Prevalence of Enterococcus Species and Their Virulence Genes in Fresh Water Prior to and after Storm Events

Abstract

Enterococcus spp. isolates (n = 286) collected from six surface water bodies in subtropical Brisbane, Australia, prior to and after storm events, were identified to species level and tested for the presence of seven clinically important virulence genes (VGs). Enterococcus faecalis (48%), Enterococcus faecium (14%), Enterococcus mundtii (13%), and Enterococcus casseliflavus (13%) were frequently detected at all sites. The frequency of E. faecium occurrence increased from 6% in the dry period to 18% after the wet period. The endocarditis antigen (efaA), gelatinase (gelE), collagen-binding protein (ace), and aggregation substance (asa1) were detected in 61%, 43%, 43%, and 23% of Enterococcus isolates, respectively. The chances of occurrence of ace, gelE, efaA, and asa1 genes in E. faecalis were found to be much higher compared to the other Enterococcus spp. The observed odds ratio of occurrence of ace and gelE genes in E. faecalis was much higher at 7.96 and 6.40 times, respectively. The hyl gene was 3.84 times more likely to be detected in E. casseliflavus. The presence of multiple VGs in most of the E. faecalis isolates underscores the importance of E. faecalis as a reservoir of VGs in the fresh water aquatic environment. Consequently, if contaminated surface water is to be used for production of potable and nonpotable water some degree of treatment depending upon intended use such as detention in basins prior to use or chlorination is required.

Environmental waters as a source of antibiotic-resistant Enterococcus species in Belgrade, Serbia

“…Several studies have focused on enterococci isolates from surface water (Sidhu et al 2014;Michael et al 2013) and from the environment to achieve a greater understanding of the origin, spread, and persistence of antibiotic-resistant enterococci. However, data about antibiotic-resistant enterococci from Balkan Peninsula surface waters are still unavailable.…”

“…Enterococci are not indigenous to water and their prevalence in water sources depends on environmental factors including the geographical area, potential sources and types of sewage, and the presence of industrial zones and agricultural sites (Sidhu et al 2014). Detailed studies of individual locations are necessary in order to understand the distribution of Enterococcus species and provide useful information about the dissemination of resistance genes into surface water (Di Cesare et al 2014;Niederhausern et al 2013).…”

Investigation of the Presence and Virulence Traits of Vancomycin-Resistant Enterococcus in Water Samples

“…Contrary to our findings regarding virulence genes, Rathnayake et al (2012) noticed the presence of esp and gelE genes in E. faecalis and E. faecium water isolates. Recently, gelE, efaA, ace and asa1 genes were reported to occur in Enterococcus isolates from surface waters (Sidhu et al, 2014). A study made by Messi et al (2006) suggested that 3 (0.7%) isolates from superficial waters belonged to the vanA, 53 (13.7%) to the vanB and 43 (11.1%) to the vanC phenotype.…”

“…Enterococcal surface protein, encoded by the esp gene has been related contributing with colonization of urinary tract, and biofilm formation. The collagen-binding protein gene, ace, is involved in attachment and colonization of renal tissue in animal models (Sidhu et al, 2014). The aggregation substance (agg) takes a part on adhesion to eucaryotic cells and extracellular matrix proteins.…”

“…Entrococcus species has advanced active gene transfer mechanisms for transmission of antibiotic resistance and virulence factor genes by plasmids (Chajecka-Wierzchowska et al, 2016). Habitats such as water, soil and food are considered as possible reservuars of antimicrobial resistance and virulence genes of Enterococcus strains (Sidhu et al, 2014).…”