Abstract
BACKGROUND: Escherichia coli accounts for 70%–95% of urinary tract infections (UTIs). UTI is a serious health
problem with respect to antibiotic resistance and biofilms formation being the prime
cause for the antibiotic resistance. Biofilm can restrict the diffusion of substances
and binding of antimicrobials. In this context, the present study is aimed to perform
in vitro detection of biofilm formation among E. coli strains isolated from urine and to correlate
their susceptibility pattern with biofilm formation.
MATERIALS AND METHODS: A total of 100 E. coli strains isolated from patients suffering from UTI were included in the study. The
identification of E. coli was performed by colony morphology, Gram staining, and standard biochemical tests.
The detection of biofilm was carried out by Congo Red Agar (CRA) method, tube method
(TM), and tissue culture plate (TCP) method. Antimicrobial sensitivity testing was
performed by Kirby–Bauer disc diffusion method on Muller–Hinton agar plate.
RESULTS: Of the 100 E. coli strains, 49 (49%) and 51 (51%) were from catheterized and noncatheterized patients,
respectively. Biofilm production was positive by CRA, TM, and TCP method were 49 (49%),
55 (55%), and 69 (69%), respectively. Biofilm producers showed maximum resistance
to co-trimoxazole (73.9%), gentamicin (94.2%), and imipenem (11.6%) when compared
to nonbiofilm producers. Significant association was seen between resistance to antibiotic
and biofilm formation with a P = 0.01 (<0.05).
CONCLUSION: A greater understanding of biofilm detection in E. coli will help in the development of newer and more effective treatment. The detection
of biofilm formation and antibiotic susceptibility pattern helps in choosing the correct
antibiotic therapy.
Key words
Antibiotic resistance - biofilm -
Escherichia coli
