Microbio Flashcards
strep viridans
inhabitants of oral cavity that can caused bacteremia
- will adhere to damaged sites, like damaged valves, or fibrin-platelet aggregates at damaged endothelium
borrelia burgdorferi
lyme disease
pasteurella multocida
GN rod in oral flora of cats and dogs
- rapidly progressive soft tissue infection
sporothrix schenckii
cutaneous infections begin as ulcerating papule at site of inoculation and spreads proximally through lymphatics
bacillus anthracis
cutaneous infections have toxins that lead to local edema and formation of papule that evolves into painless necrotic wound covered in black eschar
tx: cipro
rickettsia rickettsiae
Rocky mountain spotter fever
skin lesions: palmoplantar erythematous macules that migrate centripetally TOWARDS trunk
actinomyces israelii
GP organism of normal oral flora
can cause chronic face and neck abscesses c/b cutaneous sinus tracts
tx: IV PCN and surgical debridement
corynebacterium diphtheria produces what toxin … and what action does it have
A) diphtheria toxin
B) inactivates EF-2 via ribosylation –> inhibits host protein synthesis
pseudomonas aeruginosa produces what toxin … and what action does it have
A) exotoxin A
B) inactivates EF-2 via ribosylation –> inhibits host protein synthesis
staphylococcus aereus produces what toxin… and what action does it have (2 of them)
A) enterotoxin
B) superantigen that acts in GI tract –> vomiting
A) TSS toxin
B) T-cells –> cytokine storm –> TSS
clostridium difficile produces what toxin … and what action does it have
A) cyototoxin B
B) induces actin depolymerization of actin cytoskeleton leading to mucosal death, necrosis of colonic mucosal surfaces w/ fibrin deposition –> pseudomembrane formation
clostridium botulinum produces what toxin … and what action does it have
- 3D’s
A) botulinum toxin
B) blocks presynaptic release of Ach @ NMJ –> flaccid paralysis
- diplopia, dysphagia, dysphonia w/in 12-46 hrs
bordetella pertussis produces what toxin… and what action does it have
A) pertussis toxin
B) disinhibits AC via Gi GPCR –> increases cAMP–> increased histamine sensitivity and phagocyte dysfunction
vibrio cholerae produces what toxin … and what action does it have
A) cholera toxin
B) activates AC via Gs GPCR –> increases cAMP –> secretory diarrhea, dehydration, electrolyte imbalances
strongyloides stercoralis
human parasitic roundworm “threadworm”
- lives in mucosa of small intestine
- filariform larva is infectious
- rabditoide larva is not, but that’s the one in feces
schistosoma haematobium
urinary schistosomiasis
freshwater snails in North Africa, Sub-Sahra, Middle east
organisms travel to vesical venous plexus and live there, laying eggs
- terminal hematuria
- dysuria
- frequent urination
- pyelo
- ## squamous cell carcinoma of bladder
schistosoma mansoni
and
schistosoma japonicum
intestinal schistosomiasis
sub-sahara, middle east, south america, caribbean
organism stravel to mesenteric venules of intestine
- diarrhea/abd pain
- intestinal ulceration –> iron def anemia
Hepatic Schistosomiasis
- HSM
- periportal fibrosis and subsequent portal HTN
gonorrhea tx
ctx
or
fluuroquiniflone
chlamydia tx
azithromycin x 1d
or
doxycycline x multiple days
Pseudomonas therapy
1) PCN: ticarcillin, piperacillin
2) Cephalosporins: ceftazidime (3rd gen)
cefepime (4th gen)
3) aminoglycosides
amikacin
gentamicin
tobramycin
4) fluoroquinolones
cipro
levo
5) monobactams
aztreonam
6) carbapenems
imipenem
meropenem
legionella clinical and lab features
facultative intracellular GN bacilli
neuro, GI, pulm sxs’s
- hyponatremia
- sputum showing many neutrophils but few organisms
- fever and bradycardia
- h/a and confusion
HIV gp41 protein action
needed for MB fusion and entry of HIV genome into target
HIV gp120 protein action
viral envelope protein tha tmediates attachment to CD4 MB
Enterobius vermicularis life cycle and where if affects
dx
pinworm
adults live in intestine (cecum, appendix)… female migrates to perianal skin to deposit eggs
scotch tape test –> flattened eggs w/bean-shaped apperance
Vibrio cholerae
1) oxidase: + or -
2) GN or GP
3) shape?
4) alkaline medium: grow or no grow
5) mechanism of its toxin
6) leukocytes and erythrocytes?
7) which e. coli is similar with
1) oxidase +
2) GN
3) comma shaped rods
4) can grow
5) incresaes cAMP –> efflux of NaCl from intestinal epithelia
6) neither b/c they don’t invade mucosa or cause enteric death
7) ETEC
Salmonella enteritidis
- stool microscopy shows what cell profile?
many leukocytes
neutrophils prominant
(invasive diarrhea w/out hemorrhage)
cause of diarrhea with peripheral eosinophilia
strongyloides
Invading diarrhea organisms
- EIEC
- shigella
many erythrocytes and some leukocytes
Mycolic acids
- what are they
- what organisms rely on them
- long branched saturated FA’s w/about 90 C’s
- Mycobacterium … it’s what makes them “acid fast”
Enterococci can develop resistance to what abx? ((5)
- PCN
- PCNase-resistant PCN
- aminoglycosides
- trimethoprim-sulfamethoxazole
- vanco
how does enterococci acquire resistance to aminoglycosides?
- how is it acquired?
- they produce aminoglycoside-modifying enzymes that transfer chemical groups (acetyl, adenyl, phosphate) to the abx outside of the bacterium –> prevents them from binding to ribosomes
- plasmids or transposons, not by chromosome
how does enterococci acquire resistance to PCN? (2)
- beta-lactamase
2. low-affinity PCN binding protein
how does enterococci acquire resistance to vanco?
how is it acquired?
- they acquire ligases that alter D-alanylD-alanine cell-wall precursors to D-alanineD-lacate –> prevents vanco from binding to cell wall
- plasmids/transposons
how does enterococci acquire resistance to tetracycline? (2)
- synthesis of protein that allows ribosomes to do translation despite abx
- increased drug efflux
how does enterococci acquire resistance to fluoroquinolone?
mutantions in DNA gyrase or topoisomerase
some obligate organisms
divided into obligate intracellular and facultative intracellular organisms
obligate: Chlamydia and Rickettsiae
facultative: legionella, listeria, mycobacterium, neisseria, salmonella
some exotoxin producing ones (5)
- staph enterotoxins
- botulinum
- diphtheria
- tetanus
- pertussis
staph epidermidis
coagulase negative staph species
good at making biofilms
Central or South American pt w/achalasia
- how does it do damage
- what else can it cause
Trypanosoma cruzi
- neurotoxin that destroys myenteric plexus that causes intramural, parasympathetic denervation or smooth muscle
- chagas
CMV infections commonly affect where? (5)
- retinitis
- esophagitis
- pna
- hepatitis
- diarrhea
Isospora belli causes what
chronic, watery, profuse diarrhea in immunocompromised pts
