Role of semi-quantitative bacteriological culture in management of chronic wound infections

Abstract

Introduction: The role of quantitative microbiology in the management of wound infections is very crucial. In this study semi-quantitative swab technique is used as a simple procedure for assessing the bacterial load of chronic non healing wounds, thereby distinguishing the patients with infected ulcers from colonized one, thereby restricting the use of antibiotics only to the appropriate infected population. Aim: To assess the role of semi-quantitative bacterial culture of chronic non healing wounds in differentiating between colonised and infected wounds based on bacterial load. Setting and Design: This is a cross sectional study carried out in the Department of Microbiology in a tertiary care government medical College. Materials and Methods: Two wound swabs were taken using sterile cotton swabs from 100 patients with chronic non healing ulcer wounds. Semi-quantitative aerobic bacterial culture was done. Results: Among 100 patients for whom semi-quantitative culture was done, 72 patients showed growth, of which 21 patients had poly-microbial growth making a total of 93 isolates. Out of the total 93 isolates, 73 isolates had a significant count of ?3+, hence considered as pathogens. The most commonly isolated pathogens were Staphylococcus aureus (24.6%) and Pseudomonas aeruginosa (24.6%). 55.5% were Methicillin resistant Staphylococcus aureus (MRSA). 65% of Enterobacteriaceae were ESBL producers and 15% were AmpC ?-lactamase producers. Conclusion: This study emphasizes the importance and benefits of semi-quantitative bacterial culture technique in differentiating between pathogens and colonisers and enable refinement of antibiotic regimens and thereby curbing antibiotic resistance. Keywords: Chronic ulcers, Semi-quantitative culture, Bacterial load, Antibiotic resistance, ESBL, MRSA.