Abstract:
A total of 55 food and clinical S. Schwarzengrund isolates were assayed for plasmid content, among which an IncFIB-IncFIC(FII) fusion plasmid, conferring streptomycin resistance, was detected in 17 isolates. Among the 17 isolates, 9 were food isolates primarily collected from poultry meat, and 8 clinical isolates collected from stool, urine, and gallbladder. SNP-based phylogenetic analyses showed that the isolates carrying the fusion plasmid formed a subclade indicating the plasmid was acquired and is now maintained by the lineage. Phylogenetic analysis of the plasmid suggested it is derived from avian pathogenic plasmids and might confer an adaptive advantage to the S. Schwarzengrund isolates within birds. IncFIB-IncFIC(FII) fusion plasmids from all food and three clinical isolates were self-conjugative and successfully transferred into E. coli J53 by conjugation. Food and clinical isolates had similar virulome profiles and were able to invade human Caco-2 cells. However, the IncFIB-IncFIC(FII) plasmid did not significantly add to their invasion and persistence potential in human Caco-2 cells.
摘要:
总共对55种食物和临床S.Schwarzengrund分离株进行了质粒含量测定,其中IncFIB-IncFIC(FII)融合质粒,赋予链霉素抗性,在17个分离株中检测到。在17个分离株中,9是主要从禽肉中收集的食物分离物,和从粪便中收集的8个临床分离株,尿液,和胆囊。基于SNP的系统发育分析表明,携带融合质粒的分离株形成了一个亚进化枝,表明该质粒已获得并由谱系维持。质粒的系统发育分析表明,它来自禽类致病性质粒,可能会给鸟类中的S.Schwarzengrund分离株带来适应性优势。来自所有食物和三种临床分离株的IncFIB-IncFIC(FII)融合质粒是自缀合的,并通过缀合成功地转移到大肠杆菌J53中。食物和临床分离株具有相似的病毒组特征,并且能够侵入人Caco-2细胞。然而,IncFIB-IncFIC(FII)质粒并未显着增加其在人Caco-2细胞中的侵袭和持久性潜力。