Antimicrobial resistance in Salmonella isolates from apparently healthy food-producing animal from 2000 to 2003: the first stage of Japanese veterinary antimicrobial resistance monitoring (JVARM)

Antimicrobial susceptibility of 183 Salmonella isolates from apparently healthy food-producing animals obtained during the period from 2000 to 2003 throughout Japan was examined. Of 29 serovars identified, Salmonella Infantis (37.7%) was the most prevalent, followed by S. Typhimurium (19.7%). Salmonella bacteria resistant to dihydrostreptomycin (77.6%) were about 10% more prevalent than those resistant to oxytetracycline (67.8%), though the nation-level veterinary use of tetracycline antibiotics is much greater than that of streptomycin in Japan. In seventeen isolates (9.3%) resistant to nalidixic acid, single point mutations were detected at 84 or 87 in the quinolone resistance-determining region of the gyrA gene.