The outer membrane protein, ompA, ofAeromonas veronii has a role in the virulence of the organism and is a potential candidate for vaccine development. In this study, ompA I ofAeromonas veronii strain WA106 was cloned...The outer membrane protein, ompA, ofAeromonas veronii has a role in the virulence of the organism and is a potential candidate for vaccine development. In this study, ompA I ofAeromonas veronii strain WA106 was cloned and sequenced, then, it was expressed in Escherichia coli BL21. The nucleotide sequence of ompA I gene was 1 023 base pairs （GenBank Accession NO.KC748024）, which showed 100% homology with that of A. veronii （NO.AB290200.1）. This predicted protein was composed of 340 amino acid residues. Its molecular weight was 35.78 ku and isoelectric point was 5.18. The protein was a hydrophilic protein containing alpha helix and random coil with percentage of 35.0% and 49.7%, respectively. The tertiary structure, quaternary structure prediction showed that ompA I protein contained two peptide chains. SDS-PAGE showed that the actual value of the fusion protein was consistent with the expected result. It will facilitate further study of the role of ompA I protein.展开更多
The catfishes are a group of economically important freshwater fish in China,which in recent years have suffered heavy losses as a result of bacterial outbreaks.In this study,we examined the diversity of the microbiom...The catfishes are a group of economically important freshwater fish in China,which in recent years have suffered heavy losses as a result of bacterial outbreaks.In this study,we examined the diversity of the microbiome of infected skin mucus of yellow catfish(Pelteobagrus fulvidraco)and channel catfish(Ictalurus punctatus)and analyzed the bacterial pathogens.We found several common pathogenic bacteria,such as Aeromonas spp.,Vibrio spp.,Moraxella spp.and Proteus spp.present in both fish species,but with significantly different bacterial community structures.We isolated and cultured Aeromonas veronii and Proteus mirabilis and validated their infectivity in zebrafish(Danio rerio)and yellow catfish.Intraperitoneal injection of either bacteria into zebrafish,but not immersion,caused 100%mortality and ovary fragmentation.Yellow catfish was more sensitive than zebrafish with 100%mortality in the immersion challenges with A.veronii or P.mirabilis,and with a higher abundance of A.veronii in the P.mirabilis-challenged group compared to control.To our knowledge,this is the first study on the pathogenicity of P.mirabilis in yellow catfish,and the results will help to develop effective strategies for the disease prevention and control in catfish farming.展开更多
Motile Aeromonads are responsible for various diseases in fishes that cause significant economic losses in aquaculture.Aeromonas spp.are also frequently isolated from fish suffering from Epizootic Ulcerative Syndrome(...Motile Aeromonads are responsible for various diseases in fishes that cause significant economic losses in aquaculture.Aeromonas spp.are also frequently isolated from fish suffering from Epizootic Ulcerative Syndrome(EUS).The present study was conducted to isolate and identify A.veronii from Vietnam climbing perch(Anabas testudineus)suffering from EUS,evaluate the pathogenicity of the isolates,and find out antibiogram profile and susceptibility of the isolates to medicinal plant extracts.Vietnam climbing perch(A.testudineus)suffering from EUS was collected from fish farms located at Savar,Dhaka and bacteria were isolated from the external ulcerative lesion,and kidney and liver of the infected fish on nutrient agar plates.Preliminary phenotypic identification of the bacterial isolates was performed following morphological,physiological and biochemical characterization tests.The 16S rRNA gene sequencing was accomplished for further molecular identification of five selected isolates.To evaluate the pathogenicity of the isolates in vivo artificial infection challenge test was conducted through immersion method.Another in vivo pathogenicity test was done at three different temperatures(18◦C,28◦C,and 37◦C)to examine the effects of temperature on the pathogenicity of the isolates.Ten commercial antibiotics were used to find out the antibiogram profile of the isolates.Finally,susceptibility of the isolates was screened against 19 medicinal plants extracts.A total of 38 out of 46 isolates isolated from Vietnam climbing perch(A.testudineus)suffering from EUS were phenotypically identified as Aeromonas sp.Five randomly selected isolates were further confirmed as A.veronii by analyzing the 16S rRNA gene sequence homology.The pathogenicity of the isolates was found moderate to high(41%-80%mortality)in the artificially challenged fish.The highest and lowest mortality was obtained in the fish challenged with the isolates BFKA33 and BFKA12,respectively.The isolates were found resistant to several antibiotics,including amoxicillin,ampicillin,penicillin-G,and vancomycin.Nevertheless,extracts of three medicinal plant(Allium sativum,Syzygium aromaticum,and Tamarindus indica)demonstrated antibacterial activity to the isolates(BFKA12,BFKA15,BFKA18,BFKA29,and BFKA33).展开更多
Mucosal vaccination,which has the potential to induce both mucosal and systemic immune responses,is considered the most suitable method of preventing infectious diseases in farmed fish.Aeromonas veronii and Edwardsiel...Mucosal vaccination,which has the potential to induce both mucosal and systemic immune responses,is considered the most suitable method of preventing infectious diseases in farmed fish.Aeromonas veronii and Edwardsiella ictaluri are two pathogenic bacteria found in yellow catfish and often infect the fish through mucosal surfaces.Delivery of a bivalent inactivated vaccine by injection has been shown to induce a strong systemic immune response against both bacterial infections.However,mucosal immune responses and protective efficiency induced by this inactivated vaccine administrated via immersion are yet to be investigated.We developed a bivalent vaccine containing formalin-inactivated A.veronii and E.ictaluri and evaluated the immune response in yellow catfish after immersion vaccination using body fluids biochemistry indices,agglutinating antibody titers,and the expression level of immune-related genes in the skin,gills,spleen,and head kidney.The activities of innate immune-related enzymes and specific agglutination antibody titers in body fluids,as well as the expression of innate and adaptive immune-related genes in both the mucosal and systemic tissues of vaccinated fish,were significantly higher than that in control fish.Next,we assessed the protective efficacy by a challenge model of virulent strains of E.ictaluri and A.veronii.The relative survival percent of vaccinated fish was 80%and 87%after challenging fish with E.ictaluri and A.veronii,respectively,which was higher than unvaccinated control fish(43%and 57%).These results confirm that the bivalent inactivated vaccine administered via immersion induces a strong mucosal immune response and confers good protection against both E.ictaluri and A.veronii.Our results also reinforce the notion that immersion vaccination could stimulate both mucosal and systemic immunity contributing to protection against pathogens.展开更多
Macrobrachium nipponense is an economically important freshwater prawn that is often threatened by many aquatic pathogens.In this study,comparative transcriptomic analysis was fi rstly used to explore the transcriptio...Macrobrachium nipponense is an economically important freshwater prawn that is often threatened by many aquatic pathogens.In this study,comparative transcriptomic analysis was fi rstly used to explore the transcriptional response of M.nipponense to Aeromonas veronii or Staphylococcus aureus stimulation.A total of 400.19 million clean reads were obtained and assembled into 56944 unigenes with an average length of 1253 bp.A total of 1857 diff erentially expressed genes were found after A.veronii infection,including 677 genes that were up-regulated and 1180 genes that were down-regulated,while 1061 signifi cant diff erentially expressed genes were identifi ed after S.aureus infection,including 390 up-regulated and 671 down-regulated genes.Many immune-related genes including Spaetzle,prophenoloxidase activating factor,C-type lectin,anti-lipopolysaccharide factor,and inhibitor of apoptosis 2 protein were commonly up-regulated after A.veronii or S.aureus infection.This study will enrich our understanding of the immune response to gram-positive and gram-negative bacteria infection in crustaceans.展开更多
基金Supported by the Science&Technology Department of Sichuan Province(2013FZ0014)the Construction Project of Postgraduate Academic Degree in Southwest University for Nationalities(2015XWD-S071007)
文摘The outer membrane protein, ompA, ofAeromonas veronii has a role in the virulence of the organism and is a potential candidate for vaccine development. In this study, ompA I ofAeromonas veronii strain WA106 was cloned and sequenced, then, it was expressed in Escherichia coli BL21. The nucleotide sequence of ompA I gene was 1 023 base pairs （GenBank Accession NO.KC748024）, which showed 100% homology with that of A. veronii （NO.AB290200.1）. This predicted protein was composed of 340 amino acid residues. Its molecular weight was 35.78 ku and isoelectric point was 5.18. The protein was a hydrophilic protein containing alpha helix and random coil with percentage of 35.0% and 49.7%, respectively. The tertiary structure, quaternary structure prediction showed that ompA I protein contained two peptide chains. SDS-PAGE showed that the actual value of the fusion protein was consistent with the expected result. It will facilitate further study of the role of ompA I protein.
基金supported by National Key Research and Development Program of China[2018YFD0900601]The Belt and Road international joint laboratory construction projects of science and technology innovation action plan from Science and Technology Commission of Shanghai Municipality[19590750500]to L.Chen.
文摘The catfishes are a group of economically important freshwater fish in China,which in recent years have suffered heavy losses as a result of bacterial outbreaks.In this study,we examined the diversity of the microbiome of infected skin mucus of yellow catfish(Pelteobagrus fulvidraco)and channel catfish(Ictalurus punctatus)and analyzed the bacterial pathogens.We found several common pathogenic bacteria,such as Aeromonas spp.,Vibrio spp.,Moraxella spp.and Proteus spp.present in both fish species,but with significantly different bacterial community structures.We isolated and cultured Aeromonas veronii and Proteus mirabilis and validated their infectivity in zebrafish(Danio rerio)and yellow catfish.Intraperitoneal injection of either bacteria into zebrafish,but not immersion,caused 100%mortality and ovary fragmentation.Yellow catfish was more sensitive than zebrafish with 100%mortality in the immersion challenges with A.veronii or P.mirabilis,and with a higher abundance of A.veronii in the P.mirabilis-challenged group compared to control.To our knowledge,this is the first study on the pathogenicity of P.mirabilis in yellow catfish,and the results will help to develop effective strategies for the disease prevention and control in catfish farming.
文摘Motile Aeromonads are responsible for various diseases in fishes that cause significant economic losses in aquaculture.Aeromonas spp.are also frequently isolated from fish suffering from Epizootic Ulcerative Syndrome(EUS).The present study was conducted to isolate and identify A.veronii from Vietnam climbing perch(Anabas testudineus)suffering from EUS,evaluate the pathogenicity of the isolates,and find out antibiogram profile and susceptibility of the isolates to medicinal plant extracts.Vietnam climbing perch(A.testudineus)suffering from EUS was collected from fish farms located at Savar,Dhaka and bacteria were isolated from the external ulcerative lesion,and kidney and liver of the infected fish on nutrient agar plates.Preliminary phenotypic identification of the bacterial isolates was performed following morphological,physiological and biochemical characterization tests.The 16S rRNA gene sequencing was accomplished for further molecular identification of five selected isolates.To evaluate the pathogenicity of the isolates in vivo artificial infection challenge test was conducted through immersion method.Another in vivo pathogenicity test was done at three different temperatures(18◦C,28◦C,and 37◦C)to examine the effects of temperature on the pathogenicity of the isolates.Ten commercial antibiotics were used to find out the antibiogram profile of the isolates.Finally,susceptibility of the isolates was screened against 19 medicinal plants extracts.A total of 38 out of 46 isolates isolated from Vietnam climbing perch(A.testudineus)suffering from EUS were phenotypically identified as Aeromonas sp.Five randomly selected isolates were further confirmed as A.veronii by analyzing the 16S rRNA gene sequence homology.The pathogenicity of the isolates was found moderate to high(41%-80%mortality)in the artificially challenged fish.The highest and lowest mortality was obtained in the fish challenged with the isolates BFKA33 and BFKA12,respectively.The isolates were found resistant to several antibiotics,including amoxicillin,ampicillin,penicillin-G,and vancomycin.Nevertheless,extracts of three medicinal plant(Allium sativum,Syzygium aromaticum,and Tamarindus indica)demonstrated antibacterial activity to the isolates(BFKA12,BFKA15,BFKA18,BFKA29,and BFKA33).
文摘Mucosal vaccination,which has the potential to induce both mucosal and systemic immune responses,is considered the most suitable method of preventing infectious diseases in farmed fish.Aeromonas veronii and Edwardsiella ictaluri are two pathogenic bacteria found in yellow catfish and often infect the fish through mucosal surfaces.Delivery of a bivalent inactivated vaccine by injection has been shown to induce a strong systemic immune response against both bacterial infections.However,mucosal immune responses and protective efficiency induced by this inactivated vaccine administrated via immersion are yet to be investigated.We developed a bivalent vaccine containing formalin-inactivated A.veronii and E.ictaluri and evaluated the immune response in yellow catfish after immersion vaccination using body fluids biochemistry indices,agglutinating antibody titers,and the expression level of immune-related genes in the skin,gills,spleen,and head kidney.The activities of innate immune-related enzymes and specific agglutination antibody titers in body fluids,as well as the expression of innate and adaptive immune-related genes in both the mucosal and systemic tissues of vaccinated fish,were significantly higher than that in control fish.Next,we assessed the protective efficacy by a challenge model of virulent strains of E.ictaluri and A.veronii.The relative survival percent of vaccinated fish was 80%and 87%after challenging fish with E.ictaluri and A.veronii,respectively,which was higher than unvaccinated control fish(43%and 57%).These results confirm that the bivalent inactivated vaccine administered via immersion induces a strong mucosal immune response and confers good protection against both E.ictaluri and A.veronii.Our results also reinforce the notion that immersion vaccination could stimulate both mucosal and systemic immunity contributing to protection against pathogens.
基金Supported by the Research on the Diversity of Freshwater Fish,Shrimp and Crab in Macao(No.20183300042411016)the Guangdong Special Environmental Fund(Nos.PM-zx555-202107-208,PM-zx555-202106-195)。
文摘Macrobrachium nipponense is an economically important freshwater prawn that is often threatened by many aquatic pathogens.In this study,comparative transcriptomic analysis was fi rstly used to explore the transcriptional response of M.nipponense to Aeromonas veronii or Staphylococcus aureus stimulation.A total of 400.19 million clean reads were obtained and assembled into 56944 unigenes with an average length of 1253 bp.A total of 1857 diff erentially expressed genes were found after A.veronii infection,including 677 genes that were up-regulated and 1180 genes that were down-regulated,while 1061 signifi cant diff erentially expressed genes were identifi ed after S.aureus infection,including 390 up-regulated and 671 down-regulated genes.Many immune-related genes including Spaetzle,prophenoloxidase activating factor,C-type lectin,anti-lipopolysaccharide factor,and inhibitor of apoptosis 2 protein were commonly up-regulated after A.veronii or S.aureus infection.This study will enrich our understanding of the immune response to gram-positive and gram-negative bacteria infection in crustaceans.
