Prevalence and Antimicrobial Resistance of serotypes Isolated from Poultry Meat in Japan.

The prevalence and antimicrobial susceptibility of in 512 poultry meat samples collected from retail stores and poultry-processing plants in Japan between 2015 and 2016 were investigated. The results showed that 55.9% of poultry meat samples were contaminated with , with nine different serotypes represented. The most frequent serovar was serovar Infantis, followed by . Schwarzengrund, together accounting for 78.2% of the isolates. High antimicrobial resistance rates were observed against tetracycline (80.9% . Infantis and 83.9% . Schwarzengrund), streptomycin (53.4% . Infantis and 76.8% . Schwarzengrund), and kanamycin (33.6% . Infantis and 82.1% . Schwarzengrund). All tested isolates were susceptible to colistin and ciprofloxacin. In addition, a high proportion (65.6% of Infantis, 85.7% of Schwarzengrund) of isolates were resistant to two or more antimicrobials, and 22 and 17 different resistance patterns were observed in the two strains, respectively. The predominant antibiotic resistance patterns were streptomycin-tetracycline (32/131, 24.4% of Infantis) and streptomycin-kanamycin-tetracycline-sulfamethoxazole/trimethoprim (43/112, 38.4% of Schwarzengrund). These data indicate that multidrug-resistant . Infantis and . Schwarzengrund have spread among poultry meat in Japan.