Rapid Molecular Detection of Escherichia coli O157:H7.
- Author:
Hyoung Shik SHIN
1
;
Tae Geun OH
;
Jong Sung SHIN
;
Jung Hoon JI
;
Bo Ra SON
;
Kyeong Seob SHIN
Author Information
1. Department of Internal Medicine, College of Medicine, Chungbuk National University, Cheongju, Korea.
- Publication Type:Original Article
- Keywords:
Escherichia coli O157:H7;
Colony Hybridization;
Polymerase Chain Reaction
- MeSH:
Agar;
Diagnosis;
Escherichia coli O157;
Escherichia coli*;
Escherichia*;
Oligonucleotide Probes;
Polymerase Chain Reaction;
Shiga Toxin;
Sorbitol;
Vancomycin
- From:Korean Journal of Infectious Diseases
2001;33(2):97-103
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
BACKGROUND: Sorbitol fermenting Escherichia coli O157 were reported. And E. coli O157:H7 produce various Shiga toxin (Stx) such as Stx1, Stx2, or variants of Stx2. In this study, we tried to establish laboratory methods that detect E. coli O157:H7 quickly and precisely by analyzing sensitivity of colony hybridization test and PCR technique. METHODS: Stx1-producing E. coli ATCC 43890, Stx2-producing E. coli ATCC 43889, and Stx2vha- producing E. coli ATCC 51435 were tested. Three strains of E. coli were diluted with 0.1 g of diarrheal stools from 107 CFU to 101 CFU respectively. The stool samples were incubated overnight in MacConkey agar plates. A mean of 63 colonies were hybridized by stx1- and stx2-specific oligonucleotide probes. PCR for stx1 gene and stx2 gene was done after overnight- incubation of stool samples in the LB broth with vancomycin (6 ug/mL). Positive colonies by colony hybridization were confirmed by PCR for stx1 gene and stx2 gene. RESULTS: Colony hybridization test could detect Stx1-producing E. coli at 103 CFU per 0.1 g of stool, Stx2-producing E. coli at 105 CFU per 0.1 g of stool, and Stx2vha-producing E. coli at 104 CFU per 0.1 g of stool. PCR technique after enrichment in LB broth with vancomycin (6 ug/mL) could detect stx1-, stx2-, and stx2vha-containing E. coli at 10 CFU per 0.1 g of stool respectively. CONCLUSOIN: A combination of colony hybridization and PCR after enrichment in broth with vancomycin (6 ug/mL) is useful for the rapid and precise diagnosis of infections of Shiga toxin-producing E. coli O157:H7.
