Klebsiella
gram-negative, lactose positive, oxidase negative
Escherichia coli
gram-negative, lactose positive, oxidase negative
Enterobacter
gram-negative, lactose positive, oxidase negative
Citrobacter
gram-negative, lactose positive, oxidase negative
Serratia
gram-negative, lactose positive, oxidase negative
Shigella
gram-negative, lactose negative, oxidase negative
Salmonella
gram-negative, lactose negative, oxidase negative
Proteus spp.
gram-negative, lactose negative, oxidase negative
Yersinia enterocolitica
gram-negative, lactose negative, oxidase negative
Yersinia pestis
gram-negative, lactose negative, oxidase negative