Study of Virulence Genes, Antimicrobial Resistance, and Genetic Relatedness of Foodborne Salmonella Isolates from Tunisia

Abstract

Non-typhoidal Salmonella (NTS) strains are among the major foodborne pathogens with emerging multidrug-resistant phenotypes. In this study, antimicrobial susceptibilities of a collection of Salmonella isolates (n=54) recovered from poultry and bivalve molluscs were performed. The study also investigated the virulence and resistance genes profiling as well as the phylogenetic relationships through PFGE and ERIC/PCR fingerprinting. Results revealed the presence of multiple virulence genes among Salmonella isolates. siiA , sopB , cat2 , safC , sefB and sopE2 genes were present in most (83.32%-100%) of the isolates, while the remaining tested genes ( spvC , spvB, and sopE ) were exclusively detected within the serotype Enteritidis. The highest resistance rates were observed for oxacillin (94.4%), ampicillin (37%) and nalidixic acid (27.7%), followed by cefotaxime and amoxicillin/clavulanic acid (14.8%), trimethoprim/sulfamethoxazole (9.3%) and ciprofloxacin (5.5%). The results of the present study indicate that S. Enteritidis serotype possessed the widest range of virulence determinants and increasing levels of resistance. Such high-risk clones should be particularly controlled in Tunisia. Overall, increased resistance and virulence confers a selective advantage for the evolution of the bacteria which represents an alarming problem for global public health. The genetic study via Pulsed-field gel electrophoresis (PFGE) and enterobacterial repetitive intergenic consensus PCR (ERIC/PCR) showed the high diversity of the clonal origins of the bacteria and the sources of contamination,and revealed the great capacity of the pathogen to diversify within food-producing animals.

Comprehensive profiling of serotypes, antimicrobial resistance and virulence of Salmonella isolates from food animals in China, 2015–2021

“…The studies on the number of ARGs carried by strains, results showed that all strains carried more than three ARGs, and one strain carried 18 ARGs, which warranted in-depth study. These results are consistent with the reported results ( Akinyemi et al, 2011 ; Ammar et al, 2016a ; Abraham et al, 2022 ; Hassena et al, 2022 ; Kong-Ngoen et al, 2022 ; Tang et al, 2022 ), which all concluded that Salmonella carries multiple ARGs. The results of our analysis for the three main prevalent serotypes carried ARGs, showed that S .…”

“…Our results suggested that antimicrobial resistance was present in the majority of Salmonella isolates, 80% isolates were resistant to ampicillin, neomycin, nalidixic acid, tetracycline, doxycycline, and sulfadiazine/trimethoprim. The outcome was consistent with those reports (Fang et al, 2019;Asefa Kebede and Duga, 2022;Borah et al, 2022;Hassena et al, 2022). Noteworthy, meropenem resistance appeared in fewer isolates (0.5%) in our study.…”

“…The role of some of these virulence-associated plasmids in the dissemination of increased virulence in food-animal environments and humans ( Ammar et al, 2016b ; Khajanchi and Foley, 2022 ). While the main differences between isolates were attributed to the serotype-specific diversity of virulence genes, SPIs, virulence plasmids, and phages ( Hassena et al, 2022 ). The presence of some virulence genes was serotype specific ( Sedrakyan et al, 2022 ).…”

Resistensi Antibiotik terhadap Bakteri Salmonella Typhi: Literature Review

“…Tingkat resistensi yang sedang ditemukan terhadap AMC dan CTX (14,8% untuk kedua obat), diikuti oleh STX (9,3%) dan CIP (5,5%). Frekuensi resistensi terendah diamati untuk CAZ dan ETP serta ditemukan 20,4% dari isolat yang multiresisten terhadap antibiotik (9).…”