Salmonella spp. are members of the family Enterobacteriaceae. They are Gram negative, facultatively anaerobic rods. Salmonella species are classified into serovars (serotypes) based on the lipopolysaccharide (O), flagellar protein (H), and sometimes the capsular (Vi) antigens. There are more than 2500 known serovars. Within a serovar, there may be strains that differ in virulence.

A number of Salmonella serotypes have been found associated with reptiles and/or amphibians including, the S. enterica subsp. enterica serovars Chameleon, Java, Marina, Poona, Stanley and Typhimurium, among others. S. bongori, S. enterica subsp. salamae, S. enterica subsp. arizonae, S. enterica subsp. diarizonae, S. enterica subsp. houtenae, S. enterica subsp. indica, are usually found in poikilotherms (including reptiles, amphibians and fish) and in the environment. Some of these organisms are occasionally associated with human disease.