Department of Acute Infectious Diseases Control and Prevention, Yunnan Provincial Centre for Disease Control and Prevention, Kunming, China.
State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Beijing, China.
PeerJ. 2022 Sep 5;10:e14016. doi: 10.7717/peerj.14016. eCollection 2022.
infection (CDI) caused by toxigenic strains leads to antibiotic-related diarrhea, colitis, or even fatal pseudomembranous enteritis. Previously, we conducted a cross-sectional study on prevalence of CDI in southwest China. However, the antibiotics resistance and characteristics of genomes of these isolates are still unknown.
Antibiotic susceptibility testing with E-test strips and whole genome sequence analysis were used to characterize the features of these isolates.
Forty-nine strains of were used in this study. Five isolates were non-toxigenic and the rest carried toxigenic genes. We have previously reported that ST35/RT046, ST3/RT001 and ST3/RT009 were the mostly distributed genotypes of strains in the children group. In this study, all the isolates were sensitive to metronidazole, meropenem, amoxicillin/clavulanic acid and vancomycin. Most of the strains were resistant to erythromycin, gentamicin and clindamycin. The annotated resistant genes, such as , , , , , and were mostly identified related to macrolide, glycopeptide, and fluoroquinolone resistance. Interestingly, 77.55% of the strains were considered as multi-drug resistant (MDR). Phylogenetic analysis based on core genome of bacteria revealed all the strains were divided into clade 1 and clade 4. The characteristics of genome diversity for clade 1 could be found. None of the isolates showed 18-bp deletion of as RT027 strain as described before, and polymorphism of showed a high degree of conservation than gene.
Most of the isolates in this study were resistant to macrolide and aminoglycoside antibiotics. Moreover, the MDR strains were commonly found. All the isolates belonged to clade 1 and clade 4 according to phylogenetic analysis of bacterial genome, and highly genomic diversity of clade 1 was identified for these strains.
产毒菌株引起的感染（CDI）可导致抗生素相关性腹泻、结肠炎，甚至致命的伪膜性肠炎。此前，我们在中国西南部进行了一项 CDI 患病率的横断面研究。然而，这些分离株的抗生素耐药性和基因组特征尚不清楚。
采用 E 试验条进行抗生素敏感性试验和全基因组序列分析，对这些分离株的特征进行了分析。
本研究共使用了 49 株。其中 5 株为非产毒株，其余均携带产毒基因。我们之前曾报道过，ST35/RT046、ST3/RT001 和 ST3/RT009 是儿童组菌株分布最多的基因型。在本研究中，所有分离株对甲硝唑、美罗培南、阿莫西林/克拉维酸和万古霉素均敏感。大多数菌株对红霉素、庆大霉素和克林霉素耐药。注释的耐药基因，如、、、、、和，与大环内酯类、糖肽类和氟喹诺酮类耐药相关。有趣的是，77.55%的菌株被认为是多药耐药（MDR）。基于细菌核心基因组的系统发育分析显示，所有菌株均分为 1 群和 4 群。可以发现 1 群的基因组多样性特征。与以前描述的 RT027 株一样，没有分离株显示 18-bp 的缺失，而且与基因相比，多态性表现出高度的保守性。
本研究中大多数分离株对大环内酯类和氨基糖苷类抗生素耐药。此外，还发现了大量的多药耐药株。根据细菌基因组的系统发育分析，所有分离株均属于 1 群和 4 群，并且鉴定出 1 群的基因组高度多样化。
