Korean J Pediatr.  2015 Jan;58(1):20-27. 10.3345/kjp.2015.58.1.20.

Molecular typing of uropathogenic Escherichia coli isolated from Korean children with urinary tract infection

• Yun KW
• Kim DS
• Kim W
• Lim IS

• KMID: 2284463
• DOI: http://doi.org/10.3345/kjp.2015.58.1.20

Abstract

PURPOSE
We investigated the molecular types of uropathogenic Escherichia coli (UPEC) by using conventional phylogrouping, multilocus sequence typing (MLST), and fimH genotyping.
METHODS
Samples of patients younger than 18 years of age were collected from the Chung-Ang University Hospital over 2 years. Conventional phylogenetic grouping for UPEC strains was performed by polymerase chain reaction (PCR). Bacterial strain sequence types (STs) were classified on the basis of the results of partial sequencing of seven housekeeping genes. In addition, we analyzed nucleotide variations in a 424-base pair fragment of fimH, a major virulence factor in UPEC.
RESULTS
Sixty-four UPEC isolates were analyzed in this study. Phylogenetic grouping revealed that group B2 was the most common type (n=54, 84%). We identified 16 distinctive STs using MLST. The most common STs were ST95 (35.9%), ST73 (15.6%), ST131 (12.5%), ST69 (7.8%), and ST14 (6.3%). Fourteen fimH allele types were identified, of which 11 had been previously reported, and the remaining three were identified in this study. f1 (n=28, 45.2%) was found to be the most common allele type, followed by f6 and f9 (n=7, 11.3% each). Comparative analysis of the results from the three different molecular typing techniques revealed that both MLST and fimH typing generated more discriminatory UPEC types than did PCR-based phylogrouping.
CONCLUSION
We characterized UPEC molecular types isolated from Korean children by MLST and fimH genotyping. fimH genotyping might serve as a useful molecular test for large epidemiologic studies of UPEC isolates.

Keyword

Uropathogenic Escherichia coli; Phylogeny; Multilocus sequence typing; fimH protein

MeSH Terms

Alleles
Child*
Epidemiologic Studies
Genes, Essential
Humans
Molecular Typing*
Multilocus Sequence Typing
Phylogeny
Polymerase Chain Reaction
Urinary Tract Infections*
Uropathogenic Escherichia coli*
Virulence