Bacterial spectrum in surgical wound infection, its susceptibility pattern and biofilm formation among isolates

Abstract

Topic: Bacterial spectrum in surgical wound infection, its susceptibility pattern and biofilm formation among isolates. Aim: To identify the spectrum of bacterias associated with wound infection and their antimicrobial susceptibility pattern and biofilm formation. Introduction: Chronic wounds are severe worldwide problem. Wounds are considered chronic when healing fails to proceed normally and anatomic and functional integrity of the skin is not achieved in approximately 1 month. Chronic wound include diabetic foot ulcer, pressure or decubitus ulcer, venous leg ulcer and non-healing surgical site infection.1Annual incidence is of diabetic ulcer in India in a population based study is 1.0 to 4.1% 1. Biofilm formation is widespread in chronic wounds. The biofilm phenotype gives rise to drug resistant strains resulting in treatment failure. Materials and Methods: A prospective study was done at a tertiary care Hospital in North Karnataka for a period of 1 year from February 2017 to January 2018. A total of 241 samples in an age group of 20 to 70 years with history of wound infection attending surgery department were collected with a sterile cotton swab and processed as per CLSI standards.2 Detection of biofilm formation by modified congo red agar method, tissue culture plate method and tube assay method. Results: A total of 241 pus samples were collected. 65.56% (158) showed bacterial growth and 34.43% (83) showed no growth. The study group comprised 139 male and 102 female patients in the ratio of 1.39:1. Age range was 20-70 years Maximum samples were in the age group of 21-30 years. 44.93% (71) of isolates were obtained Gram positive organisms and 55.06 % (87) were Gram negative. Escherichia coli was the predominant isolated organism 16.18% (39). Followed by staphylococcus aureus 9.54% (23). 76 out of 158 sample showed biofilm formation (48.01%). Staphylococcus aureus was dominant biofilm former. 81.57% (62) of biofilm producers were multiple drugs resistant. Conclus