Biofilm Production and Antibiogram Profiles in Escherichia coli and Salmonella

Salmonella and Escherichia coli are important enteric pathogens associated with a variety of infections. Biofilm formation and antimicrobial resistance are important characteristics making these pathogens a concern in terms of strong attachment to substrates, expression of virulence markers and difficult removal. The present study investigates the biofilm-forming ability and antibiogram patterns among E. coli and Salmonella spp. A total of 200 E. coli and 100 Salmonella isolates received at National Salmonella and Escherichia Centre were identified by biochemical testing, followed by serotyping. Biofilm production was detected by Tissue Culture Plate method. The isolates were further subjected to Antibiotic Susceptibility Testing by the Kirby-Bauer disk diffusion method. 113 (56.5%) E. coli isolates and 79 (79%) Salmonella isolates were detected as biofilm producers. A total of 114(57%)E. coli isolates and 31(31%) Salmonella isolates were found to be resistant to multiple drugs when Antibiotic Susceptibility Testing was carried out. Antibiotic resistance was found to be significantly higher in biofilm producing salmonella (p = 0.001) whereas in the case of E. coli the difference remained non-significant (p = 0.4454). The capability to produce biofilm along with acquiring high level of antimicrobial resistance in salmonella and E. coli provide enhanced survival potential in adverse environments. Therefore, it becomes a serious cause of concern for public health authorities considering the virulence of these bacteria and their association with different disease conditions and requires urgent intervention with regards to control and prevention strategies.