Salmonella

Salmonella

[‚sal·mə′nel·ə]

(microbiology)

A genus of gram-negative, facultatively anaerobic bacteria belonging to the family Enterobacteriaceae that cause enteric infections with or without blood invasion. Most species are motile, utilize citrate, decarboxylate ornithine, form gas from glucose, and produce hydrogen sulfide. Salmonellae do not ferment lactose, produce indole, or split urea; the Voges-Proskauer reaction is negative.

Salmonella

 

a genus of nonsporogenous rod-shaped bacteria that are 1–7 μm long and approximately 0.3–0.7 μm wide. It includes gram-negative facultative aerobes, most of which are motile because they are peritrichous. Salmonella was named in honor of the American pathologist D. E. Salmon (1850–1914).

Salmonellas form round grayish white colonies on solid nutrient mediums and an opacity and sediment and sometimes a film when grown in broth. They ferment carbohydrates, including glucose, mannose, xylose, and dextrin, and alcohols, including inositol and dulcite; an acid and sometimes a gas are formed as well.

Salmonellas generally inhabit the intestine of animals and man. Most belong to pathogenic species that produce various antigens, including the thermolabile flagellate H antigen and the O and V antigens, which consist of carbohydrates. There are more than 20 species in the genus, with more than 1,200 serotypes that differ in antigenic structure and biochemical properties. Among salmonellas are the causative agents of typhoid fever and paratyphoid in humans and salmonelloses in humans and animals.

A. A. IMSHENETSKII