Random Review Part 2 Flashcards
Beta hemolytic bacteria
GAS, GBS, Staph aureus, listeria
“Lancet shaped gram positive diplococci”
Strep pneumo
Infecting heart valves
Strep viridans: makes dextrans to bind fibrin-platelet aggregates on damaged heart valves
Staph epidermidis: produces adherent biofilms
Staph aureus: can fuck shit up and make fibrin clots around itself
Weird stuff about GAS
Produces CAMP factor: enlarges area of hemolysis by S.aureus.
Hippurate test +
Take your baby camping
Weird stuff about Enterococci (faecalis)
Lancefield grouping, based on differences in C carbohydate on bacterial cell wall
Can cause subacute endocarditis after GI/GU procedures
To remember this bacteria, just remember this is where VRE comes from
Diptheriae can cause (dangerous)
Myocarditis, arrthmias
Diagnose: Gram + rods with metachromatic granules (blue/green), Elek + for toxin
Gram positive rods
Bacillus
Corynebacterium
Listeria
Clostridium
To kill spores:
Autoclave by steaming at 121C for 15 minutes
Spore produces: Clostridium, bacillus, coxiella
C. tetani location of action
Renshaw cells in spinal cord
Baby with constipation
Can be botulism starting out
C. perfringens can also cause
late onset food poisoning (watery diarrhea)
Tx c.diff
Metronidazole + PO vanc
Recurrent: repeat or fidaxomicin (macrolide)
Medussa head colonies
Anthrax
Listeria
- Rocket tails (actin polymerization) in vitro, and tumbling motility which works better in cold temperatures (4C)
- Only gram + to produce endotoxin
Actinomyces
- Anaerobe, not acid fast, normal oral flora
- Causes oral/facial abscesses that drain through sinus tracts, yellow sulfur granules. Pronounce “acnemycs” to remember abscesses and that its normal flora.
Nocardia
- Aerobe, partially acid fast, found in soil
- Since its aerobic, causes pulmonary infection in immunocompromised or cutaneous infections s/p trauma in normal people
Treatment of actinomyces/nocardia
Treatment is a SNAP
Sulfonamides - Nocardia, Actinomyces - Penicillin
PPD false negative
Anergic (steroids, malnutrition, immunocomprimised), or sarcoidosis
If BCG vaccine (false positive), use Interferon-y release assay for fewer false positives
TB special virulence factor
Cord factor – inhibits macrophage maturation and induces release of TNF-a.
Leprosy
Lepromatous: Th1 compromised, so predominantly Th2 mediated (humoral)
Tuberculoid: Th1 not compromised, so predominantly Th1 mediated (cell mediated), which is preferred
Tx: Dapsone + rifampin for tuberculoid
add clofazimine for lepromatous form
PPx for N. meningitidis
Rifampin (also use for h.flu), cipro, ceftriaxone
H.flu tx
Amp+/-clav
Meningitis: ceftriaxone
H.flu vacc is against what?
PRP (polyribosylribitol phosphate)
Legionella quick facts
SIADH (hyponatremia), relative bradycardia
urine antigen
Tx w/macrolides or quinolone (erythromycin)
Pontiac fever is a mild flu like syndrome caused by it
GI symptoms
Pseudomonas drugs
- Extended spectrum B-lactams (piperacillin, ticarcillin, cefepime) FYI: pip and tic are listed as “antipseudomonals” in FA
- Carbapenems (imipenem, meropenem)
- Monobactams (aztreonam)
- Fluoroquinolones (cipro)
- Aminoglycosides (gentamicin, tobramycin)
- MDR strains: Colistin, polymyxin B
Erythema gangerenosum
necrotic cutaneous lesion, caused by pseudomonas, immunocompromised patients
General pseudomonas
Hot tub foliculitis Burn victims (aerobic reminder)
EIEC vs EHEC
EIEC produces similar manifestions of shigella since it invades, but doesnt produce the shiga like toxin that EHEC does. Remember that Shigella’s key to pathogencitiy is invasion, not toxin production*** EHEC doesnt need to invade to cause dysentery, the toxin alone is enough
How to differentiate EHEC from all other E. Coli?
DOES NOT ferment on sorbitol
HUS
Caused be EHEC
Anemia, thrombocytopenia, acute renal failure, schistocytes, platelet consumption
Looks like TTP but renal predominant
Since TTP/HUS/DIC can all look similar, pay attention to clinical scenario and lab values
Klebsiella pneumonia
Lobar, current jelly sputum
Salmonella typhi
H2S, Flagella, Endotoxin + Vi capsule, inactivated by gastric acids, response mediated by monocytes, causes constipation and rose spots on abdomen, followed by diarrhea, oral vaccine is live while IM vaccine is Vi capsular polysaccharide. Carrier state w/gallbladder colonization
Salmonella (non-typhi)
Same as typhi except PMN predominant response, bloody diarrhea (no constipation), no vaccine available (no Vi capsule), and doesnt produce rose spots.
Shigella
Only spreads cell to cell, no H2S or flagella, PMN predominant response, bloody diarrhea, no vaccine. Invasion = key to pathogenicity, doesnt even need the toxin.
Pseudoappendicitis
Yersinia enterocolitica
H plyori triple therapy
PPI, clarithromycin, amoxicillin (metronidazole if PCN all.)
3 spirochetes:
Borrelia - largest, can be visualized with wright/giemsa stain as a result
Leptospira
Treponema - dark field microscopy
Leptospira can cause 2 diseases:
Leptospirosis - flu like, myalgias (CALVES), jaundice, photophobia, conjunctival suffusion. SURFERS in TROPICS
Weil (whale) disease - severe form of jaundice and azotemia from liver/kidney dysfunction, fever, hemorrhage, anemia
Contaminated waters with animal urine
Borrela burdorferi
Natural reservoir is mouse, transmitted by Ixodes deer tick
Syphilis lesions
Primary = Painless chancre, Secondary = Condylomata lata, Tertiary = Gummas
*Condylomata acumulata = HPV
Neurosyphilis signs
Broad based ataxia, + romberg, charcot joint, stroke WITHOUT htn
VDRL false positives
Viral infection (mono, hepatitis)
Drugs
Rheumatic fever
Lupus anticoagulant/Leprosy
Gram variable rod
Gardnerella vaginalis
Clue cells, not an STD but associated with sexual activity. Tx with metronidazole or clinda
Rash on palms and soles
Coxsackie A infection
Rocky mountain spotted fever
Syphillus (secondary)
CARS
Rocky mountain spotted fever
Headache, RASH, fever. Tick vector
Typhus vectors
Flees (endemic)
Human body louse (epidemic)
Ehrlichiosis presentation
RMSF w/o rash. Tick vector.Morulae monocytes (berry like inclusions) To complete this notecard, required to do an internet search for image
Anaplasmosis presentation
Tick vector. Same as ehrlichiosis, no rash.
Q fever (coxiella). Its queer, why?
No rash, no arthropod vector. Comes from sheep/cattle amniotic fluid aersolized. Most common cause of culture negative endocarditis
2 forms of chlamydiae
1) Elementary bodies: Enfectious, enters cell via Endocytosis–> transforms into reticulate body. Analagous to spore, small and dense.
2) Reticulate bodies: Replicates in cell by fission, reorganizes into elementary bodies
Chlamydiae treatment
Azithromycin (favored), or doxycycline
Bird related disease, atypical pneumonia
Chlamydiae psittaci
Types of chlamydia trachomatis (serotypes)
A,B,C: Africa, Blindness (follicular cnjunctivitis), Chronic infection
D-K: “Everything else” Urethritis/PID, neonatal pneumonia (staccato cough) w/eosinophilia, neonatal conjunctivitis
L1, L2, L3: Lymphogranuloma venereum - painless geneital ulcers, painful inguinal lymphadenopathy. tx w/doxycycline
Mycoplasma pneumoniae high yield
Xray looks worse High cold agglutinins IgM, can lyse RBCs Grown on Eaton agar (cholesterol) Military recruits, prisons Macrolides, doxy, fluoroquinolone
Systemic Mycoses high yield
Histo: Hides in macrophages. Bird/bat droppings. Ovoid cells. Smaller than RBC
Blasto: Buds broadly, Granulomatous nodules. Doubly refractile wall. Can disseminate to bone/skin. Same size as RBC.
Coccidio: Spherules. Can disseminate to bone (arthralgias)/skin (erythema nodosum). Larger than RBC.
Paracoccidio: Captain’s wheel. Latin America.
Tinea versicolor
NOT a dermatophyte despite being called tinea
Degradation of lipids –> acids –> damage melanocytes
Spaghetti and meatbballs
Opportunistic infection high yield
Candida: Budding yeast/pseudohyphae. T cell for superficial protection, neutrophils for hematogenous spread. Can cause endocarditis in IV drug users. Normal inhabitant.
Aspergillus: Acute angles. Septate hyphae. Allergic bronchopulmonary aspergillosis associated with ASTHMA and CYSTIC FIBROSIS. Causes bronchiectasis and eosinophilia. Aspergillomas s/p TB. Can produce aflatoxins (p53 mutation inducing) –> HCC.
Cryptococcus: Yeast, heavily encapsulated. Also in soil/bird poop like histo. Culture on sab, stain with india ink and mucicarmine. Latex agglutination test specific. Soap bubble lesions in brain.
Mucor and Rhizopus: Wide angles, nonseptate hypae. Similar presentation as aspergillus (look at histology). Penedrate bloo vessel walls, enter brain via cribriform plate. Black eschar on face.
Treat/prophylaxis for PCP
Bactrim
Sporothrix schenckii
Dimorphic, cigar shaped. Roses. Ascending lymphangitis. Tx w/itraconazole or POTassium iodide (plant a rose in a POT)
Protozoa - GI infection high yield
Get from cysts in water, or oocysts in water for crypto
Giardia - foul-smelling, fatty diarrhea. Diag: trophozoits or cysts in stool. Tx: metronidazole
Entamoeba histolytica (amebiasis) - DYSENTERY, liver abscess, anchovy paste exudate, RUQ pain, flask shaped ulcer. Diag: serology and/or trophozoits or cysts in stool. Tx: metronidazole. Iodoquinol for asymtpomatic cyst
Cryptosporidium - AIDS causes severe diarrhea, mild watery diarrhea for everyone else. Diag: oocysts on acid fast stain. Tx: nitazoxanide
Toxo treatment
Sulfadiazine + pyrimethamine
Naegleria fowleri
Rapidly fatal meningoencephalitis. Nalgene filled w/fresh water. Enters via cribriform plate. Amoebas in spinal fluid. Amphotericin B, but rarely works.
Trypanosoma brucei
African sleeping sickness: Enlarged lymph nodes, recurring fever, somnolence and coma. get it from Tsetse fly bite (PAINFUL). Tx w/Suramin for blood born disease or melarsoprol for CNS penetration
“It SURe is nice to go to sleep. MELAtonin helps with sleep”