Antibiotic resistance, biofilm forming ability, and clonal profiling of clinical isolates of from southern and northeastern India.

Background: is a pathogen endemic in India and sometimes deadly for patients in intensive care units.

Objectives: To determine the antibiotic-resistance pattern, biofilm forming ability, and clonal type of from isolates collected in Tamil Nadu (south) and the Mizoram (northeast) regions of India.

Methods: We collected isolates from diagnostic laboratories in Tamil Nadu and Mizoram. An antibiotic susceptibility test was performed according to Clinical Laboratory and Standards Institute methods. Antibiotic-resistant determinants such as , , , , , and were confirmed by polymerase chain reaction (PCR). All isolates were further studied for biofilm forming ability. Enterobacterial repetitive intergenic consensus (ERIC)-PCR was used for clonal analysis.

Results: A study of 206 clinical isolates showed 52.9% prevalence of methicillin-resistant in Tamil Nadu and 49.4% in Mizoram. Minimum inhibitory concentration tests showed a high prevalence of 67% oxacillin resistance in isolates from Tamil Nadu and 49% in isolates from Mizoram. PCR showed 53% in Tamil Nadu and 49% in Mizoram. Vancomycin-intermediate resistance (VISA) prevalence was lower in isolates from Tamil Nadu (4%) and Mizoram (5%). All methicillin-resistant (MRSA) isolates formed biofilms. Clonal analysis revealed a genetic relatedness between the isolates.

Conclusions: The prevalence of MRSA is high in the regions studied, with most of the clinical isolates being multidrug resistant. Adopting appropriate community-based preventive measures and establishing antimicrobial stewardship is highly recommended to minimize the dissemination in antibiotic resistance.