Antibiotic Resistance in Non-Typhoidal Salmonella enterica Strains Isolated from Chicken Meat in Indonesia.

The increase in antibiotic resistance in non-typhoidal Salmonella enterica (NTS) has been confirmed in Indonesia by this study. We confirmed the virulence genes and antimicrobial susceptibilities of clinical NTS ( n = 50) isolated from chicken meat in Indonesia and also detected antimicrobial resistance genes. Of 50 strains, 30 (60%) were non-susceptible to nalidixic acid (NA) and all of them had amino acid mutations in gyrA . Among 27 tetracycline (TC) non-susceptible strains, 22 (81.5%) had tetA and/or tetB . The non-susceptibility rates to ampicillin, gentamicin or kanamycin were lower than that of NA or TC, but the prevalence of bla TEM or aadA was high. Non-susceptible strains showed a high prevalence of virulence genes compared with the susceptible strains ( tcfA , p = 0.014; cdtB , p < 0.001; sfbA , p < 0.001; fimA , p = 0.002). S . Schwarzengrund was the most prevalent serotype (23 strains, 46%) and the most frequently detected as multi-antimicrobial resistant. The prevalence of virulence genes in S . Schwarzengrund was significantly higher than other serotypes in hlyE ( p = 0.011) and phoP/Q ( p = 0.011) in addition to the genes above. In conclusion, NTS strains isolated from Indonesian chicken had a high resistance to antibiotics and many virulence factors. In particular, S. Schwarzengrund strains were most frequently detected as multi-antimicrobial resistant and had a high prevalence of virulence genes.