摘要

在临床肠球菌中已经广泛研究了致病能力，但是在社区来源的肠球菌中的致病能力较低。尽管人们越来越关注由屎肠球菌引起的医院感染，但迄今为止在健康婴儿肠球菌中的大多数研究都集中在粪肠球菌上。在这项工作中，我们研究了来自西班牙健康母乳喂养婴儿的26株粪肠球菌和15株屎肠球菌的抗生素耐药性和毒力决定因素。总体而言，所研究的共生肠球菌含有抗生素抗性和毒力基因，尽管它们的模式不符合抗生素耐药性医院相关肠球菌的描述。没有一株对万古霉素有耐药性，尽管大多数菌株对某些抗生素表现出抗药性。粪肠球菌分离株含有比屎肠球菌分离物更多的毒力决定簇，但与定殖相关的一些基因在两种物种中都很丰富。在任何分离物中未检测到溶血素活性;当明胶酶基因存在时，在屎肠球菌中沉默，而在研究的粪肠球菌分离株的一半中发生明胶酶活性。这些结果表明一些毒力决定因素作为发病机制的元素具有矛盾的作用。

Pathogenic ability has been extensively studied in clinical enterococci, but to a lesser extent in community-derived ones. Most studies to date in enterococci from healthy infants have been focused on Enterococcus faecalis, despite the growing concern about nosocomial infections caused by E. faecium. In this work, we studied the antibiotic resistance and virulence determinants of 26 E. faecalis and 15 E. faecium intestinal isolates from Spanish healthy breastfed infants. Overall, commensal enterococci studied contained antibiotic resistance and virulence genes, although their patterns were not according to those described for antibiotic-resistant hospital-associated enterococci. None of the isolates was resistant to vancomycin, although the majority showed resistance to some antibiotics. E. faecalis isolates harbored considerably more virulence determinants than E. faecium isolates, but some genes linked to colonization were abundant in both species. Hemolysin activity was not detected in any of the isolates; and the gelatinase gene, when present, was silent in E. faecium, whereas gelatinase activity occurred in half of the E. faecalis isolates studied. These results suggest an ambivalent role of some virulence determinants as elements of pathogenesis.

https://www.liebertpub.com/doi/abs/10.1089/mdr.2016.0320