Aerobic Bacterial Pathogens and their Antimicrobial Susceptibility Pattern in a Tertiary Care Centre from Kanchipuram District, Tamil Nadu, India- A Retrospective Study

Abstract

Introduction: The infections of wound play an important role in delaying the healing of wound. Moreover, the widespread uses of antibiotics, together with the length of time lead to the emergence of resistant bacterial pathogens contributing to morbidity and mortality. So, there is a need for understanding the distribution of pathogens and the susceptibility pattern of the locality which becomes crucial in the treatment of wound infections. Aim: To determine the frequency and distribution of bacterial isolates and their drug susceptibility pattern isolated from inpatients and outpatients with pus and wound discharge. Materials and Methods: This retrospective study was conducted in the Department of Microbiology at Melmaruvathur Adhiparasakthi Institute of Medical Sciences and Research, Kanchipuram, Tamil Nadu, India, from May 2018 to April 2019. The pus samples were collected from the patients who visited outpatient department and were admitted at In Patient Department (IPD) in the hospital with skin and soft tissue infection. Bacteria were identified by culture and biochemical tests and antibiotic susceptibility test was done by disc diffusion method. Methicillin Resistant Staphylococcus aureus (MRSA) and Extended Spectrum Beta Lactamase (ESBL) in gram negative isolates were detected by cefoxitin disc diffusion method and double disc diffusion method respectively. Results: S.aureus (28.4%) was the most prevalent pathogen followed by P.aeruginosa (20.6%), Proteus (15%), Klebsiella (11.6%), Acinetobacter (8.3%), E.coli (7.6%), Enterococcus sp. (4.8%), S.pyogenes (3.3%). S.aureus and S.pyogenes were sensitive to vancomycin and linezolid. MRSA was found in 61% of isolates and of 61%, 13% of isolates showed inducible clindamycin resistance. Klebsiella, Pseudomonas and Acinetobacter isolates were resistant to multiple antibiotics including third generation cephalosporins. ESBL production was observed in 47% and 31% of Klebsiella and Pseudomonas isolates, respectively. The highest carbapenemase production was found in 21% of Acinetobacter sp. Conclusion: The findings of this study clearly help us to understand the developing resistance percentage among the bacteria causing wound and soft tissue infections and a need for the judicial use of antibiotics, an updated antibiotic policy for the hospital and practice of strict hospital infection control measures.

Keywords

• antimicrobial resistance
• bacterial isolates
• exudates
• pus