Detection of virulence genes in multidrug-resistant Salmonella serovars isolated from different meat sources

The aim of this study was to detect virulence gene expression associated with multidrug-resistant (MDR) Salmonella serovars isolated from retail meats in Ha Noi, Vietnam. Six out of nine MDR Salmonella was selected for mRNA sequencing to detect virulence genes. All MDR Salmonella serovars produced fimbrial adherence determinants (bcfC, fimD, safC, stbC, sthE, sthC, sthB, and mgtB), nonfimbrial adherence determinants (ratB, shdA, and phoQ), SPI-1 (hilA, invA, invC, invE, invG, prgH, and spaS), SPI-2 (ssaC, ssaD, ssaN, ssaU, ssaV, sseC, and ssrA), SPI-3 (misL), SPI-4 (siiE), SPI-9 (bapA and slrP), TTSS-1 translocated effectors (sptP, sipA, sipC, sipB, sopA, and sopB/sigD), TTSS-2 translocated effectors (sseJ), and effectors outside of SPIS and other virulence factors (cheA, flgI, flgK, flhA, flhB, fliF, fliI, iroB, iroC, iroD, iroN, and STM0570). The findings in this study indicate that retail meats tested were widely contaminated with drug-resistant Salmonella and various virulence genes are expression among the MDR Salmonella serovars isolated from retail meats in Vietnam, suggested high potential for pathogenicity. Further surveillance programs and research are a necessity to understand their epidemiology and to limit the spread of MDR Salmonella spp.