| Vibrio is a common bacterium found in oceans,estuaries and animals.It is also a common pathogen of marine aquatic animals.It causes huge economic losses to the aquaculture industry and seriously endangers the healthy development of the aquaculture industry.At the same time,this bacterium is also important.Of zoonotic pathogens.With the emergence of large-scale,intensive,intensive and multiple breeding modes of the shellfish aquaculture industry,vibriosis has become a common disease of cultured shellfish,causing more and more shellfish deaths.Therefore,the prevalence of vibriosis in major economic shellfish,the distribution of virulence genes closely related to the pathogenicity and the drug resistance of vibrio are ascertained,providing theoretical data for the establishment of early warning mechanisms and prevention and control methods for shellfish vibriosis,to provide a scientific basis for the development of shellfish vibriosis prevention and control technology.In order to investigate the prevalence of Vibrio in the ocean,this study collected shellfish samples from six coastal areas in Shandong Province in 2019 and 2020,separated and identified Vibrio through selective media and other methods,and used PCR to identify the main virulence of the isolated strains.Genes,using the drug-sensitive disc diffusion method to analyze the drug resistance of the strains,the results are as follows:1.Vibrio is one of the common bacteria in the marine environment.In the 230 samples collected,359 different types of Vibrio were isolated.The isolated Vibrio include Vibrio alginolyticus,Vibrio harveyi,and Vibrio parahaemolysis,Vibrio orientalis,Vibrio sodium-requiring,Vibrio owensii,Vibrio chagasii,etc.The statistical results show that the higher detection rates are Vibrio harveyi,Vibrio alginolyticus and Vibrio parahaemolyticus,which are 13.9%,25.3% and 8.9%,respectively.The detection rate of Vibrio in different shellfish is not the same.The isolation rate of Vibrio parahaemolyticus in oysters and clams is higher,each with 15.6%,and the isolation rate of Vibrio harveyi in oysters is higher,at 18%,Vibrio alginolyticus is more isolated in Clams,13.2%.The detection rate of Vibrio in different regions is different.Among them,the detection rate of Vibrio harveyi is higher in Binzhou,which is 30%;the detection rate of Vibrio alginolyticus in Rizhao,Dongying is 26.4%,28.6.%;The high detection rate of Vibrio parahaemolyticus in Rizhao is 25%.2.The isolated 359 strains of Vibrio were treated with cefotaxime,ampicillin,amoxicillin,tetracycline,doxycycline,minocycline,compound trimethoprim,kanamycin,clindamycin,and tetracycline.The drug susceptibility test of carnaval,florfenicol,enrofloxacin,spectinomycin,polymyxin B,aztreonam showed that the isolated strains were resistant to cefotaxime,spectinomycin,enrofloxacin,the sensitivity of compound sulfamethoxazole is higher,99.72%,94.71%,91.64%,94.99%,respectively.The resistance rates of ampicillin and amoxicillin were higher,59.89% and 33.98%,respectively.This suggests that we can use spectinomycin,enrofloxacin,and compound trimethoprim for the prevention and control of vibrio diseases in the future.3.Vibrio harveyi,Vibrio alginolyticus,and Vibrio parahaemolyticus are the most common pathogens in food-borne disease outbreaks in coastal areas of my country.In recent years,they have been caused by the widespread circulation of seafood in the market.The number of food poisoning incidents has also gradually increased.There are many virulence genes in Vibrio,the main virulence genes include toxR,tdh,trh,tlh,FlaA,OmpW,AspA,Fur and so on.The detection rate of parahaemolytic bacteria regulatory gene toxR was 43.75%,and the virulence contribution gene OmpW was detected in 34.38%.The detection rate of the virulence gene LuxR of Vibrio harveyi was 36%,and the detection rate of the regulatory gene toxR was 48%.The virulence regulating genes toxS,tcpA,fur virulence genes are found in Vibrio alginolyticus,51.65%,43.96%,43.96% were detected respectively,and the virulence gene zot was detected 18.68%.In summary,through the epidemiological survey of shellfish vibriosis in Shandong Province in 2019 and 2020,we have grasped the prevalence of shellfish vibriosis,and provided a basis for the establishment of a vibriosis prevention and control early warning mechanism.Data basis;through the drug susceptibility test of the isolated Vibrio resistance results,it provides a basis for the prevention and control of shellfish vibriosis and drug screening;the distribution law of the main virulence genes of the isolated Vibrio is analyzed,which is the virulent strain The identification and screening of pathogenic strains provide a basis,and at the same time provide a scientific basis for effectively preventing large-scale outbreaks of Vibrio infectious diseases. |
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