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Öğe Carriage of antimicrobial resistance genes in Escherichia coli of bovine origin(Polska Akad Nauk, Polish Acad Sciences, Univ Warmia & Mazury Olsztyn, 2024) Ozbey, G.; Tanriverdi, E. S.; Acik, M. N.; Kalin, R.; Otlu, B.; Zigo, F.The present study aimed to search for the presence of the plasmid-mediated antimicrobial resistance genes in 106 Escherichia coli (E. coli) isolates from a total of 240 fresh fecal samples collected from 12 private cattle farms in Bingol province of East Turkey from November 2021 to January 2022. In those colistin-resistant E. coli (mcr-1 to-9), the major carbapenemase ( bla OXA-48 , bla NDM-1 , bla IMP, bla VIM, and bla KPC ), beta-lactamase (blaTEM-1, bla CTX-M and bla SHV-1 ) and OXA-48 like beta- lactamase ( bla OXA-162 , bla OXA-163 , bla OXA-181 , bla OXA-204 and bla OXA-232 ) resistance genes were searched for determined a multiplex polymerase chain reaction (PCR) method and Next-generation sequencing (NGS)- PCR Amplicons with Nanopore Technology. Only the mcr-4 gene was found in one isolate and the remaining genes (mcr-1-9) were not shown in all E. coli isolates from cattle. The minimal inhibitory concentration (MIC) to colistin was detected in mcr-4 positive E. coli isolates using broth microdilution. We assessed the antimicrobial susceptibilities of mcr-4 positive E. coli isolates using the Kirby-Bauer disk diffusion method. E coli isolate was detected as negative for carbapenemase and OXA-48 like beta-lactamase resistance genes and positive for beta-lactamase. In addition, E. coli isolates carrying mcr-4 were more resistant to colistin. Antimicrobial susceptibility testing using the disk diffusion assay indicated that all 106 E. coli isolates (100%) were sensitive to AMK, 105 E. coli isolates (99.1%) exhibited sensitivity to imipenem, meropenem and doripenem, and 1 E. coli isolate (0.9%) had intermediate resistance to imipenem, meropenem and doripenem; It was observed that all strains (100%) were resistant to cefotaxime. E. coli isolates are resistant to ampicillin (95.3%), amoxicillin/clavulanic acid (95.3%), cefepime (14.2%), cefixime (19.8%), cephalexin (74.5%), gentamicin (42.5%), kanamycin (37.7%), streptomycin (69.8%), tetracycline (80.2%), ciprofloxacin (60.4%), norfloxacin (13.2%), chloramphenicol (59.4%) and trimethoprim/sulfamethoxazole (68.9%). When we investigated the sequence in the Blast database, the genome of the E. coli isolate indicated high similarity with the mcr-4 sequences. To our knowledge, this is the first report investigating on the mcr-4 gene in E. coli identified from cattle in Turkey. Our results highlighted that cattle might be a potential risk in transmitting mcr genes.Öğe Identification of bacterial species in milk by MALDI-TOF and assessment of some oxidant-antioxidant parameters in blood and milk from cows with different health status of the udder(Polska Akad Nauk, Polish Acad Sciences, Univ Warmia & Mazury Olsztyn, 2022) Ozbey, G.; Cambay, Z.; Yilmaz, S.; Aytekin, O.; Zigo, F.; Ozcelik, M.; Otlu, B.This study aimed to identify bacterial pathogens in milk samples from dairy cows with sub -clinical and clinical mastitis as well as to assess the concentrations of oxidant-antioxidant param-eters [malondialdehyde (MDA), reduced glutathione (GSH), and total GSH levels] in both blood and milk samples. From a total of 200 dairy cows in 8 farms, 800 quarter milk samples obtained from each udder were tested in the laboratory for the presence of udder pathogens. Cultivated bacteria causing intramammary infection from milk samples were identified by Matrix-Assisted Laser Desorption/Ionization-Time of Flight (MALDI-TOF). In addition, from tested animals 60 cows were selected includ??ng 20 healthy cows that were CMT negative, 20 cows with subclini-cal mastitis (SM), and 20 cows with clinical mastitis (CM) for detection of MDA, GSH, and total GSH levels in blood and milk samples. Three hundred and eighty (47.5%; 380/800), 300 (37.5%; 300/800), and 120 (15%; 120/800) of milk samples, respectively were CMT positive or SM and CM, and those positives were cows from different farms. We observed that 87.4% (332/380), 25.3% (76/300), and 34.2% (41/120) of cows with CMT positive, CMT negative, and CM had bacterial growth. The most predominantly identified bacteria were Staphylococcus chromogenes (18.7%) obtained mainly from SM and Staphylococcus aureus (16.7%) as the most frequent cau-se of CM. According to our results, dairy cows with CM had the highest MDA levels, the lowest GSH, and total GSH levels in both blood and milk samples however, high MDA levels and low GSH levels in milk samples with SM were observed. Based on our results, lipid oxidant MDA and antioxidant GSH could be excellent biomarkers of cow???s milk for developing inflammation of the mammary gland. In addition, there was no link between nutrition and MDA and GSH levels.Öğe Investigation of Antimicrobial Activities and Molecular Docking Studies of Synthesized Sulfonamide Compounds(Springer, 2023) Ozbey, G.; Tanriverdi, E. S.; Senkal, B. F.; Korkmaz, B.; Erkan, S.; Bulut, N.; Zigo, F.Sulfonamides are commonly used worldwide. In this study, several sulfonamide compounds such as N-(4-acetylphenyl)-4-methylbenzenesulfonamide (PSASF), N-(3-acetylphenyl)-4-methylbenzenesulfonamide (PSASF-1), 1-tosyl-1H-imidazole (PSASF-x), 4-methyl-N-(pyridin-4-yl) benzenesulfonamide (PSASF-2), and 1-ethyl-4-tosylpiperazine (PSASF-3) have been synthesized, with antibacterial activities against Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, and Staphylococcus aureus ATCC 29213 have been evaluated. Antibacterial properties of drugs were studied in depth using molecular docking research. In addition, the synthesized compounds were characterized using spectral analysis. Antibacterial activities of synthesized derivates were determined against E. coli, P. aeruginosa, and S. aureus with minimum inhibitory concentration (MIC) by using the broth microdilution method. All prepared compounds exhibited significant antibacterial activity against S. aureus, E. coli, and P. aeruginosa. The MIC value for E. coli and P. aeruginosa was determined as 256 mu g/mL. MIC against S. aureus was observed to be 256 and 512 mu g/mL for the PSASF compound and the other compounds respectively. Results of the current study revealed that four of the five compounds had weaker antibacterial activity against S. aureus at a concentration of 512 mu g/mL. However, the MIC values from our experiments are significantly higher in comparison with the reference drugs such as amoxicillin, ciprofloxacin, meropenem, and vancomycin in E. coli and S. aureus. On the other hand, in a comparison of the synthesized compounds with reference drugs in P. aeruginosa, no statistical difference was demonstrated. Antibacterial activity of the produced derivates was likewise an agreement with regard to the molecular docking and the laboratory results.Öğe Prevalence and antimicrobial resistance profiles of bacterial pathogens associated with subclinical mastitis and dairy farm environments(Polska Akad Nauk, Polish Acad Sciences, Univ Warmia & Mazury Olsztyn, 2025) Ozbey, G.; Tanriverdi, E. S.; Zigo, F.This study investigated the prevalence and antimicrobial resistance (AMR) profiles of bacterial pathogens linked to subclinical mastitis in dairy cows, as well as their occurrence in milk, faecal, and environmental samples collected in eastern Turkey between February and May 2024. A total of 2,400 milk samples were collected from 600 cows affected with subclinical mastitis, along with 292 rectal faecal samples, 150 raw milk samples consumed by the public, and hand and fecal samples obtained from animal breeders in 25 cattle enterprises. In addition, environmental samples such as water, soil, feed, and bedding (five samples per enterprise), were collected. Bacterial isolates cultured from all samples were identified using Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) mass spectrometry. Of the 600 cows examined, 292 (48.6%) were CMT-positive, and bacterial growth was detected in 261 (89.7%) of these samples. The predominant isolates were coagulase-negative staphylococci (CoNS, 30.8%), Staphylococcus aureus (19.5%), Escherichia coli (8.9%), and Aerococcus viridans (5.8%). Antimicrobial susceptibility of S. aureus and CoNS against 15 antibiotics and E. coli against 17 antibiotics was assessed using the disc diffusion method, and the mecA gene was screened by PCR. Among 121 E. coli isolates, no mcr, carbapenemase, or beta-lactamase genes were detected by multiplex PCR. Tetracycline resistance was highest among E. coli isolates, particularly in milk samples from mastitic cows, rectal fecal samples, unpasteurised cow's milk, farmer's feces, soil, and feed, while resistance to amikacin, cefepime, cefoxitin, cephalexin, ertapenem, and norfloxacin remained lower. No resistance was observed against kanamycin. The mecA gene was identified in three S. aureus isolates (3/57, 5.3%): two from cows affected with subclinical mastitis and one from a farmer's hand. These findings highlighted the prevalence of major bacterial pathogens, potential therapeutic challenges and public health risks associated with the presence of AMR bacteria and raw milk consumption.
