Molecular detection and typing of methicillin-resistant and methicillin-resistant coagulase-negative staphylococci isolated from cattle, animal handlers, and their environment from Karnataka, Southern Province of India.

BACKGROUND AND AIM

Methicillin-resistant staphylococci are among the emerging pathogens which have become a threat to both human and animal health. The present investigation intended to examine the occurrence and the molecular characteristics of methicillin-resistant (MRSA) and methicillin-resistant coagulase-negative staphylococci (MRCoNS) recovered from cattle, its handlers, and their environment.

MATERIALS AND METHODS

A total of 666 specimens were subjected to culture method and genus-specific polymerase chain reaction (PCR) for the identification of . Methicillin resistance was substantiated by PCR identification of A and C resistance determinants. Species-specific identification of A positive isolates was conducted by multiplex PCR. The unidentified species were deciphered by 16S rRNA gene sequencing approach. The A positive isolates were further characterized by staphylococcal cassette chromosome (SCC) typing and multilocus sequence typing (MLST).

RESULTS

Duplex PCR identified 728 isolates, of which 66 (9%) were positive for A gene. MRSA constituted 24% of the total A positive isolates. Among MRCoNS, (42%), and (11%) were the most common species identified. Overall, 47% of the A positive isolates belonged to SCC type V. MLST analysis showed eight different sequence types (STs) among MRSA isolates of which five were novel STs. Among methicillin-resistant , 19 different STs were found, of which nine novel STs were detected.

CONCLUSION

The increase in the prevalence of A positive staphylococci, especially MRCoNS in cattle is a great concern in view of their transmission potential. Hence, continuous monitoring and molecular characterization of methicillin-resistant staphylococci should be elucidated in human and animal sectors so as to prevent the spread of these resistant pathogens.