Biofilm production and antimicrobial susceptibility pattern among urinary isolates

Urinary tract infection is the most commonly acquired bacterial infection. Bacterial biofilms play an important role in UTI and are responsible for persistent infections as well as higher antimicrobial resistance. The microorganisms in the biofilms are difficult to treat with antimicrobial agents causing public health problem. 

Aerobic bacterial isolates from urine samples submitted to microbiology laboratory.The isolates were tested for biofilm formation by Congo red agar method and Christensen tube method. Antimicrobial susceptibility tests were performed on these isolates by Kirby Bauer disk diffusion method. A total of 293 Gram negative bacilli and 59 Gram positive cocci were tested for biofilm production and antimicrobial susceptibility testing.

  • Gram-negative organisms were predominant (83.24%) of all the isolates.
  • Biofilm production was detected in 47% of the isolates.
  • Pseudomonas aeruginosa (51.7%), were the most common biofilm producing Gram negative bacilli followed by Escherichia coli (44.32%).
  • Enterococcus faecalis (77.8%) was the most common biofilm producing organism.

Biofilm forming isolates showed higher antimicrobial resistance as compared to biofilm non producer. Early detection of biofilm production in urinary isolates may aid clinicians in the treatment of urinary tract infections.