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Objective:To determine the distribution and epidemic characteristics of Vibrio parahaemolyticus in Jinshan District of Shanghai from 2016 through 2018. Methods:Serotype analysis，examination of virulence genes， including thermolabilehemolysin（TLH），thermostable direct hemolysin（TDH），and TDH related hemolysin（TRH），and antimicrobial susceptibility test and pulsed field gel electrophoresis （PFGE） molecular typing were performed on 218 Vibrio parahaemolyticus isolated from diarrhea patients. Results:A total of 218 strains were divided into 8 groups and 21 serotypes. Of them， 147 strains were serotyped，with O3：K6 as the most common serotype （57.3%）. All tested strains were divided into 25 clusters based on the similarity of 85% and above，in which the dominant cluster was JSVP02，and the total similarity was 56.3%-100.0%. Two hundred and one strains （92.2%） carried tdh gene，13 strains （6.0%） carried trh gene，and 7 strains were negative for both tdh and trh. A total of 35 strains were completely sensitive to 17 kinds of antibiotics，while the remaining 183 strains showed different drug resistance. Conclusion:Vibrio parahaemolyticus isolated from diarrhea patients in Jinshan District from 2016 through 2018 is diverse. Majority of the strains have TDH gene and are resistant to the first generation cephalosporins such as cefazolin and penicillin ampicillin. Construction of regional PFGE molecular typing database will facilitate screening，identification and early warning of high-risk strains.
RESUMO
Objective To investigate the prevalence of Vibrio parahaemolyticus(VP)in oysters in Jinshan District, Shanghai and make assessment on the risks that may cause, providing the basis for prevention and control of foodborne disease. Methods Raw oyster samples with shells were randomly collected from markets, supermarkets and restaurants in Jinshan District from July to October in 2017. The content of VP in oysters was tested in accordance with the national standard methods. The semi-quantitative risk assessment for VP in oysters was made by Risk Ranger combining with the monitoring results of diet and health status of residents in Jinshan District of Shanghai in 2012-2013. Results The overall positive rate of VP in the 40 oyster samples was 80.0%(32/40). The positive rate of VP in oyster samples from farmer's markets was the highest, 85.7%(12/14), followed by those from restaurants and supermarkets. The relative risk for VP in raw oysters was 63. The probability of illness caused by VP in oysters per day per consumer of interest was 6.85×10-4, and the total predicted patients annual incidence rate in this population was 1 247.8/105. Conclusion The contamination of VP in seafood oysters in Jinshan District is serious. Eating raw oysters is at high risk; consumers are advised to reduce or avoid eating raw oysters, and processing food before eating is an effective method to decrease VP infection. Strengthening surveillance and management is imperative in this regard.
RESUMO
Objective To investigate the status of cadmium contamination in commercially sold aquatic products and to analyze the risk of dietary intake of cadmium among residents in one district of Shanghai. Methods Multistage sampling was used to collect 397 animal aquatic products from agricultural markets and supermarkets in 11 communities (townships), the District from 2018 to 2019.Cadmium content was tested according to national standard.The status of cadmium contamination was assessed by single factor pollution index(Pi)method.Risk of dietary intake of cadmium among residents was assessed by point evaluation method in combination with food consumption and dietary survey in 2013 and calculation of safe limits for cadmium in various aquatic diets(MOS). Results The detection rate of cadmium was 75.06% in the 397 animal aquatic products and the content of cadmium in 10 samples which crabs were totally exceeded the standard, accounting for 2.52%.The average contents of cadmium in crabs, bivalves which were higher than in shrimps(11.0 μg/kg), gastropods(7.6 μg/kg) and marine fish(3.8 μg/kg) were respectively 140.0 μg/kg and 90.0 μg/kg(χ2=186.41, P < 0.005), but no cadmium was detected in freshwater fish.The single factor pollution index(Pi) of crabs was 0.280 which meant light pollution and the Pi of other kinds of aquatic products was respectively under 0.100 that meant no cadmium contamination.The consumption of animal aquatic products was the highest in freshwater fish followed by shrimps, marine fish and crabs.The MOS of every kind of aquatic products is higher than 1 which meant cadmium intake from commercially sold animal products was an acceptable health risk for the population. Conclusion The risk level of cadmium intake by residents in the district through commercially sold animal aquatic products is relatively low, but the cadmium pollution status of commercially sold crustacean crabs should be vigilant, and the intake of crabs is advised to be reduced as far as possible.Relevant departments should also pay attention and strengthen monitoring and management in this regard.