Dear Editor,For the past few decades,mosquito-borne orthoflaviviruses,such as dengue virus,Zika virus,and West Nile virus(WNV),have posed significant threats to global public health.The Orthoflavivirus genus comprises...Dear Editor,For the past few decades,mosquito-borne orthoflaviviruses,such as dengue virus,Zika virus,and West Nile virus(WNV),have posed significant threats to global public health.The Orthoflavivirus genus comprises more than 70 viruses,many of which are responsible for a wide range of diseases in humans and animals,including febrile illnesses,encephalitis,and hemorrhagic febrile illness.These viruses are associated with approximately 400 million infections and 100 million symptomatic cases worldwide each year(Van Leur et al.,2021).Among them,Usutu virus(USUV)is an emerging pathogen classified alongside WNV within the Japanese encephalitis virus(JEV)serogroup of the Orthoflavivirus genus,the Flaviviridae family.USUV has spread from Africa to Europe since the late 20th century.It primarily causes central nervous system disorders in birds,with several large-scale mortality events recorded in Europe.USUV can also infect humans,it typically leads to neurological complications in rare cases(Roesch et al.,2019).展开更多
Dear Editor,Duck Tembusu virus(DTMUV),a member of the Flavivirus genus within the Flaviviridae family,has caused huge economic losses to the poultry industry in China and even in Asia since 2010(Zhang et al.2017).The ...Dear Editor,Duck Tembusu virus(DTMUV),a member of the Flavivirus genus within the Flaviviridae family,has caused huge economic losses to the poultry industry in China and even in Asia since 2010(Zhang et al.2017).The first strain of Tembusu virus(TMUV)MM_1775 was isolated from mosquitoes in 1955 in Malaysia(Platt et al.1975).DTMUV CQW1 strain(GenBank:KM233707.1)was isolated from the liver tissue of Cherry Valley ducks in southwest China in 2015(Zhu et al.2015).The positive control rCQW1 was rescued from an infectious clone that contained the full-length cDNA of CQW1.And the complete cDNA was positioned under the control of the T7 promoter elements for in vitro transcription(Chen et al.2018).The relationship between TMUV evolution and pathogenic variants has not been revealed.The fundamental reason is the lack of the in vitro operation platform for the prototypical strain genome.展开更多
Pasteurella multocida(PM)has been infecting a variety of hosts for a long time,causing sustained economic losses worldwide;however,there have been limited studies on its extensive adaptability(Aktories et al.2012).Ana...Pasteurella multocida(PM)has been infecting a variety of hosts for a long time,causing sustained economic losses worldwide;however,there have been limited studies on its extensive adaptability(Aktories et al.2012).Analysis of strains data collected in our laboratory revealed that PM typically acquires foreign genes through transformation and conjugation,rather than transformation and fusion.Integrative and conjugative elements(ICEs)are a crucial mechanism that leads to abrupt changes in niche preferences and enhances environmental adaptability for bacteria,with their number far exceeding the number of plasmids and phages(Wozniak and Waldor 2010;Johnson and Grossman 2015;Botelho and Schulenburg 2021).Previous research has shown that the European bovine-sourced strain Pm36950 contains the experimentally transferable resistant ICEPmu1,which could integrate into the host chromosome or forming a circular intermediate(Michael et al.2012).Additionally,a few studies have suggested that PM strains isolated from European bovine and Asian swine might contain ICEs,but these claims lack experimental verification(Klima et al.2014;Moustafa et al.2015;Kadlec et al.2017;Peng et al.2017;Beker et al.2018;Schink et al.2022).Currently,there is no data available on ICE-carrying PM strains isolated from hosts outside of European cattle or Chinses swine.This letter presents a report on a novel ICE identified in the hypervirulent and multidrug-resistant PM HN141014 strain isolated from Chinese duck.The ICE was specifically analyzed for its resistance genes,transferable capacity and host diversity.展开更多
Dear Editor,Duck Tembusu virus(DTMUV)is the causative agent of a new,acute and severe infectious disease in ducks(Su et al.,2011).TMUV was first isolated from Culex tritaeniorhynchus in Malaysia in 1955(Platt et al.,1...Dear Editor,Duck Tembusu virus(DTMUV)is the causative agent of a new,acute and severe infectious disease in ducks(Su et al.,2011).TMUV was first isolated from Culex tritaeniorhynchus in Malaysia in 1955(Platt et al.,1975),and this strain is regarded as a reference strain.In our previous study,an infectious clone for the mosquito-derived Tembusu virus prototypical strain MM_1775(GenBank:JX477685.2)was constructed,and the rMM_1775 virus was rescued successfully(Wang et al.,2021).And the TMUV strain rCQW1 was rescued by a reverse genetic system using the viral RNAs of CQW1(GenBank:KM233707.1)(Chen et al.,2018;Guo et al.,2020),which was isolated from ducks in 2013(Zhu et al.,2015).展开更多
革兰氏阴性菌包含有两层组分不同的膜结构——内膜和外膜,对大多数革兰氏阴性菌而言,脂多糖(lipopolysaccharides,LPS)是其外膜上最主要的脂质成分,锚定在外膜小叶(the outer leaflet of the OM)上,是革兰氏阴性菌固有免疫的重要组成部...革兰氏阴性菌包含有两层组分不同的膜结构——内膜和外膜,对大多数革兰氏阴性菌而言,脂多糖(lipopolysaccharides,LPS)是其外膜上最主要的脂质成分,锚定在外膜小叶(the outer leaflet of the OM)上,是革兰氏阴性菌固有免疫的重要组成部分。脂多糖运输系统(lipopolysaccharide transport system,Lpt)将胞内装配完整的LPS正确装配到外膜,使得与脂多糖相关的阻渗、有机溶剂耐受性、疏水性抗生素耐受性、膜通透性等功能得以实现。该运输系统的正确作用主要依赖7个不同的脂多糖运输蛋白(Lpt ABCDEFG)协同完成,整个系统贯穿细菌内膜至外膜,由内膜上ABC转运体复合物Lpt B2FG、胞质内转运协同蛋白Lpt A/C及被许多学者称作脂多糖运输的"命门"的外膜蛋白复合物Lpt DE共同构成。本文就革兰氏阴性菌脂多糖的具体结构功能进行简介,进而综述脂多糖运输系统的7个蛋白的构成和作用机制,以期为进一步研究该系统中每个蛋白的功能提供理论基础及参考。展开更多
基金funded by grants from the National Key Research and Development Program of China(2022YFD1801900)National Natural Science Foundation of China(32272976&32302848)+3 种基金Sichuan Provincial Department of Science and Technology international scientific and technological innovation cooperation(2022YFH0026)the earmarked fund for China Agricultural Research System(CARS-42-17)Program Sichuan Veterinary Medicine and Drug Innovation Group of China Agricultural Research System(SCCXTD-2021-18)the Innovation and Demonstration of Industry and Education Integration in Feed Industrial Chain Transformation and Upgradation,Sichuan Province,China.
文摘Dear Editor,For the past few decades,mosquito-borne orthoflaviviruses,such as dengue virus,Zika virus,and West Nile virus(WNV),have posed significant threats to global public health.The Orthoflavivirus genus comprises more than 70 viruses,many of which are responsible for a wide range of diseases in humans and animals,including febrile illnesses,encephalitis,and hemorrhagic febrile illness.These viruses are associated with approximately 400 million infections and 100 million symptomatic cases worldwide each year(Van Leur et al.,2021).Among them,Usutu virus(USUV)is an emerging pathogen classified alongside WNV within the Japanese encephalitis virus(JEV)serogroup of the Orthoflavivirus genus,the Flaviviridae family.USUV has spread from Africa to Europe since the late 20th century.It primarily causes central nervous system disorders in birds,with several large-scale mortality events recorded in Europe.USUV can also infect humans,it typically leads to neurological complications in rare cases(Roesch et al.,2019).
基金This work was funded by grants from,the National Key Research and Development Program of China(2017YFD0500800)the Sichuan-international joint research for science and technology(2018HH0098)+1 种基金China Agricultural Research System(CARS-42-17)the Program Sichuan Veterinary Medicine and Drug Innovation Group of China Agricultural Research System(SCCXTD-2020-18)。
文摘Dear Editor,Duck Tembusu virus(DTMUV),a member of the Flavivirus genus within the Flaviviridae family,has caused huge economic losses to the poultry industry in China and even in Asia since 2010(Zhang et al.2017).The first strain of Tembusu virus(TMUV)MM_1775 was isolated from mosquitoes in 1955 in Malaysia(Platt et al.1975).DTMUV CQW1 strain(GenBank:KM233707.1)was isolated from the liver tissue of Cherry Valley ducks in southwest China in 2015(Zhu et al.2015).The positive control rCQW1 was rescued from an infectious clone that contained the full-length cDNA of CQW1.And the complete cDNA was positioned under the control of the T7 promoter elements for in vitro transcription(Chen et al.2018).The relationship between TMUV evolution and pathogenic variants has not been revealed.The fundamental reason is the lack of the in vitro operation platform for the prototypical strain genome.
基金supported by the earmarked fund for China Agriculture Research System(CARS-42-17)the Sichuan Veterinary Medicine and Drug Innovation Group of China Agricultural Research System(SCCXTD-2021-18)。
文摘Pasteurella multocida(PM)has been infecting a variety of hosts for a long time,causing sustained economic losses worldwide;however,there have been limited studies on its extensive adaptability(Aktories et al.2012).Analysis of strains data collected in our laboratory revealed that PM typically acquires foreign genes through transformation and conjugation,rather than transformation and fusion.Integrative and conjugative elements(ICEs)are a crucial mechanism that leads to abrupt changes in niche preferences and enhances environmental adaptability for bacteria,with their number far exceeding the number of plasmids and phages(Wozniak and Waldor 2010;Johnson and Grossman 2015;Botelho and Schulenburg 2021).Previous research has shown that the European bovine-sourced strain Pm36950 contains the experimentally transferable resistant ICEPmu1,which could integrate into the host chromosome or forming a circular intermediate(Michael et al.2012).Additionally,a few studies have suggested that PM strains isolated from European bovine and Asian swine might contain ICEs,but these claims lack experimental verification(Klima et al.2014;Moustafa et al.2015;Kadlec et al.2017;Peng et al.2017;Beker et al.2018;Schink et al.2022).Currently,there is no data available on ICE-carrying PM strains isolated from hosts outside of European cattle or Chinses swine.This letter presents a report on a novel ICE identified in the hypervirulent and multidrug-resistant PM HN141014 strain isolated from Chinese duck.The ICE was specifically analyzed for its resistance genes,transferable capacity and host diversity.
文摘Dear Editor,Duck Tembusu virus(DTMUV)is the causative agent of a new,acute and severe infectious disease in ducks(Su et al.,2011).TMUV was first isolated from Culex tritaeniorhynchus in Malaysia in 1955(Platt et al.,1975),and this strain is regarded as a reference strain.In our previous study,an infectious clone for the mosquito-derived Tembusu virus prototypical strain MM_1775(GenBank:JX477685.2)was constructed,and the rMM_1775 virus was rescued successfully(Wang et al.,2021).And the TMUV strain rCQW1 was rescued by a reverse genetic system using the viral RNAs of CQW1(GenBank:KM233707.1)(Chen et al.,2018;Guo et al.,2020),which was isolated from ducks in 2013(Zhu et al.,2015).
文摘革兰氏阴性菌包含有两层组分不同的膜结构——内膜和外膜,对大多数革兰氏阴性菌而言,脂多糖(lipopolysaccharides,LPS)是其外膜上最主要的脂质成分,锚定在外膜小叶(the outer leaflet of the OM)上,是革兰氏阴性菌固有免疫的重要组成部分。脂多糖运输系统(lipopolysaccharide transport system,Lpt)将胞内装配完整的LPS正确装配到外膜,使得与脂多糖相关的阻渗、有机溶剂耐受性、疏水性抗生素耐受性、膜通透性等功能得以实现。该运输系统的正确作用主要依赖7个不同的脂多糖运输蛋白(Lpt ABCDEFG)协同完成,整个系统贯穿细菌内膜至外膜,由内膜上ABC转运体复合物Lpt B2FG、胞质内转运协同蛋白Lpt A/C及被许多学者称作脂多糖运输的"命门"的外膜蛋白复合物Lpt DE共同构成。本文就革兰氏阴性菌脂多糖的具体结构功能进行简介,进而综述脂多糖运输系统的7个蛋白的构成和作用机制,以期为进一步研究该系统中每个蛋白的功能提供理论基础及参考。
