The unravelled Enterococcus faecalis zoonotic superbugs: Emerging multiple resistant and virulent lineages isolated from poultry environment

Abstract

This study aimed to investigate the zoonotic potential by virtue of phylogenetic analysis, virulence and resistance gene profiles of Enterococcus faecalis originating from poultry environment. The ERIC, BOX and RAPD PCR analysis showed the clustering of E. faecalis strains (n = 74) into five groups (G1-G5) and fifteen sub-clusters (B1-B15), which share 50%-80% similarities with ATCC E. faecalis and clinical strains of human infection. E. faecalis strains harboured seven enterocins genes including ent1097 (85%), entB (84%), enterolysinA (51%), entSEK4 (51%), entL50 (31%), entA (25.7%) and ent1071 (14.9%). The highest prevalence of gelE-sprE (90%), lip-fl (90%) followed by cylL (62%), hyl (60%), katA (16%) and cylA (5.4%) was observed in poultry isolates. The fsr operon and gelE-sprE was co-associated in 66.2% strains. E. faecalis also harboured biofilm and endocarditis-associated genes, including efaAfs (97%), ebp-pilli (ebpABC and srtC 69.9%-80%), asa1 (71%), agg (55%), ace (54%) and esp-Tim (3%). Despite all found sensitive to vancomycin, 98.6% strains were multi-drug resistant to five to twelve tested antimicrobials. An increased-level of resistance (≥32 μg/ml) was observed to ampicillin (8.1%), meropenem (21.6%), chloramphenicol (73.4%), erythromycin (90.5%), tetracycline (100%) and high-level resistance to kanamycin (79.7%) and gentamicin (52.7%). The multi-drug resistant E. faecalis (MDRe.f) were carried pbp4 (90%), tetL (90%), tetM (70%), ermB (81%), cat (52.7%), acc6-aph2 (58.1%), aaph(3)-III (49.9%), gyrA (97%) and parC (98%) genes. Moreover, these MDRe.f were also harboured, hospital-associated marker IS16 (58%) and pheromone responsive genes, that is ccf (88%), cpd (74%), cob (62%) and eep (66%). Thus, regardless of the distinct phylogenetic background of E. faecalis of poultry origin, ATCC E. faecalis and clinical strains of human origin, we found major similarities in virulence, resistance gene profiles and mobile genetic elements (IS16 and pheromone responsive plasmids), supporting the zoonotic/reverse zoonotic risk associated with this organism.

Occurrence, Antimicrobial Resistance and Molecular Diversity of Enterococcus faecium in Processed Pork Meat Products in Korea

“…As enterococci are part of the normal microbiota of animals and they are able to survive in biotic and abiotic environments, they are also found in foods of animal and plant origin. Enterococci are recognized as a hygienic indicator in foods and as sentinel organisms for tracking antimicrobial resistance trends [1,8]. In the food industry, some strains of enterococci have been used as probiotics for human and animal use, as well as starter cultures for fermented food production [5,9].…”

<p>In vitro Antibacterial Activity of Isopropoxy Benzene Guanidine Against Multidrug-Resistant <em>Enterococci</em></p>

“…Currently, Enterococcus faecalis and Enterococcus faecium have emerged as a major cause of zoonotic and nosocomial infections worldwide. 3,4 A wide armamentarium of natural resistance, along with the capacity to acquire and disseminate multiple antibiotic resistance and virulence determinants in Enterococci is of significant concern with limited therapeutic alternatives. [5][6][7] Concurrent with the declining discovery rate of novel antibiotics, there are some strains of Enterococci have become resistant to last-resort drugs.…”

The Genus Enterococcus and Its Associated Virulent Factors

“…Till now only food consumption is considered as an option for the spread of antibiotic resistant bacteria to humans but the detection of resistant bacteria in soil opens a new route for the exposure of environmental antibiotic resistance to humans. Results of different studies from our lab concludes that soil, poultry, animals and birds carried high burdens of ENT which are fully armed with potential virulent and antibiotic resistance genes [107][108][109][110]. In Pakistan, there is paucity of information regarding prevalence, types and genetic characteristics of enterococci along with their resistance/virulence genes and clones especially from clinical and other environmental sources.…”