Whole-Genome Sequencing of Shiga Toxin-Producing Escherichia coli OX18 from a Fatal Hemolytic Uremic Syndrome Case.

We report a fatal case of hemolytic uremic syndrome with urinary tract infection in Japan caused by Shiga toxin-producing Escherichia coli. We genotypically identified the isolate as OX18:H2. Whole-genome sequencing revealed 3 potentially pathogenic lineages (OX18:H2, H19, and H34) that have been continuously isolated in Japan.

Investigation of immunity level against diphtheria and reinforcement of immunity by booster vaccination for infection control staff in Okayama prefecture.

The prevalence of immunity against diphtheria among Okayama local government staff members involved in diphtheria infection control was measured. Diphtheria booster vaccination was administered to staff members with low antitoxin levels (<0.1 IU/ml) in order to reinforce of immunity. Ninety-one (36.7%) of 248 staff members, 20-69 years of age, had fully protective antitoxin levels (> or =0.1 IU/ml), and the remaining 157 (63.3%) showed levels of <0.1 IU/ml. The rate of full protection was higher in females (44.9%) than in males (22.8%) and was also higher in the diphtheria-pertussis mixed vaccine (born in 1958-1967) and diphtheria-pertussis-tetanus mixed vaccine (born in 1968-) (58.3-61.0%) groups than in diphtheria vaccine (born in 1948-1957) and non-vaccinated (born until 1947) (7.4-18.9%) groups. Though antitoxin levels of 13 (68.4%) out of 19 staff members given booster vaccinations increased to 0.1 IU/ml, 50% of these individuals then showed levels of <0.1 IU/ml after 3 years. Most of the staff members with antitoxin levels of > or =0.1 IU/ml in the non-booster vaccination group maintained their immunity levels for 2-4 years, independent of their history of vaccination. To ensure that staff members of the local government have fully protective antitoxin levels against diphtheria, periodical confirmation of antitoxin levels and booster vaccination should both be systematically carried out.

[A rare outbreak of food poisoning caused by Salmonella enterica serovar. Oranienburg--a case report and features of isolates].

A rare food poisoning outbreak caused by S. Oranienburg occurred at a junior high school athletic meet in Kurashiki, Okayama, in September 2005. The 70 patients included junior high school students, teachers and other school staff, and their families. This bacillus was isolated from stools of two employees and another in catered sandwiches. The cause of the outbreak was determined by evidence and epidemiological investigation to be sandwiches served at the athletic meet. Biochemical features, sensitivity to 12 antibacterial agents, and DNA patterns determined by pulse field gel electrophoresis (PFGE) and enterobacterial repetitive intergenic sequence PCR (ERIC2-PCR) agreed for all isolates from outbreak samples. Isolates resembled strains isolated from broilers and a patient stool in an outbreak involving cuttlefish chips from 1998 to 1999 in Okayama Prefecture. A number of differences in strains isolated from broilers, chicken appendix content, and feed were detected in 2004, so we concluded that few outbreaks of food poisoning occurred due to S. Oranienburg in Okayama, attention is required for food poisoning by S. Oranienburg in the future because the dissemination of S. Oranienburg strains showing different features has been confirmed.

[Isolation of enteroaggregative escherichia coli (EAggEC) from patients with diarrheal disease in an outbreak case of overseas tour].

Twenty four patients out of 78 Cambodia tourists (31%) suffered from diarrhea and/or abdominal pain. Though the stools of 20 patients were examined in some local health centers and institutes, well-known pathogens were detected in only a low level and the cause of the outbreak remained unclear. We suspected the enteroaggregative Escherichia coli (EAggEC) as a cause of this outbreak. We examined E. coli strains isolated from stools of 8 patients (Okayama:7, Aichi:1) at first by the PCR method targeted both the aggR and the astA genes related to the virulence factors of EAggEC. As a result, the E. coli strains with positive aggR and/or astA genes were isolated from 8 patients. And the E. coli strains with positive both aggR gene and clump formation isolated from 3 patients adhered aggregatively to HEp-2 cells and accordingly identified as EAggEC. The plasmid profiles, PFGE patterns and drug resistance patterns of these EAggECs agreed completely. From these results, we concluded that at least 3 patients were infected with EAggEC of the same origin. Though we could not examine all samples from 20 patients, it is possible that the still uncommon EAggEC might be a cause of the outbreak. The E. coli strains with positive aggR gene did not always aggregatively adhered to HEp-2 cells. So we recommend to perform stepwise EAggEC screening tests by the PCR and the clump formation, and final confirmation test by the aggregative adhesion to HEp-2 cells.