PDF(Pubmed)
Abstract：
Enterococci are ubiquitous microorganisms in almost all environments, from the soil we step on to the food we eat. They are frequently found in naturally fermented foods, contributing to ripening through protein, lipid, and sugar metabolism. On the other hand, these organisms are also leading the current antibiotic resistance crisis. In this study, we performed whole-genome sequencing and comparative genomics of an Enterococcus faecium strain isolated from an artisanal Mexican Cotija cheese, namely QD-2. We found clear genomic differences between commensal and pathogenic strains, particularly in their carbohydrate metabolic pathways, resistance to vancomycin and other antibiotics, bacteriocin production, and bacteriophage and CRISPR content. Furthermore, a bacteriocin transcription analysis performed by RT-qPCR revealed that, at the end of the log phase, besides enterocins A and X, two putative bacteriocins not reported previously are also transcribed as a bicistronic operon in E. faecium QD-2, and are expressed 1.5 times higher than enterocin A when cultured in MRS broth.
摘要：
肠球菌是几乎所有环境中普遍存在的微生物，从我们踩到我们吃的食物的土壤。它们经常出现在自然发酵食品中，通过蛋白质促进成熟，脂质，和糖代谢。另一方面,这些生物也导致了目前的抗生素耐药性危机。在这项研究中,我们对从墨西哥Cotija奶酪中分离出的屎肠球菌菌株进行了全基因组测序和比较基因组学，即QD-2。我们发现共生菌株和致病菌株之间存在明显的基因组差异，特别是在它们的碳水化合物代谢途径中，对万古霉素和其他抗生素的耐药性，细菌素生产，噬菌体和CRISPR含量。此外，通过RT-qPCR进行的细菌素转录分析显示，在日志阶段结束时，除了肠霉素A和X,先前未报道的两种推定的细菌素也在屎肠球菌QD-2中转录为双顺反子，当在MRS肉汤中培养时，其表达比肠菌素A高1.5倍。
