loss, coughing, rust colored sputum (only in an advance case), chest pain, malaise, night sweats pathogenesis mostly due to host's immune response rather than bacterial toxicity Lesions called tubercles form from dead macrophages and bacteria and appear on X ray hollow cavity is then formed in the tubercle where MTB can grow, chemotherapy of multiple drugs given over a long period of time multiple drug resistant strains exist A positive skin test can mean many things, Smoking, aging, overcrowded living conditions, substance abuse and immunosuppression predisposes individuals to TB Vaccine: Drugs include Isoniazid, ethambutol, Rifampin, Pyrazinamide, Ciprofloxacin and Streptomycin, M. bovis is BCG vaccine, live, attenuated |
