Assessment of Biofilm Forming Capability and Antibiotic Resistance in Proteus mirabilis Colonizing Indwelling Catheter

Background and Objective: Urinary tract infections from the use of an indwelling urinary catheter are one of the most common infections caused by Proteus mirabilis. Due to their biofilm-producing capacity and the increasing antimicrobial resistance in this microorganism, this study aimed to determine the prevalence, biofilm-producing capacity, antimicrobial resistance patterns, multidrug resistance and plasmid mediated resistance of the recovered isolates. Materials and Methods: A total of 50 urinary samples were collected from May to August, 2018 from patients on indwelling urinary catheters. Using routine microbiological and biochemical methods, 37 P. mirabilis were isolated. Biofilm forming capability was determined among the isolates using the tube method while antimicrobial susceptibility and plasmid curing were also performed. Results: All isolates were biofilm producers with 17(46%) being moderate producers while 20(54%) were strong biofilm formers. The study isolates exhibited a high resistance rate to empiric antibiotics, including ceftazidime (75.8%), cefuroxime (54.5%), ampicillin (69.7%) and amoxicillin-clavulanic acid (51.5%). Low resistance was seen in the fluoroquinolones, gentamicin and nitrofurantoin. Plasmid curing experiment revealed that most isolates lost their resistance indicating that resistance was borne on plasmids. Plasmid carriage is likely the reason for the high MDR rate of 56.8% observed. Conclusion: These findings necessitate the provision of infection control programs which will guide and implement policies.