Characterization of Methicillin-Resistant Isolated from Healthy Turkeys and Broilers Using DNA Microarrays.

Methicillin-resistant (MRSA) is a major human health problem and recently, domestic animals are described as carriers and possible reservoirs. Twenty seven isolates from five turkey farms ( = 18) and two broiler farms ( = 9) were obtained by culturing of choana and skin swabs from apparently healthy birds, identified by Taqman-based real-time duplex -A-PCR and characterized by typing as well as by a DNA microarray based assay which covered, amongst others, a considerable number of antibiotic resistance genes, species controls, and virulence markers. The antimicrobial susceptibility profiles were tested by agar diffusion assays and genotypically confirmed by the microarray. Five different types (3 in turkeys and 2 in broilers) were detected. The majority of MRSA isolates (24/27) belonged to clonal complex 398-MRSA-V. The most frequently occurring types were accordingly t011, t034, and t899. A single CC5-MRSA-III isolated from turkey and CC398-MRSA with an unidentified/truncated SCC element in turkey and broiler were additionally detected. The phenotypic antimicrobial resistance profiles of isolated from both turkeys and broilers against 14 different antimicrobials showed that all isolates were resistant to ampicillin, cefoxitin, oxacillin, doxycycline, and tetracycline. Moreover, all isolated from broilers were resistant to erythromycin and azithromycin. All isolates were susceptible to gentamicin, chloramphenicol, sulphonamides, and fusidic acid. The resistance rate against ciprofloxacin was 55.6% in broiler isolates and 42.1% in turkey isolates. All tetracycline resistant isolates possessed genes K/M. All erythromycin-resistant broiler isolates carried . Only one broiler isolate (11.1%) carried genes , and , while 55.6% of turkey isolates possessed A and B genes. Neither PVL genes (F/S-PV), animal-associated leukocidin (M and -P83) nor the gene encoding the toxic shock syndrome toxin (1) were found in turkey and broiler isolates. In conclusion, the detection of MRSA in healthy turkeys and broilers with even additional antibiotic resistance markers is of major public health concern. The difference in antibiotic resistance and virulence markers between MRSA isolates from turkeys and broilers was addressed.