Virulence characteristics of Shiga toxin-producing Escherichia coli from raw meats and clinical samples.

Shiga toxin producing Escherichia coli (STEC) are dangerous foodborne pathogens. Foods are considered as important sources for STEC infection in human. In this study, STEC contamination of raw meats was investigated and the virulence factors of 120 clinical STEC strains characterized. STEC was detected in 4.4% of tested samples. Among 25 STEC strains from meats, five strains (20%) were positive for the eae gene, which encodes intimin, an important binding protein of pathogenic STEC. The remaining strains (80%) were eae-negative. However, 28% of them possessed the saa gene, which encodes STEC agglutinating adhesin. The ehxA gene encoding for enterohemolysin was found in 75% of the meat strains and the subAB gene, the product is of which subtilase cytotoxin, was found in 32% of these strains. The stx2a gene, a subtype of Shiga toxin gene (stx), was the most prevalent subtype among the identified meat STEC bacteria. None of the meat STEC was O157:H7 serotype. Nevertheless, 92% of them produced Shiga toxin (Stx). Among 120 clinical STEC strains, 30% and 70% strains harbored single and multiple stx subtypes, respectively. Most clinical STEC bacteria possessed eae (90.8%) and ehxA (96.7%) genes and 92.5% of them showed Stx productivity. Our study shows that some raw meat samples contain non-O157 STEC bacteria and some strains have virulence factors similar to those of clinical strains.

Therapeutic psychosocial intervention for elderly subjects with very mild Alzheimer disease in a community: the tajiri project.

Elderly subjects with mild memory impairment but not apparent dementia are the focus of early intervention trials. To examine the effects of structural psychosocial intervention for elderly subjects with very mild Alzheimer disease, i.e., Clinical Dementia Rating 0.5. The design is a prospective study. The experimental group (14 Clinical Dementia Rating 0.5 subjects) and the control group (11 Clinical Dementia Rating 0.5 subjects) were studied. Subjects with cerebrovascular disease as shown by magnetic resonance imaging were excluded. The experimental group participated in activities in a day-care-like setting once a week over a period of 6 months, whereas the control group did not. Each group was reevaluated after approximately 9 months. The effects of intervention were evaluated by cognitive tests, affective scales, a global clinical measure, an observation scale in the sessions, and a projective test. The experimental group showed a significant improvement on the word fluency test, whereas the control group showed a significant decline on the Mini-Mental State Examination, the digit span, and the Trail Making-A test. The experimental group revealed significantly higher levels on the Mini-Mental State Examination and the digit span compared with the control group after the 6-month intervention. A significant improvement was found for the global clinical measure, the observation scale, and the projective test in the experimental group after the intervention. After controlling the potential confounders (age, educational level, baseline cognitive, and affective status) in a multiple regression analysis, the same results were found. We considered that psychosocial intervention had beneficial effects for subjects with very mild Alzheimer disease.