Prevalence and molecular characterization of Enterococcus faecalis from spring water

Spring water is an important direct drinking water resource. Enterococcus faecalis is a significant opportunistic pathogen from environment that causes human neonatal sepsis and urinary tract infections. Our study investigated the prevalence, virulence genes, antimicrobial resistance, and molecular characterization of E. faecalis from spring water in Guangdong, China. A total of 285 spring water samples were collected from January 2017 to January 2018, in which 47 (16.49%) samples were contaminated by E. faecalis. Antimicrobial susceptibility result showed that many isolates were resistant to tetracycline (93.6%), gentamicin (29.8%), and ciprofloxacin (25.5%). The virulence gene test revealed the positive rate of gelE, asa1, ace, and cylA were 100, 82.3, 76.6, and 70.2%, respectively. Enterobacterial repetitive intergenic consensus-polymerase chain reaction and multilocus sequence typing classified 47 isolates into 12 and 5 clusters, respectively, which revealed the genetic relatedness and diversity. This finding illustrated the presence of virulence genes and provided understanding on the spread of antibiotic-resistant and genetic diversity isolates. It can help us gradually increase our knowledge of microbiological risk management in E. faecalis from spring water. Practical applications Investigating the prevalence of Enterococcus faecalis isolates from spring water could increase this microbial safety ondrinking water. In our research, antibiotic susceptibility, virulence genes, serotypingand molecular characteristic were selected to thorough comparison among Enterococcus faecalis isolates. Spring water is common in China as drinking water, then understanding the dissemination and monitoring the prevalence of this microorganism is necessary to improve the drinking water safety.