Correlation between biofilm formation and antimicrobial susceptibility pattern toward extended spectrum β-lactamase (ESBL)- and non-ESBL-producing uropathogenic bacteria

Abstract

Background: Urinary tract infections (UTIs) are the most common bacterial infection encountered worldwide and are associated with significant morbidity and mortality. Methods: The present study was undertaken to investigate the biofilm-forming ability, antibiotic susceptibility patterns and extended spectrum β-lactamase (ESBL) production of seven uropathogenic isolates comprising both Escherichia coli and Klebsiella pneumoniae. The morphological, cultural and biochemical tests for the identification of the isolates, antibiotic susceptibility test, detection of ESBL production, biofilm formation on 96-well microtiter plate and Congo red agar (CRA) media are performed. Results: The antimicrobial susceptibility profiles obtained in this study showed that the most active drugs gentamicin, amikacin and imipenem (100% sensitivity) were followed by amoxicillin-clavulanic acid (85% sensitivity), co-trimoxazole, ciprofloxacin (57% sensitivity) ceftazidime and kanamycin (50% sensitivity). All the isolates showed resistance to amoxicillin followed by ceftriaxone and cefotaxime (71% resistance), and the scenario gets more complicated because of the production of ESBL by five isolates (three E. coli isolates and two K. pneumoniae). The strains were also able to form biofilm as tested on CRA medium and by microtiter plate assay. The correlation between ESBL, non-ESBL and biofilm-producing E. coli and K. pneumonia was determined along with the multiple drug resistance patterns of E. coli and K. pneumonia. Conclusions: The findings of the study indicate that the emergence and rapid spread of such multidrug-resistant pathogens are of great concern. Early detection of ESBL-producing pathogen is of paramount clinical importance; therefore, strict infection control practices as well as therapeutic guidance for confirmed infection can be rapidly initiated.