Unmasking Bioflim- producing Gram Positive Cocci in Post-Operative Wound Infections

Abstract

Introduction-The third most frequent nosocomial infection to be documented is surgical site infection. They are responsible for the rising expense, morbidity, and death rates associated with surgery. The risk of surgical site infections has ranged from 2.5% to 41.9%.  Staphylococcus aureus are common from wound infections during surgery, which might act as stimulants for the development of systemic infections.  Objectives-The objective of this study was to isolate and identify various Gram  positive cocci from surgical site infected cases and detect their antimicrobial susceptibility pattern along with their capability of biofilm production. Materials and Methods- A total of 166 culture positive gram-positive cocci were isolated from infected surgical sites. Standard procedure and protocol were followed for identification of isolates. Antimicrobial susceptibility testing was done by Kirby Bauer disc diffusion method as per current CLSI guidelines. Methicillin resistance in staphylococcus isolates was tested by cefoxitin disc diffusion method. Biofilm formation detection done by Congo red and tube method. Results- Out of 166 Gram positive cocci, 112 were S. aureus and 54 were Enterococci. S. aureus isolates showed highest percentage resistance to penicillin (95.53) and erythromycin (59.82%). Methicillin resistance was found to be 43.75 %. Enterococci isolates (including Enterococci spp. and Enterococcus faecalis) showed highest percentage resistance to penicillin (98.14%) followed by ampicillin (88.88%). Among the 112 isolates of S. aureus, a significant majority, 84 isolates (75%), were found to be biofilm producers, in contrast, of the 54 isolates of Enterococcus spp., 30 isolates (55.5%) were biofilm producers. This indicates that a higher proportion of S. aureus isolates are capable of producing biofilms compared to Enterococcus spp.