School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai, 200093, China.
Centre of Analysis and Test, School of Chemistry & Molecular Engineering, East China University of Science and Technology, Shanghai, 200237, China.
BMC Microbiol. 2024 Nov 25;24(1):497. doi: 10.1186/s12866-024-03651-4.
Salmonella Enteritidis is a major foodborne pathogen, and the emergence of multidrug-resistant (MDR) S. Enteritidis poses a serious public health challenge. In this study, we report the genomic characterization of five S. Enteritidis isolates from clinical. These isolates exhibited resistance to seven classes of antimicrobials with four of the five characterized as MDR. Isolate 33 A exhibited resistance to colistin and polymyxin B, while no associated antimicrobial resistance genes (ARGs) were identified in its genome. Isolate 21 A and 44 A were extended-spectrum beta-lactamases-producing (ESBLs). Whole genome sequencing analysis revealed the presence of multiple mobile genetic elements (MGEs), including plasmids, prophages, and genomic islands, which may have facilitated the acquisition and dissemination of ARGs. Notably, several ARGs, including bla, bla, bla, aph(3')-IIa, aph(3'')-Ib, aph(6)-Id, tet(A), floR, fosA3, and sul2, were identified on plasmids. In addition, chromosomal point mutations in gyrA (D87G and D87Y) and acrB (F28L and L40P) were also observed in each isolate. Multiple virulence genes associated with the type III secretion system were identified on Salmonella pathogenicity islands (SPIs) SPI-1 and SPI-2. Phylogenetic analysis revealed that the five isolates, along with a clinical and chicken origin isolates in the database, clustered together, suggesting a probable common source of infection. Our findings highlight the intricate genetic mechanisms behind MDR in S. Enteritidis, emphasizing the ongoing necessity for surveillance and appropriate antimicrobial usage. This contributes to our understanding of S. Enteritidis transmission within the food chain.
肠炎沙门氏菌是一种主要的食源性病原体，多重耐药（MDR）肠炎沙门氏菌的出现对公共健康构成了严重挑战。本研究报告了 5 株来自临床的肠炎沙门氏菌分离株的基因组特征。这些分离株对 7 类抗菌药物表现出耐药性，其中 4 株被鉴定为 MDR。分离株 33 A 对黏菌素和多黏菌素 B 表现出耐药性，但其基因组中未发现相关的抗菌药物耐药基因（ARGs）。分离株 21 A 和 44 A 是产超广谱β-内酰胺酶（ESBLs）的。全基因组测序分析显示，存在多种移动遗传元件（MGEs），包括质粒、噬菌体和基因组岛，这可能促进了 ARGs 的获得和传播。值得注意的是，几个 ARGs，包括 bla、bla、bla、aph(3')-IIa、aph(3'')-Ib、aph(6)-Id、tet(A)、floR、fosA3 和 sul2，被鉴定在质粒上。此外，在每个分离株中还观察到染色体上 gyrA（D87G 和 D87Y）和 acrB（F28L 和 L40P）的点突变。在沙门氏菌致病性岛（SPI）SPI-1 和 SPI-2 上也鉴定到了与 III 型分泌系统相关的多个毒力基因。系统进化分析显示，这 5 株分离株与数据库中来自临床和鸡源的分离株聚集在一起，提示可能存在共同的感染源。我们的研究结果突出了肠炎沙门氏菌中 MDR 背后的复杂遗传机制，强调了对监测和适当使用抗菌药物的持续需求。这有助于我们理解食物链中肠炎沙门氏菌的传播。
