The aim of this study was to detect Shiga toxins (stx1 and stx2), enterohaemolysin (EhlyA) and intimin (eaeA) virulence genes of 11 Escherichia coli O157:H7 strains isolated from faecal samples of 300 clinically healthy Anatolian water buffaloes by PCR. Multiplex PCR was used for the detection of stx1 and stx2, and singleplex PCRs were used for the detection of EhlyA and eaeA virulence genes respectively. A total of three (27.3%) strains were determined to harbour both of the stx1 and stx2 genes, of these, one (9.1%) only harboured these two genes alone, one (9.1%) also contained the EhlyA gene and one (9.1%) additionally contained the EhlyA and the eaeA genes. EhlyA gene was obtained from eight (72.7%) strains, six (54.5%) of these were alone. eaeA gene was positive in only one (9.1%) strain. Only one (9.1%) of the 11 E. coli O157:H7 strains harboured all the four virulence genes. Two (18.2%) of the isolates had none of the virulence genes. Enterohaemolysin was found to be the most common virulence factor. In conclusion, the virulence factors of E. coli O157:H7 strains isolated from the faeces of Anatolian water buffaloes were investigated and detected for the first time in Turkey.

This study was carried out to determine the chemical and microbiological quality of Anatolian buffalo milk. A total of 120 Anatolian buffalo raw milk samples were collected monthly from Afyonkarahisar province, throughout the year for this study. In the chemical analysis of Anatolian buffalo milk samples the mean total solid value, non-solid fat, lipid, protein, lactose, ash and pH values were detected as 16.38%, 8.56%, 7.04%, 4.36%, 4.19%, 0.72% and 6.55, respectively. Total bacteria count (TCA), coliform, lactic acid bacteria (LAB), Escherichia coli, Staphylococcus aureus and yeast-mold (log 10 cfu/ml) levels in the milk samples were detected as 6.36, 2.95, 5.74, 1.10, 2.46 and 2.63, respectively.

The purpose of the study was to isolate Staphylococcus aureus from bovine subclinical mastitis, determine their antibiotic susceptibilities and investigate the coagulase gene polymorphism by using a PCR-based restriction fragment length polymorphism (RFLP) method. Milk samples from 463 CMT positive udders from 237 cows cultured. The antimicrobial susceptibility of the isolates were determined by disc diffusion method. A total of 82 out of the 83 isolates (98.8%) were found to be resistant at least one out of the 16 antibiotics studied. In this experiment 53 isolates (63.8%) were found to be resistant to penicillin; 52 (62.67%) to trimethoprim/sulphamethoxazole; 51 (61.5%) to ampicillin; 40 (48.2%) to erytromycin; 29 (34.9%) to tetracycline; 18 (21.6%) to ciprofloxacin, 16 (19.3%) to clindamycin, 13 (15.6%) to chloramphenicol; 8 (9.6%) to gentamicin; 5 (6.0%) to cefoxitin; 4 (4.9%) to vancomycin; 3 (3.6%) to cephalotin; 2 (2.4%) nafcillin; one (1.2%) to oxacillin and one to (1.2%) furazolidon. No imipenem resistance was seen in the S. aureus isolates. The coagulase gen polymorphism were examined by PCR amplification of coagulase gene followed by AluI digestion of repeating 81 bp DNA sequences. After nested PCR, double bands were produced in 8 of the isolates while there were single band in remaining 75 isolates. Following AluI digestion, isolates that formed single band in length of approximately 300 bp showed 3 different groups. Keywords: Bovine subclinical mastitis, Staphylococcus aureus, Antibiotic susceptibility, Coagulase gene polymorphism Subklinik Mastitli İneklerden İzole Edilen Staphylococcus aureus İzolatlarinin Antibiyotik Duyarlılık Profillerinin Çıkarılması ve Koagulaz Geni Polimorfizmine Göre Tiplendirilmesi ÖzetBu çalışmanın amacı subklinik mastitisli sığırlardan Staphylococcus aureus'u izole etmek, bunların antibiyotiklere duyarlılığını belirlemek ve bir PCR tabanlı restriksiyon fragment lengh polimorfizmi (RFLP) yöntemi kullanarak koagulaz gen polimorfizmi araştırmaktır. 463 sığırdan CMT pozitif olan 237 sığır memesinden süt örnekleri alınarak ekim yapılmıştır. İzolatların antimikrobiyal duyarlılığı disk difüzyon yöntemi ile belirlenmiştir. Toplam 83 izolatın 82'si (%98.8) uygulanan 16 antibiyotikten en az bir antibiyotiğe dirençli bulundu. Bu çalışmada 53 izolat (%63.8) penisiline, 52 izolat (%62.67 trimethoprim/sulphamethoxazole, 51 izolat (%61.5) ampisiline, 40 izolat (%48.2) eritromisine, 29 izolat (%35.0) tetrasikline, 18 izolat (%21.7) siprofloksasine, 16 izolat (%19.3) klindamisine, 13 izolat (%15.6) kloramfenikole, 8 izolat (%9.6) gentamisine, 5 izolat (%6.0) sefoksitine, 4 izolat (%4.9) vankomisine, 3 izolat (%3.6) sefalotine, 2 izolat (%2.4) nafsiline ve 1'er (%1.2) izolat ise oksasilin ve furazolidona dirençli bulundu. S. aureus izolatlarında imipenem dirençliliği görülmedi. Koagulaz gen polimorfizmi koagulaz genin tekrarlanan 81 bp DNA dizisinin AluI sindirimini müteakiben koagulaz genin amplifikasyonu ile incelenmiştir. Nested PCR'den sonra izolatların 8'inde çift bant görülm...

SummaryThe aim of this study was to detect enterohemolysin (EhlyA) and intimin (eaeA) virulence genes of 14 Escherichia coli O157:H7 strains isolated from 457 fecal samples (237 calves and 220 cattle) by PCR. While EhlyA gene was determined in 13 (92.8%) strains, the eaeA gene was positive in 8 (57.1%) strains. Of the 8 eaeA genes, 4 (50.0%) were obtained from diarrheic calves, 2 (25.0%) from non-diarrheic calves, and 2 (25.0%) from healthy cattle. A total of 7 (50.0%) strains were determined to harbour both of the EhlyA and eaeA genes. This study confirmed that calves, especially diarrheic, and cattle are a reservoir of E. coli O157:H7 strains that may be pathogenic for human.

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