IntroductionEnterococci are important foodborne pathogens and inhabitants of gut flora in chicken which may readily penetrate and spread within the food chain through contaminated poultry commodities [1]. The pathogenic potential of Enterococci may cause a variety of health problems in humans such as urinary tract infection, bacteraemia, intra-abdominal infections, and endocarditis [2]. This pathogenic potential is augmented by virulence factors asa (aggregation substance),esp (enterococcal surface protein) and ace (collagen-binding adhesin) due to their association with colonization ofEnterococcus [3], [4]. Furthermore, other virulence factors like gelatinase, DNase, haemagglutinin, lipase and haemolysin had been critical in virulence and pathogenicity of infection in human and animal models [5].Being pathogen of public health importance, emergence of AMR in Enterococci against several critical antibiotics of human medicine such as aminoglycosides, cephalosporins, semisynthetic penicillin probably due to indiscriminate and irresponsible use of large quantity of antimicrobial agents in commercial poultry for disease prevention, treatment and growth promotion is worrisome [6], [7]. Resistant Enterococci present a substantial threat to human health owning to their potential to be transmitted to humans[8] through food chain which may lead to treatment failure and complicated enterococcal infections in humans.Generally, Enterococcus infections are treated by a synergistic combination of a cell wall mediating glycopeptide along with an aminoglycoside such as gentamicin [9]. However, high level gentamicin resistance (HLGR) phenomenon in Enterococci mainly conferred by gene aac(6´)Ie-aph(2˝)Ia , inactivates gentamicin, kanamycin, tobramycin, netilmicin and amikacin [10]. Though β-lactam antibiotics are the first line of treatment for humanEnterococcal infections, However, vancomycin is used under conditions of penicillin and β-lactam resistance and allergy [9], [11].Recent studies have reported notable AMR in Enterococci against several antimicrobials in humans, poultry, and food samples [8], [9], [12], [13], [14], [15]. Although, the role of certain antimicrobial resistant Enterococci has been demonstrated in clinical cases in human population in India [15], [16], [17]. However, such information on the Enterococcus isolates of poultry origin is not readily available. The goal of the current investigation was to identify and isolate Enterococcus species from meat samples from chickens and quails. It also aimed to identify important virulence genes, phenotypic virulence factors, and antibiotic-resistant genotypes (vancomycin resistance, high-level aminoglycoside resistance, and β-lactamase resistance) of Enterococcus species of global public health significance.

A total of 27 samples from 9 different ghat locations along the course of Krishna River (in triplicate) in the Vijayawada city landscape were collected and analysed for presumptive coliform tests. From the positive presumptive coliform test samples, 44 E. coli isolates were recovered and confirmed by biochemical tests and molecular tests targeting 16s rRNA. All 44 E. coli isolates were further subjected for the detection of virulence genes i.e. stx1, stx2, eaeA and hlyA genes using multiplex PCR. Out of 44 isolates two isolates carried all four genes, one isolate harbored stx2, eaeA and hlyA genes and one isolate showed the presence of eae and hlyA genes in combination. The 44 E. coli isolates were subjected to antimicrobial sensitivity/resistance against 12 antimicrobial agents by disc diffusion method. Higher resistance was observed for naladixic acid (40.9%) followed by ampicillin (38.63%), ceftazidime (34%) and ceftriaxone (27.27%). Out of 44 isolates of E. coli, ten isolates harbored β-lactamase genes, with bla TEM being predominant gene detected (15.9%, 7/44). ERIC and REP-PCR analysis revealed a greater degree of genetic diversity among the ten β-lactamase producing E. coli isolated from Krishna River water.