Biofilm formation and antibiotic resistance of urinary catheter associated bacteria from hospitalized patients, Bangladesh

Aims: Biofilm formation of bacteria inside the surface of urinary catheters triggers severe urinary tract infections (UTIs). This study aims to determine the biofilm forming capacity of bacteria isolated from urinary catheters of patients diagnosed with UTIs as well as comparison of antibiotic sensitivity patterns between biofilm and non-biofilm forming isolates. Methodology and results: A total of 40 urinary catheters were collected from 96 h catheterized patients. The isolated uropathogenic bacteria were identified and examined for biofilm formation using the microtiter plate method. Later, the isolates were subjected to antimicrobial susceptibility towards 12 antibiotics that commonly used for treating UTIs using the disk diffusion method. All the catheters were found colonized with two to five different bacterial species individually. Out of the 131 isolates from 40 catheters, Pseudomonas aeruginosa (38/131, 29%) was the predominant isolated bacteria followed by Escherichia coli (31/131, 24%), Proteus vulgaris (24/131, 18%), Klebsiella pneumoniae (21/131, 16%) and Staphylococcus aureus (17/131, 13%). Among these, the highest biofilm forming capacity was observed in P. aeruginosa (26%), followed by P. vulgaris (16%) and K. pneumoniae (13%). Regarding antibiotic resistance, biofilm forming bacteria showed resistance to multiple drugs except for carbapenems. Moreover, biofilm formers exhibited higher resistance than non-biofilm formers against antibiotics such as trimethoprim/sulfamethoxazole (100% vs 82%), amoxicillin-clavulanic acid (81% vs 55%), cefixime (85% vs 55%), ceftriaxone (81% vs 45%), cefalexin (93% vs 55%), amikacin (70% vs 45%), ampicillin (89% vs 73%), ciprofloxacin (70% vs. 36%) and ceftriaxone (81 vs 45%), (p- value<0.05). Conclusion, significance and impact of study: Most of the isolated uropathogenic bacteria from catheters were biofilm formers and multiple antibiotic resistant. Appropriate selection of antibiotics, meticulous hygiene practices in hospital settings and limiting the duration of catheterization can reduce biofilm formation and the emergence of antibiotic resistance.