Mohakud Nirmal Kumar, Panda Rakesh Kumar, Patra Saumya Darshana, Sahu Bikash Ranjan, Ghosh Mrinmoy, Kushwaha Gajraj Singh, Misra Namrata, Suar Mrutyunjay
School of Biotechnology, KIIT University, Bhubaneswar, 751024, India.
Kalinga Institute of Medical Sciences (KIMS), KIIT University, Bhubaneswar, 751024, India.
Gut Pathog. 2022 Jun 28;14(1):28. doi: 10.1186/s13099-022-00498-w.
In India, multi-drug resistance in Salmonella enterica serovar Typhimurium poses a significant health threat. Indeed, S. Typhimurium has remained unknown for a large portion of its genome associated with various physiological functions including mechanism of drug resistance and virulence. The whole-genome sequence of a Salmonella strain obtained from feces of a patient with gastroenteritis in Odisha, India, was analyzed for understanding the disease association and underlying virulence mechanisms.
The de novo assembly yielded 17 contigs and showed 99.9% similarity to S. enterica sub sp enterica strain LT2 and S. enteric subsp salamae strain DSM 9220. S. Typhimurium ms202 strain constitutes six known Salmonella pathogenicity islands and nine different phages. The comparative interpretation of pathogenic islands displayed the genes contained in SPI-1 and SPI-2 to be highly conserved. We identified sit ABCD cluster regulatory cascade in SPI-1. Multiple antimicrobial resistance genes were identified that directly implies antibiotic-resistant phenotype. Notably, seven unique genes were identified as "acquired antibiotic resistance". These data suggest that virulence in S. enterica Typhimurium ms202 is associated with SPI-1 and SPI-2. Further, we found several virulent genes encoding SPI regions belonging to type III secretion systems (T3SS) of bacteria were significantly upregulated in ms202 compared to control LT2. Moreover, all these genes were significantly downregulated in S. enterica Typhimurium ms202 as compared to control LT2 on adding Mn exogenously.
Our study raises a vital concern about the potential diffusion of a novel multi-drug resistant S. enterica Typhimurium ms202. It justifies this clinical pathogen to demonstrate a higher degree survival due to higher expression of virulent genes and enhanced ability of metallic ion acquisition.
在印度，肠炎沙门氏菌鼠伤寒血清型中的多重耐药性对健康构成了重大威胁。实际上，鼠伤寒沙门氏菌基因组中很大一部分与包括耐药机制和毒力在内的各种生理功能相关的区域仍不为人所知。为了解疾病关联和潜在的毒力机制，对从印度奥里萨邦一名肠胃炎患者粪便中分离出的一株沙门氏菌菌株进行了全基因组测序分析。
从头组装产生了17个重叠群，与肠炎沙门氏菌亚种肠炎菌株LT2和肠炎沙门氏菌亚种萨拉马菌株DSM 9220显示出99.9%的相似性。鼠伤寒沙门氏菌ms202菌株包含六个已知的沙门氏菌致病岛和九个不同的噬菌体。对致病岛的比较分析显示，SPI-1和SPI-2中包含的基因高度保守。我们在SPI-1中鉴定出sit ABCD簇调控级联。鉴定出多个抗菌耐药基因，这直接暗示了抗生素耐药表型。值得注意的是，七个独特基因被鉴定为“获得性抗生素耐药性”。这些数据表明，肠炎沙门氏菌鼠伤寒ms202的毒力与SPI-1和SPI-2相关。此外，我们发现与对照LT2相比，ms202中编码属于细菌III型分泌系统（T3SS）的SPI区域的几个毒力基因显著上调。此外，与对照LT2相比，在体外添加锰后，肠炎沙门氏菌鼠伤寒ms202中所有这些基因均显著下调。
我们的研究引发了对新型多重耐药肠炎沙门氏菌鼠伤寒ms202潜在传播的重大担忧。这证明了这种临床病原体由于毒力基因的高表达和金属离子获取能力的增强而具有更高的生存度。
