Molecular epidemiological investigation of enterohaemorrhagicEscherichia coliisolates in Japan

Abstract

SUMMARY We have established several measures for control and prevention of EHEC infection including designation of the disease as notifiable since there was the sudden increase in the incidence of infection with EHEC O157:H7 in Japan in 1996, involving multiple outbreaks. Improvements in methodologies for isolation of these organisms and enhanced laboratory screening have revealed a variety of sources in food and animals. Although there seems to be a bovine reservoir for O157 EHEC in Japan as well as North America and UK, different foods have been linked to EHEC infection including salads, radish sprouts and salmon roe. There is clear evidence that divergent clones of EHEC O157:H7 are prevalent throughout Japan based on laboratory surveillance, however, we still need to better define the role of EHEC serogroups other than Escherichia coli O157 as important causes of human infection.

Use of epidemiologic data to measure the impact of food safety control programs

“…All laboratories use standardized methods to subtype E. coli O157:H7, other EHEC, Salmonella, L. monocytogenes, Shigella, and Staphylococcus aureus, and they can rapidly compare the molecular fingerprints of their isolates with all patterns in the national data base. The network has spread internationally to Australia, Canada and Europe, and is beginning in Asia and Latin America (Swaminathan, Barrett, Hunter, & Tauxe, 2001;Terajima, Izumiya, Tamura, & Watanabe, 2002). However, subtyping protocols can take considerable time and effort to develop, concurrence among laboratories with the standardized protocol is not automatic, and subtyping networks are not sustainable without good centralized QA/QC programs.…”

The use of randomization tests to assess the degree of similarity in PFGE patterns of E. coli O157 isolates from known outbreaks and statistical space–time clusters

“…Escherichia coli O157 is a significant human pathogen that is routinely detected in public health surveillance programmes in Europe, North America, and Japan [1][2][3][4]. It is a major cause of gastroenteritis, haemorrhagic colitis, and haemolytic-uraemic syndrome in these regions [5].…”

Development of a PCR-Restriction Fragment Length Polymorphism Assay for the Epidemiological Analysis of Shiga Toxin-Producing Escherichia coli

“…Field inversion gel electrophoresis of BglI digest (B) and EcoRV digest (C) of LA-PCR products obtained from 6 control strains and 24 representative strains differentiated by the PCR-RFLP assay. Lanes: 1, -HindIII digest; 2, 32, 1-kb DNA ladder; 3, C600 (Stx1); 4, C600 (Stx2-I); 5, C600 (Stx2-II); 6, C600 (933W phage); 7, RIMD0509952 (Sakai strain; VT1-Sakai phage, VT2-Sakai phage); 8, 1-A (Okayama, Japan); 9, 2-B (Osaka, Japan); 10, 3-C (Okayama, Japan); 11, 4-D (Okayama, Japan); 12, 5-E (Okayama, Japan); 13, 6-F (Okayama, Japan); 14, 7-G (Osaka, Japan); 15, 8-H (Osaka, Japan); 16, 9-I (Osaka, Japan); 17, 10-J (Osaka, Japan); 18, 11-K (Nagano, Japan); 19, 12-L (Nagano, Japan); 20, 13-M (Nagano, Japan); 21, 14-N (Nagano, Japan); 22 STEC, because of its high resolution and reproducibility (17,20,(52)(53)(54). However, there are some disadvantages to using PFGE.…”

“…In 1996, the largest outbreak caused by STEC O157:H7 occurred in Japan (33). Although the number of large outbreaks caused by STEC has diminished since 1996, the number of sporadic cases, including diffuse outbreaks caused by a single clone in different areas, has increased (52)(53)(54). Therefore, it is important to rapidly identify the strain associated with diffuse outbreaks.…”