More than 60% human infectious diseases have zoonotic origin. Cross species transmission of pathogens is a continuous, dynamic process that occurs throughout the world, giving rise to epizootic (temporary, limited inf...More than 60% human infectious diseases have zoonotic origin. Cross species transmission of pathogens is a continuous, dynamic process that occurs throughout the world, giving rise to epizootic (temporary, limited infection), endemic (on-going infection limited to a defined geographic region) and pandemic viral infections (infection spreading to every part of the world) like the current COVID-19 pandemic, which depends on the existing conditions on the ground. In Nov 2021, sudden mortality of numerous migrating demoiselle cranes was reported from their resting site near Jodhpur, Rajasthan. The symptomatic cranes became gradually weak and were unable to fly. They eventually fell dead which caused concern locally, given the current prevailing SARS-CoV-2 pandemic situation the world over. By the end of Dec 2021, the number of cranes with mortality and morbidity reduced, making it a temporary “epizootic infection”. Molecular diagnosis carried out at a specialized laboratory identified the etiological agent to be the highly pathogenic Avian Influenza Virus H5N1 (HPAIV), which has been responsible for morbidity of avian species from different parts of the world. There was no report of spreading the H5N1 AIV infection from the infected migratory cranes to nearby chicken farms or pig farms for now. In the absence of vaccines against the highly pathogenic H5N1 AIVs, and the inherent ability of influenza viruses, both avian AIV and human IAVs to constantly mutate its envelope gene or the surface antigens, resulting from the error-prone nature of the viral RNA Polymerase enzyme are the roadblocks for development of a universal, broad-spectrum influenza vaccine. Even when such a universal vaccine against H5N1 is available, vaccinating a large number of wild migratory cranes would be difficult. However, it is possible and indeed necessary to vaccinate chickens in poultry farms and pigs in farms that raise pigs for human consumption.展开更多
To correctly assess and properly manage the public health risks associated with exposure to contaminated water,it is necessary to identify the source of fecal pollution in a watershed.In this study,we evaluated the ef...To correctly assess and properly manage the public health risks associated with exposure to contaminated water,it is necessary to identify the source of fecal pollution in a watershed.In this study,we evaluated the efficacy of our two previously developed real time-quantitative PCR(qPCR)assays for the detection of swine-associated Bacteroidales genetic markers(gene 1-38,gene 3-53)in the Yangtze Delta watershed of southeastern China.The results indicated that the gene 1-38 and 3-53 markers exhibited high accuracy(92.5%,91.7%conditional probability,respectively)in detecting Bacteroidales spp.in water samples.According to binary logistic regression(BLR),these two swine-associated markers were well correlated(P<0.05)with fecal indicators(Escherichia coli and Enterococci spp.)and zoonotic pathogens(E.coli O157:H7,Salmonella spp.and Campylobacter spp.)in water samples.In contrast,concentrations of conventional fecal indicator bacteria(FIB)were not correlated with zoonotic pathogens,suggesting that they are noneffective at detecting fecal pollution events.Collectively,the results obtained in this study demonstrated that a swinetargeted qPCR assay based on two Bacteroidales genes markers(gene 1-38,gene 3-53)could be a useful tool in determining the swine-associated impacts of fecal contamination in a watershed.展开更多
The practice of integrated fish farming and the use of local fish meal and manure for fish feeding in Cameroon constitute potential sources of resistant pathogenic bacteria in the fish pond environment.Therefore,a per...The practice of integrated fish farming and the use of local fish meal and manure for fish feeding in Cameroon constitute potential sources of resistant pathogenic bacteria in the fish pond environment.Therefore,a periodical and constant monitoring of the microbiological quality of fish pond is imperative.This study was to assess the microbial contamination of Mfou aquaculture production site and evaluate the antibiotic resistance profile of bacterial fish isolates.Samples of pond water(n=36),sediment(n=36),fishmeal(n=12)and African catfish(Clarias gariepinus),kanga(Heterotis niloticus)and Nile Tilapia(Oreochromis niloticus)(n=36,each)were collected to determine TVAC(Total Viable Aerobic Bacterial Count),FC(Fungal Count),SAC(Staphylococcus aureus count),TCC(Total Coliform Count)and FCC(Feacal Coliform Count).The fish skin isolates of S.aureus,Enterobacter sakazakii,Citrobacter freundii,Serratia fonticola,Klebsiella oxytoca,Proteus spp.,Aeromonas hydrophila,Kluyvera spp.,Moraxella spp.,Pasteurella multocida and Pseudomonas fluorescens were tested against penicillin G(10μg),chloramphenicol(30μg),sulfamethoxazole/trimethoprim(25μg),erythromycin(15μg),tetracycline(30μg),using the disk diffusion method.Results reveal a heavy contamination of fish farms with microbial load above the recommended limits.Our study indicates that fish ponds are sources of zoonotic pathogens underlining their epidemiological and clinical relevance.All bacterial isolates were multiresistant with a multiple antibiotic resistance index above 0.2.These data raise concern about the microbial contamination of aquaculture and associated public health risks in Cameroon.展开更多
Nipah virus (NiV) is a highly infectious zoonotic pathogen that poses a significant threat to human and animal health. First identified in Malaysia in 1998, NiV has since caused several outbreaks in Southeast Asia, wi...Nipah virus (NiV) is a highly infectious zoonotic pathogen that poses a significant threat to human and animal health. First identified in Malaysia in 1998, NiV has since caused several outbreaks in Southeast Asia, with sporadic cases reported in Bangladesh and India. The virus is primarily transmitted to humans through direct contact with infected animals, primarily fruit bats, or through the consumption of contaminated fruits and their juices. NiV infection presents a wide spectrum of clinical features, ranging from mild respiratory illness to severe encephalitis, with a high case fatality rate. The incubation period typically ranges from 4 to 14 days, during which patients develop fever, headache, myalgia, and respiratory symptoms such as cough and sore throat. As the disease progresses, neurological signs become prominent, including altered consciousness, seizures, and focal deficits. Severe cases may exhibit acute respiratory distress syndrome and multi organ failure. Laboratory findings often include lymphocytopenia, thrombocytopenia, and elevated liver enzymes. Diagnosis of NiV infection requires specialized laboratory testing, including reverse transcription-polymerase chain reaction (RT-PCR) and serological assays. Currently, no specific antiviral treatment exists for NiV infection, and management primarily focuses on supportive care. Prevention and control strategies encompass public health interventions, surveillance, and raising awareness among healthcare providers and the general population. The emergence and re-emergence of NiV highlight the urgent need for continued research, improved diagnostic capabilities, and the development of effective vaccines and therapeutics to mitigate the impact of this deadly virus.展开更多
Background:This scoping review provides a baseline summary of the current records of the ticks,fleas,and mites of public health importance that are present in Bangladesh.It summarizes their geographic distributions an...Background:This scoping review provides a baseline summary of the current records of the ticks,fleas,and mites of public health importance that are present in Bangladesh.It summarizes their geographic distributions and reports the levels of their infestation of livestock,pets,wildlife,and humans,and the clinical and epidemiological studies pertinent to these vectors and their pathogens.Methods:Sixty-one articles were identified in a literature search,including 43 published since 2011.Results:Twelve articles contained reliable information on ticks and their associated hosts.However,informa-tion on fleas and mites in Bangladesh is very limited.Seventeen species of ixodid ticks that commonly parasitize peridomestic animals and can bite humans are described:Rhipicephalus microplus,R.appendiculatus,R.sanguineus,Haemaphysalis bispinosa,Hyalomma anatolicum,and Amblyomma testudinarium.Thirty-eight veterinary articles de-scribe livestock pathogens,including Babesia,Anaplasma,and Theileria,and the diseases they cause.Few of those studies used modern molecular techniques to identify these pathogens.Eleven articles reported human diseases or surveillance studies,10 from the last 10 years.Two country-wide serosurveys of 1,209 and 720 patients,us-ing Enzyme Linked Immunosorbent Assay(ELISA)and Indirect Immunofluorescence Assay(IFA),respectively,reported human exposure to Orientia tsutsugamushi(8.8%–23.7%),typhus and spotted-fever group rickettsiae(19.7%–66.6%),and Coxiella burnetii(3%).The seropositivity rates varied regionally.PCR-based studies con-firmed that febrile patients in Bangladesh may be infected with O.tsutsugamushi,Rickettsia typhi,Rickettsia felis,or Bartonella elizabethae.Only limited molecular research has been done with dogs and cats.These studies have reported PCR-confirmed canine infections with Babesia gibsoni(30%),Anaplasma bovis(58%),or Rickettsia monace-nis(14%,n=50),and feline infections with Rickettsia felis(21%,n=100).Similarly,fleas from cats tested positive for Rickettsia felis(20.6%).Conclusions:These findings indicate that diseases borne by non-mosquito vectors in Bangladesh urgently require more attention from public health,medical,and veterinary specialists to establish their true occurrence.展开更多
Zoonotic diseases, which constitute 60% of all human infectious diseases, present substantial risks to public health, economies, and livelihoods. These diseases emerge at the human-animal-environment interface, with o...Zoonotic diseases, which constitute 60% of all human infectious diseases, present substantial risks to public health, economies, and livelihoods. These diseases emerge at the human-animal-environment interface, with occupational exposure representing a critical yet underexamined dimension of zoonotic risk. Workers in high-risk sectors such as agriculture, wildlife management, and laboratory research face elevated exposure to zoonotic pathogens, often under conditions of inadequate preventive measures and resource constraints. Neurological disorders resulting from zoonotic infections, including Guillain-Barré syndrome, encephalitis, and meningitis, illustrate the severe health consequences for occupational groups. Cases linked to swine hepatitis E virus, West Nile virus, Streptococcus suis, and Baylisascaris procyonis underscore the urgent need for robust surveillance and targeted interventions.The Ecohealth approach, integrated with the One Health framework, provides a transformative model for managing zoonotic risks by addressing the upstream drivers of disease emergence. By emphasizing environmental stewardship, ecological balance, and socio-economic equity, Ecohealth fosters sustainable preventive strategies. Occupational medicine is crucial in linking workplace safety with public health through tailored risk management, enhanced surveillance, and targeted education.Despite these frameworks, significant barriers persist, including data gaps, underreporting of occupational diseases, and insufficient coordination among health sectors. Addressing these challenges requires implementing standardized occupational health surveillance systems, enhancing reporting mechanisms through digital tools, and promoting cross-sectoral data-sharing initiatives. Successful models, such as sentinel surveillance programs in agricultural sectors and integrated biosurveillance networks, demonstrate the feasibility of these strategies. Leveraging these approaches can facilitate early detection, improve reporting accuracy, and support evidence-based interventions.展开更多
Introduction:Lymphocytic choriomeningitis virus(LCMV)is a globally distributed zoonotic pathogen transmitted primarily by rodents.Its nonspecific clinical presentation in the general population frequently results in u...Introduction:Lymphocytic choriomeningitis virus(LCMV)is a globally distributed zoonotic pathogen transmitted primarily by rodents.Its nonspecific clinical presentation in the general population frequently results in underdiagnosis and underreporting.To date,no large-scale seroprevalence surveys of LCMV have been conducted in China.Methods:During 2023,this study collected 661 serum/plasma samples from healthy individuals and tested for anti-LCMV IgG antibodies using an enzyme-linked immunosorbent assay(ELISA).Samples tested positive by ELISA underwent confirmatory testing via indirect immunofluorescence analysis(IFA)and neutralization assay(NTA).Results:ELISA detected anti-LCMV IgG antibodies in 18.31%(121/661)of samples,while IFA confirmed seropositivity in 1.97%(13/661).Four samples demonstrated neutralizing antibody activity with reduced viral infectivity.Seropositive cases were sporadically distributed across the study region,with farmers representing the predominant occupational group.Key at-risk populations identified included farmers,rural residents,and individuals with lower educational attainment.Conclusion:This study provides the first serological evidence of past LCMV infections in humans in Gansu Province.Targeted health education interventions tailored to high-risk populations are recommended to reduce future transmission.展开更多
Vibrio parahaemolyticus(Vp)is an aquatic zoonotic pathogen that causes vibriosis in marine animals as well as sepsis,gastroenteritis and wound infection in human.In vertebrates,the innate immune system plays a critica...Vibrio parahaemolyticus(Vp)is an aquatic zoonotic pathogen that causes vibriosis in marine animals as well as sepsis,gastroenteritis and wound infection in human.In vertebrates,the innate immune system plays a critical defense mechanism against Vp infection including transmigration of neutrophils.In this study,we have examined the genetic recombination and infectious process of Vp in the zebrafish(Danio rerio),a vertebrate model system extensively used for studying host-pathogen interactions.A pathogenic Vp strain,Vp57,tagged with red fluorescent protein(RFP)(Vp57^(RFP))was introduced into larval zebrafish at 3 days post fertilization(dpf),in which the innate immunity is present whereas the adaptive immunity has not yet developed.Vp57 and Vp57^(RFP)showed similar LD50 and induced similar symptoms and pathological changes in the hosts.We microinjected 579 colony-forming units(CFU)Vp57^(RFP)into the zebrafish caudal vein,and observed that neutrophils were recruited to the injection site and within 3 h post infection(hpi)Vp57^(RFP)were mainly distributed in the tail,eyes,heart and optic vesicle.After 3 hpi,the fish died with slight spine bending.Several Vp57^(RFP)were also detected in somites,the phagocytosis of neutrophils was activated through the progress of bacterial infections.We found that chemotaxis and phagocytosis of neutrophils occurs when zebrafish is infected by Vp57^(RFP),whereas Vp57^(RFP)can escape from neutrophils and colonize other remote regions using the blood circulation system.展开更多
文摘More than 60% human infectious diseases have zoonotic origin. Cross species transmission of pathogens is a continuous, dynamic process that occurs throughout the world, giving rise to epizootic (temporary, limited infection), endemic (on-going infection limited to a defined geographic region) and pandemic viral infections (infection spreading to every part of the world) like the current COVID-19 pandemic, which depends on the existing conditions on the ground. In Nov 2021, sudden mortality of numerous migrating demoiselle cranes was reported from their resting site near Jodhpur, Rajasthan. The symptomatic cranes became gradually weak and were unable to fly. They eventually fell dead which caused concern locally, given the current prevailing SARS-CoV-2 pandemic situation the world over. By the end of Dec 2021, the number of cranes with mortality and morbidity reduced, making it a temporary “epizootic infection”. Molecular diagnosis carried out at a specialized laboratory identified the etiological agent to be the highly pathogenic Avian Influenza Virus H5N1 (HPAIV), which has been responsible for morbidity of avian species from different parts of the world. There was no report of spreading the H5N1 AIV infection from the infected migratory cranes to nearby chicken farms or pig farms for now. In the absence of vaccines against the highly pathogenic H5N1 AIVs, and the inherent ability of influenza viruses, both avian AIV and human IAVs to constantly mutate its envelope gene or the surface antigens, resulting from the error-prone nature of the viral RNA Polymerase enzyme are the roadblocks for development of a universal, broad-spectrum influenza vaccine. Even when such a universal vaccine against H5N1 is available, vaccinating a large number of wild migratory cranes would be difficult. However, it is possible and indeed necessary to vaccinate chickens in poultry farms and pigs in farms that raise pigs for human consumption.
基金supported by the National Key Research and Development Program of China(No.2016YFD0501105)the Science and Technology Department of Zhejiang Province(No.2015C02044)the National Natural Science Foundation of China(No.31301492)
文摘To correctly assess and properly manage the public health risks associated with exposure to contaminated water,it is necessary to identify the source of fecal pollution in a watershed.In this study,we evaluated the efficacy of our two previously developed real time-quantitative PCR(qPCR)assays for the detection of swine-associated Bacteroidales genetic markers(gene 1-38,gene 3-53)in the Yangtze Delta watershed of southeastern China.The results indicated that the gene 1-38 and 3-53 markers exhibited high accuracy(92.5%,91.7%conditional probability,respectively)in detecting Bacteroidales spp.in water samples.According to binary logistic regression(BLR),these two swine-associated markers were well correlated(P<0.05)with fecal indicators(Escherichia coli and Enterococci spp.)and zoonotic pathogens(E.coli O157:H7,Salmonella spp.and Campylobacter spp.)in water samples.In contrast,concentrations of conventional fecal indicator bacteria(FIB)were not correlated with zoonotic pathogens,suggesting that they are noneffective at detecting fecal pollution events.Collectively,the results obtained in this study demonstrated that a swinetargeted qPCR assay based on two Bacteroidales genes markers(gene 1-38,gene 3-53)could be a useful tool in determining the swine-associated impacts of fecal contamination in a watershed.
文摘The practice of integrated fish farming and the use of local fish meal and manure for fish feeding in Cameroon constitute potential sources of resistant pathogenic bacteria in the fish pond environment.Therefore,a periodical and constant monitoring of the microbiological quality of fish pond is imperative.This study was to assess the microbial contamination of Mfou aquaculture production site and evaluate the antibiotic resistance profile of bacterial fish isolates.Samples of pond water(n=36),sediment(n=36),fishmeal(n=12)and African catfish(Clarias gariepinus),kanga(Heterotis niloticus)and Nile Tilapia(Oreochromis niloticus)(n=36,each)were collected to determine TVAC(Total Viable Aerobic Bacterial Count),FC(Fungal Count),SAC(Staphylococcus aureus count),TCC(Total Coliform Count)and FCC(Feacal Coliform Count).The fish skin isolates of S.aureus,Enterobacter sakazakii,Citrobacter freundii,Serratia fonticola,Klebsiella oxytoca,Proteus spp.,Aeromonas hydrophila,Kluyvera spp.,Moraxella spp.,Pasteurella multocida and Pseudomonas fluorescens were tested against penicillin G(10μg),chloramphenicol(30μg),sulfamethoxazole/trimethoprim(25μg),erythromycin(15μg),tetracycline(30μg),using the disk diffusion method.Results reveal a heavy contamination of fish farms with microbial load above the recommended limits.Our study indicates that fish ponds are sources of zoonotic pathogens underlining their epidemiological and clinical relevance.All bacterial isolates were multiresistant with a multiple antibiotic resistance index above 0.2.These data raise concern about the microbial contamination of aquaculture and associated public health risks in Cameroon.
文摘Nipah virus (NiV) is a highly infectious zoonotic pathogen that poses a significant threat to human and animal health. First identified in Malaysia in 1998, NiV has since caused several outbreaks in Southeast Asia, with sporadic cases reported in Bangladesh and India. The virus is primarily transmitted to humans through direct contact with infected animals, primarily fruit bats, or through the consumption of contaminated fruits and their juices. NiV infection presents a wide spectrum of clinical features, ranging from mild respiratory illness to severe encephalitis, with a high case fatality rate. The incubation period typically ranges from 4 to 14 days, during which patients develop fever, headache, myalgia, and respiratory symptoms such as cough and sore throat. As the disease progresses, neurological signs become prominent, including altered consciousness, seizures, and focal deficits. Severe cases may exhibit acute respiratory distress syndrome and multi organ failure. Laboratory findings often include lymphocytopenia, thrombocytopenia, and elevated liver enzymes. Diagnosis of NiV infection requires specialized laboratory testing, including reverse transcription-polymerase chain reaction (RT-PCR) and serological assays. Currently, no specific antiviral treatment exists for NiV infection, and management primarily focuses on supportive care. Prevention and control strategies encompass public health interventions, surveillance, and raising awareness among healthcare providers and the general population. The emergence and re-emergence of NiV highlight the urgent need for continued research, improved diagnostic capabilities, and the development of effective vaccines and therapeutics to mitigate the impact of this deadly virus.
文摘Background:This scoping review provides a baseline summary of the current records of the ticks,fleas,and mites of public health importance that are present in Bangladesh.It summarizes their geographic distributions and reports the levels of their infestation of livestock,pets,wildlife,and humans,and the clinical and epidemiological studies pertinent to these vectors and their pathogens.Methods:Sixty-one articles were identified in a literature search,including 43 published since 2011.Results:Twelve articles contained reliable information on ticks and their associated hosts.However,informa-tion on fleas and mites in Bangladesh is very limited.Seventeen species of ixodid ticks that commonly parasitize peridomestic animals and can bite humans are described:Rhipicephalus microplus,R.appendiculatus,R.sanguineus,Haemaphysalis bispinosa,Hyalomma anatolicum,and Amblyomma testudinarium.Thirty-eight veterinary articles de-scribe livestock pathogens,including Babesia,Anaplasma,and Theileria,and the diseases they cause.Few of those studies used modern molecular techniques to identify these pathogens.Eleven articles reported human diseases or surveillance studies,10 from the last 10 years.Two country-wide serosurveys of 1,209 and 720 patients,us-ing Enzyme Linked Immunosorbent Assay(ELISA)and Indirect Immunofluorescence Assay(IFA),respectively,reported human exposure to Orientia tsutsugamushi(8.8%–23.7%),typhus and spotted-fever group rickettsiae(19.7%–66.6%),and Coxiella burnetii(3%).The seropositivity rates varied regionally.PCR-based studies con-firmed that febrile patients in Bangladesh may be infected with O.tsutsugamushi,Rickettsia typhi,Rickettsia felis,or Bartonella elizabethae.Only limited molecular research has been done with dogs and cats.These studies have reported PCR-confirmed canine infections with Babesia gibsoni(30%),Anaplasma bovis(58%),or Rickettsia monace-nis(14%,n=50),and feline infections with Rickettsia felis(21%,n=100).Similarly,fleas from cats tested positive for Rickettsia felis(20.6%).Conclusions:These findings indicate that diseases borne by non-mosquito vectors in Bangladesh urgently require more attention from public health,medical,and veterinary specialists to establish their true occurrence.
文摘Zoonotic diseases, which constitute 60% of all human infectious diseases, present substantial risks to public health, economies, and livelihoods. These diseases emerge at the human-animal-environment interface, with occupational exposure representing a critical yet underexamined dimension of zoonotic risk. Workers in high-risk sectors such as agriculture, wildlife management, and laboratory research face elevated exposure to zoonotic pathogens, often under conditions of inadequate preventive measures and resource constraints. Neurological disorders resulting from zoonotic infections, including Guillain-Barré syndrome, encephalitis, and meningitis, illustrate the severe health consequences for occupational groups. Cases linked to swine hepatitis E virus, West Nile virus, Streptococcus suis, and Baylisascaris procyonis underscore the urgent need for robust surveillance and targeted interventions.The Ecohealth approach, integrated with the One Health framework, provides a transformative model for managing zoonotic risks by addressing the upstream drivers of disease emergence. By emphasizing environmental stewardship, ecological balance, and socio-economic equity, Ecohealth fosters sustainable preventive strategies. Occupational medicine is crucial in linking workplace safety with public health through tailored risk management, enhanced surveillance, and targeted education.Despite these frameworks, significant barriers persist, including data gaps, underreporting of occupational diseases, and insufficient coordination among health sectors. Addressing these challenges requires implementing standardized occupational health surveillance systems, enhancing reporting mechanisms through digital tools, and promoting cross-sectoral data-sharing initiatives. Successful models, such as sentinel surveillance programs in agricultural sectors and integrated biosurveillance networks, demonstrate the feasibility of these strategies. Leveraging these approaches can facilitate early detection, improve reporting accuracy, and support evidence-based interventions.
基金Supported by the Major Project of Guangzhou National Laboratory(Grant No.GZNL2024A01025)the Science and Technology Projects of Xizang Autonomous Region,China(Grant No.XZ202501JD0012).
文摘Introduction:Lymphocytic choriomeningitis virus(LCMV)is a globally distributed zoonotic pathogen transmitted primarily by rodents.Its nonspecific clinical presentation in the general population frequently results in underdiagnosis and underreporting.To date,no large-scale seroprevalence surveys of LCMV have been conducted in China.Methods:During 2023,this study collected 661 serum/plasma samples from healthy individuals and tested for anti-LCMV IgG antibodies using an enzyme-linked immunosorbent assay(ELISA).Samples tested positive by ELISA underwent confirmatory testing via indirect immunofluorescence analysis(IFA)and neutralization assay(NTA).Results:ELISA detected anti-LCMV IgG antibodies in 18.31%(121/661)of samples,while IFA confirmed seropositivity in 1.97%(13/661).Four samples demonstrated neutralizing antibody activity with reduced viral infectivity.Seropositive cases were sporadically distributed across the study region,with farmers representing the predominant occupational group.Key at-risk populations identified included farmers,rural residents,and individuals with lower educational attainment.Conclusion:This study provides the first serological evidence of past LCMV infections in humans in Gansu Province.Targeted health education interventions tailored to high-risk populations are recommended to reduce future transmission.
基金This work was supported by the Innovation Program of Shanghai Municipal Education Commission(13ZZ127)the Project Sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry(D-8002-15-0042)+1 种基金the Doctor Startup Fund of Shanghai Ocean University(A-0209-13-0105344)the SHOU&MSU Marine Joint Research Center Grant(A1-0209-15-0806).
文摘Vibrio parahaemolyticus(Vp)is an aquatic zoonotic pathogen that causes vibriosis in marine animals as well as sepsis,gastroenteritis and wound infection in human.In vertebrates,the innate immune system plays a critical defense mechanism against Vp infection including transmigration of neutrophils.In this study,we have examined the genetic recombination and infectious process of Vp in the zebrafish(Danio rerio),a vertebrate model system extensively used for studying host-pathogen interactions.A pathogenic Vp strain,Vp57,tagged with red fluorescent protein(RFP)(Vp57^(RFP))was introduced into larval zebrafish at 3 days post fertilization(dpf),in which the innate immunity is present whereas the adaptive immunity has not yet developed.Vp57 and Vp57^(RFP)showed similar LD50 and induced similar symptoms and pathological changes in the hosts.We microinjected 579 colony-forming units(CFU)Vp57^(RFP)into the zebrafish caudal vein,and observed that neutrophils were recruited to the injection site and within 3 h post infection(hpi)Vp57^(RFP)were mainly distributed in the tail,eyes,heart and optic vesicle.After 3 hpi,the fish died with slight spine bending.Several Vp57^(RFP)were also detected in somites,the phagocytosis of neutrophils was activated through the progress of bacterial infections.We found that chemotaxis and phagocytosis of neutrophils occurs when zebrafish is infected by Vp57^(RFP),whereas Vp57^(RFP)can escape from neutrophils and colonize other remote regions using the blood circulation system.
