Comparison of Tissue Culture Plate and Modified Tissue Culture Plate Method for Biofilm Detection in Members of Family Enterobacteriaceae

Abstract

Introduction: Microorganisms associated with biofilm formation have tendency to delay healing and show increased resistance to antimicrobial drugs resulting in chronic infection. This increases morbidity of patient as well as cost of treatment. Among the several methods of biofilm detection, Tissue Culture Plate (TCP) method and Modified Tissue Culture Plate (MTCP) method were studied. Aim: 1) To detect biofilm production in pus isolates by TCP method and MTCP method; 2) To compare Antimicrobial Susceptibility Testing (AST) of biofilm producing and biofilm non-producing isolates. Materials and Methods: In the present study, 240 pus samples obtained from patients attending Pt. B.D. Sharma PGIMS, Rohtak were studied. The organism was identified using standard microbiological procedures and AST was done by Kirby-Bauer disc diffusion method in accordance with CLSI guidelines 2016. Biofilm production was detected by TCP and MTCP methods. Results: A total of 160 isolates were studied which included Klebsiella spp. (n=51), Escherichia coli (n=41), Citrobacter spp. (n=32), Proteus spp. (n=26), Enterobacter spp. (n=10). Out of these, 52.5% isolates showed biofilm production by TCP and 65.6% by MTCP method. The sensitivity of MTCP was found to be higher than TCP method. Also, it was observed that 79.7% biofilm producing isolates were multidrug resistant as compared to 29% non- biofilm producing strains. Overall 55.6% isolates were found to be multidrug resistant. Conclusion: MTCP was found to be more accurate method for biofilm detection and quantification.

Keywords

• antimicrobial resistance
• biofilm detection
• wound infection