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    Characterisation of Phenotypic and Genotypic Antibiotic Resistance Profile of Enterococci from Cheeses in Turkey
    (Korean Soc Food Science Animal Resources, 2016) Kurekci, Cemil; Onen, Sevda Pehlivanlar; Yipel, Mustafa; Aslantas, Ozkan; Gundogdu, Aycan
    The aim of this study was to determine the prevalence of enterococci in cheese samples and to characterize their antimicrobial resistance profiles as well as the associated resistance genes. A total of 139 enterococci were isolated from 99 cheese samples, the isolates were identified as E. faecalis (61.2%), E. faecium (15.1%), E. gallinarum (12.9%), E. durans (5.0%), E. casseliflavis (2.9%) and E. avium (2.9%). The most frequent antimicrobial resistance observed in enterococci isolates was to lincomycin (88.5%), followed by kanamycin (84.2%), gentamycin (low level, 51.1%), rifampin (46.8%) and tetracycline (33.8%). Among the isolates, the frequencies of high level gentamycin and streptomycin resistant enterococci strains were 2.2% and 5.8%, respectively. Apart from the mentioned antibiotics, low levels of resistance to ciprofloxacin, erythromycin and chloramphenicol were found. Moreover no resistance was observed against penicillin and ampicillin. The antimicrobial resistance genes including tetM, tetL, ermB, cat, aph(3')-Illa, ant(6)-Ia and aac(6')-leaph(2 '')-Ia were found in enterococci from Turkish cheese samples. In the current study, we provided data for antibiotic resistance and the occurrence of resistance genes among enterococci. Regulatory and quality control programs for milk and other dairy products from farms to retail outlets has to be established and strengthened to monitor trends in antimicrobial resistance among emerging food borne pathogens in Turkey.
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    Characteristics of ciprofloxacin resistant Campylobacter spp. isolated from chicken meat in Turkey
    (Springer, 2017) Kurekci, Cemil; Onen, Sevda Pehlivanlar
    The objective of the current study was to investigate mutations in the gyrA and 23S rRNA gene fragments the high level ciprofloxacin resistant (HL-Cip(R)) Campylobacter isolates (C. jejuni n = 6 and and C. coli n = 9) obtained from chicken meat samples, in Turkey. PCR-based restriction fragment length polymorphism (RFLP) was used to characterize these isolates. In addition, the presence of several virulence traits among these isolates was also examined. Of the 15 HL-Cip(R) Campylobacter strains, there were eight unique RFLP banding patterns. All HL-Cip(R) Campylobacter strains had mutations in codon 86 (Thr-86 to Ile) in the gyrA gene. Four C. jejuni isolates had missense mutation of Asp-203 to Ser, whereas one C. jejuni strain also presented a change at Ala-40 to Ser. A2075G substitution in the 23S rRNA gene was identified in five isolates (C. coli n = 3 and C. jejuni n = 2), whereas none of the isolates had A2074G substitution. The tetO gene conferring resistance to tetracycline were observed among five Campylobacter isolates. Of Campylobacter strains, 13 (86.6 %) were found to be positive for one or more virulence factors, the cdt genes being the most detected. The results of the current study extends the current knowledge about molecular mechanisms for erythromycin and ciprofloxacin resistance as well as virulence traits by investigation of HL-Cip(R) Campylobacter isolates from chicken meat sold in Turkey.
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    Investigation into toxin and slime genes in staphylococci isolated from goat milk and goat cheese in southern Turkey
    (Chulalongkorn Univ, 2018) Onen, Sevda Pehlivanlar; Cantekin, Zafer; Mebkhout, Faiza; Aygun, Osman; Ergun, Yasar
    The aim of this study was to investigate the presence of Staphylococcus aureus and coagulase-negative staphylococci (CNS) isolated from goat milk and cheese, as well as their toxin genes and slime genes. S. aureus and CNS isolates were subjected to polymerase chain reaction (PCR) analyses to determine the prevalence of enterotoxin (sea, seb, sec, sed, see), toxic shock syndrome (TSS) toxin (tst), exfoliative toxin (eta and etb) and slime genes (icaA and icaD). sec, sed and tst genes together were detected in 4 (33.3%), sec + tst genes in 2 (16.7%) and tst gene in 1 (8.3%) of the 12 S. aureus isolates. However, see gene was detected in 6 (9.7%), sed gene and tst gene were detected in 1 (1.6%) and 7 (11.3%) of the 62 CNS isolates, respectively. No sea, seb, see, eta or etb genes were detected in the S. aureus isolates, whereas no sea, seb, sec, eta or etb genes were detected in the CNS isolates. At least one ica gene was present in all S. aureus isolates and in 36 of the 62 CNS isolates. The presence of icaA and icaD genes in the S. aureus isolates was clearly higher than those in the CNS isolates. In conclusion, toxin and slime genes were detected in the S. aureus and CNS isolates from goat milk and goat cheese. The potential risk of enterotoxigenic CNS should not be ignored as well as S. aureus in food safety and public health.
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    Occurrence and Molecular Characterization of Cephalosporin Resistant Escherichia coli Isolates from Chicken Meat
    (Kafkas Univ, Veteriner Fakultesi Dergisi, 2020) Bilge, Nebahat; Sezer, Cigdem; Vatansever, Leyla; Onen, Sevda Pehlivanlar
    Contamination of retail meat with extended spectrum beta-lactamase (ESBL) and/or AmpC type beta-lactamase (AmpC) producing Escherichia coli may contribute to increased incidences of infections in humans. Regular monitoring of these bacteria is required in the view of one health approach. In this study, 100 chicken meat samples obtained from Kars, Turkey were analysed and 214 isolates recovered from 72/100 samples were identified as E. coli. Antibiotic susceptibility tests showed that 15.42% of isolates (33/214) were resistant to at least one cephalosporin antibiotic, 20 (9.34%) were beta-lactamase producer. Among beta-lactamase producing E. coli isolates 8 had blaTEM, 7 had blaCTX- M and 3 had blaSHV genes. Plasmid-mediated AmpC beta-lactamase (blaCMY) gene was present in 13 isolates. Plasmid mediated quinolone resistance genes were also screened by polymerase chain reaction and identified by sequencing of the isolates. As a result, 3 isolates were found to be positive for qnrB, whereas the qnrS gene was detected in 4 isolates. Regarding the virulence genes 19 isolates were positive for fimH and 2 isolates were carrying kpsMT II. Phylo-group D2, A0, A1, B1 and D1 were detected in 13, 2, 2, 2 and 1 isolates, respectively. Our findings indicate that poultry meat could be an important carrier of ESBL positive E. coli.
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    Prevalence of ?-Lactamase Producing Escherichia coli from Retail Meat in Turkey
    (Wiley, 2015) Onen, Sevda Pehlivanlar; Aslantas, Ozkan; Yilmaz, Ebru Sebnem; Kurekci, Cemil
    Extended spectrum beta-lactamase (ESBL) and plasmid-mediated AmpC beta-lactamase (pAmpC) producing Escherichia coli have been shown to be present in humans and animals representing a significant problem worldwide. This study aimed to search the presence of ESBL and/or AmpC-producing E. coli in retail meats (chicken and beef) in Turkey. A total of 88 beta-lactamase-producing E. coli were isolated from chicken (n = 81/100) and beef meat (n = 7/100) samples and their susceptibility to several antimicrobials were tested using disc diffusion method. E. coli isolates were further characterized for their phylogenetic groups. beta-Lactamase encoding (bla(TEM), bla(SHV), bla(OXA), bla(CTX-M), and bla(AmpC)) and quinolone resistance genes (qnrA, qnrB, qnrS, qepA, and acc(6')-Ib-cr) were also secreened by polymerase chain reaction (PCR). However, in regard to beta-lactamase genes, 84 of 88 isolates were positive for bla(CTX-M-1) (n = 39), bla(CTX-M-3) (n = 5), bla(CTX-M-15) (n = 4), bla(TEM-1b) (n = 2), bla(SHV-12) (n = 1), bla(CTX-M-1/blaTEM-1b) (n = 10), bla(CTX-M-1)/bla(TEM-1b)/bla(SHV-5) (n = 1), bla(CTX-M-1)/bla(CMY-2) (n = 1) and bla(TEM-1b)/bla(CMY-2) (n = 6), bla(CTX-M-15)/bla(SHV-12) (n = 1), bla(CTX-M-15)/bla(TEM-1b) (n = 1), bla(TEM-1b)/bla(SHV-12) (n = 1), and bla(CMY-2) (n = 12) genes. Resistance to cefuroxime (75.6% and 85.7%), nalidixic acid (89% and 85.7%), tetracycline (91.4% and 100%), streptomycin (40.2% and 100%), and trimethoprim-sulfamethoxazole (36.6% and 85.7%) was observed among strains isolated from chicken and beef, respectively. However, all isolates were found to be susceptible to amikacin, imipenem, and cefepime. Resistance to ampicillin and cefoxitin was significantly linked to bla(CMY-2) gene, while there was a significant correlation between CTX-M type ESBL and antimicrobial resistance to cefuroxime and streptomycin (P < 0.05). The results of this study suggest that raw chicken retail meats are highly contaminated with ESBL-producing E. coli implementing a great risk to human health in Turkey.
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    Prevalence, antimicrobial resistance and virulence traits in enterococci from food of animal origin in Turkey
    (Elsevier Science Bv, 2016) Yilmaz, Ebru Sebnem; Aslantas, Ozkan; Onen, Sevda Pehlivanlar; Turkyilmaz, Suheyla; Kurekci, Cemil
    The objective of this work was to investigate the antibiotic susceptibility, the mechanisms implicated and the potential virulence genes (gelatinase [ge/E], cytolysins [cylA, cylM, cylB], cell wall adhesins [efaAfs and efaAfrn], enterococcal surface protein [esp], sex pheromones [cpd, cob, ccf], enhanced expression of pheromone [eep], aggregation substance [aggA]) in enterococci isolated from retail chicken and beef meat samples in Hatay, Turkey. Hundred-one (96%) isolates from chicken meat and sixty-three (63%) from minced meat isolates showed resistance to at least one of the 12 antimicrobial agents tested. The highest frequency of resistance was against tetracycline (89.5% and 53%), erythromycin (59% and 2%), ciprofloxacin (35.2% and 12%) and trimethoprim/sulfamethoxazole (34.3% and 7%) for isolates from chicken and beef samples, respectively. The ermB, tetM and tetL genes were predominantly detected by PCR. Five enterococci from chicken meat were found to be phenotypically resistant to vancomycin and carried the vanA gene. The presence of virulence genes including gelE, ccf, cpd, efaAfs, and aggA were frequently detected. The results of this study show that retail chicken and beef meat is source of concern for public health due to having high prevalence of antibiotic resistance and as well as harbouring virulence factors. (C) 2015 Elsevier Ltd. All rights reserved.