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