Requires special medium that is rich in iron ph 65

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Requires special medium that is rich in iron, pH ~ 6.5,supplemented with a.a. andαketo-glutarateoAntigen detectionUrine ag (L. p. 1 only); specific, not sensitiveRespiratory secretions- mAB; specific, not sensitiveoPCRoSerology- need acute and convalescent seraTreatment:oAntibiotic must accumulate inside macrophagesIt lives intracellularlyoFluoroquinolones- levofloxacin & moxifloxacinoMacrolides- azithromycin bestoRifampin- probably not alone.oRole of combination therapy not established.
Lecture 5: Enteric BacteriaBasic Characteristics:Gram – rods; Aerobes and facultative anaerobesFerment glucoseOxidase negativeno cytochrome C oxidaseCatalase +Reduce nitratenititeNot inhibited by bile (not fastidious)Grow on media: EMB, MacCinkey’s agarBiggest differentiator in this family: lactose and non-lactose fermentersoLactose fermenters:C-CitrobacterE-EnterobacterE-E. ColiK-Klebsiella (non-motile)oLactose Non-fermenters:Sh- Shigella(nonmotile, no H2S)Y - Yersinia(nonmotile, no H2S)P- Proteus(motile, H2S made)S- Salmonella(motile, H2S made)oDifferentiating from Pseudomonas: does not fermentglucose/lactose; oxidase positive; polar flagella; obligate aerobePeritrichousflagella (if motile): All around hairVirulence genes encoded on plasmids, bacteriophages, or chromosomesoInsertions of DNA containing multiple genes called islandso1+ genes has virulence fxnregion called pathogenicity islandoVirulence factors:genes that cause problemsSurface Antigens:O outer membrane LPS EndotoxinoInside toxinreleased in body; LPSsignals large volumes of inflammatoryresponsesH flagellar (motility)K capsule avoids phagocytosis e.g. SalmonellaTyphi, ViPili or fimbriae (adherence to cell membrane)ExotoxinShiga-like toxinHemolytic Uremic SyndromeToxin that is excretedType III secretion systems and 2 component regulatorsSalmonella:S.bongoriandS.enterica-human pathogensID from serotypes based on O and H antigensSalmonella Entericaassociated with:oEnterocolitis: Hundreds of serovars (inflammation of gut)oBacteremia: Salmonella Enterica serotype Typhimurium,Enteritidis,Dublin, Choleresuis. (bacteria in blood stream)ALWAYS NEEDS TREATMENToEnteric fever: Salmonella Enterica Serotype Typhi orS.paratyphiEpidemiology:oAnimal reservoirs (animal guts)oTransmission through food, raw poultry, eggs, pet reptilesoRequired moderate infective doseoMost vulnerable: young, elderly, immunocompromiseoEverything aboutS. Typhiis in a completely different entitiyOnly carried in humansSymptoms:oNausea, headache, vomiting, diarrhea, fever; WBC’s in stooloStool can remain positive for weeks after recoveryLab characteristics: Highly motil; Lactose non-fermenters; All make H2SHow does it cause disease?

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Term
Spring
Professor
staff
Tags
Bacteria, Gram stain, Virulence factors

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