Objective Campylobacter jejuni NCTC11168 is commonly used as a standard strain for flagellar biosynthesis research.In this report,two distinguished phenotypic isolates(CJ1Z,flhA mutant strain,lawn;CJ2S,flhA complement...Objective Campylobacter jejuni NCTC11168 is commonly used as a standard strain for flagellar biosynthesis research.In this report,two distinguished phenotypic isolates(CJ1Z,flhA mutant strain,lawn;CJ2S,flhA complemented strain,normal colony)appeared during laboratory passages for NCTC11168.Methods Phenotypic assessments,including motility plates,transmission electron microscopy,biofilm formation assay,autoagglutination assay,and genome re-sequencing for these two isolates(CJ1Z,flhA mutant strain;CJ2S,flhA complemented strain)were carried out in this study.Results Transmission electron microscopy revealed that the flagellum was lost in CJ1Z.Phenotypic assessments and genome sequencing of the two isolates were performed in this study.The capacity for biofilm formation,colony auto-agglutination,and isolate motility was reduced in the mutant CJ1Z.Comparative genomic analysis indicated a unique native nucleotide insertion in flhA(nt,2154)that caused the I719Y and I720Y mutations and early truncation in flhA.Conclusion FlhA has been found to influence the expression of flagella in C.jejuni.To the best of our knowledge,this is the first study to describe the function of the C-terminal of this protein.展开更多
During the COVID-19 epidemic,Wuhan city had the hardest hit in China.The treatment capacity of the local medical system exceeded due to the rapid growth of COVID-19 cases.As a result,a considerable part of diagnosed p...During the COVID-19 epidemic,Wuhan city had the hardest hit in China.The treatment capacity of the local medical system exceeded due to the rapid growth of COVID-19 cases.As a result,a considerable part of diagnosed patients could not be admitted to hospitals for isolation and treatment in time,causing the risk of spreading in the community.To effectively achieve the goals of controlling the source of infection by cutting off the transmission route,increasing the cure rate and reducing the mortality rate,Wuhan has reconstructed several makeshift hospitals based on large public places.展开更多
Objective To determine the distribution of two important virulence factors[lipooligosaccharide(LOS)and capsular polysaccharide(CPS)]in Campylobacter jejuni(C.jejuni)isolated from different sources in China and to deve...Objective To determine the distribution of two important virulence factors[lipooligosaccharide(LOS)and capsular polysaccharide(CPS)]in Campylobacter jejuni(C.jejuni)isolated from different sources in China and to develop a rapid screening method for Guillain–Barrésyndrome(GBS)-associated strains.Methods Whole-genome sequencing was carried out for 494 C.jejuni strains.The Ortho MCL software was used to define the LOS/CPS gene clusters.CPS genotyping was performed with serotype-specific sequence alignment using the BLAST software.Real-time Polymerase chain reaction(PCR)was developed with the unique sequences of specific CPS types.Results Nine novel and 29 previously confirmed LOS classes were identified.LOS classes A,B,and C were the most common(48.2%,238/494)among the 494 strains.Twenty-six capsular types were identified in 448 strains.HS2,HS4c,HS5/31,HS19,and HS8/17 were the most frequent CPS genotypes(58.7%,263/448).Strains of 17 CPS genotypes(strain number>5)had one or two prevalent LOS classes(P<0.05).Multiplex real-time PCR for rapid identification of HS2,HS19,and HS41 was developed and validated with strains of known serotypes.Conclusion Our results describe the genetic characteristics of the important virulence factors in C.jejuni strains in China.The multiplex real-time PCR developed in this study will facilitate enhanced surveillance of GBS-associated strains in China.展开更多
On December 14, 2017, a faculty member of a university in Hunan Province reported that an anthrax vaccine strain might have recovered virulence during an undergraduate experiment and potential exposure could not be ru...On December 14, 2017, a faculty member of a university in Hunan Province reported that an anthrax vaccine strain might have recovered virulence during an undergraduate experiment and potential exposure could not be ruled out for the students involved. Upon receiving the case report, the CDC, health bureaus, and local governments at the county, prefectural, and provincial levels promptly organized experts in different fields (including epidemiologists, biosafety experts, and laboratory testing experts) for case investigation, evaluation, and response. As the investigation results showed, no virulence recovery was identified in the involved anthrax vaccine strain;and no contamination of Bacillus anthracis was detected at the involved areas. Thus, the university returned to normal functioning.展开更多
基金supported by the National Key Research and Development Program of China[2021YFC2301000]the Project for Novel Detection Techniques of Bacterial Pathogens[32073]+1 种基金Enhancement of Comprehensive Monitoring,Prevention,and Control Capabilities for Traditional Infectious Diseases Such as Plague,Cholera,and Brucellosis[102393230020020000002]Prevention and Intervention of Bacterial and Fungal Infectious Diseases[102393220020020000031]。
文摘Objective Campylobacter jejuni NCTC11168 is commonly used as a standard strain for flagellar biosynthesis research.In this report,two distinguished phenotypic isolates(CJ1Z,flhA mutant strain,lawn;CJ2S,flhA complemented strain,normal colony)appeared during laboratory passages for NCTC11168.Methods Phenotypic assessments,including motility plates,transmission electron microscopy,biofilm formation assay,autoagglutination assay,and genome re-sequencing for these two isolates(CJ1Z,flhA mutant strain;CJ2S,flhA complemented strain)were carried out in this study.Results Transmission electron microscopy revealed that the flagellum was lost in CJ1Z.Phenotypic assessments and genome sequencing of the two isolates were performed in this study.The capacity for biofilm formation,colony auto-agglutination,and isolate motility was reduced in the mutant CJ1Z.Comparative genomic analysis indicated a unique native nucleotide insertion in flhA(nt,2154)that caused the I719Y and I720Y mutations and early truncation in flhA.Conclusion FlhA has been found to influence the expression of flagella in C.jejuni.To the best of our knowledge,this is the first study to describe the function of the C-terminal of this protein.
文摘During the COVID-19 epidemic,Wuhan city had the hardest hit in China.The treatment capacity of the local medical system exceeded due to the rapid growth of COVID-19 cases.As a result,a considerable part of diagnosed patients could not be admitted to hospitals for isolation and treatment in time,causing the risk of spreading in the community.To effectively achieve the goals of controlling the source of infection by cutting off the transmission route,increasing the cure rate and reducing the mortality rate,Wuhan has reconstructed several makeshift hospitals based on large public places.
基金supported by the National Key Research and Development Program of China[2021YFC2301000]the Sanming Project of Medicine in Shenzhen[SZSM201803081]。
文摘Objective To determine the distribution of two important virulence factors[lipooligosaccharide(LOS)and capsular polysaccharide(CPS)]in Campylobacter jejuni(C.jejuni)isolated from different sources in China and to develop a rapid screening method for Guillain–Barrésyndrome(GBS)-associated strains.Methods Whole-genome sequencing was carried out for 494 C.jejuni strains.The Ortho MCL software was used to define the LOS/CPS gene clusters.CPS genotyping was performed with serotype-specific sequence alignment using the BLAST software.Real-time Polymerase chain reaction(PCR)was developed with the unique sequences of specific CPS types.Results Nine novel and 29 previously confirmed LOS classes were identified.LOS classes A,B,and C were the most common(48.2%,238/494)among the 494 strains.Twenty-six capsular types were identified in 448 strains.HS2,HS4c,HS5/31,HS19,and HS8/17 were the most frequent CPS genotypes(58.7%,263/448).Strains of 17 CPS genotypes(strain number>5)had one or two prevalent LOS classes(P<0.05).Multiplex real-time PCR for rapid identification of HS2,HS19,and HS41 was developed and validated with strains of known serotypes.Conclusion Our results describe the genetic characteristics of the important virulence factors in C.jejuni strains in China.The multiplex real-time PCR developed in this study will facilitate enhanced surveillance of GBS-associated strains in China.
基金supported by the National Science and Technology Major Project on Important Infectious Diseases Prevention and Control [2018ZX10734-404]Key technology research for standardized identification of important pathogens and establishment of relevant reference librariesthe National Health and Family Planning Commission [201302006]
文摘On December 14, 2017, a faculty member of a university in Hunan Province reported that an anthrax vaccine strain might have recovered virulence during an undergraduate experiment and potential exposure could not be ruled out for the students involved. Upon receiving the case report, the CDC, health bureaus, and local governments at the county, prefectural, and provincial levels promptly organized experts in different fields (including epidemiologists, biosafety experts, and laboratory testing experts) for case investigation, evaluation, and response. As the investigation results showed, no virulence recovery was identified in the involved anthrax vaccine strain;and no contamination of Bacillus anthracis was detected at the involved areas. Thus, the university returned to normal functioning.
