Abstract：
Nontyphoidal Salmonella strains are among the major foodborne pathogens with emerging multidrug-resistant phenotypes. In this study, antimicrobial susceptibility testing of a collection of Salmonella isolates (n = 54) recovered from poultry and bivalve molluscs was performed. The study also investigated profiling of virulence and resistance genes as well as phylogenetic relationships through pulsed-field gel electrophoresis (PFGE) and enterobacterial repetitive intergenic consensus (ERIC)-PCR fingerprinting. Results revealed the presence of multiple virulence genes among Salmonella isolates. Salmonella intestinal infection A (siiA), Salmonella outer protein (sopB and sopE), putative 4-hydroxybutyrate coenzyme A transferase (cat2), Salmonella atypical fimbria C (safC), and Salmonella Enteritidis fimbria B (sefB) were present in most (83.32 to 100%) of the isolates, whereas the remaining tested genes (Salmonella plasmid virulence [spvC and spvB]), and the sopE gene, 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 indicate that the Salmonella 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 confer a selective advantage for the evolution of these bacteria and represent an alarming problem for global public health. The genetic study via PFGE and ERIC-PCR showed the high diversity of the clonal origins of these bacteria and the sources of contamination and revealed the great capacity of Salmonella to diversify within food-producing animals.
摘要：
非伤寒沙门氏菌菌株是具有新出现的多药耐药表型的主要食源性病原体之一。在这项研究中,对从家禽和双壳类软体动物中回收的沙门氏菌分离株(n=54)进行抗菌药物敏感性试验.该研究还通过脉冲场凝胶电泳（PFGE）和肠细菌重复基因间共识（ERIC）-PCR指纹图谱研究了毒力和抗性基因的概况以及系统发育关系。结果显示沙门氏菌分离株中存在多个毒力基因。沙门氏菌肠道感染A（siiA），沙门氏菌外蛋白（sopB和sopE），推定的4-羟基丁酸辅酶A转移酶（cat2），沙门氏菌非典型菌毛C（safC），和肠炎沙门氏菌菌毛B（sefB）存在于大多数（83.32％至100％）的分离物中，而其余的测试基因（沙门氏菌质粒毒力[spvC和spvB]），还有sopE基因,仅在肠炎血清型中检测到。苯唑西林耐药率最高(94.4%),氨苄青霉素（37%），和萘啶酸(27.7%)，其次是头孢噻肟和阿莫西林-克拉维酸(14.8%)，甲氧苄啶-磺胺甲恶唑（9.3%），和环丙沙星(5.5%)。结果表明，肠炎沙门氏菌血清型具有最广泛的毒力决定子范围和不断增加的抗性水平。在突尼斯，应特别控制此类高风险克隆。总的来说,增强的抗性和毒力为这些细菌的进化提供了选择性优势，并代表了全球公共卫生的一个令人担忧的问题。通过PFGE和ERIC-PCR进行的遗传研究表明，这些细菌的克隆起源和污染源的高度多样性，并揭示了沙门氏菌在食品生产动物中多样化的巨大能力。
