Micro Flashcards
Isolate in medium of: vanc colistin nystatin TMP
N. gonorrhoeae
(Thayer-Martin medium - chocolate agar based)
Abx inhibit other growth: vanc - gram + colistin (polymyxin) - gram - nysatin - yeast tmp - proteus (GN)
unexplained oral thrush otherwise health person
think HIV
life cyle of Hep B
- entry into host cell
- capsid released into cytoplasm
- nuclear import of viral genome
- partially dsDNA repaired (full ds)
- transcription
(out to cytosol) - translation of proteins
- reverse transcription of RNA template into partially dsDNA in new capsid
- envelope aquired via budding into endoplasmic reticulum (contains virally-coded proteins)
HiB vaccine composition
cell wall polysaccharide conjugated with protein toxoid (diptheria or tetanus)
HiB vaccine prevents
meningitis
pneumonia
sepsis
epiglottitis
salmonella virulence factor
Vi antigen
- capsular protein
- protects it from opsonization/phagocytosis
(note: some salmonella can produce exotoxin –> typhoid fever not osteomyelitis)
main virulence factor of staph aures in osteomyelitis
adhesion to collagen
HAV decontam
- water chlorination
- bleach (1:100 dilution)
- formalin
- UV irradiation
- boiling to 85 degC for one minute
- autoclave (120degC for 20 min)
NOT:
- drying (stable for weeks)
- diethyl either, choroform, trichloroethane (no lipid soluble env)
- acid (can withstand acidic gastric env)
Mother:
HBsAg+, HBeAg+
Infant…
(high risk for tranmission during delivery during active infection)
neonate:
- high levels of HBV replication
- mildly elevated liver enzymes
- high risk for chronic infx (90%)
Hep B vaccine given at birth; if HBV+ mom, give anti HBV IgG to newborn
Increased risk of HepB to baby…
HBeAg+ (90% vs 20%)
Acute infx in 3rd trimester
streptococcal antibodies
anti- streptolysin
anti - DNaseB
anti- hyaluronidase
MCC of E.coli bactermia
UTI
dx of mucormycosis
bx
MaConkey agar restricts grown of most…
gram positive
contains bile salt
Bordet-Gengou medium
bordetella pertussis
Post strep GN follows ___
Rhumatic fever follows ____
GN - either skin or throat GAS
Rhumatic fever - only throat GAS
major pathogenic mechanism of shigella
mucosal invasion
- invades M cells that overlie Peyer’s patches
(not all shigella have shiga toxin)
host inflammatory response to shigella
neutrophils
neisseria gonorrhea often seen w/in
neutrophils
mechanism of acquiring virulence in cornyebacterium
lysogenization by a phage
phage conversion
–> tox gene –> AB exotoxin production
major virulence factor of s. pneumo?
how is it aquired?
capsule
via transformation
e.coli acquire the ability to form pili via..
conjugation
toxin synthesis under environmental influence
which bacteria
bacillus
clostridium
trigger for b.anthracis to make toxin
- warming to 37deg
- presence of appropriate concentration of protein and CO2
trigger for C. tetani to germinate/make toxin
anaerobic env
e.g. necrotic wounds
exquisite ear pain
drainage
granulation tissue in ear canal
malignant otitis externa
pseudomonas
MCC of death w/diphteria
cardiomyopathy
myocarditis?
major virulence factor for Strep pyogenes (A)
Protein M
- inhibits phagocytosis and the activation of complement
- cytotoxic for neutrophils in serum
- mediator for bacterial attachment
streptolysin O
produced by most GAS
oxygen-labile
immunogenic
extracellular
lyses erythrocytes and polymorphonuclear leukocytes
does not convey resistance to phogocytosis
DNase
- produced by stretococcus
- depolymerizes viscous DNA in pus and
- disintegrates polymorphonuclear leukocytes
(allows it to move more freely in tissue)
vaginal pH during candida vaginitis
normal (3.8-4.2)
initial empiric tx of coag-neg staph should include…
vancomycin
(due to widespread resistance, esp in nosocomila infx)
can be switched to naf or oxacillin if tests sens
dextrans
prod by viridans strep
facilitate adherence to fibrin –> form valvular veg
why do viridans strep require prior damage to valves
w/o endothelial damage –> no platelets or fibrin –> viridans unable to adhere
Abx tx of strep throat decreases risk of…
rhumatic fever
NOT glomerular nephritis
risk of more severe form of hansen disease
weak Th1 (cell mediated) immune response –> lepromatous leprocy
macrophages are told to kill mycobacteria–> disseminates widely
m. leprae growth conditions
temp slighly lower than core body temp –> extremities, skin, superficial nerves, eyes, testes
mild form of hansen
tuberculoid leprosy
infx limited by cell-med immune –> mild skin plaques (hypopig, hair loss, focally decreased sensation)
neutropenia (ANC
gram negative
eg pseudomonas
p. aeruginosa virulence factors that contribute to EG
- exotoxin A (protein synth inhib)
- elastase (–> blood vessle destruction)
- phospholipase c (degrades cell membranes)
- pyocyanin (gen reactive ox species)
bacillary angiomatosis
bartonella henselae in immunocompromised pts –>
- red-purple papular skin lesions
- vascular prolif also w/in viscera
- fatal if left untreated
triad of HUS
- microangiopathic hemolytic anemia
- thrombocytopenia
- renal unsuff
Bartonella causes…
- cat scratch disease
- bacillary angiomatosis
- culture-neg endocarditis
Kills spores out of: etoh chlorohxidine H2O2 iodine
H2O2
Iodine
sterilization of hospital instruments that cannot withstand autoclave
alklyating agents cross-link DNA and proteins
- formaldhyde
- glutaraldehyde
Antipseudomonals
some pens:
- ticar
- piper
some cephs:
- ceftazidime (3rd)
- cefepime (4th)
some aminos:
- amikacin
- gent
- tobra
some fluor:
- cipro
- levo
(NOT moxy)
Aztreonam
Carbapenems
dx of strongloides
rhabditiform larvae in stool
rhabditiform vs filariform larvae
rhab = less mature; found in stool
filariform - infect through skin or go to lung through large intestine
tx for strongloides
ivermectin
ETEC enterotoxins
heat labile (LT)
- choleragen-like
- activates adenylate cyclase
heat stabile (ST) - activates guanylate cyclase
tx for recurrent c.diff (or an increased risk of recurrence)
fidaxomicin
what is seen in stool of cholera
mucus and some sloughed epithelial cells
NO leukocytes or RBCs b/c non inflammatory
tx for giardia
metronidazole
mebendezole use
roundworms
- anclyostoma
- ascaris
- enterobius
albendazole use
echinoccos granulosus
[tapeworm/cestode that causes cysts in liver]
**will also need surgery! – first cysts killed w/ etoh injection to prevent anaphalaxis if leak out)
immune rx to shistosoma
Th2 mediated granulomatous response against eggs –> Th2, eosinophils, macrophages –> ulceration and scarring of bowel or bladder/ureters
B. anthracis produce what type of capsule
antiphagocytic D-glutamate capsule
instead of polysaccharide
lecinthinase mech
aka phospholipase C
aka alpha toxin
catalyzes the splitting of phospholipid molecules –> cell lysis (inc RBCs –> tissue necrosis and edema
Protein A on Staph aureus
- binds Fc portion of IgG (at complement binding site)–> impairs complement activation, opsonization, and phagocytosis
(on peptidoglycan cell wall)
