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Frequency of type 1 fimbriae among E.coli subtypes isolated from patients with urinary and gastrointestinal tract infection
Hosein Heydari 1, Mohmmad Reza Shokrollahi1, Zahra Movahedi 1*
1- Department of Pediatric Infectious Diseases, School of Medicine, Qom University of Medical Sciences and Health Services, Qom, Iran
*Corresponding author: [email protected]
Abstract: The gut constitutes an important reservoir of bacteria causing extra intestinal infections such as urinary tract infection (UTI). According to the fecal–vaginal–urethral hypothesis, E. coli strains causing UTI usually derive immediately from the host’s own fecal and perineal flora. We assessed multiplex PCR assays to detect type 1 fimbriae among E.colisubtypes in children with symptom of urinary tract or gastrointestinal infection. Material and Methods: We used multiplex PCR assays that detect enteropathogenic E. coli (EPEC) isolates, enteroaggregative E. coli (EAEC) isolates, enterotoxigenic E. coli (ETEC) isolates, enteroinvasive E. coli (EIEC) isolates, and enterohemorrhagic E. coli (EHEC) isolates. Also the isolates were examined for type 1 fimbriae. The targets selected for each group were eae for EPEC isolates, aggR for EAEC isolates, and the genes encoding heat-labile and heat-stable toxins for ETEC isolates, stx1 and stx2 for EHEC isolates, invE for EIEC isolates and fimH for detection of type 1 fimbriae. Results: In this study more than 80% of E. coli isolates from the Urine and rectal swab samples of childrens have the genes for type 1 fimbriae. Among 101 rectal swab specimens tested, 48.5% had fimHgene, 2% were EHEC, 3% ETEC and 4% EAEC; we also detected mixed infections, 1% with ETEC and EHEC, 4% EHEC withfimH gene, 11.9% ETEC with fimH gene, 5.9% EAEC with fimH gene, 6.9% EHEC with ETEC with fimH gene, 1% EHEC and EAEC with fimH gene, 2% ETEC and EAEC with fimH gene. EIEC and EPEC were not found among the isolates tested. From 101 urine specimens tested 56.4% had fimH gene, 2% were EHEC, 2% ETEC, 3% EAEC; we also detected mixed infections, 1% with EAEC and EHEC, 7.9% EHEC with fimH gene, 9.9% ETEC with fimH gene and 3% EAEC with fimH gene. EIEC and EPEC were not found among the isolates tested. Discussion: As our understanding of the molecular aspects and detection of more than 80% fimH gene in E. coli strains it has been possible to design vaccines that target adaptive responses against specific bacterial proteins such as FimH tip adhesin of type 1 fimbriae. The antibodies produced can interfere with the function of essential bacterial virulence factors and can prevent the bacteria from adhering to and invading the host.
[Hosein Heydari, Mohmmad Reza Shokrollahi, Zahra Movahedi. Frequency of type 1 fimbriae among E.coli subtypes isolated from patients with urinary and gastrointestinal tract infection. Life Sci J 2013;10(7s):578-582] (ISSN: 1097-8135). http://www.lifesciencesite.com. 91
Key Word: E. coli subtypes, multiplex PCR, type 1 fimbriae.
