Phenotypic and genotypic analysis for antibiotic resistance of Enterococcus species with chicken and gull origin

Abstract

In this study, faecal samples of backyard chickens in the city of Van and its districts and gulls in contact with humans in Van Lake basin have been obtained and examined for Enterecoccus species. For this purpose, 1000 faecal samples have been obtained as 500 from chickens and 500 from gulls. In the study, Entrerecoccus has been isolated and identified from a total of 311 (31.1%) faecal samples as 192 (38.4%) from chickens and 119 (23.8%) from gulls. 41 (21.3%) of chicken-origin isolates have been identified as Enterococcus faecalis, 110 (57.3%) as E. faecium, 9 (4.7%) as E. casseliflavus/gallinarum, 27 (14.1%) as E. hirae, 5 (2.6%) E. durans while 78 (65.5%) of gull-origin isolates have been identified as E. faecalis, 21 (17.6%) as E. faecium, 10 (8.4%) as E. hirae, 7 (5.9%) as E. casseliflavus/gallinarum, 2 (1.7%) as E. raffinosus and 1 (0.8%) as E. durans. Phenotypically antibiotic susceptibility testing (disc diffusion method) was performed for analysis. Genotypically 16S rRNA, 16S and 23S intergenic transcribed spacer region, esp, vanA, vanB and vanC (C-1, C-2, C-3) was analyzed genes. When antibiotic resistance of whole isolates have been taken into consideration; the highest level of resistance was determined to cefadroxil (99.5%) while the lowest resistance was determined to imipenem (0.8%). While 9 (2.9%) of the isolates have been determined as resistant to vancomycin; genotypically vancomycin resistance gene (van) has been determined 20 (6.4%) of the isolates. 6 of E. faecalis (1 chicken, 5 gull origin) and 3 of E. faecium (gull origin) isolates have been determined as carrying vanA, 6 E. casseliflavus/ gallinarum as carrying vanC1 (2 chicken, 4 gull origin) and 5 E. casseliflavus/gallinarium (chicken origin) as carrying vanC2/3 gene. In gull isolates, while vanC2/3 gene was not determined in gull isolates; all chicken and gull origin isolates have been found negative for vanB gene. As a result, for the first time in our region, this research has revealed the presence of vancomycin-resistant Enterococcus species.