To identify the cause of mass mortality of adult Macrobrachium rosenbergii in a farm in Gaoyou City,Jiangsu Province,China,a dominant strain named DKQ-1 was isolated from the hepatopancreas of dying M.rosenbergii and ...To identify the cause of mass mortality of adult Macrobrachium rosenbergii in a farm in Gaoyou City,Jiangsu Province,China,a dominant strain named DKQ-1 was isolated from the hepatopancreas of dying M.rosenbergii and identified as Aeromonas dhakensis by purification culture,biochemical characterization,and 16S rRNA and gyrB gene sequence analysis.The results of the challenge test revealed that the strain was highly pathogenic and the 50%lethal dose(LD_(50))in 72 h to M.rosenbergii was 1.54×10^(5)CFU/mL.The amplification results of virulence genes show that strain DKQ-1 carried 9 virulence genes,including ascV,aexT,aer,act,lip,ompAI,gcaT,acg,and exu,supporting the strong virulence of strain DKQ-1 to M.rosenbergii.Histopathological observation of the hepatopancreas,gills,and intestines indicated that DKQ-1 injection into M.rosenbergii could cause serious tissue damage,which further supported the strong virulence of this strain.In addition,a drug susceptibility test revealed that strain DKQ-1 was sensitive to 16 kinds of antibiotics,resistant to 9 kinds of antibiotics,and had intermediate resistance to spectinomycin and kanamycin.This study is the first report of A.dhakensis isolated from M.rosenbergii and provided a reference for the pathogen identification of bacterial diseases in M.rosenbergii,and for the prevention and treatment caused by A.dhakensis.展开更多
Litopenaeus vannamei is the most extensively cultured shrimp species globally,recognized for its scale,production,and economic value.However,its aquaculture is plagued by frequent disease outbreaks,resulting in rapid ...Litopenaeus vannamei is the most extensively cultured shrimp species globally,recognized for its scale,production,and economic value.However,its aquaculture is plagued by frequent disease outbreaks,resulting in rapid and massive mortality.etiological research often lags behind the emergence of new diseases,leaving the causal agents of some shrimp diseases unidentified and leading to nomenclature based on symptomatic presentations,especially in cases involving co-and polymicrobial pathogens.Comprehensive data on shrimp disease statuses remain limited.In this review,we summarize current knowledge on shrimp diseases and their effects on the gut microbiome.Furthermore,we also propose a workflow integrating primary colonizers,“driver”taxa in gut networks from healthy to diseased states,disease-discriminatory taxa,and virulence genes to identify potential polymicrobial pathogens.We examine both abiotic and biotic factors(e.g.,external and internal sources and specific-disease effects)that influence shrimp gut microbiota,with an emphasis on the“holobiome”concept and common features of gut microbiota response to diverse diseases.After excluding the effects of confounding factors,we provide a diagnosis model for quantitatively predicting shrimp disease incidence using disease common-discriminatory taxa,irrespective of the causal agents.Due to the conservation of functional genes used in designing specific primers,we propose a practical strategy applying qPCR-assayed abundances of disease common-discriminatory functional genes.This review updates the roles of the gut microbiota in exploring shrimp etiology,polymicrobial pathogens,and disease incidence,offering a refined perspective for advancing shrimp aquaculture health management.展开更多
Antarctic krill Euphausia superba plays a key role in the Antarctic food web.The trophic linkage between krill and other macro-organisms has been studied in the past decades,but the variability of parasites in krill i...Antarctic krill Euphausia superba plays a key role in the Antarctic food web.The trophic linkage between krill and other macro-organisms has been studied in the past decades,but the variability of parasites in krill is less studied and remains poorly understood.Therefore,it is important to understand the factors that influence abundance and infection of parasites in krill.Moreover,the relationship between the infection intensity of parasite and krill diet needs to be clarified,which is helpful for understanding the role of parasite in the food web.We investigated the abundance of the highly prevalent gregarine parasites in the digestive tract of krill and the factors influencing the gregarine infection to krill in the East Antarctic.The infection rate of Cephaloidophora pacifica Avdeev,1985 to krill(n=50 individuals)was 94%.The results of generalized linear model show the infection intensity of C.pacifica to the host was related significantly to the station,krill size,and maturity stage,but not the food species and abundance in the stomach of krill.Abundance of C.pacifica in krill differed among stations,and the lowest abundance occurred in the station nearest to the coast.Gregarines abundance varied among sexual maturity stages of krill and increased with krill size.展开更多
基金Supported by the Earmarked Fund for the China Agriculture Research System(No.CARS-48)the Key Scientific and Technological Grant of Zhejiang for Breeding New Agricultural Varieties(No.2021 C 02069-4-3)the Major Research&Development Program(modern agriculture)of Jiangsu Province(No.BE 2019352)。
文摘To identify the cause of mass mortality of adult Macrobrachium rosenbergii in a farm in Gaoyou City,Jiangsu Province,China,a dominant strain named DKQ-1 was isolated from the hepatopancreas of dying M.rosenbergii and identified as Aeromonas dhakensis by purification culture,biochemical characterization,and 16S rRNA and gyrB gene sequence analysis.The results of the challenge test revealed that the strain was highly pathogenic and the 50%lethal dose(LD_(50))in 72 h to M.rosenbergii was 1.54×10^(5)CFU/mL.The amplification results of virulence genes show that strain DKQ-1 carried 9 virulence genes,including ascV,aexT,aer,act,lip,ompAI,gcaT,acg,and exu,supporting the strong virulence of strain DKQ-1 to M.rosenbergii.Histopathological observation of the hepatopancreas,gills,and intestines indicated that DKQ-1 injection into M.rosenbergii could cause serious tissue damage,which further supported the strong virulence of this strain.In addition,a drug susceptibility test revealed that strain DKQ-1 was sensitive to 16 kinds of antibiotics,resistant to 9 kinds of antibiotics,and had intermediate resistance to spectinomycin and kanamycin.This study is the first report of A.dhakensis isolated from M.rosenbergii and provided a reference for the pathogen identification of bacterial diseases in M.rosenbergii,and for the prevention and treatment caused by A.dhakensis.
基金National Natural Science Foundation of China(32371596,32071549)Key Research and Development Project of Zhejiang Province(2021C02062)+2 种基金Key Scientific and Technological Grant of Zhejiang for Breeding New Agricultural Varieties(2021C02069-5-2)Key Project of Ningbo Science and Technology Bureau(2023S003)One Health Interdisciplinary Research Project of Ningbo University(HZ202404)。
文摘Litopenaeus vannamei is the most extensively cultured shrimp species globally,recognized for its scale,production,and economic value.However,its aquaculture is plagued by frequent disease outbreaks,resulting in rapid and massive mortality.etiological research often lags behind the emergence of new diseases,leaving the causal agents of some shrimp diseases unidentified and leading to nomenclature based on symptomatic presentations,especially in cases involving co-and polymicrobial pathogens.Comprehensive data on shrimp disease statuses remain limited.In this review,we summarize current knowledge on shrimp diseases and their effects on the gut microbiome.Furthermore,we also propose a workflow integrating primary colonizers,“driver”taxa in gut networks from healthy to diseased states,disease-discriminatory taxa,and virulence genes to identify potential polymicrobial pathogens.We examine both abiotic and biotic factors(e.g.,external and internal sources and specific-disease effects)that influence shrimp gut microbiota,with an emphasis on the“holobiome”concept and common features of gut microbiota response to diverse diseases.After excluding the effects of confounding factors,we provide a diagnosis model for quantitatively predicting shrimp disease incidence using disease common-discriminatory taxa,irrespective of the causal agents.Due to the conservation of functional genes used in designing specific primers,we propose a practical strategy applying qPCR-assayed abundances of disease common-discriminatory functional genes.This review updates the roles of the gut microbiota in exploring shrimp etiology,polymicrobial pathogens,and disease incidence,offering a refined perspective for advancing shrimp aquaculture health management.
基金Supported by the‘Inter-governmental Science and Technology Innovation(STI)Cooperation Special Program’of the National Key Research and Development Program(No.2023 YFE 0104500 to GPZ)。
文摘Antarctic krill Euphausia superba plays a key role in the Antarctic food web.The trophic linkage between krill and other macro-organisms has been studied in the past decades,but the variability of parasites in krill is less studied and remains poorly understood.Therefore,it is important to understand the factors that influence abundance and infection of parasites in krill.Moreover,the relationship between the infection intensity of parasite and krill diet needs to be clarified,which is helpful for understanding the role of parasite in the food web.We investigated the abundance of the highly prevalent gregarine parasites in the digestive tract of krill and the factors influencing the gregarine infection to krill in the East Antarctic.The infection rate of Cephaloidophora pacifica Avdeev,1985 to krill(n=50 individuals)was 94%.The results of generalized linear model show the infection intensity of C.pacifica to the host was related significantly to the station,krill size,and maturity stage,but not the food species and abundance in the stomach of krill.Abundance of C.pacifica in krill differed among stations,and the lowest abundance occurred in the station nearest to the coast.Gregarines abundance varied among sexual maturity stages of krill and increased with krill size.
