Lesson 8a: Enterobacteriaceae Flashcards
General Description of Enterobacteriaceae
• gram negative rods
• growth on non-enriched media
• oxidase-negative
• facultative anaerobes, catalase positive
• most are motile by peritrichous flagella
• ferment glucose, reduce nitrate to nitrite
• enteric bacteria which tolerate bile salts in MacConkey agar
• Cause a variety of clinical infections
• Major enteric and systemic pathogens: ESCHERICHIA COLI, SALMONELLA SEROTYPES, YERSINIA SPECIES
• Opportunistic pathogens: PROTEUS SPECIES, ENTEROBACTER SPECIES, KLEBSIELLA SPECIES
• Non-pathogenic Enterobacteriaceae: HAFNIA SP. and ERWINIA SP.
• the term ‘coliform’, formerly only used to describe Enterobacteria capable of fermenting lactose, is now sometimes used to describe other members of the family.
are used to detect O (somatic) and H (flagellar) antigens in all three species and sometimes detection of K (capsular) antigens is carried out.
Slide agglutination test with antisera
allows identification of the organisms involved in disease outbreaks and has application in epidemiological investigation
Serotyping
Major enteric and systemic pathogens
Escherichia coli, Salmonella serotypes, Yersinia species
Opportunistic pathogens
Proteus species, Enterobacter species, Klebsiella species
Non-pathogenic Enterobacteriaceae
Hafnia sp. and Erwinia sp.
used to describe Enterobacteria capable of fermenting lactose, is now sometimes used to describe other members of the family
Coliform
tolerate bile salts in MacConkey agar
Enteric bacteria
Ferment glucose, reduce nitrate to nitriteee
Enterobacteriaceae
Salmonella serotypes
° Salmonella typhimurium
° Salmonella dubin
° Salmonella enteroidis
Yersinia species
° Y. pestis
° Y. enterocolitica
° Y. pseudotuberculosis
cultural characteristics of E. coli
some strains haemolytic
cultural characteristics of proteus species
Swarming growth
what opportunistic pathogencultural characteristics is mucoid
Enterobacter aerogenes and Klebsiella pneumoniae
