Antibiotic resistance profiles of biofilm-forming bacteria associated with urine and urinary catheters in a tertiary hospital in Ile-Ife, Nigeria

Abstract

Background: Microorganisms that infect humans differ in pathogenesis, virulence factors and antimicrobial resistance profiles. In natural settings, bacterial cells are most often found in close association with surfaces and interfaces, in the form of multicellular aggregates commonly called biofilms. Given their ubiquity and importance in the microbial world, it is hardly surprising that biofilms have attracted the attention of the scientific community. Biofilm formation on medical implant devices such as catheters is also a major problem that is closely tied to the adhesion and resistance-related abilities of the biofilm.

Methodology: The ability of 216 bacterial isolates from mid-stream urine (100), catheter-stream urine (52) and catheter tips (64) to form biofilms was investigated using the tissue culture plate method, the tube and Congo red agar methods as well as their antibiotic resistance profiles using the agar disc diffusion method.

Results: These revealed that Klebsiella spp. was the predominant bacterial genera accounting for 45.8% of the total isolates. A total of 50 isolates were biofilm-formers with 22% identified by the tissue culture plate method and 78% identified by the Congo red agar method. Klebsiella spp. had the highest ability to form biofilm while antibiotic resistance profiles showed all the biofilmformers to be multiply antibiotic resistant with least resistance to ofloxacin.

Conclusion: It can therefore be concluded that some bacterial isolates associated with urinary tract infections have a propensity to form biofilm, thereby becoming multiply antibiotic resistant, and ofloxacin remains the antibiotic of choice in the treatment of such infections.