Microbiology Unit, Department of Biological Sciences, Covenant University, Ota, Nigeria.
Department of Medical Microbiology, Federal Medical Centre, Abeokuta, Nigeria.
Sci Rep. 2024 Aug 20;14(1):19326. doi: 10.1038/s41598-024-67388-w.
The whole genome sequence (WGS) of prevalent MRSA strains harboring mecA gene obtained from skin and soft tissue infections (SSTIs) in Nigerian hospitals were profiled for pathogenomic structure and evaluated for clonal diversity. The two MRSA strains identified among 66 isolated multi-drug resistant S. aureus from a collection of 256 clinical samples were phenotyped for antibiotic resistance and genotyped for mecA, SCCmec, and spa types. The mecA positive MRSA was analysed using whole-genome sequencing for resistomes, virulomes, phylogenomic profiles and clonal diversity. The identified MRSA-CC7-ST789-t091-SCCmecV strains from a female child (aged 1 year) with severe otorrhea and an adult male (aged 23) with purulent wound abscess showed high-level resistance to streptomycin, vancomycin, kanamycin, sulfamethoxazole and ciprofloxacin. Both strains harbored abundant resistomes, inherent plasmids, chromosomal replicons and typical seven housekeeping genes (arc3, aroE4, glpF1, gmk4, pta4, tpi6, yqiL3). The most abundant putative virulomes were pathogenesis-associated proteins (included hemolysin gamma, leucocidins, proteases, staphylococcal superantigen/enterotoxin-like genes (Set/Ssl), capsule- and biofilm-associated genes, and hyaluronate lyase). Comparative phylogenomic analysis revealed the relatedness of the two clonal strains with prevalent MRSA-CC7 pathotypes observed in Italy (2013 and 2014), Denmark (2014), Thailand (2015 and 2016), USA (2018), and Nigeria (2016 and 2020); and share high genetic similarities with livestock strains from cow milk and cattle. Identified MRSA-CC7-ST789-t091-SCCmecV pathotypes implicated in SSTIs from Nigeria harboring repertoires of antibiotic resistance and virulence genes, and genetic relatedness with livestock strains; show the possibility of gene transfer between animal and human. Adequate hospital MRSA infection control and geno-epidemiological surveillance for animal and human transfer is required.
从尼日利亚医院的皮肤和软组织感染（SSTI）中获得的流行型耐甲氧西林金黄色葡萄球菌（MRSA）菌株的全基因组序列（WGS）被用于分析其病原体基因组结构，并评估其克隆多样性。从 256 份临床样本中收集的 66 株多药耐药性金黄色葡萄球菌中鉴定出了两种 MRSA 菌株，对其进行了抗生素耐药性表型分析，并对 mecA、SCCmec 和 spa 型进行了基因分型。对 mecA 阳性的 MRSA 进行全基因组测序分析，以研究其耐药组、毒力组、系统发育组和克隆多样性。从一名 1 岁患有严重耳漏的女性儿童和一名 23 岁患有脓性伤口脓肿的成年男性中分离出的 MRSA-CC7-ST789-t091-SCCmecV 菌株对链霉素、万古霉素、卡那霉素、磺胺甲恶唑和环丙沙星表现出高水平耐药。两种菌株均携带丰富的耐药组、固有质粒、染色体复制子和典型的七个管家基因（arc3、aroE4、glpF1、gmk4、pta4、tpi6、yqiL3）。最丰富的假定毒力组是与发病机制相关的蛋白（包括溶素γ、白细胞毒素、蛋白酶、葡萄球菌超抗原/肠毒素样基因（Set/Ssl）、荚膜和生物膜相关基因以及透明质酸酶）。比较系统发育基因组分析显示，这两个克隆株与意大利（2013 年和 2014 年）、丹麦（2014 年）、泰国（2015 年和 2016 年）、美国（2018 年）和尼日利亚（2016 年和 2020 年）流行的 MRSA-CC7 型具有相关性，并且与牛牛奶和牛的畜群菌株具有很高的遗传相似性。从尼日利亚的 SSTI 中分离出的 MRSA-CC7-ST789-t091-SCCmecV 型与携带抗生素耐药性和毒力基因的畜群菌株具有相关性，并且与畜群菌株具有遗传相关性；表明动物和人类之间存在基因转移的可能性。需要对医院内的 MRSA 感染进行适当的控制和对动物和人类之间的基因转移进行基因流行病学监测。
