Debalina Das1, Parthasarathi Chakrabarty2, Sipra Saha3, Nandita Pal4, Susmita Bhattacharya5
BACKGROUND
Urinary tract infections are some of the most common community-acquired as well
as nosocomial infections with E. coli being the most common pathogen. There is
increased antimicrobial resistance among bacteria worldwide. One of the
important mechanisms of resistance and virulence of bacteria is biofilm formation.
This study was conducted to find out the association between antibiotic resistance
pattern and biofilm formation in E. coli in non-catheterised patients of UTI in a
tertiary care hospital. We further wanted to determine the association between
the ability of E. coli to form biofilm and their ability to produce extended-spectrum
beta-lactamases (ESBLs) and carbapenemase in non-catheterised patients.
METHODS
Urine samples collected from 300 non-catheterised patients who had symptoms of
UTI were inoculated into MacConkey’s agar and blood agar media. Then
identification and antibiotic susceptibility tests were done. Phenotypic detection of
ESBL production was done by double disc diffusion test and carbapenemase
production was done by mCIM (modified carbapenem inactivation method) and
eCIM (EDTA carbapenem inactivation method) tests according to Clinical and
Laboratory Standards Institute (CLSI) 2019 guideline. Biofilm detection was done
by Congo red agar (CRA) method.
RESULTS
Out of 78 isolates E. coli were the commonest (61.5 %) isolate. Out of 48 E. coli
isolates from non-catheterised UTI patients, 26 (54.1%) were biofilm producers.
Antibiotic sensitivity pattern among the E. coli isolates showed the highest
susceptibility of the strains to amikacin, whereas the least susceptibility was for
amoxicillin. Out of 48 E. coli, 20 (41.6 %) were ESBL producers, 16 (33.33 %) E.
coli were carbapenemase producers. Significant association was found between
ESBL and biofilm production. However, no statistical significance was found
between the association of carbapenemase production and biofilm formation.
CONCLUSIONS
Uropathogenic E. coli is not an uncommon pathogen for biofilm formation even in
non-catheterised patients. The antibiotic-resistance rate was higher among biofilm
producing E. coli isolates. The biofilm forming ability was found to be significantly
higher among ESBL producing strains but was not statistically significant for
carbapenemase producing strains of E. coli.
