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Öğe Antimicrobial Resistance among Commensal Escherichia coli from Broilers in Turkey(Israel Veterinary Medical Assoc, 2018) Aslantas, O.In this study it was aimed to determine the antimicrobial susceptibility, resistance mechanisms, the prevalence of class 1 and 2 integrons and phylogenetic groups in 300 Escherichia coli isolates from poultry farms in Turkey. The antimicrobial susceptibility of the isolates was determined by disk diffusion method, the occurence of antimicrobial resistance genes, class 1 and 2 integrons and phylogenetic grouping were investigated by polymerise chain reaction (PCR). In ciprofloxacin resistant E. coli isolates, gyrA and parC mutations were detected by mismatch amplification mutation assay-PCR (MAMA-PCR). All extended spectrum beta-lactamase (ESBL) and plasmidic AmpC beta-lactamase (pAmpC) positive E. coli isolates were investigated for presence of ESBL and pAmpC genes, and following DNA sequencing. Antimicrobial test results revealed that 86.7% of the isolates had multidrug resistance (MDR) phenotype. MDR profiles were observed in all of the integron-positive isolates, whereas 81.4% of non-integron-carrying isolates were MDR (p <0.001). Phylogenetic analysis showed that integron carrying isolates mainly belonged to D (54.5%), A (32.5%), B1 (10.6%) and B2 (2.4%). The results indicate a high level of MDR and prevalence of class 1 and 2 integrons among commensal E. coli from Turkish broiler flocks. Urgent measures should be taken to promote prudent use of antimicrobials and to limit use of antimicrobials in broiler flocks.Öğe Effects of dietary supplementation of synbiotics and phytobiotics on performance, caecal coliform population and some oxidant/antioxidant parameters of broilers(Wiley, 2010) Erdogan, Z.; Erdogan, S.; Aslantas, O.; Celik, S.P>The current study was conducted to evaluate the effects of dietary supplementation of synbiotics and phytobiotics on performance, small intestine weight, pH and caecal coliform counts of broilers. The influences of synbiotics and phytobiotics on oxidant/antioxidant status in the blood of broilers were also assessed. A total of 200 broiler chicks were randomly allotted to four dietary treatments, either fed a basal diet or the same diet supplemented with 1 g/kg synbiotic, 1 g/kg phytobiotic or 1 g/kg synbiotic plus 1 g/kg phytobiotic. The diet supplemented with both synbiotic and phytobiotic had no effect on body weight, body weight gain, feed intake and feed efficiency of broilers at the end of the study (p > 0.05). Neither small intestine weight nor pH was affected by any of the treatments. Supplementation of both synbiotic and phytobiotic to diet decreased the caecal coliform count (p < 0.01). Addition of synbiotics and phytobiotics in combination significantly increased plasma malondialdehyde (MDA) levels (p < 0.05), whereasphytobiotic addition alone showed only a slight increase. Similarly, elevated nitric oxide (NO) level was recorded in the synbiotic- and phytobiotic-fed group and in the phytobiotic-fed group (p < 0.001). Superoxide dismutase (SOD) activities did not differ between the groups. In conclusion, dietary supplementation of synbiotic and phytobiotic improved the gut health by decreasing the caecal total coliform count, but growth performance was not affected by the supplementations. Further investigations are needed to determine the effects of phytobiotics on oxidative/antioxidative metabolism as regards their compositional analysis.Öğe Effects of rolipram on oxidative stress and inflammation in the early phase of B-melitensis infection(Blackwell Publishing, 2006) Aslantas, O.; Erdogan, S.; Celik, S.[Abstract Not Available]Öğe Elevated cAMP levels reverse Brucella melitensis-induced lipid peroxidation and stimulate IL-10 transcription in rats(Elsevier Sci Ltd, 2007) Erdogan, S.; Celik, S.; Aslantas, O.; Kontas, T.; Ocak, S.Brucella species are able to survive and replicate within the phagocytic vacuole of macrophages that induce chronic infection in humans and domestic animals. The activation of oxidative bactericidal activity is one of the defense systems which protect the host from the toxic effects of pathogens. The aim of this study was to evaluate lipid peroxidation, NO production, antioxidative system and inflammation during a period of brucella infection in a rat model; in addition to investigate the role of elevated intracellular cyclic AMP on Brucella-induced events. Brucella significantly induced lipid peroxidation in plasma, liver and spleen by 3-5-fold at 7 days postinfection. NO concentration was significantly elevated in the liver and spleen while unchanged in plasma. Cyclic AMP elevating agent, rolipram, administration (1 mg/kg/day i.p., 3 days) gradually suppressed lipid peroxidation and NO formation to the basal level in plasma and spleen whilst only a slight decrease was observed in liver. Brucella considerably decreased SOD activity in the liver and spleen, with rolipram restoring the enzyme activity in liver and activity in spleen being unchanged. Reverse transcriptase PCR analyses showed that Brucella melitensis does not alter TNF-alpha and IFN-gamma transcriptions in liver and spleen. The pathogen did not consistently induce nitric oxide synthase mRNA transcriptions in animals; even in those housed in the same group. IL-10 transcription was induced by rolipram in spleen but not in liver. Our results suggest that activation of the cAMP/PKA pathway suppressed lipid peroxidation and the elevated NO concentrations caused by B. melitensis, Moreover, rolipram induced anti-inflammatory cytokine IL-10 transcription and SOD activity, albeit in a tissue dependent manner. (c) 2006 Elsevier Ltd. All rights reserved.Öğe Evaluation of selected cytokines, anti-oxidative system and lipid peroxidation in the brains of Brucella melitensis-infected rats(Blackwell Publishing, 2006) Melek, I.; Erdogan, S.; Duman, T.; Celik, S.; Kontas, T.; Aslantas, O.[Abstract Not Available]Öğe High Occurence of Methicillin Resistant Staphylococcus sciuri (MRSS) and First Detection of mecC from Broiler Flocks in Turkey(Israel Veterinary Medical Assoc, 2020) Aslantas, O.In this study, twelve broiler farms were randomly sampled in three different cities (Adana, Hatay and Sakarya) in Turkey, to investigate the presence and genetic diversity of methicillin resistant coagulase-negative staphylococci (MRCoNS). Four houses for each broiler flock were selected for sampling and one hundred throat swabs from each house, from each broiler flock were collected and divided into five pools of 20 swabs. Overall, 63 methicillin resistant S. sciuri were isolated, and mecA was alone detected in 56 isolates, seven isolates were positive not only for mecA, but also for mecC. Most of the isolates (77.8%) were non-typeaple for SCCmec and ten isolates (15.9%) carried SCCmec type III. All isolates were resistant to cefoxitin and penicillin, and the frequency of the isolates for trimethoprim/sulfamethoxazole, clindamvcin, erythromycin, tetracycline resistance ranged between 66.7% and 73%. The PFGE analysis revealed the presence of 47 distinct pulsotypes. The most common resistant genes detected were lnuA and tet genes. None of the isolates was positive for toxin and disinfectant resistance genes. The present study is the first reporting the presence of the mecC gene among CoNS in Turkey. The results of this study also indicated that broiler flocks were potential source of multi-resistant methicillin resistant S. sciuri, with a high diversity.Öğe Investigation and Molecular Characterization of Colistin Resistance in Commensal Escherichia coli Strains Isolated from Broiler Flocks(Israel Veterinary Medical Assoc, 2023) Aslantas, O.; Kucukaltay, K.The emergence and dissemination of plasmid-mediated colistin resistance pose a serious threat to global public health. In this study, a total of 454 commensal Escherichia coli strains isolated from cloacal swabs taken from broiler flocks between 2013 and 2014 were first screened for phenotypic colistin resistance by the broth microdilution method. Twelve phenotypically colistin-resistant isolates were screened for mcr-1 to mcr-5 genes by multiplex PCR. Five of these isolates were found to carry the mcr-1 by PCR. Whole-genome sequencing of the mcr-1 carrying isolates revealed the presence of additional antimicrobial resistance genes and chromosomal gyrA and parC mutations conferring resistance to fluoroquinolones. Analysis of virulence gene content revealed 5-20 virulence genes in the isolates and two isolates were defined as avian enteropathogenic E. coli (APEC). Phylogenetic analysis based on whole-genome and multilocus sequence typing revealed that the strains were closely related to mcr-1 carrying isolates from chicken and human clinical isolates previously reported from different parts of the World. The findings further emphasize the urgent need to implement effective control programs to prevent the emergence and dissemination of colistin-resistant bacteria.Öğe Investigation of antimicrobial resistance in pigeons (Columba livia domestica) using indicator bacteria(Hellenic Veterinary Medical Soc, 2020) Aslantas, O.; Govce, N.The aim of this study was to determine the prevalence of antibiotic resistance as well as presence of resistance-associated genes in Escherichia coli and Enterococcus spp. strains isolated from pigeons. One hundred and fifty cloacal swabs were collected from apparently healthy pigeons in Hatay, Turkey, between March 2014 and June 2014. Antimicrobial susceptibilities of the isolates were tested with disc diffusion method, and resistance genes were investigated by polymerase chain reaction (PCR). E. coli were isolated from 94.7% (142) of the examined cloacal swab samples. E. coli isolates revealed higher resistance rates to tetracycline (51.4%) and ampicillin (50%), followed by nalidixic acid (19.7%), streptomycin (12.7%), amoxycillin-clavulanic acid (15.5%), trimethoprim-sulfamethoxazole (10.6%), cephalothin (7.0%), ciprofloxacin (6.3%), kanamycin (4.9%), gentamicin (4.2%), tobramycin (4.2%), ceftazidime (4.2%), cefotaxime (4.2%), chloramphenicol (2.8%), aztreonam (2.8%), and cefoxitin (0.7%), respectively. Twentyeight (%19.7) E. coli isolates were susceptible to all tested antimicrobials. A total of 136 (90.7%) Enterococcus spp. were isolated and species distribution of the isolates was determined by species-specific PCR. The isolates were identified as 64 (47.1%) E. hirae, 17 (12.5%) E. faecium, 8 (5.9%) E. faecalis, 4 (2.9%) E. columbea, and 2 (1.5%) E. durans. The rest of the isolates (30.1%) were identified as Enterococcus spp. with the used primers. Enterococcus spp. were resistant to tetracycline (67.6%), erythromycin (23.5%), rifampicin (17.6%), chloramphenicol (6.6%) and ciprofloxacin (5.9%). By contrast, 38 (27.9%) Enterococcus spp. were sensitive to all tested antimicrobials. The data obtained in the study showed that pigeons were carriers of antimicrobial resistant E. coli and Enterococcus spp. in their intestinal microbiota, and may pose public health risk due to not only transmission of these resistant bacteria to humans but also contamination of the environment. The current status of antimicrobial resistance in different animal species should be continuosly monitored and control measures should also be taken.Öğe Investigation of Faecal Carriage of High-Level Gentamicin Resistant Enterococci in Dogs and Cats(Israel Veterinary Medical Assoc, 2022) Aslantas, O.The emergence and spread of high-level gentamicin resistant (HLGR) enterococci have been a concern due to the eliminatation of bactericidal effect between aminoglycosides and cell-wall-active antimicrobials. Therefore, this study to determine the fecal carriage of (HLGR) enterococci in dogs and cats, to investigate the antimicrobial resistance, resistance mechanisms implicated and virulence genes of the isolates. A total of 465 rectal swab samples from dogs (n=226) and cats (n=239) from three different cities (Istanbul, Ankara and Mersin) of Turkey were used for the analysis of HLGR enterococci. The antimicrobial susceptibilities of HLGR isolates were searched by disc diffusion method, resistance and virulence genes by polymerase chain reaction (PCR) and minimum inhibitory concentration (MIC) values for gentamicin were determined by macrodilution method. HLGR enterococci were detected in 25 (11.1%) dogs and in 28 (11.7%) cats. Based on PCR results, 12 were identified as Enterococcus feacalis and 41 as Enterococcus faecium. All of the isolates showed a MIC value of >= 2048 mu g/ml for gentamicin, and except one isolate, the rest of the isolates showed multidrug resistance (MDR) phenotype. None of the isolates displayed vancomycin resistance phenotype. The bifunctional enzyme encoded by aac(6)-Ie-aph(2)-Ia were detected in HLGR isolates as well as other aminoglycoside resistance genes at varying rates. Virulens genes were only detected in 11 (20.8%) E. faecalis isolates with different combinations. However, none of the isolates carried the bly gene. The results showed that both dogs and cats are a potential reservoir for MDR HLGR enterococci which may play an important role in the spread of these nosocomial pathogens.Öğe Isolation and Molecular Characterization of ESBL/pAmpC Producing Escherichia coli in Household Pigeons in Turkey(Israel Veterinary Medical Assoc, 2018) Aslantas, O.; Govce, N.In this study it was aimed to determine the prevalence of extended-spectrum beta-lactamase (ESBL) and/or plasmidic AmpC beta-lactamase (pAmpC) producing Escherichia coli among household pigeons in Hatay, Turkey. For this purpose, 150 cloacal swab samples were taken from apperently healthy household pigeons and the isolates were characterised by phylogenetic grouping, plasmid replicon typing, pulsed field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) analysis. ESBL producing E. coli was detected in five (3.3%) of the cloacal swabs: all the strains carried the bla(CTX-M-15) gene together with bla(TEM-1) (four phylogenetic group B1 and ST446 and one phylogenetic group A and ST665). pAmpC producing E. coli was detected in one (0.7%) isolate and this isolate harbored the bla(CMY-2) (phylogroup B2 and ST4906). Three plasmid replicon types detected among the strains IncII/I., IncFIB and IncFrepB were the most common. Three distinct PFGE pulsotypes were found among the isolates and multidrug resistance (MDR) phenotype was only observed in two isolates. The current study was, to the best knowledge of the authors, the first showing that household pigeons in Turkey are fecal carries of ESBL/pAmpC producing E. coli and a significant potential source of these bacteria for humans.Öğe Molecular Characterization of Methicillin- and Multidrug-Resistant Staphylococcus pseudintermedius Strain Isolated from a Case of Feline Otitis Externa(Israel Veterinary Medical Assoc, 2023) Aslantas, O.; Olgun, E.; Bayirli, M.; Buyukaltay, K.Methicillin-resistant Staphylococcus pseudintermedius (MRSP) is an emerging zoonotic pathogen in veterinary medicine. Whole-genome sequencing (WGS) is highly preferred today as a valid method for molecular typing of bacterial pathogens due to its high discriminatory power and characterization efficiency. This study describes the WGS-based characterization of an MRSP strain named HMKU-VET-MRSP-2020 from a case of cat otitis externa in Turkiye. The strain was classified as MLST sequence type 71 and SCCmec type IIIA. WGS analysis indicated the presence of several antimicrobial resistance genes and mutations consistent with the resistance phenotype. Phylogenetic analysis showed that the strain was clusterized with the isolates from dog clinical cases previously reported from different countries of Europe and one human isolate from the USA. The study is the first report on the isolation and molecular characterization of MRSP from a cat in Turkiye and provides insights into the zoonotic potential of this microorganism.Öğe Molecular Characterization of Staphylococcus aureus from Clinical Sheep Mastitis Cases(Israel Veterinary Medical Assoc, 2022) Aslantas, O.; Keskin, O.; Yucetepe, Gullu A.In the current study, it was aimed to examine the genes encoding toxin, biofilm and microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) of 62 Staphylococcus aureus isolated from sheep clinical mastitis cases using polvmerase chain reaction (PCR). Besides, accessory gene regulator (agr) groups and the antibiotic susceptibilities of the isolates were also determined. Most of the isolates (87.1%) were susceptible to all tested antimicrobials. The sec (38, 61.3%) and sell (50, 80.6%) were the only staphylococcal enterotoxin (SE) genes detected among the isolates. The tst gene was observed in 43 (57.3%) isolates. Whereas co-existence of sec, sell, tst was detected in 36 (48%) isolates; none of them isolates harbored eta and eth genes. However, eight (12.9%) isolates were found to be negative for SE, ET and TSST-1 genes. Hemolysin genes were detected in all isolates and the frequency of bla,hlb,hld, and hlg2 were 100%, 95.2%, 98.4%, and 61.3%, respectively. The lukED and lukM were found together in 40 (64.5%) of the isolates, and /ukED was found alone in 22 (35.5%) of the isolates. Of the biofilm-related genes, icaD was the only gene detected with a frequency of 83.9% (52). MSCRAMMs genes eno, cna, ebps, fib, fnb, clfA, and c()13 were detected in 100%, 79%, 100%, 95.2%, 100%, and 100%, respectively. None of the isolates carried the bbp gene. This study indicated that S. aureus isolates from clinical sheep mastitis possessed several virulence-associated determinants.
