The aim of this study was to evaluate the factors influencing the inactivation effect of intense pulsed light(IPL)on Aeromonas salmonicida grown on chicken meat and skin,and to further develop prediction models of ina...The aim of this study was to evaluate the factors influencing the inactivation effect of intense pulsed light(IPL)on Aeromonas salmonicida grown on chicken meat and skin,and to further develop prediction models of inactivation.In this work,chicken meat and skin inoculated with meat-borne A.salmonicida isolates were subjected to IPL treatments under different conditions.The results showed that IPL had obvious bactericidal effect in the chicken skin and thickness groups when the treatment voltage and time were 7 V combined with 5 s.In addition,the lethality curves of A.salmonicida were fitted under IPL conditions of 3.5-7.5 V.The comparison of statistical parameters revealed that the Weibull model could best fit the mortality curves and could accurately predict the mortality dynamic of A.salmonicida grown on chicken skin.And further a secondary model between the scale factor b and the treatment voltage in Weibull model was established using linear equations,which determined that the secondary model could accurately predict the inactivation of A.salmonicida.This study provides a theoretical basis for future prediction models of Aeromonas,and also provides new ideas for sterilization approaches of meat-borne Aeromonas.展开更多
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
[Objectives]To explore the function of hcp gene in Aeromonas hydrophila.[Methods]A pair of specific primers was designed referring to the hcp gene sequence of A.hydrophila.The hcp gene was amplified by PCR,and perform...[Objectives]To explore the function of hcp gene in Aeromonas hydrophila.[Methods]A pair of specific primers was designed referring to the hcp gene sequence of A.hydrophila.The hcp gene was amplified by PCR,and performed bioinformatics analysis.[Results]The hcp gene had a total length of 1650 bp and encoded 549 amino acids.The theoretical molecular weight of the protein predicted was about 59476.44 kDa.After predicting the N-terminal signal peptide structure of the amino acid sequence,neither obvious signal peptide cleavage site nor signal peptide was found,and the protein had no transmembrane region.The amino acid sequence had a N-glycosylation site,4 protein kinase C phosphorylation sites,7 casein kinase II phosphorylation sites,9 N-myristoylation sites,4 isoprene binding sites,10 microbody C-terminal target signal sites,and an ATP/GTP binding site motif A(P-ring).The amino acid sequence of hcp gene of A.hydrophila was performed homology analysis with other Aeromonas strains,and it showed higher homology with A.veronii.In the secondary structure,theα-helix,β-sheet,random coil and extended strand accounted for 45.36%,6.01%,37.52%and 11.11%,respectively.The tertiary structure model consisted of 18α-helix and 22β-sheet.Analysis of protein-protein network interaction demonstrated that the proteins interacting with Hcp protein were AHA_3407,nrfA,nirB-1,nirB-2 and AHA_1112.[Conclusions]Through the bioinformatics prediction results,the basic information of hcp gene of A.hydrophila is preliminarily understood,and the possible function of this protein is predicted,in order to provide guidance for subsequent vaccine research.展开更多
Objective:To investigate a case of mass mortality of Garra rufa(G.rufa)from a fish hatchery farm in Slovakia.Methods:Causative bacterial agent was swabbing out of affected fish skin area and subsequently identified us...Objective:To investigate a case of mass mortality of Garra rufa(G.rufa)from a fish hatchery farm in Slovakia.Methods:Causative bacterial agent was swabbing out of affected fish skin area and subsequently identified using commercial test system.Antibiotic susceptibility was determined by the disk diffusion method.Results:Infected G.rufa was characterized by abnormal swimming behaviour,bleeding of skin lesions and local haemorrhages.Despite of using recommended aquatic antibiotic treatment no improvement was achieved and Aeromonas sobria{A.sobria)was identified as a causative agent of fish mortality.Due to massive fish mortality,antibiotic susceptibility of pure isolated culture of A.sobria was evaluated employing eight antibiotics against human infections.A.sobria was resistant only against one antibiotic,namely ampicilin.Conclusions:These results indicate that A.sobria can act as a primary pathogen of G.rufa and may be a potential risk factor for immunodeficient or immunoincompetent patients during the ichthyotherapy.展开更多
Vibrio scophthalmi and Aeromonas salmonicida can cause high turbot mortality and huge economic losses.Presently,vaccination is the most promising method for preventing communicable diseases.In this study,we used forma...Vibrio scophthalmi and Aeromonas salmonicida can cause high turbot mortality and huge economic losses.Presently,vaccination is the most promising method for preventing communicable diseases.In this study,we used formalin to kill V.scophthalmi and A.salmonicida cells,and mixed with the mineralized oil adjuvant(Montanide^(TM)ISA 763 AVG)to prepare the bivalent inactivated vaccine.The results showed that turbot inoculated with the bivalent inactivated vaccine exhibited strong tolerance to the infection of V.scophthalmi and A.salmonicida,and no obvious clinical symptoms and pathological changes were observed.The activities of enzymes lysozyme,acid phosphatase and complement C3 had significantly increased after the vaccination.The antibody titer response of vaccinated turbot was greatly boosted,which was positively connected with the immunological impact according to ELISA results.Simultaneously,the expression levels of immune-related genes such as MHC-IIα,MHC-IIβ,CD4,CD8,TNF-αand IL^(-1)βwere up-regulated,demonstrating that it might stimulate humoral and cellular immunological response in turbot.These findings highlight the potential of the bivalent inactivated vaccine for controlling V.scophthalmi and A.salmonicida infections in turbot.展开更多
Aeromonas hydrophila is a Gram-negative pathogen that can infect various fish,including largemouth bass(Micropterus salmoides),which have caused huge economic losses.In present study,largemouth bass anti-A.hydrophila ...Aeromonas hydrophila is a Gram-negative pathogen that can infect various fish,including largemouth bass(Micropterus salmoides),which have caused huge economic losses.In present study,largemouth bass anti-A.hydrophila antibodies were produced,then a highly immunogenic outer membrane proteins,AHA_3793,was identified by combined western blotting and mass spectrometry analysis.Moreover,AHA_3793 was expressed,and its immunogenicity was further verified by western blotting.Subsequently,the protective efficacy of AHA_3793 were evaluated in largemouth bass.The results showed that rAHA_3793 could produce a relative percentage survival(RPS)of 61.76% for largemouth bass against A.hydrophila challenge.ELISA analysis showed the specific serum antibodies of largemouth bass against rAHA_3793 and A.hydrophila in vaccinated group in weeks 4 and 5 after immunization were significantly higher than those in control group,which suggested that rAHA_3793 induced production of specific serum antibodies against rAHA_3793 and A.hydrophila.The qRT-PCR analysis showed that expressions of CD4-2 and MHC Ⅱα were also significantly up-regulated after immunization.These results collectively demonstrated that rAHA_3793 could induce a strong humoral immune response of largemouth bass,and then produce high immune protection ef fects against A.hydrophila infection.展开更多
Rationale:Aeromonas hydrophila,a bacterium commonly found in a variety of soils,aquatic habitats,and other natural environments,is known for causing infections and hemorrhagic diseases in both aquatic and terrestrial ...Rationale:Aeromonas hydrophila,a bacterium commonly found in a variety of soils,aquatic habitats,and other natural environments,is known for causing infections and hemorrhagic diseases in both aquatic and terrestrial animals.Patients with leukemia,when infected by Aeromonas hydrophila following chemotherapy,face an increased risk of developing necrotizing fasciitis.Patient concerns:A 48-year-old male with a history of acute myeloid leukemia presented with swelling and pain in his right hand after being stabbed by a grass carp two days ago.The injury occurred on the fifth day after his last chemotherapy session when he was accidentally punctured in the right thumb and ring finger by a carp while fishing.Two days following the injury,the skin isurrounding the wound turned black immediately,while the rest of his hand was reddened,swollen,and bleeding.Diagnosis:Aeromonas hydrophila infection in the soft tissue of the right hand.Interventions:Intravenous antibiotics and local debridement.Outcomes:The patient experienced an alleviation of systemic poisoning symptoms,effective control of the local wound infection.Lessons:It is important for physicians to appreciate the potential for highly unusual and life-threatening infections in patients with acute myeloid leukemia.Early diagnosis and prompt treatment can prevent the development of necrotizing fasciitis and save patients’lives.展开更多
基金supported by projects funded by grants from the Natural Science Foundation of Jiangsu Province in China(BK20221515)the National Natural Science Foundation of China(32172266)the Changzhou Science and Technology Support Program(CE20222002)。
文摘The aim of this study was to evaluate the factors influencing the inactivation effect of intense pulsed light(IPL)on Aeromonas salmonicida grown on chicken meat and skin,and to further develop prediction models of inactivation.In this work,chicken meat and skin inoculated with meat-borne A.salmonicida isolates were subjected to IPL treatments under different conditions.The results showed that IPL had obvious bactericidal effect in the chicken skin and thickness groups when the treatment voltage and time were 7 V combined with 5 s.In addition,the lethality curves of A.salmonicida were fitted under IPL conditions of 3.5-7.5 V.The comparison of statistical parameters revealed that the Weibull model could best fit the mortality curves and could accurately predict the mortality dynamic of A.salmonicida grown on chicken skin.And further a secondary model between the scale factor b and the treatment voltage in Weibull model was established using linear equations,which determined that the secondary model could accurately predict the inactivation of A.salmonicida.This study provides a theoretical basis for future prediction models of Aeromonas,and also provides new ideas for sterilization approaches of meat-borne Aeromonas.
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Supported by Outstanding Graduate Entering Laboratory Project of College of Fisheries,Guangdong Ocean UniversityNational Natural Science Foundation of China(32073015)+1 种基金Undergraduate Innovation and Entrepreneurship Training Program of Guangdong Ocean University(CXXL2023008)Undergraduate Innovation Team of Guangdong Ocean University(CCTD201802).
文摘[Objectives]To explore the function of hcp gene in Aeromonas hydrophila.[Methods]A pair of specific primers was designed referring to the hcp gene sequence of A.hydrophila.The hcp gene was amplified by PCR,and performed bioinformatics analysis.[Results]The hcp gene had a total length of 1650 bp and encoded 549 amino acids.The theoretical molecular weight of the protein predicted was about 59476.44 kDa.After predicting the N-terminal signal peptide structure of the amino acid sequence,neither obvious signal peptide cleavage site nor signal peptide was found,and the protein had no transmembrane region.The amino acid sequence had a N-glycosylation site,4 protein kinase C phosphorylation sites,7 casein kinase II phosphorylation sites,9 N-myristoylation sites,4 isoprene binding sites,10 microbody C-terminal target signal sites,and an ATP/GTP binding site motif A(P-ring).The amino acid sequence of hcp gene of A.hydrophila was performed homology analysis with other Aeromonas strains,and it showed higher homology with A.veronii.In the secondary structure,theα-helix,β-sheet,random coil and extended strand accounted for 45.36%,6.01%,37.52%and 11.11%,respectively.The tertiary structure model consisted of 18α-helix and 22β-sheet.Analysis of protein-protein network interaction demonstrated that the proteins interacting with Hcp protein were AHA_3407,nrfA,nirB-1,nirB-2 and AHA_1112.[Conclusions]Through the bioinformatics prediction results,the basic information of hcp gene of A.hydrophila is preliminarily understood,and the possible function of this protein is predicted,in order to provide guidance for subsequent vaccine research.
基金supported by the Operational Program Research and Development and European Fund for Regional Development(EFRD)(grant No.ITMS 26240220020)
文摘Objective:To investigate a case of mass mortality of Garra rufa(G.rufa)from a fish hatchery farm in Slovakia.Methods:Causative bacterial agent was swabbing out of affected fish skin area and subsequently identified using commercial test system.Antibiotic susceptibility was determined by the disk diffusion method.Results:Infected G.rufa was characterized by abnormal swimming behaviour,bleeding of skin lesions and local haemorrhages.Despite of using recommended aquatic antibiotic treatment no improvement was achieved and Aeromonas sobria{A.sobria)was identified as a causative agent of fish mortality.Due to massive fish mortality,antibiotic susceptibility of pure isolated culture of A.sobria was evaluated employing eight antibiotics against human infections.A.sobria was resistant only against one antibiotic,namely ampicilin.Conclusions:These results indicate that A.sobria can act as a primary pathogen of G.rufa and may be a potential risk factor for immunodeficient or immunoincompetent patients during the ichthyotherapy.
基金supported by the Fish Innovation Team of Shandong Agriculture Research System (No. SDAIT-1206)the Aquatic Animal Immunologic Agents Engineering Research Center of Shandong Province, the Qingdao Agricultural University Doctoral Start-Up Fund (6631122030)+5 种基金the National Natural Science Foundation of China (No. 32002421)the Advanced Talents Foundation of QAU (No. 6651118016)the Natural Science Foundation of Shandong Province (No. ZR2019BC009)the ‘First-Class Fishery Discipline’ program of Shandong Province, the special top talent plan ‘One Thing One Decision (Yi Shi Yi Yi)’the Key Research and Development Program in Shandong Province (No. 2018YFJH0703)Breeding Plan of Shandong Provincial Qingchuang Research Team (2019)
文摘Vibrio scophthalmi and Aeromonas salmonicida can cause high turbot mortality and huge economic losses.Presently,vaccination is the most promising method for preventing communicable diseases.In this study,we used formalin to kill V.scophthalmi and A.salmonicida cells,and mixed with the mineralized oil adjuvant(Montanide^(TM)ISA 763 AVG)to prepare the bivalent inactivated vaccine.The results showed that turbot inoculated with the bivalent inactivated vaccine exhibited strong tolerance to the infection of V.scophthalmi and A.salmonicida,and no obvious clinical symptoms and pathological changes were observed.The activities of enzymes lysozyme,acid phosphatase and complement C3 had significantly increased after the vaccination.The antibody titer response of vaccinated turbot was greatly boosted,which was positively connected with the immunological impact according to ELISA results.Simultaneously,the expression levels of immune-related genes such as MHC-IIα,MHC-IIβ,CD4,CD8,TNF-αand IL^(-1)βwere up-regulated,demonstrating that it might stimulate humoral and cellular immunological response in turbot.These findings highlight the potential of the bivalent inactivated vaccine for controlling V.scophthalmi and A.salmonicida infections in turbot.
基金Supported by the National Natural Science Foundation of China(No.32102824)the Zhejiang Provincial Natural Science Foundation of China(No.LQ18B060005)the Zhejiang Sci-Tech University Foundation(Nos.11612932611702,11612832611909)。
文摘Aeromonas hydrophila is a Gram-negative pathogen that can infect various fish,including largemouth bass(Micropterus salmoides),which have caused huge economic losses.In present study,largemouth bass anti-A.hydrophila antibodies were produced,then a highly immunogenic outer membrane proteins,AHA_3793,was identified by combined western blotting and mass spectrometry analysis.Moreover,AHA_3793 was expressed,and its immunogenicity was further verified by western blotting.Subsequently,the protective efficacy of AHA_3793 were evaluated in largemouth bass.The results showed that rAHA_3793 could produce a relative percentage survival(RPS)of 61.76% for largemouth bass against A.hydrophila challenge.ELISA analysis showed the specific serum antibodies of largemouth bass against rAHA_3793 and A.hydrophila in vaccinated group in weeks 4 and 5 after immunization were significantly higher than those in control group,which suggested that rAHA_3793 induced production of specific serum antibodies against rAHA_3793 and A.hydrophila.The qRT-PCR analysis showed that expressions of CD4-2 and MHC Ⅱα were also significantly up-regulated after immunization.These results collectively demonstrated that rAHA_3793 could induce a strong humoral immune response of largemouth bass,and then produce high immune protection ef fects against A.hydrophila infection.
文摘Rationale:Aeromonas hydrophila,a bacterium commonly found in a variety of soils,aquatic habitats,and other natural environments,is known for causing infections and hemorrhagic diseases in both aquatic and terrestrial animals.Patients with leukemia,when infected by Aeromonas hydrophila following chemotherapy,face an increased risk of developing necrotizing fasciitis.Patient concerns:A 48-year-old male with a history of acute myeloid leukemia presented with swelling and pain in his right hand after being stabbed by a grass carp two days ago.The injury occurred on the fifth day after his last chemotherapy session when he was accidentally punctured in the right thumb and ring finger by a carp while fishing.Two days following the injury,the skin isurrounding the wound turned black immediately,while the rest of his hand was reddened,swollen,and bleeding.Diagnosis:Aeromonas hydrophila infection in the soft tissue of the right hand.Interventions:Intravenous antibiotics and local debridement.Outcomes:The patient experienced an alleviation of systemic poisoning symptoms,effective control of the local wound infection.Lessons:It is important for physicians to appreciate the potential for highly unusual and life-threatening infections in patients with acute myeloid leukemia.Early diagnosis and prompt treatment can prevent the development of necrotizing fasciitis and save patients’lives.