Salmonella are non-lactosefermenters, and most strains are H2Sproducers. Fecal-Oralroute of entry is associated with childreninfection and food poisoning. The most common sources of human infections are poultry, eggs, and dairyproducts. Serotypes such as Salmonella typhiand Salmonella paratyphiare highly adapted to man. The capsule could be illustrated microscopically by India Ink stain.Įnterobacteriaceae The Genus Salmonella: Salmonella are found in many animals, including poultry, reptiles, rodents, domestic animals, birds, and human. Mucoidcolonies are capsulated So it should be stained by Capsule Stain. Indole production: positive.Įnterobacteriaceae The genus Klebsiella: Klebsiellaspecies are Lactose fermenter that produce mucoid colonies on MacConkey’s agar. All are motile (having peritichousflagellae) except Klebsiella and Shigella.Įnterobacteriaceae Biochemical identification of Enterobacteriaceae:Įnterobacteriaceae The API 20 E strips showing the biochemical reactions of two different Enterobacteriaceaespecies: Anautomated bacterial identification System:Įnterobacteriaceae Escherichia coli:Escherichia coli is a normal flora of human small intestinal tracts. Non-lactose fermenters as: Salmonella, Shigella, Proteus, Morganella, Yersinia, and Serratia.Įnterobacteriaceae Microscopy: All Enterobacteriaceae species are Gram's negative short bacilli, and non-spore producers. 5- All ferment glucose with acid or acid and gas production and reduce nitrate to nitrite.Įnterobacteriaceae Based on lactose fermentation they are divided into: Lactose fermenters as: Escherichia coli, Klebsiellapneumoniae, Enterobacter and Citrobacter. 4- Oxidase negative and catalase positive. 2- All are motile (having peritichousflagellae) except Klebsiella and Shigella 3- Facultative anaerobes. General characteristics: 1- They are short rods with rounded edge 4-5 microns in length, non-spore formers. Gram Negative Bacilli Enterobacteriaceae Family: They include large heterogeneous group of gram negative rods whose natural habitat is the intestinal tract of man or animals.