Investigation of virulence and cytolethal distending toxin genes in Campylobacter spp. isolated from sheep in Turkey.

The presence of virulence and cytolethal distending toxin (Cdt) genes was investigated in isolates of Campylobacter jejuni, C. coli, C. lanienae, and C. lari that originated from intestinal contents and gallbladders of clinically healthy sheep. These genes have important roles in the pathogenicity of campylobacters. A total of 363 Campylobacter isolates (221 C. jejuni, 135 C. coli, five C. lanienae, and two C. lari) were used in this study. The frequency of racR, dnaJ, ciaB, pldA, flaA, and cadF virulence genes in all the isolates were determined to be 34.4%, 30%, 24.8%, 30.9%, 95%, and 81.3%, respectively, while the virB11 virulence gene could not be detected in any isolates. CdtA, cdtB, and cdtC genes were detected in 54.5%, 55.9%, and 52.3% of the isolates, respectively. None of the virulence and toxin genes examined here were detected in a total of 19 Campylobacter isolates consisting of 10 C. jejuni and nine C. coli. This is the first study investigating the presence of virulence and toxin genes in a large number of Campylobacter species isolated from clinically healthy sheep by scanning a large area. In addition, this is the first report investigating the presence of virulence and toxin genes in sheep-originated C. lanienae and C. lari isolates.

Investigation of toxin genes by polymerase chain reaction in Staphylococcus aureus strains isolated from bovine mastitis in Turkey.

Staphylococcus aureus causes a number of diseases in humans and animals, and it is the most common etiological agent of contagious bovine mastitis. The agent produces several virulence factors such as coagulase (coa), clumping factor, protein A, exfoliative toxins, staphylococcal enterotoxins (SEs), and toxic shock syndrome toxin-1. The aim of the present study was to characterize coa-positive S. aureus strains (n = 92) isolated from bovine subclinical mastitis in Turkey by polymerase chain reaction (PCR) amplification of exfoliative toxin (eta and etb) and toxic shock syndrome toxin-1 (tsst) genes. In addition, a multiplex PCR was employed to investigate the presence of SE genes sea, seb, sec, sed, see, seg, seh, sej, and sei. By PCR amplification, while eta and etb were not detected, only three isolates (3.3%) were positive for tsst. Twenty-seven (29.3%) isolates harbored one or more SE genes, and sei was the most common pattern by multiplex PCR. None of the isolates harbored the genes encoding sea, see, and seh. The application of this multiplex PCR assay could enable more samples to be rapidly characterized for enterotoxin production of S. aureus isolates from milk for epidemiological studies.

Isolation of Mycoplasma bovis from broiler chickens in Turkey.

Mycoplasma bovis normally affects cattle, in which it causes pneumonia in calves, mastitis, arthritis and other diseases. In the present article we report the isolation of this bovine pathogen from the tracheas of broiler chickens with no clinical signs. The most probable source of infection was the cattle herd sharing the farm with the chickens.

Coagulase gene polymorphisms detected by PCR in Staphylococcus aureus isolated from subclinical bovine mastitis in Turkey.

The genetic relatedness of coagulase (coa) positive Staphylococcus aureus isolated from cows with subclinical mastitis in Turkey was investigated by polymerase chain reaction (PCR)-based restriction fragment length polymorphism (RFLP) analysis. Among 700 milk samples positive in the California Mastitis Test (CMT), species specific PCR identified 200 (28.6%) isolates as S. aureus and 161 (80.5%) of these isolates were positive for the 3' end of the coa gene by PCR. Most isolates (n=135, 83.9%) produced a single band on coa PCR, with molecular sizes ranging from 500 to 1400bp, whereas a small number of isolates (n=26, 16.1%) yielded two amplification products. Coa RFLP analysis using AluI and Hin6I revealed 23 and 22 band patterns, respectively. The detection of double bands by coa PCR, previously reported in human isolates, suggests that milking personnel can play a role in the transmission of S. aureus.

Identification of Corynebacterium pseudotuberculosis isolates from sheep and goats by PCR.

The present study was carried out to estimate the prevalence of caseous lymphadenitis (CL) in sheep and goats slaughtered at the local abattoir in Elazig province located in the east of Turkey, between September and December 2000. A total of 2046 sheep and 2262 goat carcasses were examined during the study period and 118 abscessed lymph nodes, 89 from sheep and 29 from goats, were collected. Corynebacterium spp. strains were isolated from 81.4% of the abscesses, giving an overall prevalence of 2.2%. The prevalence was 3.5 and 1.1% in sheep and goats, respectively. PCR on DNA extracted from 96 suspicious isolates, using a pair of Corynebacterium pseudotuberculosis-specific primers, was positive for 93. Although cross-reaction with C. ulcerans, a human/bovine species, was observed, the PCR assay used in this study may successfully be applied for the diagnosis of CL in goats and sheep as an alternative to conventional methods, owing to its advantages of specificity and speed.