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182 Cards in this Set
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On gram stain, you see gram positive cocci
a. what are 2 possible organisms b. what are 2 features you can use to distinguish the specific organism |
a. staph, strep
b. staph = clusters, catalase positive (bubbles when H202 applied) strep = chains, catalase negative |
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How can you S. aureus apart from other staphylococci?
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S. aureus is coagulase positive
others are coagulase negative |
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Patient has gram pos cocci in clusters
-catalase positive -coagulase negative a. what 2 organisms could it be b. how do you test |
a. s. saprophyticus or s. epidermidis
b. Novobiocin test -Saprophyticus is Resistent, Epidermidis is Sensitive "on the office's STAPH retreat, there was no StRES" |
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Patient has gram pos cocci in chains
-catalase negative -alpha hemolytic what are 2 possible organisms How do you tell them apart |
S. pneumoniae or viridans streptococci
Optochin test Viridans Resistent, Pneumoniae Sensitive OVRPS |
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Patient has gram positive cocci in chains
-catalase neg -complete hemolysis on blood agar (beta) what two organisms could it be? how do you tell them apart? |
Group A (S. pyogenes) or Group B (s. agalactiae)
Bacitracin - B are Resistent, A are Sensitive B-BRAS |
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On blood agar, you find a green ring surrounding an organism
what type of hemolysis what could the organisms be |
a hemolysis
s. pneumo (optochin sensitive) viridans (optochin resistant) |
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on blood agar, you find clear hemolysis
what type of hemolysis is this what are 4 possible organisms |
beta
1. staph aureus (catalase, caogulase pos) 2. Strep pyogenes (bacitracin resistant) 3. S. agalactae (bacitracin sensitive) 4. Listeria (tumbling motility, meningitis in newborns, unpasturized milk) |
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Function of catalase?
How can it be used to distinguish gram pos. cocci |
catalase degrades H2O2 before it can be converted to HOCl by myeloperoxidase
staph is catalase pos strep is calase neg |
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Staph that makes coagulase and toxins
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Staph aureus
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What do you fear in people with chronic granulomatous disease (NADPH oxidase deficiency)
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recurrent infections by catalase-producing microbes
these microbes degrade any H2O2 around, preventing ROS production |
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Major virulence factor of Staph aureus
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Protein A - binds Fc portion of Ig, prevents opsonization and phagocytosis
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3 staph aureus mediated disease classes
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1. inflammatory - direct invasion of bacteria
2. toxin mediated 3. MRSA infection |
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Staph aureus - inflammatory-mediated diseases (6)
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1. Pneumonia
2. Meningitis/brain abscess 3. osteomyelitis 4. Acute endocarditis 5. septic arthritis 6. Skin infection |
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Staph aureus
3 types of toxins and their diseases |
1. TSST-1 toxin --> toxic shock
2. Exfoliative toxin --> scalded skin syndrome 3. Enterotoxin --> food poisoning (pre-formed toxin in food) |
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Patient using a tampon for a long time/surgical sutures/subcutanous infection/childbirth infection comes in with
-fever, vomiting, erythematous rash, low BP what's going on? path? |
S. aureus --> TSST-1 mediated toxic shock
TSST is a superantigen, binds to MHCII and TCR --> polyclonal T cell activation (IL-2, IFNg) |
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Patient presents with cleavage of the middle epidermis --> sheets of skin peel off with moist red skin underneath
-patient does not have an allergy what kind of bacterial infection do you think this is? DX? |
S. aureus =
exofoliative toxin Scalded Skin Syndrome |
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Patient ate something, and now has
-nausea/vomiting -diarrhea -fever Condition lasted 24 hrs what organism is implicated? toxin? |
S. aureus
pre-formed enterotoxin in food |
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MRSA
a. what is it resistant to and how? b. where does it cause infections |
a. resists b-lactams due to altered penicillin binding protein (can make peptidoglycan even when transpeptidase is inhibited)
b. causes nosocomial and community-acquired infections |
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When you have a prosthetic device or IV catheter, what is the most likely cause of infection of these things?
Where is this organism normally? What is the effect of this organism on blood cultures? |
s. epidermidis - produces biofilms on prosthetic devices
Lives on skin flora normally can contaminate blood cultures |
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Strep Pneumo
Most common cause of what 4 conditions |
MOPS
Meningitis Otitis Media (kids) Pneumonia Sinusitis |
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Patient suffers from
-fever, shaking chills -shortness of breath, chest pain with respirations -rusty sputum -consolidation on CXR -gram stain reveals lancet-shaped diplococci a. what are this organisms virulence factors b. what is a vaccine that could protect someone from this organism in adults, children |
Strep pneumo
Capsule, IgA protease Pneumovax vaccine contains 25 capsular polysaccharides (adults) 7-capsular antigen vaccine used for kids to prevent otitis media |
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Most common cause of
Meningitis Otitis media (kids) Pneumonia Sinusitis a. optochin sensitivity b. associated with what in a patient with sickle cell or splenectomy c. associated with what in a patient with pneumonia |
Strep Pneumo
a. MOPS = Most OPtochin Sensitive b. Sepsis c. rusty sputum |
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Patient has otitis media
-you recovered gram positive lancet shaped organisms that were optochin sensitive -Quellung positive how do you treat? |
S. pneumoniae
give high dose penicillin and cephalosporins if resistent, vancomycin |
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2 conditions caused by strep viridans
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1. dental carries (strep mutans)
2. subacute endocarditis (s. sanguis) |
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S. viridans
a. normal living spot b. how to differentiate |
a. normal oropharynx flora
b. gram pos, chain, a-hemolytic, optochin resistent (OVRPS) "Viridans live in mouth because they are not afraid OF-THE-CHIN (Optochin resistant)" |
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Patient has low grade fever
-fatigue -anemia -heart murmur dx. how do you know that this is not caused by s. aureus |
subacute infective endocarditis caused by strep viridans
s. aureus acute endocarditis characterized by -IV drug use -abrupt shaking, high spiking fevers -rapid valve destruction |
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GABHS - what conditions are caused by l
a. pyogenic (pus) b. toxigenic (exotoxin) c. immunologic (antibodies) |
a. pharyngitis, skin infection (cellulitis, impetigo)
b. Scarlet fever, toxic shock c. Rheumatic fever, acute glomerulonephritis |
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How can you distinguish S. pyogenes infection
a. gram stain b. blood test |
Gram: gram pos cocci in chain, catalase neg, beta hemolytic, Group A, bacitracin sensitive
blood test: ASO (anti-streptolysin O antibodies) |
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Major virulence factor of s. pyogenes
on the other hand how can this help the immune system |
M protein - antiphagoycytic, can give rise to rheumatic fever
antigenic --> body produces antibodies to M protein |
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Patient has
-red swollen tonsils and pharynx -purulent exudate on tonsils -high temp -swollen lymph nodes what test might you want to get? what do you suspect? |
Suspect s. pyogenes pharyngitis (Strep throat)
get rapid antigen detection test (ASO), throat culture |
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Treat for GABHS pharyngitis
What conditions can follow this (immunolically mediated) |
penicillin can speed recovery
can cause rheumatic fever or glomerulonephritis "PHaryngitis can cause PHever or glomerulonePHritis" |
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Patient is a child with
-vesicular, blistered eruption on skin --> crusty flaky skin around mouth 2 possible organisms? how do you treat? |
Impetigo
staph or GABHS treat with penicillinase resistent pen (dicloxacillin) |
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Patient sore throat and fever now has diffuse rash that began on trunk and neck, now spreads to extremities
-rash is not on face dx? Confirm? |
S. pyogenes infection
pharyngitis, followed by exotoxin release --> scarlet fever ASO titer |
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Patient has toxic shock caused by GABHS
treat? |
high dose penicillin
clindamycin (inhibits 50s ribosome) |
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Patient has sore throat a week ago, now comes in with fever +
-subcutaneous plaques -polyarthritis -erythema marginatum -chorea -carditis dx? how did this happen? treat? |
Rheumatic fever secondary to S. pyogenes infection
(No "Rheum" for SPECCulation) antibodies to M protein attack host tissues Treat with prophylactic penicillin for life |
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Post streptococcal glomerulonephritis can follow what 2 conditions
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strep pharyngitis or skin infection
caused by nephritogenic strains of GABHS |
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What is the cause of post strep glomerulonephritis
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Nephritogenic strains of GABHS --> Ab response following skin or throat infection --> antigen-antibody complexes deposited in glomerular basement membrane --> activate complement --> local glomerular destruction
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Child comes into office
-face is puffy -tea colored urine -high BP he had a sore throat/skin infection a week ago dx. treat? |
glomerulonephritis secondary to GABHS infection
puffy face = edema (kidney damage) dark urine = hematuria high BP = fluid retention treat with penicillin + clindamycin |
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Strep agalactiae
how do you distinguish it |
gram pos cocci, chain
catalase neg beta hemolytic bacitracin resistant |
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s. agalactiae
who does it mainly affect? 3 conditions it causes |
Babies!
infant meningitis, sepsis, pneumonia |
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top 3 causes of infant meningitis
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Group B strep
e. coli listeria |
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top 2 causes of meningitis after infancy
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h. influenzae
neisseria meningitides |
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How is meningitis in babies different from adults
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babies - no nuchal rigidity, non-specific symptoms
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normal living place of group B strep
who normally is infected |
vagina
Babies |
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what should you screen for in a pregnant woman to avoid infant meningitis/pneumonia/sepsis
when should you do the screen what should you do if it is positive |
Group B strep
35-37 weeks if positive, give prophylactici penicillin |
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CAMP factor
What produces it? What does it do? |
produced by group B strep
enlarges the area of hemolysis formed by S. aureus |
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Enterococcus faecalis and E. faecium
a. lancefield group b. normal where c. cause what diseases |
a. D
b. colonic flora c. UTI, subacute endocarditis, biliary tract infection |
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Vancomycin-resistant enterococci cause what
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nosocomial infections
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What special conditions can enterococcus grow in
what kind of infection does this make them more prone to causing |
can grow in 6.5% NaCl and bile
can cause biliary tract infection |
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Strep Bovis
a. where does it live b. conditions it causes |
a. colonizes gut
b. bacteremia and subacute endocarditis in colon cancer patients Bovis in Blood, beware of Cancer in bowel |
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Child comes in with sore throat, fever
-pharynx has dark, thick inflammatory exudate (too dark to be strep) what do you suspect? how should you test? |
suspect corynebacterium diphtheria
-Gram pos rods with metachromatic (blue and red) granules -Tellurite-Lofflers see dark colonies C. diphtheria is serious so TELL yoUR InTErn not to LOAF around (Tellurite lofflers) |
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Cornyebacterium diphtheria
how does it cause disease |
1. invades pharyn --> pseudomembranous pharyngitis with lympadenopathy
2. releases exotoxin (AB) --> ADP ribosylates EF-2 --> affects heart and CNS |
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C. diptheria toxin
a. encoded by what b. type of toxin c. mechanism |
a. encoded by lysogenic b-prophage
b. AB toxin c. ADP ribosylates EF-2 |
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patient has pseudomembrane in back of throat.
what should you do to treat? (3 things) |
diphtheria
1. give antitoxin 2. pen or erythromycin c. toxoid vaccine |
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Spore forming bacteria found
a. in soil (3) b. other places |
a. bacillus anthracis, c. perfringens, c. tetani
b. b. cereus, c. botulinum |
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During the bacterial life cycle, when do spores form?
They are responding to what? |
end of stationary phase
responding to diminishing nutrients |
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Spores
a. resist what b. what do they have at their core c. what kind of activity? d. how do you kill |
a. resist heat, chemical destruction
b. have dipicolinic acid c. no metabolic activity d. autoclave 121 degrees for 15 min |
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Gram positive bacilli, spore forming, obligate anaerobe
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Clostridium
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4 types of clostrdia
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c. tetani
c. botulinum c. perfringens c. difficile |
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patient comes in with
-spastic paralysis -trismus (lockjaw, risus sardonicus) a. bacteria b. toxin c. what cells the toxin is affecting |
a. clostridium tetani
b. tetanospasmin c. renshaw cells in spinal cord, inhibits GABA and glycine release |
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Baby was given honey, now has flaccid paralysis
a. bacteria b. what did the baby ingest, how is this different from adult form c. action of the bacterial toxin |
a. c. botulinum
b. baby ingested spores (adults ingest heat labile toxin) c. toxin inhibits ACh release at NMJ |
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baby vs. adult botulism
a. source b. course |
a. baby = honey w/spores in it
adult = food w/preformed heat labile toxin b. baby = just floppy adult =needs ventilator support |
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How does Clostridium perfringens cause gas gangrene?
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inoculated in trauma into muscle
secretes alpha toxin (a phospholipase called lecithinase) --> gas formation from carb fermentation --> degradation of muscle and tissue --> myonecrosis (gas gangrene), hemolysis PERFringens PERForates a gangrenous leg |
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2 toxins produced by C. difficile and what do they do
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1. Toxin A enterotoxin - binds to gut brush border
2. Toxin B cytotoxin - destroys cytoskeleton of enterocytes --> pseudomembranous colitis --> diarrhea |
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Patient took clindamycin/ampicillin and now has horrible diarrhea, abdominal pain, and fever
what do you suspect? how do you confirm? how do you treat? |
suspect c. difficile
check stool for exotoxin treat with metronidazole "DIfficile causes DIarrhea" |
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Gram positive rod, spore forming, aerobic
what is so special about its capsule |
bacillis anthracis
has polypeptide capsule (D-glutamate) |
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patient has black exchar (painless ulcer) surrounded by edematous ring.
What type of bacterial infection does he have? what can the course of this be if you don't treat it with penicillin? |
b. anthracis --> cutaneous anthrax
can progress to bacteremia and death |
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3 parts of b. anthracis toxin
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1. Edema factor = calmodulin-dependent adenylate cyclase --> upreg. cAMP --> impairs PMN function --> edema
2. Protective antigen = allows EF to enter 3. Lethal factor = inactivates protein kinase --> stimulates macrophage release of IL1 and TNF |
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Patient works with wool, now has
-flulike symptoms, progressing to -fever -pulmonary hemorrhage (shows up as mediastinal widening on CT) -mediastinitis -shock dx? path? |
pulmonary anthrax - woolsorter's disease
Inhaled spores taken up by macrophages --> hilar and mediastinal LNs --> germination --> release exotoxin |
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Gram positive rod
non-spore forming facultatively intracellular tumbling motility |
listeria
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2 sources of listeria monocytogenes
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1. unpasteurized milk/cheese, deli meats
2. vaginal transmission during birth |
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How does listeria move from cell to cell
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actin rockets
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bacteria that can cause that affects:
meningitis in neonates, elderly, immunocompromised can cause spontaneous abortion in pregnant women gastroenteritis, granulomatosis, septicemia, aminonitis HOW TO TREAT? |
listeria
ampicillin or trimethoprim-sulfamethoxazole |
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gram positive anaerobe that causes oral/facial abscesses that main drain through sinus tracts, leaving yellow "sulfur granules"
dx? treat? where does this organism reside normally? |
actinomyces israelii
penicillin normal oral flora |
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gram positive/weakly acid fast aerobe found in soil
what does this cause in immunocompromised patients how do you treat it |
nocardia asteroides
causes pulmonary infection in immunocompromised patients treat with trimethoprim-sulfamethoxazole |
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Treatment for actinomyces and nocardia
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SNAP
Sulfa (sulfamethoxazole-trimethoprim) for Nocardia Actinomcyces give Penicillin |
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How is m. tuberculosis acquired
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respiratory droplets from infected person
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what forms in primary TB?
Is it dangerous? |
subclinical
ghon focus (calcified granuloma on lower lobe) forms Ghon complex = ghon focus + hilar LN calcified granuloma |
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4 possible courses of primary TB?
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1. Ghon complex heals by fibrosis, patient has immunity and hypersensitivity (PPD pos)
2. Progressive lung disease --> cavitary lesions w/air fluid level on CXR (only in immunocompromised) --> death 3. Bacteremia --> miliary TB --> death 4. Lymphatic or hematogenous dissemination --> dormant infection in many organs |
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What is the effect of reactivation of TB on the
a. lungs b. CNS c. Skeletal d. Lymph nodes e. Renal |
a. apical, fibrocaseous cavitary lesions --> fever, night sweats, wt. loss, productive cough
b. parenchymal granulomas or meningitis c. Pott's disease = destruction of intervertebral discs and vertebral bodies in thoracic and lumbar spine d. lymphadenitis (scrofula) e. sterile pyuria |
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When is your PPD+
When is PPD - |
positive: current infection, past exposure, or BCG vaccinated
negative: no infection or anergic (steroids, immunocompromise, sarcoidosis, manutriition) |
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you take a culture of sputum and see caseating granulomas with multinucleated giant cells
dx? |
TB
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what do the following cause
a. m. kansasii b. m. avium intracellulare -how do you treat this |
a. TB-like symptoms
b. disseminated disease in AIDS resistant to multiple drugs, give prophylactic treatment with azithromycin |
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Hansen's disease
a. organism b. where does it like to go c. reservoir in US |
a. mycobacteria leprae
b. likes to go to cool temperatures (skin, superficial nerves) c. armadillos |
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Treatment of hansen's disease
a. primary treatment b. toxicity c. alternative treatment |
a. long term oral dapsone
b. hemolysis, methemoglobinemia c. rifampin and combo of clofazimine and dapsone |
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2 forms of hansen's disease
when does each occur |
lepromatous = occurs when patient has weak T-cell mediated immunity, must rely on Th2 antibody response
tuberculoid = in patients with high cell-mediated immunity (Th1) |
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difference clinically between lepromatous and tuberculoid leprosy?
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lepromatous = many thick nodular, hypopigmented skin lesions, stocking-glove neuropathy, leonine facis (loss of eyebrows, nasal collapse, lumpy earlobe)
tuberculoid = 1 or 2 hairless skin lesions that lack sensation |
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Gram neg. cocci
a. maltose fermenter b. maltose non-fermenter |
neisseria
a. meningitides b. gonorrhoeae |
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gram neg. coccoid rods
(2) |
H. influenzae
bordatella pertussis |
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gram neg rods
lactose fermenters |
citerobacter
klebsiella e.coli enterobacter serratia show up pink on macConKEES |
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How does e.coli ferment lactose
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has b-galactosidase, which breaks down lactose --> glucose and galactose
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gram neg rods, lactose non-fermenters
a. oxidase neg b. oxidase pos |
a. shigella, salmonella, proteus
b. pseudomonas |
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gram neg comma shaped, oxidase pos
a. grows in 42 deg b. grows in alkaline media |
a. campylobacter jejuni
b. vibrio cholerae |
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gram neg bacilli
what drugs does outer membrane layer make them resistant to? what still works against these guys |
resist pen G and vancomycin
ampicillin and other pen derivatives may work |
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Neisseria
meningitis vs. gonorrhea what do they ferment what virulence factor is common to both |
MeninGococci ferments Maltose and Glucose
Gonorrhea ferments Glucose only Both produce IgA proteases |
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meningococcus vs. gonococcus
a. capsule? b. maltose ferment? c. vaccine? d. transmission? |
a. M = capsule
G = no capsule b. M = maltose fermenter G = non-fermenter c. M = Vaccine (except type B) G= no vaccine (rapid antigenic variation of pilus proteins) d. M = respiratory and oral secretions G= STD |
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Gonorrhea
Septic arthritis Neonatal conjuctivitis PID Fitz-Hugh-Curtis what can cause these? |
neisseria gonococci
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Meningococcemia
meningitis Waterhouse friedrechson which organism prophylaxis for close contacts |
neisseria meningitides
rifampin prophylaxis |
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gram neg coccobacilli that grows only on chocolate agar with factors V (NAD) and X (hematin)
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Haemophilus influenza
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diseases caused by Haemophilus Influezae
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haEMOPhilus
Epiglottitis (cherry red in kids) Meningitis Otitis media Pneumonia |
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Child comes in with "cherry red" epiglottitis and otitis media
a. what organism b. how is it transmitted c. 2 virulence factors |
a. h. influenzae
b. aerosol c. IgA protease -capsule (type B is most invasive) |
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besides growing haemophilus influenzae on chocolate agar with factors V and X, how else can you grow it
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grow w/ s. aureus, which provides factor V
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haemophilus influenzae
a. vaccine - what is it and when should you give it, what is it conjugated with? b. treatment for meningitis c. prophylaxis for close contacts |
a. type B capsular polysacc conjugated to diphtheria toxoid, give between 2-18 months
b. ceftriaxone c. rifampin |
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-Gram neg, aerobic rod
-stains with silver stain -grow on carcoal yeast extract with iron and cysteine |
Legionella
French legionnaire with SILVER helmet, sitting around fire (CHARCOAL) with IRON dagger....he's not a sissy (CYSTEINE) |
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2 courses of legionella infection
How do you diagnose legionella as the cause |
1. Legionairre's disease = severe pneumonia, fever, low pulse, confusion, myalgias
2. Pontiac fever = mild flu-like syndrome detect legionella antigen in urine |
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How is legionella transmitted?
One notable way it is NOT transmitted? |
aerosol transmission from water source
not transmitted person to person |
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Treatment for legionella
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erythromycin (macrolide)
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macrolides, tetracycline, and quinolones together provide coverage for which types of infections
what do these infections resist to make the "atypical" |
atypical bacteria mycoplasma, legionella, chlamydia
can all cause atypical pneumonia (resistent to penicillin) |
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gram negative rod, lactose non-fermenter, oxidase positive, aerobic
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pseudomonas aeruginosa
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organism that produces blue-green pigment (pyomycyanin) and has a grape-like odor
what is the source of this infection who does it infect |
pseudomonas
water source affects immunocompromised patients |
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If a burn victim has an infection, what organism should you think of
how do you treat it |
pseudomonas
treat with aminoglycoside + extended spectrum penicillin (piperacillin, ticarcillin) |
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2 toxins created by pseudomonas
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1. endotoxin --> fever, shock
2. exotoxin A --> inactivates EF-2 (like diphtheria) |
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7 conditions caused by pseudomonas
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BE PSEUDO
-Burns -Endocarditis - right valve in IVDU -Pneumonia - CF patients -Sepsis -External otitis -UTI -Diabetic Osteomyelitis |
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What is the normal residence of e.coli
how does it become dangerous |
normal colon flora
obtains virulence factors from plasmids |
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E. coli diarrhea can resemble that of which other 2 bacteria
why? |
shigella, vibrio cholera
all rely on plasmids for virulence factors, so these organisms can share characteristics |
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E.coli virulence factors can lead to what diseases
a. fimbriae b. K capsule c. LPS endotoxin |
a. cystitis (bladder), pyelonephritis (kidney)
b. pneumonia, neonatal meningitis c. septic shock |
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Patient traveled to Mexico, now has rice water diarrhea
what is the toxin and how does it work? what does this resemble and why? |
ETEC - traveler's diarrhea
heat stabile or labile AB toxin B --> GM1 gangliosides on intestinal epithelial cells A --> inhibits reabsorption of Na, Cl, induces secretion of Cl, HCl resembles cholera because the toxin is similar in function |
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Patient has diarrhea with WBC and RBCs, fever, and abdominal pain
2 possible causes mechanism of (2) |
Shigella or EIEC
1. Organism invades intestinal epithelial mucosa 2. Shiga toxin (AB) B --> bind to microvilli in colon A --> destroy 60s ribosome --> destroys intestinal epithelial cells |
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EPEC
a. disease b. mechanism |
a. pediatric diarrhea
b. adheres to apical surface, flattens villi, prevents absorption (NO toxin) |
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Patient eats a hamburger, now complains of
-diarrhea with mucous and blood -anemia + thrombocytopenia + acute renal failure -see schistocytes what is causing these symptoms |
EHEC infection causes dysentery and HUS
Dystenary caused by Shiga-toxin destroying epithelium HUS from activation of vWF --> endothelium swells and lumen narrows --> mechanical hemolysis, reduced renal blood flow, platelet consumption |
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most common serotype of EHEC
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O157:H7
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4A's of klebsiella
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Aspiration pneumonia
Abscess in lungs Alcoholics di-A-betics |
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alcoholic/diabetic has lobar pneumonia after aspirating intestinal contents
-with red currant jelly sputum where does this organism usually live? what other type of infection can it cause? |
Klebsiella
intestinal flora Nosocomial UTI |
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How can you distinguish Shigella from E.coli and Salmonella?
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Shigella = nonmotile, lactose non-fermenter
Ecoli = motile, lactose fermenter Shigella = does not produce H2S, non motile Salmonella = does produce H2S, has flagella and can disseminate hematogenously |
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3 similarities between shigella and salmonella
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1. both are lactose non-fermenters
2. both invade intestinal mucosa 3. both can cause bloody diarrhea |
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Patient has fever, abdominal pain, diarrhea with blood and pus
-colonoscopy shows colon with shallow ulcers where cells have sloughed off 2 things on differential what is the process? |
EIEC or Shigella
invade intestinal epithelial cells and release shiga toxin (destroys 60s ribosomes) |
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EIEC, ETEC, Shiga, Cholera
Which ones are associated with fever? No fever? |
Fever = EIEC, Shigella
No fever = ETEC, cholera |
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Salmonella vs. Shigella
virulence |
shigella more virulent
shigella (10^1 organisms) salmonella (10^5 organisms) |
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What is the immune response to salmonella?
In what conditions are salmonella infections more likely? |
monocytic response from spleen to phagocytize salmonella after opsonization of its Vi capsule
asplenia or sickle cell anemia decreases monocytic response --> increased salmonella osteomyelitis |
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patient has:
-fever -diarrhea -headache -rose spots on abdomen dx. where can this infection remain? |
salmonella typhi --> typoid fever
can remain in gallbladder indefinitely |
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difference between s. typhi and other salmonella
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s. typhi has only a human reservoir
other salmonella found in animals |
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Transmission of shigella
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4F's
Food Fingers Feces Flies |
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Child had unpasteurized milk/meat
-bloody diarrhea -recover S-shaped organism organism? how would this organism grow? |
campylobacter jejuni
grows at 42 deg, oxidase positive |
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campylobacter jejuni is a common antecedent to what syndrome
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guillan barre (peripheral demyelination)
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organism is comma shaped, oxidase positive, grows in alkaline media
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vibrio cholera
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what does vibrio cholera cause and how?
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rice water diarrhea
toxin activates Gs --> upregulates cAMP --> secretion of Na, Cl, HCO3 |
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Patient has an infection that has caused him to have profound rice water diarrhea
-recovered organism is comma shaped and grows in alkaline media how do you treat |
vibrio cholera
oral rehydration |
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Outbreak of diarrhea in a daycare center
-associated with mesenteric adenitis (inflammation of mesenteric LN) dx? 3 ways that it is transmitted? |
yersinia enterocolitica
pet feces, contaminated milk, pork |
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Patient has
-gastritis -duodenal ulcers what does he have? increased risk of what 3 things |
h. pylori
peptic ulcer gastric adenocarcinoma lymphoma |
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gram neg rod
urease breath test - positive how can you treat (3 sets of triple therapies) |
triple therapy
1. metronidazole + bismuth + tetracycline or amoxacillin 2. metronidazole, omeprazole, and clarithromycin 3. PPI + clarithromycin + amoxicillin or metronidazole |
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3 types of spirochetes
how can they be visualized |
borrelia - big, can be seen with light microscopy using geimsa or wright's stain
treponema - dark field microscopy leptospira |
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After surfing in the tropics, you get
-flu-like symptoms -fever, headache, abdominal pain -jaundice -photophobia + conjunctivitis type of infection? shape? how did you catch it? |
leptospira interrogans
question-mark shape water contaminated with animal urine |
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after being in animal urine-infested waters, you get
-jaundice and azotemia (liver and kidney dysfunction) -fever -hemorrhage -anemia dx. treat? |
wiel's disease from leptospira interrogans
penicillin or doxycycline |
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Lyme disease
a. what organism b. how is it transmitted c. where is it most common |
a. borrelia burgdorferi
b. tick Ixodes, mice reservoir, deer important for tick life cycle c. NE USA |
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3 stages of Lyme disease
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1. bulls eye rash (erythema chronicum migrans), fever
2. neuro (bell's palsy), cardiac (AV block) 3. chronic monoarthritis, migratory polyarthritis BAKE a key LYME pie B = bell's palsy A= arthritis K=kardiac block E = erythema migrans |
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syphilis
a. primary syphillis b. secondary syphillis c. tertiary syphillis |
1 = painless chancre
2 = Systemic -wt loss, fever, fatigue -maculopapular rash (palms and soles - small red bumps over flat area) -condylomata lata (genital warts w/ lots of spirochetes) 3= gummas, aortitis (destroyed vaso vasorum), tabes dorsalis, argyll robertson pupil |
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infant presents with saber shins, saddle nose, CN8 deafness, Hutchinson's teeth, mulberry molars
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congenital syphilis
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patient has
-broad based ataxia -positive romberg -stroke w/o hypertension -Charcot joint check for? confirm? |
suspect tertiary syphilis (tabes dorsalis, aortitis)
screen with VDRL confrim with FTA-Abs |
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How do you treat syhilis
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Pen g
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argyll robertson pupil
what do you see |
pupil accomodates to nearness but does not react to light
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VDRL
-how does it test for syphilis -sources of false positives |
detects anti beef cardiolipin antibodies (which are for some reason made in syphilis infection)
false positives -Virus -Drugs -Rheumatic Fever -Lupus and leprosy "VDRL" |
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Zoonotic bacteria
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Big Bad Bed Bugs From Your Pet Ella
Bartonella Borrelia burgdorfi Borrelia recurrentis Brucella Francisella Yernia PasteruELLA |
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After a cat scratch, patient gets knots of capillaries all over that look like tiny angiomas
-patient is immunocompromised -patient also has a fever dx. organism? |
cat scratch fever
bartonella |
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After a tick bite person gets bullseye rash
disease organism |
lyme disease
borrelia burgdorferi |
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louse causes recurrent fever from variable surface antigens
dx? |
borrelia recurrentis
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After drinking unpasteurized dairy from a farm, you get undulant fever, muscle pain, sweating
organism disease |
Brucella
brucellosis "UNpasteurized dairy gives you an UNdulant fever" |
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After tick bite/rabbit/deer bite, I get fever, lethargy, anorexia, septicemia, large LN
dx |
francisella tularensis --> tularemnia
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Flea/prairie dog bite --> plague
organism |
yersinia petis
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cat/dog bite --> cellulitis/osteomyelitis
organism |
pasteurella
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woman comes in with gray vaginal discharge with a fishy smell
-patient is sexually active -take a swab --> clue cells a. dx? b. what are clue cells c. how do you treat |
a. gernerella vaginallis infection
b. clue cells = vaginal epithelial cells covered in bacteria c. metronidazole |
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difference between rickettsiae coxiella and other rickettsiea
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coxiella = transmitted by aerosol, causes pneumonia
others = transmitted by arthropod vector causes headache, fever, rash (vasculitis) |
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treatment of rickettsia infection
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doxycycline
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Obligate intracellular organisms that needs CoA and NAD
cause headache, fever, and rash when passed to human from an arthropod vector organism? |
rickettsiae
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Patient bitten by a tick comes in with
-fever -headache -rash on hands and feet a. dx b. organism |
a. rocky mt. spotted fever
b. rickettsia rickettsii |
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patient bitten by fleas has
-headache -fever -rash that starts centrally spreads out from trunk, but spares palms and soles a. dx b. organism |
a. endemic typhus
b. rickettsia typhi |
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Patient lives in really crowded conditions, gets
-headache -fever -rash that starts centrally spreads out from trunk, but spares palms and soles a. dx b. caused by |
epidemic typhus
r. prowazekii passed from human body louse |
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Q fever
a. how is it different from other rickettsia infections |
-no rash
-no vector -negative weil felix -comes from tick feces and cattle placenta --> inhale spores |
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treatment for all rickettsial diseases
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doxycycline
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What is the weil-felix rxn
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test for rickettsial infection
if infected, body should have antibodies to Rckettsia, which should cross react with Proteus antigens if inserted --> agglutination will be negative in coxiella infections |
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Palm and sole rash is seen on what 3 conditions
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Coxackievirus A infection
Rocky moutnain spotted fever Syphilis drive CARS using your palms and soles |
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Obligate intracellular organism (cannot make own ATP) that favors infecting columnar epithelial cells around mucous membranes
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chlamydiae
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2 forms of chlamydia and what do they do in the life cycle
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Elementary body (small, dense) Enfects and Enters via Endocytosis
Reticular body Replicates in cell by fission, seen on tissue culture |
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Reactive arthritis
conjunctivitis nongonoccocal urethritis PID see cytoplasmic inclusions on Geimsa or fluorescent antibody-stained smear dx? |
Chlamydia trachomatis
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chlamydiae pneumoniae and psittaci
a. cause what disease b. transmitted how |
a. atypical pneumonia
b. transmitted by aerosol |
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How do you treat chlamydiae infection
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azithromycin or doxycycline
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what is special about the chlamydial cell wall
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lacks muramic acid and peptidoglycan
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Chlamydia trachomatis sterotypes
which serotype of patient has -chronic infection -blindless due to follicular conjunctivitis |
Types A,B,C
Africa/Blindness/Chronic infection |
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Chlamydia trachomatis sterotypes
urethritis/PID ectopic pregnancy neonatal pneumonia (staccato cough) or neonatal conjunctivitis |
Types D-K
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Chlamydia trachomatis sterotypes
Lymphogranuloma venerium |
L1-3
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how is neonatal chlamydia transferred?
treatment? |
baby gets it when it passes through the birth canal
Azithromycin |
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patient is <30yo, lives in a military barracks, gets
-insidious onset headache -nonproductive cough -diffuse interstitial infiltrate -high titer of cold agglutinins (IgM) -can still walk around, not too sick dx? What is special about this organism's membrane? What would this organism grow on? |
Mycoplasma pneumoniae - walking pneumonia
No cell wall, only bacterial membrane with chilesterol Eaton's agar |
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Patient has walking pneumonia
How do you treat? What can't you use? |
Mycoplasma pneumoniae
Tetracycline or erythromycin Can't use penicillin because no cell wall |
