Analysis of Single Nucleotide Polymorphism in Fim H Gene from Uropathogenic E.coli

Abstract

Background: Urinary tract infection is defined as presence of microbial pathogens in the urinary tract with
associated symptoms. The infection affects both lower and upper urinary tracts and is known as acute cystitis
and polynephritis respectively. This study done to detect the variation of single nucleotide in FimH gene and
its correlation with the pathogenicity of uropathogenic Escherichia coli caused the urinary tract infection.
Materials and Methods: The study group included 150 patients with Urinary tract infection. There were
120 (80%) female and 30 female (20%) their age ranges between (5-55) years, seen in Al-Hussein Teaching
Hospital for the period from January 2019 to March 2019. The dominant form (48.39%) of patients with
urinary tract infection caused by UPEC was found in the age group of 24-39 years old. Urine samples
were collected from the patients. Bacterial isolation was identified by microscopic examination and culture
characteristic on selective media MacConky agar, Eosin Methylene Blue and Chrome agar. Then the isolated
were diagnosis by Vitek®2 system.
Results: Bacteriological results showed that 62(41.3%) isolates were characterized as Escherichia coli.
Genomic DNA was extracted from the bacterial culture for further molecular study to reveal C640T and
T591A fimH gene Polymorphism. Polymerase chain reaction-restriction fragment length polymorphism
(PCR-RFLP) technique was used for this purpose and digestion of the amplified DNA products by
ScarFI1390I and BsrI endonuclease respectively gave fragments with different molecular sizes which
express certain genotypes. This study detected that the prevalence rate of single nucleotide polymorphism
C640T FimH was (85.48%), endonuclease enzyme only affects the C allele sequence and it does not have
any influence on the T allele sequence. The prevalence rate of single nucleotide polymorphism T591A
fimH gene was (80.64%), endonuclease enzyme only affects the T allele sequence and it does not have any
influence on the A allele sequence.
The result show only 62 isolates (41.3%) were given typical morphological characteristics and biochemical
tests related to E. coli, while the rest 88 isolates (58.6%) belonged to pathogenic bacteria from different
genera.