Investigation of antimicrobial and disinfectant susceptibility, virulence factors and clonal relatedness of winged animals' salmonella isolates from İzmir, Manisa and Uşak

The aim of this study was to investigate the effects of different antibiotics and disinfectants, antibiotic resistance genes in resistant strains, different virulence genes and clonal relationships in Salmonella isolates of winged animals. The 45 strains of winged animals isolated in 2014-2015 from Poultry Diseases Diagnostic Laboratory of Bornova Veterinary Control Institute related to Turkish Republic Food, Agriculture and Livestock and serotyped in Etlik Central Research Institute Bacteriology Laboratory (Salmonella National Reference Laboratory) were taken into study. At first, Kirky Bauer disc diffusion method with 10 different types of antibiotics was applied in order to determine the antibiotic suspectibility profiles of the strains in accordance with Clinical and Laboratory Standard Institute's criteria. Then, the effects of frequently used disinfectants were examined on strains using broth microdilution method. According to the results of disc diffusion method, five antibiotic resistance genes were investigated using Polimerase Chain Reaction (PCR) in the strains which were resistant to ß-lactams and tetracyclines. Furthermore, six virulence genes which have crucial role in occurence of infection were detected by using PCR. At the end of the study, clonal relationships between the strains were evaluated with the help of Pulsed Field Gel Electrophoresis (PFGE) method. The 20 Salmonella strains were found resistant to ß-lactam (ampicillin, amoxicillin and amoxicillin+clavulanic acid) group and tetracycline (doxycycline and oxytetracycline) group antibiotics. No resistance were observed in strains to other tested antibiotics (cefepime, levofloxacin, ciprofloxacin, cefotaxime and colistin sulphate). The presence of Extended Spectrum Spectrum Beta Lactamase (ESBL) were investigated by using blaTEM, blaCTX-M and blaSHV in strains which were found resistant to ß-lactams but none of the genes were detected. Also tetA and tetB resistance genes were examined in strains which were resistant to tetracyclines and only tetA was found in seven strains. The suspectibilities of 45 Salmonella strains to four different disinfectants were studied by using broth microdilution method. 25 Salmonella strains were detected resistant to Virkon-S® . The virulence genes, invA, sopB, sopE, sifA, pefA, and pipD were investigated. InvA was found in all strains and others were determined at the rates of sopB (93.3%), sopE (37.7%), sifA (31.1%), pefA (35.5%) and pipD (%95.5). The clonal relatedness between 45 strains were researched using PFGE which is a molecular typing method. Although the test was repeated, no patterns were gained in four strains. According to the dendogram which revealed including 41 strains and 13 different serotypes, 39 distinct pulsotypes were detected. The clonal relatedness between strains was in the range of 30% and 100%. The cut-off value was taken as 53% and the formation of eight different clusters were observed. Depending on the genetical relatedness, the number of strains which belonged to clusters was determined as three and 12. Resistance to ß-lactam and tetracycline group antibiotics and a disinfectant was revealed by our study in 45 Salmonella strains which were isolated and identified from winged animals located İzmir, Manisa and Uşak in a two year period. Although ESBL wasn't observed in resistant strains, tetA was detected in some of them. Different virulence genes were found in various serotypes and high clonal relatedness levels were seen between the studied strains. More investigations are needed about Salmonella antibiotic and virulence genes in our country. Keywords : Winged animals, Salmonella spp., disinfectant, resistance, virulence