First isolation of methicillin-resistant Staphylococcus aureus from pigs’ clinical samples in Serbia

Methicillin-resistant Staphylococcus aureus is a highly important human pathogen that is also a significant concern in veterinary medicine. Despite the high prevalence of colonization, clinical infections with methicillin-resistant Staphylococcus aureus appear to be rare in pigs. Methicillin-resistant Staphylococcus aureus was isolated from a sow with endometritis and her five piglets with dermatitis originating from a Serbian farm. Identification of the strains was done by automated system and confirmed by polymerase chain reaction for mecA and nuc genes. Detection of Staphylococcal Cassette Chromosome mec type was performed by multiplex polymerase chain reaction. Antimicrobial susceptibility testing on erythromycin, clindamycin, gentamicin, kanamycin, tobramycin, ciprofloxacin, tetracycline, trimethoprim/sulfamethoxazole and vancomycin was done by disc diffusion method. Six isolated strains from the infected sow and her piglets showed resistance only to tetracycline beside resistance to all beta-lactam antibiotics. In the tested methicillin-resistant Staphylococcus aureus isolates, Staphylococcal Cassette Chromosome mec type V was present. To our knowledge, this finding is the first documented detection of methicillin-resistant Staphylococcus aureus from pigs’ clinical samples in Serbia. The results of our study indicate the emergence of methicillin-resistant Staphylococcus aureus in a pig farm in Serbia highlighting the threat of this antibiotic-resistant microorganism as a pathogen causing both animal and human infections

Genetic diversity of Mycoplasma hyopneumoniae isolates from conventional farrow-to-finish pig farms in Serbia

Mycoplasma hyopneumoniae is a primary agent associated with mycoplasma pneumonia and the porcine respiratory disease complex (PRDC). Various reports have indicated that different strains of M. hyopneumoniae are circulating in the swine population. Lysates from lung swabs from naturally infected pigs of different ages were tested according to a new variable number of tandem repeats (VNTR) genetic typing method based on the polyserine repeat motif of the P146 lipoproteoadhesin, which can be applied directly on clinical material without isolation of M. hyopneumoniae . The aim was to determine the diversity of M. hyopneumoniae isolates from conventional farrow-to-finish pig farms located in different geographical areas of Serbia. PCR amplification was carried out using M. hyopneumoniae -specific designed, conserved primers (p146MH — L and p146MH — R) flanking the region encoding the repeat motif, followed by sequencing and cluster analysis. Five groups of M. hyopneumoniae with thirteen to twenty-four serine repeats were observed. Analysis of three samples from each farm indicated that the specific isolate is ubiquitous in pigs of different ages. Furthermore, seven clusters were observed within 27 tested samples. The results indicated a considerable diversity among M. hyopneumoniae field isolates in the swine population from conventional farrow-to-finish farms in Serbia and suggest close genetic relatedness of the corresponding isolates