Microbiological Profile of Surgical Site Infections at a Tertiary Care Hospital in Rajasthan, India: A Cross-sectional Study

Introduction: The high morbidity and mortality rates and economic costs represented by Surgical Site Infections (SSIs) emphasise the rationale for monitoring SSI rates, modifying antibiotic prophylaxis policies, and reducing risk factors. Hence, the present work was carried out to study the etiological microorganisms contributing to SSIs and their antimicrobial susceptibility pattern. Aim: To study the microbiological profile of SSIs at a tertiary care hospital. Materials and Methods: The present cross-sectional study was conducted at the Department of Microbiology, JLN Medical College, Ajmer, Rajasthan, India, from December 2019 to August 2020. A total of 1828 patients who underwent surgery in the hospital during the study period, out of which, 110 patients developed signs and symptoms of SSI, were further included in the study. Samples (pus or wound swab) were received from 110 patients clinically diagnosed with SSI and processed as per standard microbiological techniques. Antimicrobial Susceptibility Testing (AST) was done by the modified Kirby-Bauer disc diffusion method. The demographic and clinical parameters, such as age, gender, type of anaesthesia used in emergency or elective surgery and wound type, were considered; they were tabulated and expressed as frequency and percentage. The findings were statistically analysed and the p-value below 0.5 was considered statistically significant. Results: The prevalence of SSI was 6.02%. The rate of SSI was highest in those over 60 years of age, 9/92 (9.78%); males, 41/592 (6.93%); those under General Anaesthesia (GA), 45/474 (9.50%); emergency surgery, 63/680 (9.26%); and those with dirty wound types, 23/72 (31.94%). There was a predominance of Gram-negative bacilli, 50/80 (62.5%), as the aetiological agents for SSI. The predominant organism isolated was E. coli 19 (23.75%), followed by Coagulase Negative Staphylococci (CoNS) 18 (22.50%), Klebsiella spp. 16 (20%), S. aureus 12 (15%), P. aeruginosa 7 (8.75%), Non fermenting Gram-negative Bacilli (NFGNB) 3 (3.75%), Enterobacter spp. 3 (3.75%), and Citrobacter spp. 2 (2.50%). Gram-positive cocci showed 100% sensitivity to linezolid, while in Gram-negative bacilli, imipenem 36/50 (72%) was found to be the most effective drug. Conclusion: SSIs are mostly caused by Gram-negative bacteria, particularly Escherichia coli and Klebsiella spp., which are the most predominant pathogens linked with SSI. The bacterial isolates detected in the present study showed a high degree of resistance for routinely prescribed antimicrobials in the facility. Therefore, a higher degree of collaboration and cooperation among hospital administration, Surgeons, and Microbiologists to formulate the effective antibiotic policy for SSI treatment based on local antibiograms and to implement stringent control measures, which are crucial for reducing SSI rates in the hospital.