Fun facts about bacteria Flashcards
H.pylori
vibrio, curved GNR, strongly urease positive, upregulates caspases, peptic ulcer disease
V. cholera
vibrio, curved GNR, fecal to oral gastroenteritis, secretes mucinase for attachment to SI, secretes choleragen with AB subunit to disrupt signal transduction using A subunit to activate adenylate cyclse
vibrio
cholera, h. pylori, halophiles, virulence factors for survival in GI- survive acid, attach to lumen
borrelia burgdorferi
spirochete, 24 hours to transmit blood infection, immune evasion, 3 stages (1-erythema migrans, 2-cardiac and neurologic involvement, 3-arthritis), Jarisch-Heixmer reaction
listeria
enterobacteria, GPR, Bhemolytic, grows well in cold, listerolysin, actA, gastroenteritis, sepsis/menigitis
rickettsia
obligate IC, GNR, ticks, RMSF bacteremia leading to vasculitis/rash, tx: doxycycline, chloramphenicol
chlamydia
obligate IC, infectious elementary body, dividing reticulate body, asymptomatic often, hides behind other STDS, tx: doxycycline or erthyromycin/amoxicillin
spirochetes themes
hard to dx, need excellent history, 3 stages of disease, easily cross into bloodstream, immune evasion (no vaccines, exotoxins, inflammation),
Jarisch-Heixmer reaction
syphilis (t. pallidum)
spirochete, not culturable, slow growing, sexual transmission, 3 stages (1-chancre, 2- maculopapular rash on hands/soles, condylomata lata lesions on genitals, 3- granulomas, gummas, CNS) Jarisch-Heixmer reaction
What are two causes of scrofula? Which population are they more likely in?
Tb- adults atypical mycobacterium (M. scrofulaceum)- children
What drug is used to treat leprosy?
dapsone and rifampin
M. leprosy
not culturable, slowest growing, 30C for growth (sticks to superficial), spread by nasal secretions and skin lesions
Which form of leprosy has granulomas/foamy histocytes? Th1/Th2? immunogenic nerve damage/bacterial nerve damage? positive skin test/negative skin test?
tuberculoid: granulomas, Th1, immunogenic, positive
lepramatous: foamy lesion, Th2, bacterial, negative
atypical mycobacterium
environmentally acquired, PPD negative, less aggressive, not lethal in guinea pigs, M. scrofulacum
What drug is used to treat Tb? What type of therapy is recommended?
isoniazid, directly observed therapy with 4 drug regimens
What is remicade? What disease can it cause resurgence of?
TNFa antagonist, depresses CMI, may reactivate Tb
What disease is Pott’s disease caused by?
Tb in the long bones, osteomyelitis in the spine
What type of menigitis does the Brudzinski’s sign indicate? Why only this kind?
Tb menigitis, high inflammation
What is a Ghon complex? Where can bacteria spread from here?
exudative lesion and draining hilar lymph node, typical of pulmonary Tb, can spread to bloodstream
Describe the cell mediated response to Tb
CD4 T cells activate macrophages to kill IC bacteria. CD8 T cells lyse infected macrophages. TNF helps maintain latency of Tb. -forms caesating granulomas
M. tuberculosis
acid fast (mycolic acid/arabinoglycan), obligate aerobe, fastidious, chromosomal drug resistance, no toxins produced, airborne transmission
Salmonella
enterobacteria, GNR, enterocolitis, attach by fimbrae, immunologic sampling to infect macrophages
s. typhi
typhoid fever, fecal to oral, trojan horse, systemic lymph node infection, necrosis of peyer’s patches, chronic carriagein gallbladder
What do you see in blood smears from HUS?
schistocytes- distorted fragmented RBCs from pushing past fibrin clots in small capillaries
What is reactive arthritis sequellae to?
shigella, salmonella, yersinia, campylobacter, chlamydia
Klebsiella pneumonia
old, COPD, alcoholic homeless men
large polysaccharide capsule, adhesins for adherence, siderophores
currant jelly sputum
Enterobacteriacae
GNR, no spores, catalase + oxidase -, faculative aerobes, promiscious to foreign DNA (virulence factors, abx resistance)
S. saprophytic
staphylococci, gram +, catalase +, coagulase -, gamma hemolytic, novobicin resistant
UTI
S. epidermidis
staphylococci, gram +, catalase +, coagulase -, gamma hemolytic, novobicin sensitive
attaches to catheters
S. aureus
staphylococci, gram +, catalase +, coagulase +, b hemolytic
staphylococci
gram +, catalse +, clumps, cause abscesses
enterococcus fecalis
streptococci, gram +, catalase -, gamma hemolytic, bile/optchin resistant
UTI, abdominal abscess, endocarditis
peptostreptococci
streptococci, gram +, catalase -, gamma hemolytics, bile/optchin sensitive
abscesses
viridans streptococci
streptococci, gram+, catalase-, alpha hemolytic, bile/optochin resistant, dental caries and endocarditis
pneumococci
streptococci (diplo), gram +, catalase -, alpha hemolytic, bile/optochin sensitive, pneumonia
capsule (can have vaccine)
group B streptococci
gram +, catalase -, beta hemolytic, bactracin resistant, capsule
group A streptococci
gram +, catalase -, beta hemolytic, bacitracin sensitive, pili/M protein/kinases/toxins
streptococci
gram +, catalase -, chains
neisseria
gram - diplococci, oxidase +, need chocolate agar
n. meningitidis
gram -, maltose +, capsule (have vaccine), endotoxin LPS
n. gonorrhea
gram -, maltose -, endotoxin LOS, pili
What is the reducing agent added to anaerobic culture to eliminate oxygen?
thioglycolate
clostridium
GPR, spore forming
c. tetani–tetanus–tetanospasmin
c. botulinum–botulism–botulinium toxin
c. perfingens–gas gangrene–tissue degrading enzymes
c. perfingens-food poisoning-enterotoxin
c. dificile-psueodmembranous colitis-exotoxinA/B
What mechanism of pathogenicity does c.dificile use?
AB subnit, A- disrupts tight junctions, intestinal swelling and inflammation, B- depolymerizes actin
What mechanism of pathogenicity does c.tetani use?
tetanospasmin exotoxin, AB subunit, intereference with signal transduction
large subunit binds presynaptic motor neuron so small one can do retrograde axonal transport, cleaves synaptobrevin so can’t release GABA or gly
What do GNAB cause? virulence factors?
abscesses, tissue degrading enzymes, capsule
actinomyces
gram + rod, no spores, no exotoxins, causes actinomycosis/abscess
What two cocci have superantigen?
s. aureus, s. pyogenes
