Virulence Genes, Antibiotic Susceptibility Profiles and Molecular Characterization of Campylobacter Species Isolated from Different Slaughterhouses

Abstract

The aim of this study was to investigate the frequency of Campylobacter species, to detect the antibiotic resistance profiles and the virulence genes and to determine the clonal proximity of the isolates in the samples of cutting board, slaughterhouse waste water, wall, knife and carcass from three different slaughterhouses in Kayseri region. For this purpose, a total of 150 samples, 10 of each from knife, wall, cutting board, carcass smear sample and slaughterhouse wastewater were collected from each of the three types of slaughterhouses in 2018 in Kayseri. For the isolation of the Campylobacter species, following preenrichment, the suspensions were inoculated onto modified charcoal cefoperazone desoxycholate (CCD) agar and were incubated at 37°C under microaerophilic condition for 48-72 hours. Suspicious colonies with gray-white color were recovered and subjected to phenotypical (Gram staining, oxidase, catalase test, and motion test) tests. Multiplex polymerase chain reaction (mPCR) was used for the molecular identification of the Campylobacter species. Antimicrobial susceptibilities of the isolates identified at the species level were detected by using the disk diffusion test and antibiotic gradient test. Virulence genes (iam, cadF, cdtA, flaA, ceuE, cdtC, cdtB and virB11) among the isolates were evaluated by PCR. The molecular typing of the isolates determined at species level was performed by Enterobacterial Repetitive Intergenic Consensus PCR (ERIC-PCR). In the study, 17 (11.3%) of the 150 samples taken from the slaughterhouse were found to be suspicious in terms of Campylobacter spp. and as a result of phenotypic identification tests, all of the isolates were verified as Campylobacter spp.. As a result of mPCR; eight of the isolates were identified as Campylobacter jejuni, eight as Campylobacter fetus and one as Campylobacter coli. The isolation of the Campylobacter species from different sources was found to be higher in slaughterhouse wastewater than those of others (p<0.001) and the difference in the proportional distribution of the Campylobacter species obtained from various sources was statistically significant (p<0.05). As a result of the disk diffusion test, while, all C.jejuni isolates were resistant to ciprofloxacin, 87.5%, 25%, 25% and 12.5% of C.jejuni isolates were resistant to enrofloxacin, neomycin, amoxicillin/clavulanic acid, and erythromycin, respectively. In addition, 25%, 25% and 12.5% of C.fetus isolates were resistant to amoxicillin/clavulanic acid, neomycin and gentamicin, respectively. C.coli isolate was not resistant to any of the antibiotics tested. Antibiotic gradient test results were found to be compatible with the disc diffusion test results. One of the virulence genes examined, virB11, was not detected in any of the isolates. Moreover, iam gene was not present in C.fetus and C.coli isolates, but only in one C.jejuni isolate. The flaA gene was detected in six C.jejuni isolates. C.coli isolate and seven C.jejuni and seven C.fetus isolates were positive in terms of the cdtC gene. The cdtA, cdtB, ceuE and cadF genes were found to be positive in all C.jejuni isolates. All isolates analyzed in the study demonstrated different ERIC-PCR profiles. In conclusion, it was shown that Campylobacter strains isolated from slaughterhouses were resistant to the most of the current antibiotics. Moreover, the presence of highly virulent Campylobacters in the slaughterhouse environment threatens public health due to the risk of contamination of the humans via carcasses and foods. Therefore, it is recommended that strict hygiene rules should be followed to reduce Campylobacter species contamination in slaughterhouses.