Risk Factors for Vibrio parahaemolyticus Infection in a Southern Coastal Region of China.

OBJECTIVES: The objectives of the study were to identify dietary and medical risk factors for Vibrio parahaemolyticus (VP) infection in the coastal city Shenzhen in China. METHODS: In April-October 2012, we conducted a case-control study in two hospitals in Shenzhen, China. Laboratory-confirmed VP cases (N = 83) were matched on age, sex, and other social factors to healthy controls (N = 249). Subjects were interviewed using a questionnaire on medical history; contact with seawater; clinical symptoms and outcome; travel history over the past week; and dietary history 3 days prior to onset. Laboratory tests were used to culture, serotype, and genotype VP strains. We used logistic regression to calculate the odds ratios for the association of VP infection with potential risk factors. RESULTS: In multivariate analysis, VP infection was associated with having pre-existing chronic disease (adjusted odds ratio [aOR], 6.0; 95% confidence interval [CI], 1.5-23.7), eating undercooked seafood (aOR, 8.0; 95% CI, 1.3-50.4), eating undercooked meat (aOR, 29.1; 95% CI, 3.0-278.2), eating food from a street food vendor (aOR, 7.6; 95% CI, 3.3-17.6), and eating vegetable salad (aOR, 12.1; 95% CI, 5.2-28.2). CONCLUSIONS: Eating raw (undercooked) seafood and meat is an important source of VP infection among the study population. Cross-contamination of VP in other food (e.g., vegetables and undercooked meat) likely plays a more important role. Intervention should be taken to lower the risks of cross-contamination with undercooked seafood/meat, especially targeted at people with low income, transient workers, and people with medical risk factors.

[Effects of amino acids on the survival of heat-exposed Drosophila].

To investigate the effects of amino acids on the survival of heat-exposed Drosophila and to select the amino acids that can protect the Drosophila from heat exposure, Drosophila melanogaster were fed with basic culture in 25 degrees C. The male virgin Drosophilas were distinguished from female. Both male and female virgin Drosophilas were divided respectively to the trail groups and control group with randomization. The trail groups were fed with culture supplying different amino acids in 37.5 degrees C. After 10 hours, the dead insects were counted every two hours until all of them were dead. The mortality rates of heat-exposed Drosophilas that feed in the culture added with the glutamine, arginine, phenylalanine, tyrosine and glutamic acid were obviously higher than that of control. The glutamine, arginine, phenylalanine, tyrosine and glutamic acid might increase survival time of heat-exposed Drosophila, but a dose-response relationship was not observed.