Medical Microbiology

280 4 BacteriaasHumanPathogens

Table4. 6 TheMostImportantGenera/Species/VarsofEnterobacteriaceaeand

theCorrespondingClinicalPictures

Genera/species/var Disease Remarks

Salmonellaenterica

S.Typhi

S.Typhimurium

S.Enteritidisandothers

Typhusabdominalis

(syn.typhoidfever)

Gastroenteritis(diarrhea)

Generalizedsepticinfection

Profusewaterydiarrhea

Shigella Bacterialdysentery Diarrhea,abdominalcramping,

tenesmus,stoolfrequently

containsbloodandmucus

Klebsiellapneumoniae Pneumonia

(Friedla ̈nder’s)

Severepneumoniainpredis-

posedpersons

Escherichiacoli

Citrobacter

Klebsiella

Enterobacter

Serratia

Proteus

Providencia

Morganellaandothers

Sepsis,woundinfections,

infectionsoftheurinary

tractandrespiratorytract

Facultativelypathogenic

bacteria;diseaseonly

manifestsifhostorganism

immunedefensesare

weakened;oftencause

nosocomialinfections;

frequentlyresistantto

antibiotics

Yersinia

Y.pestis

Y.enterocolitica

Y.pseudotuberculosis

Plague

Enterocolitis,lymphadenitis

ofthemesentericlymph

nodes

Generalizedsystemic

infection;rare

Pseudoappendicitis,reactive

arthritis,erythemanodosum

Escherichiacoli Intestinalinfections

Enteropathogenic

E.coli(EPEC)

Classicinfantdiarrhea Epidemicsinhospitals,

children’shomes

Enterotoxic

E.coli(ETEC)

Diarrhea,choleralike Causeoftravelers’diarrhea

(50%)

Enteroinvasive

E.coli(EIEC)

Dysenterylike Invasionandverocytotoxins

Enterohemorrhagic

E.coli(EHEC)

Hemorrhagiccolitis Hemolytic–uremicsyndrome

(HUS)in 5 %ofEHECcases

Enteroaggregative

E.coli(EAggEC)

Waterydiarrhea,mainly

ininfants

Adhesiontosmallintestine

mucosa;productionofa

toxin

4

Kayser, Medical Microbiology © 2005 Thieme