CORRELATION BETWEEN BIOFILM FORMATION AND ANTIBIOTIC RESISTANCE IN UROPATHOGENIC PSEUDOMONAS AERUGINOSA CAUSING CATHETER ASSOCIATED URINARY TRACT INFECTIONS

Rouchelle C. Tellis*, M. S. Moosabba and Ronald Aloysius Roche

ABSTRACT

Background and aim: Catheter associated urinary tract infections (CAUTI) accounts for 40% of nosocomial infections in hospitalized patients. P.aeruginosa is the third most common pathogen causing hospital acquired CAUTI. As there is paucity of literature about the pathogenesis of UTIs caused by P.aeruginosa, this study was undertaken with an aim to assess and correlate biofilm formation with antibiotic resistance in P.aeruginosa isolated from catheterized urine samples. Materials and Methods: 53 isolates of P.aeruginosa obtained from urine of patients with signs and symptoms of CAUTI following semi-quantitative culture on Mac Conkey agar were studied. Bacterial identification was based on colony morphology and standard biochemical tests. Antibiotic sensitivity was tested by Kirby Bauer disc diffusion method. Extended spectrum β-lactamase and metallo-β-lactamase production were detected by phenotypic disc confirmatory test and imipenem-EDTA double disk synergy test respectively. Biofilm formation was studied by microtitre plate assay. Results: Of the 53 isolates, 56.6% and 32.1% of were strong and moderate biofilm producers respectively. Among these 72.3% (24/47) were multidrug resistant which was statistically significant compared to weak/non-biofilm producers (P<0.001). MDR bacteria belonged to 5 different resistotypes. 21 (39.6%) and 11 (20.8%) isolates were ESBL and MBL producers respectively. Conclusion: This is one of the very few studies that has correlated the biofilm formation and antibiotic resistance in uropathogenic P.aeruginosa isolated from cases of CAUTI. Multi drug resistance was found to be significantly higher among the strong biofilm producers than the non-producers which implies that antibiotics should be chosen based on invitro antibiotic resistance patterns.

Keywords: Pseudomonas Aeruginosa, Uropathogenic, Biofilm, Multidrug Resistant.