Contamination of Salmonella Schwarzengrund cells in chicken meat from traditional marketplaces in Taiwan and comparison of their antibiograms with those of the human isolates

Salmonella Schwarzengrund is one of the infective Salmonella serotypes for humans and food animals, such as poultry and swine. Because consumption of foods containing salmonellae due to cross contamination or inadequate cooking may lead to human salmonellosis, in this report, the prevalence of Salmonella Schwarzengrund contamination in chicken meat samples purchased from different traditional marketplaces in Taiwan between 2000 and 2006 was investigated. In addition, 228 Salmonella Schwarzengrund strains isolated from these chicken meat samples and 30 human isolates obtained between 2004 and 2006 were compared for their antimicrobial susceptibility. Results showed that the prevalence of Salmonella Schwarzengrund contamination in raw chicken meat samples was 30.5%. Of all of the Salmonella isolates from chicken meat, Salmonella Schwarzengrund accounted for 39.3%. On the other hand, of the total Salmonella strains isolates from humans between 2004 and 2006, Salmonella Schwarzengrund accounted for 2.8%. All these chicken meat isolates and human isolates were multidrug-resistant and demonstrated high resistance to ampicillin, gentamicin, kanamycin, streptomycin, tetracycline, nalidixic acid, trimethoprim-sulfamethoxazole, and chloramphenicol. For gentamicin and kanamycin, however, the resistance gradually declined. The antibiogram study may indicate the abuse of some antibiotics for both humans and chickens. Also, transmission of Salmonella Schwarzengrund strains between humans and food of animal origin is possible