Increased Salmonella Schwarzengrund prevalence and antimicrobial susceptibility of Salmonella enterica isolated from broiler chickens inKagoshima Prefecture in Japan between 2013 and 2016

摘要

This study aimed to analyze the serovars, measure the minimum inhibitory concentration of antimicrobials, and examine the antimicrobial resistance genes of isolated from 192 broiler flocks in Kagoshima Prefecture in Japan, from 2013 to 2016. We found that all isolates belonged to threeserovars: Manhattan, Infantis, and Schwarzengrund. Among them, Schwarzengrund prevalence has recentlyincreased annually making the main serovar. Most recovered isolates were highly resistant to streptomycin, sulfamethoxazole, and oxytetracycline. We saw the reduction of third-generationcephalosporin resistance and identified the reason of increased kanamycin resistance to be the increased number of Schwazengrund isolates. Among the kanamycin-resistant isolates, constituted the main resistance gene detected.