Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal do Triângulo Mineiro, Uberaba, Minas Gerais, Brazil.
Programa de Pós-graduação em Ciências da Saúde, Universidade Federal do Triângulo Mineiro, Uberaba, Minas Gerais, Brazil.
Microb Pathog. 2022 Oct;171:105715. doi: 10.1016/j.micpath.2022.105715. Epub 2022 Aug 13.
In this study, we evaluated the antimicrobial susceptibility, the presence of gene-encoding virulence factors and CRISPR systems, as well as the ability to produce lytic enzymes among clinical E. faecalis and E. faecium isolates (n = 44). All enterococci isolates showed phenotypes of multidrug resistance. E. faecalis and E. faecium isolates exhibited high-level aminoglycoside resistance phenotype, several of them harboring the aac(6')Ie-aph(2″)Ia and aph(3')-IIIa genes. The gene vanA was the most frequent among vancomycin-resistant E. faecium. High prevalence of the virulence genes esp and efaA were observed; hyl gene was more associated with E. faecium, while ace and efaA genes were more frequently detected in E. faecalis. Caseinase activity was frequently detected among the isolates. Gelatinase and DNAse activities predominated among E. faecalis, while hemolytic capability was frequent among E. faecium isolates. Twenty-nine isolates showed at least one CRISPR system investigated. Several enterococci isolates harbored the aac(6')-Ie-aph(2″)-Ia or aph(3')-IIIa genes and a CRISPR loci. CRISPR loci were positively correlated to efaA and gelE genes, and gelatinase and DNAse activities, while CRISPR loci absence was related to hyl gene presence. These results show that clinical isolates of E. faecalis and E. faecium harboring virulence genes show the concomitant presence of CRISPR loci and antibiotic resistance determinants.
在这项研究中，我们评估了临床粪肠球菌和屎肠球菌分离株（n=44）的抗菌药敏性、编码毒力因子和 CRISPR 系统的存在情况以及产裂解酶的能力。所有肠球菌分离株均表现出多药耐药表型。粪肠球菌和屎肠球菌分离株表现出高水平氨基糖苷类耐药表型，其中一些携带 aac(6')Ie-aph(2″)Ia 和 aph(3')-IIIa 基因。万古霉素耐药屎肠球菌中最常见的基因是 vanA。观察到 esp 和 efaA 等毒力基因的高流行率；hyl 基因更与屎肠球菌相关，而 ace 和 efaA 基因在粪肠球菌中更常被检测到。分离株中经常检测到酪蛋白酶活性。明胶酶和 DNAse 活性在粪肠球菌中占主导地位，而溶血能力在屎肠球菌分离株中较为常见。29 个分离株至少具有一个研究的 CRISPR 系统。一些肠球菌分离株携带 aac(6')-Ie-aph(2″)-Ia 或 aph(3')-IIIa 基因和 CRISPR 基因座。CRISPR 基因座与 efaA 和 gelE 基因以及明胶酶和 DNAse 活性呈正相关，而 CRISPR 基因座缺失与 hyl 基因存在相关。这些结果表明，携带毒力基因的临床粪肠球菌和屎肠球菌分离株同时存在 CRISPR 基因座和抗生素耐药决定因素。
