Characterisation of Antibiogram and Some Virulence Attributes in Methicillin Resistant Staphylococcus Aureus (MRSA) of Canine Origin

The present research was planned to study the incidence, virulence properties and antibiogram of Staphylococcus aureus isolates recovered from skin and soft tissue infections in canines. The study includes 16 cases of wound and post-operative infection cases presented to Teaching Veterinary Clinical Complex of the institute. Eight of these cases revealed the presence of S. aureus. All the isolates were confirmed by the polymerase chain reaction (PCR) amplification of 280 bp of nuc gene. On drug sensitivity against commonly used antibiotics, the isolates revealed six antibiotypes. Out of eight isolates, six were methicillin-resistant and two were intermediately sensitive. None of the isolate was found resistant to vancomycin. Highest resistance was observed against-lactam antibiotics, and all the isolates were susceptible to gentamicin and amikacin. By PCR, five out of the eight isolates were positive for the amplification of the 533 bp fragment of mecA gene, but none revealed amplification of vanA gene. Apart from antibiotic resistance, for determining of pathogenic attributes, tests were performed for in-vitro biofilm formation and PCR amplification for the presence of coa gene which encodes for coagulase. In biofilm production, five isolates did not produce biofilm (62.5%), whereas three were biofilm producers (37.5%). All the isolates were found positive for PCR amplification of coa gene and revealed a single genotype based on the size of the coagulase amplicon.