School of Biomedical Sciences, Faculty of Health, Queensland University of Technology, Australia.
Syst Appl Microbiol. 2012 Jul;35(5):326-33. doi: 10.1016/j.syapm.2012.05.004. Epub 2012 Jun 26.
This study compared virulence and antibiotic resistance traits in clinical and environmental Enterococcus faecalis and Enterococcus faecium isolates. E. faecalis isolates harboured a broader spectrum of virulence determinants compared to E. faecium isolates. The virulence traits Cyl-A, Cyl-B, Cyl-M, gel-E, esp and acm were tested and environmental isolates predominantly harboured gel-E (80% of E. faecalis and 31.9% of E. faecium) whereas esp was more prevalent in clinical isolates (67.8% of E. faecalis and 70.4% of E. faecium). E. faecalis and E. faecium isolated from water had different antibiotic resistance patterns compared to those isolated from clinical samples. Linezolid resistance was not observed in any isolates tested and vancomycin resistance was observed only in clinical isolates. Resistance to other antibiotics (tetracycline, gentamicin, ciprofloxacin and ampicillin) was detected in both clinical and water isolates. Clinical isolates were more resistant to all the antibiotics tested compared to water isolates. Multi-drug resistance was more prevalent in clinical isolates (71.2% of E. faecalis and 70.3% of E. faecium) compared to water isolates (only 5.7% E. faecium). tet L and tet M genes were predominantly identified in tetracycline-resistant isolates. All water and clinical isolates resistant to ciprofloxacin and ampicillin contained mutations in the gyrA, parC and pbp5 genes. A significant correlation was found between the presence of virulence determinants and antibiotic resistance in all the isolates tested in this study (p<0.05). The presence of antibiotic resistant enterococci, together with associated virulence traits, in surface recreational water could be a public health risk.
本研究比较了临床和环境粪肠球菌和屎肠球菌分离株的毒力和抗生素耐药性特征。与屎肠球菌分离株相比，粪肠球菌分离株携带更广泛的毒力决定因素。测试了 Cyl-A、Cyl-B、Cyl-M、gel-E、esp 和 acm 等毒力特征，环境分离株主要携带 gel-E（80%的粪肠球菌和 31.9%的屎肠球菌），而 esp 在临床分离株中更为普遍（67.8%的粪肠球菌和 70.4%的屎肠球菌）。与从临床样本中分离的菌株相比，从水中分离的粪肠球菌和屎肠球菌具有不同的抗生素耐药模式。在所测试的分离株中未观察到利奈唑胺耐药，仅在临床分离株中观察到万古霉素耐药。在临床和水分离株中均检测到对其他抗生素（四环素、庆大霉素、环丙沙星和氨苄西林）的耐药性。与水分离株相比，临床分离株对所有测试的抗生素均具有更高的耐药性。与水分离株（仅 5.7%的屎肠球菌）相比，临床分离株的多药耐药更为普遍（71.2%的粪肠球菌和 70.3%的屎肠球菌）。tet L 和 tet M 基因主要存在于四环素耐药分离株中。对环丙沙星和氨苄西林耐药的所有水和临床分离株均在 gyrA、parC 和 pbp5 基因中存在突变。在本研究中测试的所有分离株中，均发现毒力决定因素与抗生素耐药性之间存在显著相关性（p<0.05）。表面娱乐水中存在抗生素耐药肠球菌及其相关毒力特征可能是公共卫生风险。
