Occurrence of fimH gene in Escherichia coli isolates from urinary tract-infected patients
Shekhar Kumar Jhaa, Milan Kumar Upretia, Sanjit Shresthab, Anup Muni Bajracharyac, Anjali Rawald, Upendra Thapa Shresthad *
a GoldenGate
International College, Department of Microbiology, Battisputali, Kathmandu,
Nepal
b Department
of Pathology, Kirtipur Hospital, Kathmandu, Nepal
c Department
of Microbiology, Balkumari College, Narayangarh, Chitwan, Nepal
d
Central Department of Microbiology, Tribhuvan University, Kirtipur, Kathmandu,
Nepal
* Corresponding author: Dr. Upendra Thapa Shrestha, Assistant
Professor, Central Department of Microbiology, Tribhuvan University, Kirtipur,
Kathmandu, Nepal. Email: upendra.thapashrestha@cdmi.tu.edu.np
/ upendrats@gmail.com
ABSTRACT
Background: Urinary tract infections (UTIs)
remain a major global public health concern, with Escherichia
coli accounting for most community-acquired cases. The
pathogenicity of uropathogenic E. coli (UPEC) is closely
linked to virulence factors such as Type 1 fimbriae, encoded by the fimH gene, which promotes
adhesion to uroepithelial cells. This study investigates the prevalence of the fimH gene in E. coli isolates recovered
from UTI patients and examines its association with extended-spectrum
β-lactamase (ESBL) production and multidrug resistance (MDR).
Methods: A hospital-based cross-sectional
study was conducted from January to July 2022 at the Department of
Microbiology, Kirtipur Hospital, Kathmandu, Nepal. A total of 1200 mid-stream
urine samples were processed during the study period to isolate and identify
the bacterial pathogens, including E. coli. The antimicrobial susceptibility patterns of E. coli isolates were
performed by using modified Kirby-Bauer disc diffusion testing following CLSI
guidelines. Phenotypic confirmation of ESBL production was
performed using the Double Disc Synergy Test. Genomic DNA was extracted using the
phenol: chloroform method, and the fimH
gene was amplified by conventional PCR using specific primers.
Results: Among 1,200 urine samples analyzed, 330
(27.5%) showed significant bacterial growth, with E. coli
representing 293 (88.8%) of isolates. Among the first-line antibiotics tested, E.
coli showed the highest resistance to amoxicillin and ceftazidime, while the
highest resistance was observed to tigecycline among second-line agents. In
contrast, resistance to imipenem, cefoperazone-sulbactam, and piperacillin-tazobactam
was limited, with no resistance to polymyxin B and colistin. ESBL production was detected in 96 (32.8%)
of E. coli strains. ESBL-producing isolates exhibited
significantly higher resistance to ceftazidime, levofloxacin, ofloxacin, nitrofurantoin,
and imipenem than non-ESBL producers. 57% of the UPEC were
MDR strains. PCR analysis revealed that 70.8% of ESBL-producing isolates and 84.4%
of MDR strains carried
the fimH gene.
Conclusion: Escherichia coli was the predominant uropathogen,
with a high prevalence of ESBL production and multidrug resistance, while
nitrofurantoin and amikacin remained the most effective antimicrobial agents.
The fimH gene was highly prevalent
among UPEC isolates, particularly in ESBL-producing and MDR strains, providing
preliminary molecular epidemiological data on circulating UPEC strains in
Nepal.
Keywords:
Uropathogenic E. coli, ESBL, Multidrug resistant, fimH
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