Rx_01.20 (Microbio) Flashcards
Enfurtivide: MOA & use
- antiretroviral therapy
- MOA = entry inhibitor
- blocking interaction between gp120 & host CD4 or by interfering w/viral gp41-mediated fusion
Rocky mountain spotted fever presentation
- vacation/travel to South Atlantic states (NC, TN, etc)
- classic triad = H/A, fever, rash
- rash = palms/soles/wrists ==> trunk
Rocky Mountain spotted fever cause/spread/tx
- cause = Rickettsia rickettsii
- spread via ticks =
- Dermacentor andersoni
- D. variabilis
- tx = immediate antibiotic therapy
- tetracycline (e.g. doxycycline)
- chloramphenicol
Causes of osteomyelitis in sickle cell patient
- S. aureus
- Salmonella
Cholera toxin: MOA
- A1 subunit ==> active adenylate cyclase ==> increased cAMP ==> increased chloride ion secretion ==> secretory diarrhea
Hepatitis E presentation + pathology
- Hepatitis E
- fecal-oral
- high infection rates @ sub-saharan Africa
- high mortality in pregnant women
- Path ==> focal hepatocyte damage ==> patchy necrosis on biopsy
Characteristics of C. albicans
- germ tube-positive fungus
- ==> white plaques (thrush) @ immunocompromised individuals (common in HIV)
branching rods on culture from pt w/oral infection ==> ? + tx
- Actinomyces israelii
- gram-positive
- branching rods
- anaerobic
- part of normal oral flora
- Tx =
- IV penicillin for 2-6 wks
- oral penicillin or amoxicillin 6-12 months
Bartonella henseleae causes….?
- cat-scratch fever
- local, chronic lymphadenitis
- commonly @ children
- bacillary angiomatosis
- usually @ AIDS patients
- ==> proliferation of blood and lymphatic vessels ==> “mulberry” lesion in skin
Characteristics of Bartonella henselae
- small gram-negative
- “proteobacterium”
- visualized w/Warthrin-Starry stain
Rotavirus mechanism of infection
- enters host cell by endocytosis
- transcribes viral mRNA w/ a viral RNA polymerase present in virion
Presentation of reactive arthritis/”Reiter’s syndrome” + cause
- urethritis, conjuctivitis, arthritis
- “can’t pee, can’t see, can’t climb a tree”
- derm sx
- most plaques on glans penis
- crusting papules
- usually male, w/HLA-B27
- autoimmune rxn post-infection:
- Chlamydia trachomatis, N. gonorrhoeae
- Salmonella, Shigella, Yersinia, Campylobacter
Characteristics of Legionella pneumophila pneumonia
- occurs @ older pts w/hx of alcoholism, smoking, DM, chronic illness, immunosuppression
- legionella =
- gram-negative rod (coccobaciliary)
- stains w/silver stain
- cultures on charcoal yeast extract
Protective factor for HIV infection
- homozygous for CCR5 mutation
- CCR5 = chemokine receptor on macrophages that facilitates viral entry
- CCR5 mutation ==> immunity to certain strains of HIV
- present in primarily caucasian individuals
Common cause of croup + virus type
- cause = paramyxoviridae family (parainfluenza virus)
- viral characteristics
- envelope + helical capsid
- RNA virus
- single-stranded
- negative-sense
- linear, nonsegment
filamentous, gram-positive organism that is weakly acid-fast =
Nocardia asteroides
Characteristics/tx of Nocardia asteroides
- filamentous, gram-positive
- weakly acid-fast
- ==> lung abscesses @ immunocompromised patients
- Tx =
- sulfonamides (MOA: inhibition of dihyropteroate synthetase)
Yellow fever characteristics
- flavivurs
- SS, RNA virus
- mosquito vector
- sx = H/A, photophobia, MSK pain, jaundice
- labs/biopsy
- AST > ALT
- councilman bodies = eosinophilic degeneration + condensed nuclear chromatin
Mechanism of staph scalded skin syndrome
- staph releases (epidermolytic) exotoxins A and B
- exotoxins bind desmoglein 1 @ desmosome ==> epidermal separation @ stratum granulosum
- ==> blistering
