Determination and molecular analysis of antibiotic resistance in enteric bacteria provided from pelophylax SP. in eastern blacksea region

The aim of this study was to molecular analyze the antimicrobial resistance in enteric bacteria from cloacal swabs of a frog species, Pelophylax sp. regarded as an indicator for environmental pollution. Fifty-four frog individuals were captured from six provinces (Samsun, Ordu, Giresun, Trabzon, Rize and Artvin) in the Eastern Blacksea Region of Turkey. One hundred and sixty bacterial colonies from three of each cloacal swab cultures were randomly picked, and the bacterial species were identified by biochemical tests, automated systems (VITEK 2) and matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS). Fifteen different genera were identified in 160 strains. Antimicrobial sensitivity tests were performed against 12 different antibiotics by disk diffusion method. The highest rate of resistance was to ampicillin and cefazoline while the lowest rate was against chloramphenicol and tetracycline in the bacterial species individually. Class 1 and/or class 2 integron gene cassettes were screened by PCR method. One of the strains (E. coli, S1C2) was positive for intI1 gene, which lacked a gene cassette, indicating an empty class 1 integron. In the resistance gene analysis eight strains had blaTEM and, four were positive for blaSHV. tetA gene was found in two tetracycline resistant strains. In one Klebsiella strain (Klebsiella pneumoniae A1B1) of three quinolone-resistant strains, the Ser83Thr substitution of the gyrA gene was detected. In addition, Glu84Val mutation was detected in the parC gene in two Klebsiella strains (Klebsiella pneumoniae A1B1, Klebsiella oxytoca G1C3). No plasmid-mediated quinolone resistance genes were detected. The clonal relations between E. coli isolates from different locations were examined by pulsed-field gel electrophoresis. Detection of the presence of class 1 integron in a strain of multi drug resistant enteric bacteria in the intestinal microbiota of a cosmopolitan frog species indicates that these animals might be a reservoire for the resistance genes, and therefore their potential for the transfer of resistance genes to human pathogenic bacteria can create a risk for public health.