Prevalence of Virulence Genes in Extended‐Spectrum β‐lactamases (ESBLs)‐Producing <italic>Salmonella</italic> in Retail Raw Chicken in China.

Abstract: Extended‐spectrum β‐lactamases (ESBLs)‐producing <italic>Salmonella</italic> is a tremendous hazard to food safety and public health. The objective of this study was to determine the prevalence of 30 virulence genes (<italic>avr</italic>A, <italic>sip</italic>A, <italic>sse</italic>C, <italic>mar</italic>T, <italic>rhu</italic>M, <italic>sii</italic>E, <italic>pip</italic>A, <italic>pip</italic>D, <italic>env</italic>R, <italic>gog</italic>B, <italic>gtg</italic>A, <italic>sod</italic>C1, <italic>sse</italic>I, <italic>irs</italic>A, <italic>sop</italic>E2, <italic>spv</italic>C, <italic>rck</italic>, <italic>spv</italic>R, <italic>fhu</italic>A, <italic>msg</italic>A, <italic>pag</italic>K, <italic>srfj</italic>, <italic>stkc</italic>, <italic>fim</italic>A, <italic>lpf</italic>D, <italic>pef</italic>A, <italic>stc</italic>C, <italic>ste</italic>B, <italic>stj</italic>B, and <italic>tcf</italic>A) in 156 ESBLs‐producing <italic>Salmonella</italic> isolates that belonged to 21 serotypes. These isolates were recovered from retail raw chicken samples collected from 5 provinces and 2 national cities in China between 2007 and 2012. The results indicated that 154 (98.7%) ESBLs‐producing <italic>Salmonella</italic> isolates carried at least 1 virulence gene, 138 (88.5%) simultaneously carried at least 5 virulence genes, 107 (68.6%) carried 10 or more, and 20 (12.8%) carried 15 or more virulence genes. The most frequently detected virulence genes were <italic>mar</italic>T (<italic>n</italic> = 127, 81.4%), <italic>sii</italic>E (<italic>n</italic> = 126, 80.8%), <italic>msg</italic>A (<italic>n</italic> = 121, 77.6%), and <italic>sip</italic>A (<italic>n</italic> = 121, 77.6%). Significant difference was identified between detection percentages of virulence genes of <italic>rhu</italic>M<italic>, pip</italic>D<italic>, env</italic>R, <italic>sop</italic>E2, <italic>pag</italic>K, <italic>lpf</italic>D, <italic>ste</italic>B, and <italic>stj</italic>B in <italic>S</italic>. Indiana, <italic>S</italic>. Thompson, <italic>S</italic>. Enteritidis, <italic>S</italic>. Typhimurium, <italic>S</italic>. Shubra, <italic>S</italic>. Edinburg, and <italic>S</italic>. Agona isolates. Distribution of virulence genes were significantly influenced by sampling districts (<italic>P </italic>< 0.01), especially for <italic>sod</italic>C1 and <italic>pip</italic>D, and then were <italic>msg</italic>A and <italic>sop</italic>E2. The heatmap showed the frequencies of virulence genes in ESBLs‐producing isolates from retail chickens in southern, central, and northern regions of China were completely different from each other. Based on our findings, ESBLs‐producing <italic>Salmonella</italic> of retail chicken origin were common carriers of multiple virulence genes and were regionally distributed. [ABSTRACT FROM AUTHOR]