MICROARRAY-BASED ANALYSIS OF STAPHYLOCOCCUS AUREUS ISOLATES FROM NON-CLINICAL SOURCE

This study was aimed to genotyped virulence, toxin and resistance genes of 30 S. aureus isolates from pigs using DNA microarray. The 30 isolates analyzed in this study all belonged to clonal complexes (CC) CC1 (3; 10%), CC5 (3; 10%), CC15 (16; 53.33%) and CC152 (8; 26.66%), respectively. Of antibiotic resistance-associated genes reported; Twenty out of 30 isolates (66.66%) carried the beta-lactamase operon (blaZ/I/R) and the tetracycline resistance gene (tetK), respectively. Also, the macrolide resistance gene (ermA/msrA) were detected in ten isolates (33.33%), the multidrug efflux pump resistance gene (sdrM) was detected in seven isolates (23.33%) and one isolates (3.33%) harboured the chloramphenicol resistance gene (cat). None of the isolates harboured genes conferring methicillin resistance. In terms of genes encoding enterotoxins; seb was detected among all isolates of CC15 while the enterotoxin gene cluster egc and a distinct variant of the enterotoxin A (sea-N315) were detected among isolates of CC5 and CC152, respectively. Two CC152 isolate was positive for genes encoding the Panton-Valentine leukocidin (lukF-PV+lukS-PV). In addition, all the isolates harboured the genes encoding for intracellular adhesion proteins (icaA/C/D) and the biofilm-associated genes (clfA and clfB) except for CC1 isolates. The capsular genes cap5 and cap8 were detected in isolates of CC5 and CC15 while only cap5 was present in CC152 isolates. The study provides detailed genotyping data on the population structure, presence of toxins and antibiotic resistance markers of S. aureus isolates and indicates the importance of the microarray technique in analyzing multiple gene contents of bacteria.