Antimicrobial Resistance, Phenotypic Characteristics, and Biofilm Production in Citrobacter freundii Isolates Obtained from Urinary Tract Infections

Abstract

Objective: To evaluate the link between phenotypic traits, antimicrobial resistance, and biofilm-producing capacity of urinary isolates of Citrobacter freundii (C. freundii). Methods: Both pan-antibiotic-susceptible and -resistant C. freundii isolates (n = 120) obtained from laboratory-confirmed urinary tract infections were analyzed for their link between antimicrobial resistance, phenotypic characteristics, and biofilm production. Results: Of the total C. freundii isolates (n = 120), 30% (37/120) of them formed large colonies. Among the total large colonies produced (n = 37), they were present in 21.62%, 10.81%, 13.5%, 16.2%, 21.62%, and 16.21% in the control group, CIP-group, FOS-group, COT-group, Gent-group, and ESBL groups, respectively. Compared to the pan-susceptible isolates, the occurrence of large-sized-colony-forming strains was relatively reduced in most of the drug-resistant groups. The overall distribution of mucoid colonies produced (n = 54) includes 9.25%, 18.51%, 16.66%, 18.51%, 20.3%, and 16.66% in the control group, CIP-group, FOS-group, COT-group, Gent-group, and ESBL groups, respectively. Of the total isolates that produced biofilm (n = 51), 11.76% of isolates showed biofilm formation in the control group. Alternatively, the rate was found to be 15.68%, 11.76%, 25.49%, 19.6%, and 15.68% in the CIP-group, FOS-group, SXT-group, Gen-group, and ESBL-groups, respectively. Conclusion: This study correlates the association between phenotypic characteristics, antimicrobial resistance, and biofilm production, the three main characteristics of C. freundii.