Oktay Keskin

Investigation of the antibiotic resistance and biofilm formation of Staphylococcus aureus strains isolated from gangrenous mastitis of ewes

In this study, Staphylococcus aureus strains (n = 110) isolated from seven ewe flocks in Sanliurfa, Turkey were screened for antibiotic resistance and biofilmforming ability as well as for genes associated with antibiotic resistance and biofilm-forming ability. All isolates were found to be susceptible to oxacillin, gentamicin, clindamycin, cefoxitin, tetracycline, vancomycin, amoxicillin-clavulanic acid, ciprofloxacin and sulphamethoxazole-trimethoprim. The percent proportions of strains resistant to penicillin G, ampicillin and erythromycin were 27.2% (n = 30), 25.4% (n = 28) and 6.3% (n = 7), respectively. Regarding the antibiotic resistance genes, 32 (29%) isolates carried the blaZ and 8 (7.2%) the ermC gene. Other resistance genes were not detected in the isolates. All isolates showed biofilm-forming ability on Congo red agar (CRA), while 108 (98.18%) and 101 (91.81%) of them were identified as biofilm producers by the use of standard tube (ST) and microplate (MP) methods, respectively. All isolates carried the icaA and icaD genes but none of them harboured the bap gene. The results demonstrated that S. aureus isolates from gangrenous mastitis were mainly resistant to penicillins (which are susceptible to the staphylococcal beta-lactamase enzyme), and less frequently to erythromycin. Furthermore, all of the S. aureus isolates produced biofilm which was considered a potential virulence factor in the pathogenesis of staphylococcal mastitis.

SALMONELLA, CAMPYLOBACTER, AND CHLAMYDOPHILA IN BALD IBIS (GERONTICUS EREMITA) FECES IN TURKEY

Abstract:  The aim of this study was to investigate the presence of Campylobacter spp., Salmonella spp., and Chlamydophila psittaci in fecal samples of bald ibises (Geronticus eremita) housed in a conservation facility in Turkey. A total of 82 fecal samples were collected from cages and evaluated by bacteriologic methods and a polymerase chain reaction (PCR) technique for Campylobacter spp. and Salmonella spp. and by PCR for C. psittaci. Campylobacter spp. were isolated from 24 of 82 fecal samples (29.2%). Of these 18 (75%), 4 (16.7%) and 2 (8.3%) were Campylobacter jejuni, Campylobacter coli, and other Campylobacter spp., respectively. Salmonella spp. were detected in 8 fecal specimens.(9.7%) by PCR. The presence of C. psittaci was not detected in the bald ibises studied. The results suggested that the bald ibises in this present study might be at a higher risk of infection with Salmonella spp. and Campylobacter spp.

Seroprevalance of Coxiellosis in cows, sheep, goats and humans in Diyarbakir region of Turkey

Dicle University, Faculty of Veterinary, Department of Microbiology, Diyarbakir, Turkey. Harran University, Faculty of Veterinary, Department of Microbiology, Sanliurfa, Turkey. Dicle University, Faculty of Medicine, Department of Microbiology, Diyarbakir, Turkey. Dicle University, Faculty of Veterinary, Department of Virolology, Diyarbakir, Turkey. Dicle University, Faculty of Veterinary, Department of Food Hygiene and Technology, Diyarbakir, Turkey.

Seroprevalence of Rhodococcus equi in horses in Israel

Rhodococcus equi is a common cause of pneumonia in foals and has extensive clinical, economic and possibly zoonotic consequences. This bacterium survives well in the environment and may be considered as normal flora of adult horses. Certain strains of this bacterium are extremely virulent in foals, and early identification and intervention is crucial for prognosis. Rhodococcus equi is endemic in many parts of the world and occasionally isolated in Israel. This study was designed to evaluate R. equi seroprevalence in adult horses in Israel to indirectly indicate the potential level of exposure of susceptible foals. Sera were collected from 144 horses during spring 2011 and from 293 horses during fall 2014, and the presence of antibodies against virulent R. equi was detected by enzyme-linked immunosorbent assay. Equine seroprevalence of R. equi was found to be 7.6% in 2011 and 5.1% in 2014. Only one farm had seropositive horses in 2011, whereas several farms had seropositive horses in 2014. No significant risk factors for seropositivity were found. Rhodococcus equi appears to be endemic in Israel. This is the first survey of R. equi in Israel that provides information on the epidemiology of this important bacterium.

Comparative evaluation of three serological tests for the detection of Brucella antibodies from infected cattle herds

ABSTRACT Three serological methods used in the diagnosis of bovine brucellosis were conducted to assess the diagnostic sensitivity of the tests in brucellosis-infected herds. A total of 487 unvaccinated bovine serum samples collected from infected herds in the southeast region of Turkey having history of abortion with a known bacteriological status for the last three years were tested for anti-Brucella antibodies detection using the Rose Bengal plate test (RBPT), the complement fixation test (CFT) and indirect enzyme-linked immunosorbent assay (i-ELISA). A protein A/G conjugate was used in i-ELISA in order to reduce background reactivity and to use the test in multispecies if required. The serum samples were found as positive in 74.3%, 83.7% and 81.3% when we employed the CFT, i-ELISA and RBPT, respectively. i-ELISA could be used as a single test or combined with the RBPT for serologic diagnosis for brucellosis in infected herds.