Bug Parade 2
Unlock all answers in this set
Unlock answersquestion
| Acinetobacter |
answer
| nosocomial pneumonia, septicemia, soft tissue infection |
question
| Anaplasma phagocytophilum biology (type, stain) |
answer
| obligate intracellular G- |
question
| Anaplasma phagocytophilum disease |
answer
| Human anaplasmosis = human granulocytic ehrlichiosis incubation 1wk flu-like, leukopenia, thrombocytopenia with severe complication, 10% get rash, co-infection with lyme disease, fatality 1% |
question
| Anaplasma phagocytophilum pathogenesis |
answer
| elementary bodies, lives in host cell vacuoles (morula) infects neutrophils |
question
| Anaplasma phagocytophilum transmission and treatment |
answer
| transmission: deer tick tx: doxycycline, 50% hospitalization |
question
| Borrelia burgdorferi biology (type, stain, shape, O2 req., motility) |
answer
| extracelluar pathogen, spirochete G- like, no LPS helical microaerophiles endoflagella in periplasm, coiled, labile |
question
| Borrelia burgdorferi culture, epidemiology, transmission, host response |
answer
| culture: yes epidemiology: rising in E coast and upper midweest trans: tick bites (hard ticks, slow feeders), mice are reservoir, deer important for life cycle, nymph tick most dangerous host response: IMR, esp for arthritis |
question
| Borrelia burgdorferi disease |
answer
| Lyme disease: Stage1: 3-30d incubation, papule spread to EM, "bulls eye rash," grows and fades 3-4wks, flu-like, lymphadenopathy Stage2: disease 1-4mo, symp 1-9mo; disseminated disease, neurological, facial/Bell's palsy, chronic fatigue, pain radiates Stage3: lyme arthritis; long-term persistence of borreliae and lipoproteins in joints cause immune complex disease |
question
| Borrelia burgdorferi dx and tx |
answer
| dx: clincal (endemic area, EM lesions) tx: doxycyline or amoxicillin |
question
| Borrelia burgdorferi viurlence factors |
answer
| highly invasive, not extremely toxic, long-term infection potent proinflammatory genome OspA - unfed ticks, essential for tick colonization OspC - only expressed during feeding, essential for mammalian phase infection |
question
| Borrelia hermsii biology (type, stain, shape, motility) |
answer
| extracellular obligate pathogen, spriochete G- like, dual membrane, no LPS, helical, dark-field detection, endoflagella |
question
| Borrelia hermsii disease |
answer
| Tick-borne relapsing fever 30-70% mortality common in Africa |
question
| Borrelia hermsii virulence factors |
answer
| Vector: Orinthodores (soft, slow feed tick) Antigenic variance with each relapse |
question
| Borrelia recurrentis biology (type, stain, shape, motility) |
answer
| extracellular obligate pathogen, spirochete G- like, dual membrane, no LPS, helical, dark-field detection, endoflagella |
question
| Borrelia recurrentis disease |
answer
| louse-borne relapsing fever common in western-mountainous US |
question
| Borrelia recurrentis virulence factors |
answer
| Vector: human louse Antigenic variance with each relapse |
question
| Bukholderia cepacia |
answer
| RT infections (CF/chronic granulmomatous disease) IV catheter-associated septicemia 2nd most important infection |
question
| Chlamydia trachomatis NGU presentation |
answer
| men - groin pain, swelling, burning urination women - 50% symp, mucopurulent cytitis, vaginal discharge, lower abdominal pain; 30% of women progress to PID (infertility, prematurity, chronic pain, death) |
question
| Chlamydia trachomatis biology (type, stain, O2 req., motility) |
answer
| obligate intracellular G-, stains poorly aerobic non-motile |
question
| Chlamydia trachomatis disease |
answer
| 1) nongonococcal urethreitis - usually co-inf with N. gonorrhea; men symptomatic, women 50% symptomatic 2) trachoma - disease of poverty, inital infection 2-3 months, repeated inf, cause of extensive scarring and blindness, tichiasis and corneal opacity 3) inclusion conjunctivitis - infected birth canal, mucopurulent discharge 2-25 dyas with inflamed edematous conjuctiva 4) neontal pneumonia - 20% progress to pneumona from conjunctivitis, 4-16wks after birth 5) lymphogranuloma venerum - most invasive; endemic in africa, asia and south america; lympho-proliferative reaction due to spread inguinal lymph node |
question
| Chlamydia trachomatis dx and tx |
answer
| dx: mucosal scrapings (look for inclusions), identify antibody in sera or tears tx: doxycycline/erythromycin |
question
| Chlamydia trachomatis reservoir, transmssion, host response, at risk pop |
answer
| reservoir: human, asymptomatic carriers transmission: STD, birth canal, fleas/flies feet, contact w/ eye host response: CMI risk pop: sexually active, endemic areas |
question
| Chlamydia trachomatis virulence factors |
answer
| no detectable PG dual membranes with LPS |
question
| Clamydophila pneumoniae biology (type, stain, O2 req., motility) |
answer
| obligate intracellular G-, stains poorly aerobic non-motile |
question
| Clamydophila pneumoniae virulence factors, transmission, at risk |
answer
| no detectable PG dual membranes with LPS transmission: resp. droplets risk: elderly (>60), 70% develop pneumonia |
question
| Clamydophila psittaci virulence factors and reservoir |
answer
| no detectable PG, dual membranes with LPS reservoir: psittacine birds, turkeys, ducts |
question
| Clamydophila psittaci biology (type, stain, O2 req., motility) |
answer
| obligate intracelluar G-, stains poorly aerobic non-motile |
question
| Clamydophila psittaci disease |
answer
| Parrot fever, psittacosis or ornithosis severe - high fever, mental confusion, interstitial pneumonitis, vomiting, cyanosis, encephalitis, coma (5-20% die) |
question
| Clamydophila psittaci treatment |
answer
| tetracylcines or macrolides quarantine to prevent spread |
question
| Coxiella burnetii biology (type, stain) |
answer
| obligate intracellular G- |
question
| Coxiella burnetii disease |
answer
| majority are asymptomatic 1) Acute Q Fever - sudden high fever, severe headache, abdom/chest pain, 30-50% develop pneumonia, most recovery in few months w/o tx 2) Chronic Q fever - rare, lasts 1-20yrs, often occurs in heart value disease or IMS, subacute endocarditis, mortality of 65% w/o tx |
question
| Coxiella burnetii dx and tx |
answer
| dx: test for Ab, culture, or PCR tx: 1) acute - none or doxycycline, quarantine; 2) doxycycline + fluoroquinolones for long time |
question
| Coxiella burnetii reservoir, transmission, risk population |
answer
| reservoir: farm animals, placenta of animals transmission: associated with ticks, aerosols, unpasteurized milk risk: people that work with farm animals, esp. pregnant sheep and cats |
question
| Ehlickia chaffeensis biology (type, stain) |
answer
| obligate intracelluar G- |
question
| Ehlickia chaffeensis disease |
answer
| Human Monocytic Ehrlichiosis (HME) 3-4 week incubation rashless Rocky Mountain Spotted fever flu-like illness, leukopenia, thrombocytopenia, abnormal liver function tests 2-3% mortality |
question
| Ehlickia chaffeensis epidemiology, transmission, host response |
answer
| epidemiology: southern states transmission: Lone Star tick, dog tick host response: CMI |
question
| Ehlickia chaffeensis pathogenesis |
answer
| elementary bodies and reticular bodies, lives in host cell vacuoles (morula) infects blood monocytes and tissue mononuclear phagocytes |
question
| Ehlickia chaffeensis treatment |
answer
| doxycycline hospitlization (50%), long recovery |
question
| Enterococcus faecalis/faecium biology (type, stain, shape, hemolysis) |
answer
| extracellular pathogen G+ cocci, short chain or diplococcic, cata(-), gamma- or alpha-hemolytic, BILE ACID TOLERANT |
question
| Enterococcus faecalis/faecium disease |
answer
| HA: bacteremia, UTI, or sepsis; associated with catheter and debilitated pts (lots of Abx) CA: subacute endocarditis (fever, wt. loss, anemia, new heart murmur, vegetation on valve) |
question
| Enterococcus faecalis/faecium tx |
answer
| Suscept and not-endocard -> penicillin or perpercillin or vanco; Suscept and endocard -> ampicillin or vanco w/ aminoglyco or ampi + ceftriax; VRE -> linezolid or daptomycin |
question
| Enterococcus faecalis/faecium virulence factors |
answer
| Abx-resistance from alternative PG synthesis pathway (changes 5th aa) |
question
| Haemophilus ducreyi biology (type, stain, shape, O2 req., growth) |
answer
| extracellular pathogen, non obligate G- coccobacilli, facultative anaerobe, requires NAD+ and Fe-hemin for growth, chocolate agar growth |
question
| Haemophilus ducreyi disease |
answer
| STD in underdeveloped countries Tender papule progresses to ulcerative, painful lesion can be accompanied by painful inguinal bulbos |
question
| Haemophilus ducreyi virulence factors |
answer
| chanchroid increases risk of HIV transmission and virus shedding |
question
| Haemophilus influenza biology (type, stain, shape, nutrient req., O2 req.) |
answer
| faculatative, extracelluar G- rod needs V (NAD+) and X (Fe-containing hemin) anaerobe |
question
| Haemophilus influenza culture, epidemiology, transmission |
answer
| culture: chocolate agar epidemiology: peak Hib meningitis btwn 6-9mo; epiglottitis in 2-4y/o, 5% carriers or 60% at daycares transmission: aerosols |
question
| Haemophilus influenza diagnosis |
answer
| spinal tap - CSF for microscopy and culture (pleomorphic G- rods, detect PRP capsular Ag of Hib) latex hemagglutinin test |
question
| Haemophilus influenza disease nontypeable |
answer
| nonencapsulated strains otitis media, sinusitis, tracheobronchitis, pneumonia (COPD and cancer patients) |
question
| Haemophilus influenza disease type B |
answer
| 1) meningitis - consequence of bacteremia, starts 1-3d after mild URD, rare before 2mo b/c of maternal IgG 2) epiglottitis - "beefy red and swollen" throat, leans forward to breath, drools profusely, croup-like barking cough 3) arthritis/cellulitis - was common in <2y> |
question
| Haemophilus influenza prevention |
answer
| vaccine for Hib (PRP conjugate protein, 3 kinds) used to be leading cause of meningitis and pneumonia before, 90% reduction since 1990s |
question
| Haemophilus influenza treatment |
answer
| less severe - amoxicillin more severe(Hib) - cephalosporins and dexamethsone (steroid) |
question
| Haemophilus influenza virulence factors |
answer
| PRP capsule - polyribital phosphate types a-f, prevents C3b deposition, antiphagocytic, antigenic LOS - endotoxin IgA peptidase Pili - adherence |
question
| Legionella pneumophilia (reservoir, transmission, and culture) |
answer
| reservoir: amoebas, humans are accidental host (cooling towers, water systems, shower heads) transmission: aerosols culture: charcoal yeast agar only |
question
| Legionella pneumophilia biology (type, stain, O2 req., motility, virulence factors) |
answer
| intracellular pathogen G-, weak staining aerobe non-motile nutritionally fastidious (Fe and Cys) |
question
| Legionella pneumophilia disease |
answer
| 1) Pontiac fever - 95% of infections, acute, self-limiting, febrile disease w/o pneumonia, fever, headache, chills, flu-like, incubate 12hrs, persist 2-5days 2) Legionnaires disease - low rate, incubate 2-10 days, abrupt onset fever, chills, headache, chest pain, dry cough, bronchopneumonia, diarrhea, liver, CNS and kidneys; fatality 15% from resp. failure |
question
| Legionella pneumophilia dx and tx |
answer
| dx: urinary antigen test (serotypes 1-6), sputum with legionella with immunofluorescent probes tx: macrolide or fluroquinolone |
question
| Legionella pneumophilia pathogenesis |
answer
| replicates in macrophages prevents phagolysosome fusion |
question
| Leptospira interrogans biology (type, stain, shape, O2 req., motility) |
answer
| extracellular G- like helical, hooked shape on one or both ends aerobe endoflagella in periplasm, coild, labile |
question
| Leptospira interrogans disease |
answer
| Yellow fever, leptospirosis, hemorrhatic jaundice, rice-field fever 1st phase - disseminate spread including CNS, flu-like illness 2nd phase - endothelium damage in vessels, conjuctivitis, sudden headache, pain 3rd phase - 10% develop Weil's disease; meningitis, hepatic dysfunction with jaundice; renal failure, 10% mortality |
question
| Leptospira interrogans dx, tx, and prevention |
answer
| dx: serology tx: penicillin G or tetra/macrolides prevention: vaccine for pets and livestock |
question
| Leptospira interrogans pathogenesis |
answer
| spread through CNS endothelium damage |
question
| Leptospira interrogans virulence factors, reservoir, epidemiology, transmission |
answer
| virulence: LPS reservoir: rodent renal tubules epidemiology: widespread in world, Brazil in rainy season transmission: contact with urine of infected animals, contaminated water |
question
| Listeria monocytogenes (reservoir, tranmission, risk populations, prevention) |
answer
| reservoir: soil, decaying veggie matter, feces of mammals, birds transmission: food-borne (milk, cheese, meat, raw veggies); transplacental risk: neonates, elderly, pregnant, IMC prevention: avoid processed meats in high risk groups |
question
| Listeria monocytogenes biology (type, stain, shape, O2 req., motility) |
answer
| faculatative intracelluar parasite G+, small rod anaerobe motile |
question
| Listeria monocytogenes disease |
answer
| symptoms: neonatal sepsis/meningitis, IMC or elderly meningitis, pregnancy 3rd tri fever 1) healthy adult - influenza-like, +/- gastro 2) IMC or pregnant - meningitis + primary bacteremia 3) transplacental - granulomatosis infantiseptica, disemminated abscesses and granulomas withing few hours after birth 4) neonates - meningitis during birth/environment withing 2 weeks |
question
| Listeria monocytogenes dx and tx |
answer
| dx: culture at 4*C tx: ampicillin |
question
| Listeria monocytogenes pathogenesis |
answer
| infects GI, penetrates enterocyte epithelium or M cells engulfed by macrophages and can disseminate (LLO and ActA) |
question
| Listeria monocytogenes virulence factors |
answer
| Can grow from 4-46*C and in high salt LLO - exotoxin listeriolysin PLC - with LLO, escapes phagolysosome ActA - induces actin polymerization to spread btwn cells |
question
| Moraxella catarrhalis biology (type, stain, shape, O2 req., oxidase reactivity) |
answer
| opportunistic, extracellular G-, diplococci strict aerobe oxidase+ |
question
| Moraxella catarrhalis disease |
answer
| sinusitis, otitis media in healthy pts bronchitis and bronchopneumonia in elderly with chronic pulm disease |
question
| Moraxella catarrhalis virulence factors, risk pop |
answer
| normal resident of URT esp. children and elderly risk: smokers |
question
| Mycobacterium avium complex or M. intrcelluare (reservoir, transmission) |
answer
| reservoir: soil, water, undercooked poultry transmission: ingestion or inhalation |
question
| Mycobacterium avium complex or M. intrcelluare biology (type, stain, shape, O2 req., motility) |
answer
| atypical MOTT, intracellular filamentous, opportunistic with AIDS G+ rod, acid-fast, Ziehl-Neelson stain aerobic non motile |
question
| Mycobacterium avium complex or M. intrcelluare diagnosis |
answer
| isolation of organism in culture of blood or lymph |
question
| Mycobacterium avium complex or M. intrcelluare disease |
answer
| non-specific symptoms: fever, night sweats, abdominal pain, diarrhea, weight loss preceding fever complications: focal lymphadenitis |
question
| Mycobacterium avium complex or M. intrcelluare treatment |
answer
| HIV medications with clarithromycin and azithromycin |
question
| Mycobacterium avium complex or M. intrcelluare virulence factors |
answer
| filamentous with complex, lipid-rich cell wall mycolic acid - INH drug target cord factor - prevents lysosome fusion, necessary for survival in macrophages, triggers Th1 response LAM - LPS-like trigger, PMN attractant, granulomas formation agent |
question
| Mycobacterium leprae (reservoir, culture, transmission, host response) |
answer
| 15% of armadillos in TX/LA and humans no culture possible aerosols or broken skin transmission CMIR host response |
question
| Mycobacterium leprae at risk population |
answer
| most common in asia (india) and africa |
question
| Mycobacterium leprae biology (type, stain, shape, O2 req., motility) |
answer
| intracellular filamentous pathogen G+ rod, acid-fast, Ziehl-Neelson stain Aerobic non-motile |
question
| Mycobacterium leprae disease |
answer
| Leprosy - chronic disease skin, peripheral nerves, URT mucosa 1) Tuberculoid/paucibacillary Hansen's disease - elicits CMIR, hypopigmented skin macules, damage to nerves 2) lepromatous/multibacillary Hansen's disease - no CMIR, disfiguring skin lesions, nodeules, extensive tissue destruction |
question
| Mycobacterium leprae pathogenesis |
answer
| infects dermal macrophages and Schwann cells |
question
| Mycobacterium leprae treatment |
answer
| combo: reverses effects, except nerve damage 1) paucibacillary - RIF + dapsone for 6 months 2) multibacillary - RIF + clofazimine |
question
| Mycobacterium leprae virulence factors |
answer
| filamentous with complex, lipid-rich cell wall Mycolic acid - INH drug target Cord factor - prevent lysosome fusion, necessary for survival in macrophages, triggers Th1 response LAM - LPS-like trigger, PMN attractant, granulotomas formation |
question
| Mycobacterium tuberculosis (reservoir, culture, transmission, host response and incubation) |
answer
| humans only reservoir cutlure Lowesnstein-Jensen transtmit by aerosols host response is CMI, contains within 2-6weeks slow growth, 3-8weeks to detect |
question
| Mycobacterium tuberculosis at risk population and prevention |
answer
| Risk: HIV, homeless, prisoners, health care workers Prevention: screen with mantoux, BCG vaccine (attenuated) |
question
| Mycobacterium tuberculosis biology (type, stain, shape, O2 req., motility) |
answer
| intracellular filamentous pathogen G+ rod, acid-fast, Ziehl-Neelson stain aerobic non-motile |
question
| Mycobacterium tuberculosis diagnosis and treatment |
answer
| chest X-ray (necrosis, ghon complex, granulomas) sputum sample (acid-fast bacilli, AFB) Mantoux test - inject PPD intradermally, check few days for size, can be false positive (with past inf or vaccine) |
question
| Mycobacterium tuberculosis disease |
answer
| 1) with strong CMI, immediate clearance 2) chronic/latent infection 3) primary/miliary TB - rapid progrression, 80% fatal, spreads to liver and spleen, recovery or chronic 4) progressive 2* TB - reactivation many years later, most severe, 10% AIDS pts get and faster after 1* 5) can have MDR |
question
| Mycobacterium tuberculosis pathgoenesis |
answer
| infect alveoli and proliferate in macrophages graulomas in chronic infection by LAM lymphadenopathy if not controlled, primary TB Ghon complex - lesion by tubercle in lung and lymph CMI - progressive destructive lung, causeation of necrosis |
question
| Mycobacterium tuberculosis treatment |
answer
| multi-drugs: INH, EMB, RIF, PZA for 2 months INH and RIF for 4 months prophylaxis = INH for 3 months |
question
| Mycobacterium tuberculosis virulence factors |
answer
| filamentous w/ complex lipid-rich cell wall mycolic acid - INH drug target Cord factor - prevent lysosome fusion, triggers Th1 response, key to survival in macrophages LAM - LPS-like trigger, PMN attractant, can lead to granulomatous tubercles chronic |
question
| Mycoplasma genitalium biology (type, shape, stain) |
answer
| extracellular obligate pathogen no cell wall, cholesterol in membrane, extremely tiny Giemsa stain, ball |
question
| Mycoplasma genitalium disease |
answer
| non-gonococcal urethritis |
question
| Mycoplasma hominis biology (type, stain) |
answer
| obligate extracellular pathogen no cell wall, cholesterol membrane, extremely tiny Giemsa stain??? |
question
| Mycoplasma hominis disease |
answer
| vaginitis, cervicitis, polynephritis, pelvic inflammatory disease, postpartum fever (prevented by hand-washing of physicians) |
question
| Mycoplasma pneumonia culture, epidemiology, transmision, host response |
answer
| culture: difficult, grows slowly, requires sterols epidemiology: summer, fall trans: aerosols host response: Ab immune-mediated symptoms |
question
| Mycoplasma pneumonia virulence factors |
answer
| P1 - attachment protein, gliding motility H2O2 - production, damages cilia causing cioliostasis and non-productive cough superantigen |
question
| Mycoplasma pneumonia biology (type, stain, shape, O2 req.) |
answer
| atypical, extracellular, obligate human pathogen no cell wall for staining very tiny aerobic |
question
| Mycoplasma pneumonia disease |
answer
| 1) mild URT - may see tracheobronchitits 2-3wks after exposure, nonproductive cough, fever, chills, malaise, sore throat 2) walking pneumonia (PAP) - productive cough, mucoid/mucopurulent sputum, can have nonpleurotic chest pain, no consolidation |
question
| Mycoplasma pneumonia dx, tx, and risk pop |
answer
| dx: bed-side test for cold agglutinins, PCR throat swab, serology, ELISA tx: empiric therapy, macrolides risk: ages 5-25 b/c humoral mediated |
question
| Mycoplasma pneumonia pathogenesis |
answer
| selective affinity for respiratory epithelium, due to P1 |
question
| Nocardia at risk populations |
answer
| chronic pulm disease, IMC pts |
question
| Nocardia biology (type, stain, shape, O2 req.) |
answer
| filamentous-like G+, weakly acid-fast aerobic |
question
| Nocardia diagnosis and treatment |
answer
| Dx: gram stain, acid-fast stain, culture; pulm and CNS symptoms together Tx: sulfanomide |
question
| Nocardia disease |
answer
| symptoms: no pathogonomic signs/symptoms, look for pulm and CNS Nocardiosis - 1* bronchopulmonary disease, can disseminate to CNS in 40% and cause brain abscesses |
question
| Rickettsia prowazekii & typhi biology (type, stain, shape, O2 req., motility) |
answer
| obligate intracellular G- rod, poor stain aerobic cell-cell spread via ActA |
question
| Rickettsia prowazekii & typhi culture, transmission, incubation |
answer
| culture: cell culture, lice eggs transmission: direct contact or arthropod vector incubation: 8-12 days with generalized flu symptoms |
question
| Rickettsia prowazekii & typhi disease with reservoirs |
answer
| Prowazekii - epidemic plague, remains endemic in africa, human lice and flying squirrels, untreated 20-70% fatality Typhi - endemic in SW states, milder form of thyphus, rat lice or flea, untreated 2% fatality |
question
| Rickettsia prowazekii & typhi dx and tx |
answer
| dx: MIF tx: tetracycline, vaccine for high risk populations |
question
| Rickettsia prowazekii & typhi pathogenesis |
answer
| grows in cytoplasm of endothelial cells using host ATP, cytolysis increased vascular permeability, thrombogenesis, peripheral vascular collapse, noncardiogenic shock (death) |
question
| Rickettsia prowazekii & typhi symptoms |
answer
| acute phase - very high fever, frontal headache, intense mm pain; rash from trunk to extremity growth rash can become hemorrhagic tissue anoxia can occur from vascular collapse death from ischemia, stroke, MI or intractable shock |
question
| Rickettsia prowazekii & typhi virulence factors |
answer
| phospholipase to degrade phagosome ActA |
question
| Rickettsia rickettsii biology (type, stain, shape, O2 req., motility) |
answer
| obligate intracellular G- rod, poor stain, low amount LPS and PG aerobic can cell-cell spread via ActA |
question
| Rickettsia rickettsii disease |
answer
| Rocky Moutntain Spotted Fever (RMSF) incubate 2-12 days (fever, severe headache) 2-4 days after that maculopapular rash starts on extremeties and moves to trunk cough, bleeding, edema, confusion, focal neurologic signs, seizures extensive thrombosis can lead to amputation (5-90% fatality) |
question
| Rickettsia rickettsii dx and tx |
answer
| dx: antibody test (MIF, cross-reactive with proteus, Weil-Felix test) tx: tetracycline or chloraphenicol |
question
| Rickettsia rickettsii pathogenesis |
answer
| grows in cytoplasm endothelial cells using host ATP, cytolysis increases vascular permeability, thromogenesis, peripheral vascular collapse, noncardiogenic shock (death) |
question
| Rickettsia rickettsii reservoir, transmission, culture |
answer
| reservoir: ticks (wood and dog) transmission: tick bites culture: cell culture, eggs |
question
| Rickettsia rickettsii virulence factors |
answer
| phospholipase to degrade phagosome ActA |
question
| Staphylococcus aureus biology (type, stain, shape, hemolysis, reactivity) |
answer
| extracellular pathogen G+ cocci, clusters, B-hemolytic, coag(+), yellow colonies, ferments mannitol |
question
| Staphylococcus aureus disseminated disease |
answer
| Dissem: septic arthritis (RA and DM associated), osteomyelitis (growth plates children, spine adults), pyomyositis, represent infected blood stream and are manifestations of endocarditis; presence in urine ->bacteremia unless catheter present CA-Bacteremia: MSSA or MRSA; endocarditis and osteomyelitis; risk with IV drug use; Tricuspid valve ->pulm emoboli or Left-sided endo (rapidly progressive) HA-Bacteremia: MRSA>>MSSA; assoc. w/ IV device, remove promptly; 25% have valve vegetation; ID consult |
question
| Staphylococcus aureus other diseases |
answer
| Pneumonia: suprative; <5% of CA-pneu (<1y>75y/o); 25% of HA-pneu (pts on vents, 45%MSSA, 55%MRSA); follows flu in nursing home; necrotizing, empyema, 50% are MRSA; 60% mort if CA Food poisoning: contaminated protein after cooked, 1-6hr inc, 6-12hr duration; staph enterotoxins (SEB, SEA, SEC) act as SUPERANTIGENS; nausea, vomit, diarrhea, MAST cells; [MOST COMMON CAUSE IN US] TSS: non-supprative, really rare; TSST in only 20% of strains; was assoc. with tampons in '80s; toxins are SUPERANTIGENS; wounds, shock, fever, vascular leak, hypotensive |
question
| Staphylococcus aureus skin diseases |
answer
| Folliculitis-suprative, pustule in hair follicle Furnuncles-suprative, boils where pustule spreads into subcutaneous, hot and tender; may have fever Carbuncles-furnuncles interconnect Impetigo-suprative, superficial epidermis only, mostly children, highly contagious 20% co-inf w/GAS Burn infection-suprative, HA-MRSA Scalded Skin: non-supprative, rare, exofoliative toxins (ETA and ETB), mucosal colonies in infants; disrupt desmosomes, INTRAepidermal separation; positive Nikolsky sign; heals w/o scar; Ab to toxin can neutralize somewhat |
question
| Staphylococcus aureus treatments |
answer
| Folliculitis/Impetigo: local antiseptics Furn/carbuncles: incision, drain; CA-MRSA-TMP/SMX or doxy; MSSA-same or B-lactam Carriers: decolonize with mupirocin CA-Bacteremia: 4-6wks IV Abx HA-Bacteremia: IV Abx only, 2-4wks MSSA: nafcillin, cefazolin HA-MRSA: vanco CA-MRSA: vanco, clinda, TMP/SMX, or doxy Food poison: supportive TSS: incision, drain; vanco + circulatory support |
question
| Staphylococcus aureus virulence factors |
answer
| MRSA and MSSA strains NF of nares and axilla/perineal skin Protein A (binds IgG and inactivates) Secreted toxins, ahesins (attach to PG and bind ECM), Techoic acid (targets epi cells), LTA and PH (trigger cytokines), lipases, nucleases, cytotoxins, hyaluronidase, fibrinolysin, Panten-Valentine Toxin (MRSA, recruits PMNs, causes granulomas), enterotoxins |
question
| Staphylococcus epidermidis biology (type, shape, stain, hemolysis, etc.) |
answer
| extracellular pathogen G+ cocci, clusters, B-hemolytic, coag(-) |
question
| Staphylococcus epidermidis disease |
answer
| 50% of sepsis cases in NICU Other disseminated diseases are association with devices |
question
| Staphylococcus epidermidis dx and tx |
answer
| Dx: erythema around device helps Tx: remove any assoc. device; if IMC/neonate Vanco 1-6wks; normal = vanco for a few days; |
question
| Staphylococcus epidermidis virulence factors |
answer
| NF of skin forms biofilms on invasive devices |
question
| Staphylococcus saparophyticus biology (type, stain, shape, hemolysis, etc.) |
answer
| extracellular pathogen G+ cocci, clusters, coag(-) |
question
| Staphylococcus saparophyticus disease |
answer
| UTI in sexually active young women (2nd most common cause) and in elderly men (uncommon cause) |
question
| Staphylococcus saparophyticus dx and tx |
answer
| Dx: culture coag(-) staph Tx: TMP/SMX |
question
| Staphylococcus saparophyticus virulence factors |
answer
| transient flora of rectum and UG (5-10% of females) |
question
| Stenotrophomonas maltophilia |
answer
| emergence of steno "superbug" MDR pneumonia, bacteremia contaminates disinfectants, resp. equipment, ice machines |
question
| Streptococcus alagacitiae (Group B) biology (type, stain, shape, hemolysis |
answer
| extracellular pathogen G+ cocci, chains, B-hemolytic, Group B Lancefield, cAMP test -> arrowhead, citrate(+), cata(-) |
question
| Streptococcus alagacitiae diagnosis |
answer
| G+ cocci in chains B-hemolytic cAMP test --> arrowhead |
question
| Streptococcus alagacitiae disease |
answer
| Neonatal: transmission at delivery, early onset -> aspiration of amniotic fluids, pneumonia; late onset -> meningitis due to colonization of gut; Elderly: pneumonia, UTI, cellulitis, bacteremia |
question
| Streptococcus alagacitiae epidemiology |
answer
| Infants -> pneumonia and meningitis Elderly DM -> cellulitis #1 cause of meningitis in neonates |
question
| Streptococcus alagacitiae treatment and prevention |
answer
| Adult: cellulitis or pneumonia, ceftriaxone or Aminoglyc+amp Infants: amp+aminoglycoside Prevent: screen preggers at 35-37 week, treat intrapartum if (+) |
question
| Streptococcus alagacitiae virulence factors |
answer
| polysaccharide capsule (Type III = 60% sialic acid, which mimics host) NF in GI and GU tracts |
question
| Streptococcus pneumoniae biology (type, stain, shape, hemolysis) |
answer
| extracellular pathogen G+ diplococcic, lancet-shaped, alpha-hemolytic, cata(-), dimple colony, optchin sensitive, bile acid senstive |
question
| Streptococcus pneumoniae diagnosis |
answer
| Clinical a-hemolytic optchin sensitive, G+ diplococci |
question
| Streptococcus pneumoniae disease |
answer
| Pneumococcal Pneumonia - follows viral inf; abrupt onset, pleurotic/chest pain, yellow/rusty sputum, diarrhea, DULL precussions, crackles, lobar consolidation, elevated WBC (if low->poor prognosis), blood culture can be positive Acute otitis media - #1 bacterial cause in US, follows viral URI, daycares, formula-fed = higher risk Sinusitis - follows viral URI Bacteremia - usually from pneumonia, 25% mort w/tx if debilitated pt Meningitis - follows bacteremia, most common causes except in neonates Conjunctivitis - unencapsulated strains, younger population, outbreak associated |
question
| Streptococcus pneumoniae prevention |
answer
| >65y/o - 23-valent-polysacc vaccine <2y>>19y/o w/ risk - PVC-13 conjugate vaccine |
question
| Streptococcus pneumoniae transmission and pathogenesis |
answer
| Trans: NF of URT, defect in resp. tract Path: gain access to lung through defect, and defect in immunity allow for dissemination |
question
| Streptococcus pneumoniae treatment |
answer
| Otitis/sinusitis - amoxicillin or clavulanic acid CA-pneumonia - ceftriax+macro or resp. Quinolone Meningitis - vanco+ceftrix; then sensitivity testing |
question
| Streptococcus pneumoniae virulence factors |
answer
| Polysaccharide capsule Pneumolysin - cytotoxin, creates pore in ciliated epi cells and WBCs, activates complement IgA protease PG, LTA, C-polysaccharide Phosphocholine-containing proteins - adherence to endo, WBCs, lung and meninges |
question
| Streptococcus pyogenes biology (type, shape, stain, O2 req., motility) |
answer
| extracellular, G+ cocci, chains, cata-, B-hemolytic, Group A Lancefield, Bacitracin senstive |
question
| Streptococcus pyogenes complications |
answer
| Acute rheumatic fever - Ab to cardiac antigen, 1wk to 1mo post-infection, follows pharyngitis Acute glomerulonephritis - abs to kidney ag, onset 1wk to 1mo post-inf, follows pharyngitis, pyoderma or impetigo |
question
| Streptococcus pyogenes diagnosis |
answer
| pharyngitis: cluture, rapid Ag detection general: Abs to GAS Necrotizing ForM: surgical explore, gram stain, culture, positive blood culture Scarlet fever: clinical TSS: GAS isolated, BP<90, >1organs, systemic dysfunction ARF: anti-ASO, anti-hyluronidase,anti-DNAse Abs AGN: anti-hyaluronidase and anti-DNAse ABs |
question
| Streptococcus pyogenes pyogenic infections |
answer
| strep throat - crowding assoc. cellulitis - subdermal, no pus impetigo - pyoderma, superficial inf. erysipelas - sharp borders on areas sepsis - endometritis, at birth process bacterial endocarditis necrotizing fasciitis - minor trauma, rare necrotizing myositis - minor trauma, rare pneumonia - epidemics in barracks |
question
| Streptococcus pyogenes toxic mediated disease |
answer
| TSS - M1 or M# serotypes, rapid progression Scarlet fever - pharyngitis, erythrogenic+ strain, diffuse rash, sandpaper feel, spares palms/soles/face, strawberry tongue |
question
| Streptococcus pyogenes treatment |
answer
| Pen, cephalosporin, clinda or macro Pharyngitis: prevent spread, tx Necrotizing: pen+clinda+surgery TSS: source, ICU care, IVIG ARF: prophylatic, low dose, anti-inflam AGN: supportive |
question
| Streptococcus pyogenes virulence factors |
answer
| PG, LTA, capsule, protein F, fibrillae M protein - serotypes, anti-phaytocytic, binds factor H and fibrinogen streptolysins, C5a peptidase, hyaluronidase, sterptokinase, DNAse, pyrogenic exotoxins |
question
| Streptococcus viridians biology (type, stain, shape, hemolysis) |
answer
| extracellular pathogen G+ cocci, chains, cata(-), A-hemolytic, >30 species |
question
| Streptococcus viridians diagnosis and treatment |
answer
| Dx: G+ cocci in chains, alpha-hemo Tx: PenS = penicillin; PenR = pen + aminoglyc or vanco; 4-6wk duration |
question
| Streptococcus viridians disease |
answer
| Subacute Endocarditis - bacteria in vegetation on valve; fever, weight loss, embolie, NEW HEART MURMUR, anemia; lasts wks-months; increased risk w/ prior valve damage Abscesses - agionosis/milleri species Bacteremia - associated with colon cancer, bovis species |
question
| Streptococcus viridians prevention |
answer
| prophylactics for high risk pts before procedures (i.e. dental extractions) |
question
| Streptococcus viridians virulence factors |
answer
| ahesins that attach to heart valves Transmission into blood via tooth brush/floss/procedure |
question
| Treponema pallidum pathogenesis |
answer
| enter mucus membranes multiply locally spread to lymph/blood |
question
| Treponema pallidum biology (type, stain, shape, O2 req., motility) |
answer
| extracelluar pathogen G- like, helical, no LPS microaerophiles endoflagella in periplasm, coiled, labile |
question
| Treponema pallidum culture, transmission, host reponse |
answer
| do not culture, cultivate in rabbit testes trans: STD, transplacentally host response: tissue destruction due to immune response |
question
| Treponema pallidum disease |
answer
| 1) Syphillus (primary) - localized lesion with 10-120d incubation, sphilitic chancre is painless, hard shallow ulcer, heals in 3-6wks, filled with treponemes 2) syphillus (secondary) - disseminated lesions, 6-8wks after primary, flu-like syndrome, few days later rash develops, filled with treponemes, heals 2-6wks 3) syphillus (early latent) - aysmptomatic, detic only in serologic tests, 1st year 4) symphillus (late latent) - not infections, but can spread transplacentally, 25% revert back to secondary during first 4 yrs of latency, trepnemes in endothelium cause chronic inflamation 5) syphillus (tertiary) - 1/3 of cases, disease after latency, immune-mediated, gumma (granulomous lesions), neurosyphillus, cardiovascular symphillus 6) congential syphillus - massive invasion of treponemes to fetus; 1* = 100% risk, 2* = 90%, latency = 30%; multiorgan malformations (blidness, deafness, CV, Hutchinson's incisors, saddle nose, saber shins) |
question
| Treponema pallidum dx and tx |
answer
| dx: darkfield, serology nontreponemal (VDRL, RPR) for anti-phospholipid Abs, treponemal (FTA-ABS) for high specificity to confirm tx: penicillin G or tetar/doxy if allergic |
question
| Treponema pallidum virulence factors |
answer
| highly invasive, not extremely toxin, long term infection few outer membrane proteins (evades IMS) hyaluronidase - facilitates perivascular penetration fibronectin - coat themselves to protect against phagocytosis |
question
| Ureaplasma urealyticum biology and disease |
answer
| extracellular pathogen NGU |
question
| Mycobacterium scrofulceum biology, VF and disease |
answer
| Facultative intracellular, G+ rod, aerobe, acid-fast VF: Wax-like wall (resist detergents and disinfectants, promotes inflammation); serpentine cord Disease: Cervical lymphadenopathy in children, rare |
question
| Mycobacterium kansasii biology, VF and disease |
answer
| Bio: facultative intracellular, G+ rod, acid-fast, aerobe VF: wax-like wall (resist detergents and disinfectants, promotes inflammation); serpentine cord Disease: TB-like, rare |
question
| Mycobacterium marinum biology, VF and disease |
answer
| Bio: facultative intracellular, G+ rod, aerobe, acid-fast VF: wax-like wall (resist detergents and disinfectants, promotes inflammation) Disease: swimming pool granuloma, rare |
question
| Francisella tularensis biology (type, shape, stain) |
answer
| faculatative intracellular, zoonotic pathogen G+ cocci |
question
| Francisella tularensis virulence factors and transmission |
answer
| zoonotic: rabbits, cats, ticks Trans: aerosols (low ID50), ingestion (high ID50), tick bite (high ID50), eye contact (high ID50) |
question
| Francisella tularensis disease |
answer
| Aerosols: pneumonia or sepsis Ingest/tick/eye: ulcers, swollen localized lymph nodes, or conjunctivitis |
question
| Francisella tularensis diagnosis and treatment |
answer
| Dx: serology, culture on cysteine-sumpplemented media TX: gentamycin, FQ, or doxy |
question
| Brucella biology (type, stain, shape) |
answer
| facultative intracellular, zoonotic pathogen G+ cocci, very tiny several species |
question
| Brucella transmission and disease |
answer
| Trans: direct contact or ingestion, assoc. w/ bison in western US Sepsis Granulomas/abscesses - lymph nodes, bone marrow, liver or spleen |
question
| Brucella diagnosis and treatment |
answer
| Dx: serology and culture Tx: Doxy + RIF w/ or w/o aminoglycoside |
question
| Chlamydia pneumoniae biology (type, stain, shape, etc.) |
answer
| obligate intracellular pathogen G- like, coccobacilli, LPS is weak, Major Outer Membrane Protein (MOMP), smallest genome |
question
| Chlamydia pneumoniae virulence factors |
answer
| energy parasite - relies on host ATP, aa, and lipids Elementary bodies - metabolically inactive, infectious Reticular bodies - metabolically active, non-infectious |
question
| Chlamydia pneumoniae transmission and pathogenesis |
answer
| Trans: resp. droplets Path: EB contact w/ host cell, induce phagocytosis, live in inclusion, differentiate to RB, proliferate, differentiate into EB, host cell lysis, release of EBs, cycles 48-72hrs |
question
| Chlamydia pneumoniae disease |
answer
| Respiratory: sinusitis, pharyngitis, bronchitis, atypical (walking)pneumonia; most cases are mild Athersclerosis: infects SMCs, artery epi cells and macrophages; assoc. w/ inflammatory plaques |
question
| Chlamydia pneumoniae diagnosis and treatment |
answer
| Dx: NAAT, difficult Tx: macro, doxy or levofloxacin |
question
| Chlamydia psittaci biology (type, stain, shape, etc.) |
answer
| obligate intracellular pathogen G- like, no PG, weak LPS, small, MOMP |
question
| Chlamydia psittaci virulence factors |
answer
| energy parsite-relies on host ATP, lipids and aa Elementary bodies - infectious, metabolically inactive Reticular bodies - noninfectious, metabolically active |
question
| Chlamydia psittaci transmission and pathogenesis |
answer
| Trans: aersol of bird feces, blood/tissue/feather contamination Path: EB contact with host cell, induces phagocytosis, live in inclusion, differentiate into RB, proliferation, differentiate to EB, host cell lysis, release of EB (CYCLES 48-72hrs) |
question
| Chlamydia psittaci disease |
answer
| Parrot Fever - aka psittaciosis or ornithosis; a resp. (alveolar and interstitial) infection; spreads from resp. to liver and spleen, causing focal necrosis, spreads via blood Fever, chills, vomit, headache, pneumonitis, CYANOSIS, ENCEPHALITIS, COMA |
question
| Chlamydia psittaci dx and tx |
answer
| Dx: serology Tx: doxy or macro |
