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Vibrio parahaemolyticus (V.parahaemolyticus, Vp) of an important food-borne pathogens, the main cause of acute gastroenteritis, Sepsis was induced by a small number of cases. Foodborne illness caused by Vp showed an increasing trend, especially in coastal areas, and the outbreak frequency and the number of people involved was significantly higher than in other regions. This thesis is to establish the quantitative detection of aquatic Vp, and the domestic the nine coastal city retail shellfish Vp monitored throughout the year, the use of monitoring results, combined with dietary surveys and variable data, nine cities the different seasons shellfish Vp exposure assessment, further microbial quantitative risk assessment theory and technology, to carry out a quantitative risk assessment of nine cities in the retail shellfish Vp preliminary study, nine urban residents in different seasons of raw shellfish caused distribution Vp gastroenteritis probability. The Vp species-specific genes tlh and major causative gene TDH target, on the basis of pre-established by the laboratory duplex PCR method, combined with the MPN method shellfish Vp quantitative. Replace the traditional biochemical identification by PCR, PCR identified 22 strains tlh biochemical identification, the results showed that the PCR method is consistent with the traditional biochemical identification PCR method has good specificity and accuracy, you can replace the cumbersome biochemical identification. Of shellfish-producing countries, according to the 2007 Yearbook of Fishery Statistics, select a the aquatic higher yield provinces nine coastal city of Qingdao, Yantai, Rizhao, Weihai, Lianyungang, Dalian, Guangzhou, Xiamen and Zhoushan. Monthly fixed sampling from October 2008 to September 2009, a total of 675 samples, adopted shellfish, including clams, oysters, mussels, Sinonovacula hair cockles, scallops. The background information obtained by monitoring the the Vp pollution in the nine cities in retail shellfish, preliminary analyzed the distribution of Vp. The results show that, Vp common in shellfish products, the range of the nine urban retail shellfish Vp detection rate of 56% -73.3%. Wherein the sunshine retail shellfish Vp detection rate of 56%, and 59.7% in Dalian, the remaining seven cities shellfish Vp detection rate is higher than 60%, the highest detection rate of Lianyungang retail shellfish Vp, reached 73.3%. The MPN quantitative results show that, Qingdao, Yantai and Weihai Sinonovacula Vp geometric mean concentration was significantly higher than other types of shellfish (P lt; 0.05), geometric mean concentrations were 86.6MPN / g, 258.4MPN / g and 494.6 MPN / the g; Guangzhou mussels all detected Vp (12/12), the geometric mean concentration (269.8MPN / g) was significantly higher than other types of shellfish (P lt; 0.05), indicating that the future of shellfish Vp monitoring be focused; sunshine, Dalian, Lianyungang, Xiamen and Zhoushan collected different shellfish, the positive rate and the bacterial content there is no significant difference (P gt; 0.05). By season found that the pollution of the different cities spring and summer retail shellfish Vp there is no significant difference between autumn and winter, the difference was significant, autumn Zhoushan pollution is the most serious, sunshine lightest; most serious winter Guangzhou, Qingdao, the most Light. The nine urban retail shellfish Vp (TDH), the average detection rate of 0.96%. The use of microbiological risk assessment theory, quantitative risk assessment Vp the nine coastal city retail shellfish. Starting point for population exposure assessment is the retail, combined with the distribution of of Vp pollution in different seasons retail shellfish, the tdh Vp ratio and the preliminary dietary survey data projections each meal of pathogenic Vp intake of the amount of the distribution, and joined the temperature, retail storage time , VP of factors such as the growth rate of the exposure assessment model calibration, Crystal Ball software residents each meal when the in different seasons consumer shellfish pathogenic Vp of exposure, the results show that the residents of each meal consumption of shellfish pathogenic Vp average exposure were highest in summer, the range of 3.26-5.32, Dalian minimum average of 3.26,50 percentile, 90th percentile and 97.5 percentile values ??were 3.04,6.95 and 7.91, Guangzhou, the highest average the 5.32,50 percentile, 90th percentile and 97.5 percentile values ??were 5.15,9.19 and 10.04. Average exposure to the lowest of the season for the winter, range 0.01-2.26, which Guangzhou highest, average 2.26,50 percentile, 90th percentile and 97.5 percentile values ??were 1.82,6.59 and 7.87; Qingdao minimum , an average of the the 0.01,50 percentile, 90th percentile and 97.5 percentile values ??were -0.02,1.65 and 2.01. Vp through retail shellfish quantitative risk assessment of the probability of occurrence of the different seasons in nine cities Vp disease caused due to consumption of raw shellfish distribution, show that the residents of raw shellfish resulting in higher frequency of occurrence of gastroenteritis, Qingdao summer Vp stomach inflammation average rate of 3.41E-03, 50 percentile bit, 90th percentile and 97.5 percentile value 2.31E-03 7.79E-01 9.18E-01 ,2004-2009 Qingdao summer (July -September) the epidemiological surveillance data show that the The Vp cause gastroenteritis incidence rate of 5.58E-5, below the average incidence of this assessment, the reason may lie in epidemiological surveillance data due to the omission of data low.
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