| Enterococci are important members of gut communities in human and many animals and opportunistic pathogens that cause many diseases,such as infections of urinary tract, wound infection and life threatening infections such as bacteremia or endocarditis. In additon, there is increasing resistence of enterococci to most of the antimicrobial agents currently approved to infections, including vancomycin-resistant enterococci(VRE).Enterococci have rapidly emerged as leading nosocomial pathogens that frequently present a considerable therapeutic challenge.Presently, there are nearly 40 Enterococcus species, classified into five groups.. Enterococci are intrinsically resistant to a number of antimicrobial agents and can acquire resistance to all currently available antibiotics.Many studys have addressed the important of enterococci as a reservoir of antibiotic resistance genes in human, animals and the environment.Recently the research on the prevalence and antibiotic resistance profiles of enterococcus species in non-hospital is less than that in hospital. Because of the risk of potentially harmful enterococcal strains being transmitted through the food chain and the contribution of enterococci to the spread of antimicrobial resistance, it is important to evaluate the prevalence and antibiotic resistance of the non-clinical sources strains.To identify enterococcus species and vancomycin-resistant genotypes simultaneously, two multiplex PCRs were developed and applied on the identification of isolates and the detection of vancomycin resistance genes of isolates. One were used to identify Enterococcus spp.and sixenterococcus species( E faecalis, E. Faecium, E. Gallinarum, E.Casselifavus, E. Durans and E. Avium). Another were used to identify E.spp., E. faecalis, E. Faecium and four vancomycin-resistance genotypes(van A, vanB, vanC1, vanC2/C3). Each reaction tube contains seven primer sets targeting the appropriate detecting genes and a primer set for amplication of 16 S r DNA as an internal PCR control to improve reliability.To evaluate evaluate the prevalence and antibiotic resistance of the non-clinical sources strains, 220 stool samples from human, broilers and swine in Henan province and 41 VRE suspected strain from animals were collected. The identification of isolates and the detection of vancomycin resistance genotypes of the strains for this study were used by the established multiplex PCRs. Antimicrobial agents sensitivity test were used to detect the susceptibility phenotype of the strains for this study.In this study, two multiplex PCRs were established and applied in the identification of isolates and the detection of vancomycin resistance genotypes of the strains successfully. The novel methods are simple and reliable for detection of the isolates characterization and vancomycin-resistant enterococci(VRE). It will be contributed to monitor VRE and prevent VRE prevalence effectively.In this study, a total of 156 E. spp. isolates were recovered from three non-hospital origins. The average isolation rate of enterococci from human broilers and swine origins was 70.91%. The most predominant species was E. faecium(31.36%) in human, while in broilers and swine was E. faecalis(28.17%, 32.00%, respectively). All isolates were sensitive to vancomycin and teicoplanin. The resistent rate of to many drugs and the multidrug-resistant(MDR) of the isolates from human, broilers and swine were statistically significant(P<0.05). The resistant rates of isolates to erythromycin(69.35%), ciprofloxacin(37.10%) and ampicilin(19.35%)from human origin E. spp. were higher than those from broilers origin and swine origin. The isolates resistant rates to tetracycline(88.24%),florfenicol(11.76%)and chloramphenicol(21.57%) from broiler origin E.spp. were higher than those from the other two origins, respectively. The MDR rate of human(35.48%) and broiler(30.19%) origin isolates was significantly higher than swine(7.84%). The observation in this study suggested that the prevalence and resistance of E. spp. from human,broilers and swine were different, and the MDR isolates were prevalent in various origins enterococci. The results of susceptibility test to vancomycin showed that 37 VREs in the 41 VRE suspected strain from animals were intermediary resistant to vancomycin. Of the VREs, 6 VREs were E.Gallinarum with vanC1 genotype, 31 VREs were E. Casselifavus with vanC2/C3. The results of strain identification, resistant phenotype and vancomycin-resistance genotypes were consistent. Based on the study results, more attention should be given on the investigation the resistance of enterococci among humans and animals to minimize the spread of antibiotic-resistant enterococci more effectively. |
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