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
Objective This study explored the potentially modifiable factors for depression and major depressive disorder(MDD)from the MR-Base database and further evaluated the associations between drug targets with MDD.Methods ...Objective This study explored the potentially modifiable factors for depression and major depressive disorder(MDD)from the MR-Base database and further evaluated the associations between drug targets with MDD.Methods We analyzed two-sample of Mendelian randomization(2SMR)using genetic variant depression(n=113,154)and MDD(n=208,811)from Genome-Wide Association Studies(GWAS).Separate calculations were performed with modifiable risk factors from MR-Base for 1,001 genomes.The MR analysis was performed by screening drug targets with MDD in the DrugBank database to explore the therapeutic targets for MDD.Inverse variance weighted(IVW),fixed-effect inverse variance weighted(FE-IVW),MR-Egger,weighted median,and weighted mode were used for complementary calculation.Results The potential causal relationship between modifiable risk factors and depression contained 459 results for depression and 424 for MDD.Also,the associations between drug targets and MDD showed that SLC6A4,GRIN2A,GRIN2C,SCN10A,and IL1B expression are associated with an increased risk of depression.In contrast,ADRB1,CHRNA3,HTR3A,GSTP1,and GABRG2 genes are candidate protective factors against depression.Conclusion This study identified the risk factors causally associated with depression and MDD,and estimated 10 drug targets with significant impact on MDD,providing essential information for formulating strategies to prevent and treat depression.展开更多
By the end of 2005,the estimated number of HIV infected people in China was 650,000. The seriousness of the epidemic calls for effective control measures to tackle the problems in order to avoid the tragedy in Africa ...By the end of 2005,the estimated number of HIV infected people in China was 650,000. The seriousness of the epidemic calls for effective control measures to tackle the problems in order to avoid the tragedy in Africa from happening in China. "Prevention First" is the cornerstone of the country's health policy. On 2003 World AIDS Day,Premier Jiabao Wen announced a new national AIDS control policy,"Four Frees and One Care". This policy clearly shows that the Chinese government has once again taken full responsibility to solve public health problems and has profound impact far beyond the AIDS field. In early 2006,the central government put scientific and technology innovation as a national priority and set the target to build an innovative China by year 2020. Since then,the government has been increasing investment in science and technology with major emphasis on both infectious diseases control and new drug research and development. For the first time,development of 100 new drugs and control of major infectious diseases (AIDS,HBV,TB and other emerging infectious diseases) have been selected as national key scientific projects. China's best minds in related fields will be pooled to work together in order to remove the technical barriers blocking efficient control of the major infectious disease in China. Knowledge on molecular epidemiology,immunology,pathogenesis,HAART,as well as HIVDR strains will certainly provide urgently needed scientific information for China's AIDS control program. Only evidence-based strategy from good research will provide long-term effective control of AIDS.展开更多
Objective Lower respiratory tract infections continue to pose a significant threat to human health. It is important to accurately and rapidly detect respiratory bacteria. To compensate for the limits of current respir...Objective Lower respiratory tract infections continue to pose a significant threat to human health. It is important to accurately and rapidly detect respiratory bacteria. To compensate for the limits of current respiratory bacteria detection methods, we developed a combination of multiplex polymerase chain reaction(PCR) and capillary electrophoresis(MPCE) assay to detect thirteen bacterial pathogens responsible for lower respiratory tract infections, including Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus, Mycoplasma pneumoniae, Legionella spp., Bordetella pertussis, Mycobacterium tuberculosis complex, Corynebacterium diphtheriae, and Streptococcus pyogenes. Methods Three multiplex PCR reactions were built, and the products were analyzed by capillary electrophoresis using the high-throughput DNA analyzer. The specificity of the MPCE assay was examined and the detection limit was evaluated using DNA samples from each bacterial strain and the simulative samples of each strain. This assay was further evaluated using 152 clinical specimens and compared with real-time PCR reactions. For this assay, three nested-multiplex-PCRs were used to detect these clinical specimens. Results The detection limits of the MPCE assay for the 13 pathogens were very low and ranged from 10^(-7) to 10^(-2) ng/μL. Furthermore, analysis of the 152 clinical specimens yielded a specificity ranging from 96.5%-100.0%, and a sensitivity of 100.0% for the 13 pathogens. Conclusion This study revealed that the MPCE assay is a rapid, reliable, and high-throughput method with high specificity and sensitivity. This assay has great potential in the molecular epidemiological survey of respiratory pathogens.展开更多
Objective Lyme disease and Human granulocytic anaplasmosis are tick‐borne diseases caused by Borrelia burgdorferi and Anaplasma phagocytophilum respectively. We have investigated infection and co-infection of the two...Objective Lyme disease and Human granulocytic anaplasmosis are tick‐borne diseases caused by Borrelia burgdorferi and Anaplasma phagocytophilum respectively. We have investigated infection and co-infection of the two diseases in the population of forest areas of eight provinces in China by measuring seroprevalence of antibodies against B. burgdorferi and A. phagocytophilum. Methods Forest areas in 8 provinces were chosen for investigation using whole sampling and questionnaire survey methods. 3 669 serum samples from people in the forest areas were tested for the presence of antibodies by indirect immunofluorescent assay (IFA). Results Seroprevalence against B. burgdorferi was 3% to 15% and against A. phagocytophilum was 2% to 18% in the study sites in the 8 provinces in China. We also found co-infection of B. burgdorferi and A. phagocytophilum in 7 of the 8 provinces (the exception being the Miyun area in Beijing). The seroprevalence for both B. burgdorferi and A. phagocytophilum was significantly higher among people exposed to ticks than among people who were not exposed to ticks. Conclusion We conclude that both pathogens are endemic in the forest areas in the eight provinces, but the prevalence of B. burgdorferi and A. phagocytophilum differs between the provinces.展开更多
Objective In the present study,the ABCA1 was used as a label to capture specific exosomes,the level of ABCA1-labeled exosomal microRNA-135 a(miR-135 a)was evaluated for the diagnosis of Alzheimer’s disease(AD),especi...Objective In the present study,the ABCA1 was used as a label to capture specific exosomes,the level of ABCA1-labeled exosomal microRNA-135 a(miR-135 a)was evaluated for the diagnosis of Alzheimer’s disease(AD),especially in patients with early stages of AD.Methods This is a preliminary research focused on the levels of ABCA1 in WBCs,RBCs,HT-22 cells,and neuron cells.The diagnostic value of ABCA1-labeled exosomal miR-135 a was examined using the CSF and serum of APP/PS1 double transgenic mice,and 152 patients with SCD,131 patients with MCI,198 patients with DAT,and 30 control subjects.Results The level of ABCA1 exosomes harvested from HT-22 cells and neuron culture medium was significantly higher compared to that of RBCs and WBCs(P<0.05).The levels of ABCA1-labeled exosomal miR-135 a increased in the CSF of MCI and DAT group compared to those of control group(P<0.05),slightly increased(P>0.05)in the serum of SCD patient group,and significantly increased in MCI and DAT patient groups compared to those of the control group(P<0.05).Conclusion This study outlines a method to capture specific exosomes and detect them using immunological methods,which is more efficient for early diagnosis of AD.展开更多
Objective To investigate the impact of impoundment and active public health interventions on rodent populations and rodent-borne diseases in the Three Gorges reservoir region from 1997 to 2012. Methods Surveillance da...Objective To investigate the impact of impoundment and active public health interventions on rodent populations and rodent-borne diseases in the Three Gorges reservoir region from 1997 to 2012. Methods Surveillance data from 1997 to 2012 were extracted from the Public Health Surveillance System of The Three Gorges established in 1997. Temporal changes in the incidences of hemorrhagic fever with renal syndrome(HFRS) and leptospirosis, rodent density, pathogen-carrying rates, and their correlations were analyzed. Results The average indoor and outdoor rodent densities decreased overall from 1997 to 2012. The average densities decreased by 47.72%(from 4.38% to 2.29%) and 39.68%(from 4.41% to 2.66%), respectively, after impoundment(2003-2012) compared with before impoundment(1997-2002). The average annual incidence rates of HFRS and leptospirosis were 0.29/100,000 and 0.52/100,000, respectively, and decreased by 85.74%(from 0.68/100,000 to 0.10/100,000) and 95.73%(from 1.47/100,000 to 0.065/100,000), respectively, after impoundment compared with before impoundment. Incidences of HFRS and leptospirosis appear to be positively correlated with rodent density in the reservoir area. Conclusion This study demonstrated that rodent density and incidences of rodent-borne diseases decreased and were maintained at low levels during construction of the Three Gorges dam. Measures that reduce rodent population densities could be effective in controlling rodent-borne diseases during large-scale hydraulic engineering construction.展开更多
Objective We aimed to assess the features of notifiable infectious diseases found commonly in foreign nationals in China between 2004 and 2017 to improve public health policy and responses for infectious diseases.Meth...Objective We aimed to assess the features of notifiable infectious diseases found commonly in foreign nationals in China between 2004 and 2017 to improve public health policy and responses for infectious diseases.Methods We performed a descriptive study of notifiable infectious diseases among foreigners reported from 2004 to 2017 in China using data from the Chinese National Notifiable Infectious Disease Reporting System(NNIDRIS). Demographic, temporal-spatial distribution were described and analyzed.Results A total of 67,939 cases of 33 different infectious diseases were reported among foreigners.These diseases were seen in 31 provinces of China and originated from 146 countries of the world. The infectious diseases with the highest incidence number were human immunodeficiency virus(HIV) of18,713 cases, hepatitis B(6,461 cases), hand, foot, and mouth disease(6,327 cases). Yunnan province had the highest number of notifiable infectious diseases in foreigners. There were different trends of the major infectious diseases among foreign cases seen in China and varied among provinces.Conclusions This is the first description of the epidemiological characteristic of notifiable infectious diseases among foreigners in China from 2004 to 2017. These data can be used to better inform policymakers about national health priorities for future research and control strategies.展开更多
Ebola virus disease reemerged in Western Africa in 2014.Chinese Center for Disease Control and Prevention dispatched the first Ebola virus(EBOV)detection team to run newly established Sierra Leone-China Friendship Bio...Ebola virus disease reemerged in Western Africa in 2014.Chinese Center for Disease Control and Prevention dispatched the first Ebola virus(EBOV)detection team to run newly established Sierra Leone-China Friendship Biological Safety Laboratory.The aims of study were to understand epidemiology,clinical manifestations and survival time of EBOV in patient’s blood.A total of 913specimens were tested between March 11 and展开更多
West Nile virus(WNV)causes West Nile fever and West Nile encephalitis.Because infection by WNV creates serious public health problems,its simple,rapid,and visual detection is very important in clinical practice,especi...West Nile virus(WNV)causes West Nile fever and West Nile encephalitis.Because infection by WNV creates serious public health problems,its simple,rapid,and visual detection is very important in clinical practice,especially in resource-limited laboratories.We have developed a rapid,specific,and highly sensitive internally controlled reverse transcription recombinase-aided amplification(RTRAA)assay to detect WNV,using both real-timefluoresce nee and the lateral flow dipstick(LFD)at39.0°C for 30 min.The analytical sensitivity of theRT-RAA assay was 10 plasmid copies and 1.6 pfu perreacti on with real-time fluoresce nee,and 1,000plasmid copies per reaction with the LFD.No crossreactionwith other control viruses was observed.Compared with the RT-qPCR assay,the RT-RAA assaydemonstrated 100%sensitivity and 100%specificityfor WNV.展开更多
Parkinson’s disease(PD)is a typical degenerative disease,which is characterized by the most obvious symptoms of movement dysfunction,including shaking,rigidity,slowness of movement and difficulty in walking and gait....Parkinson’s disease(PD)is a typical degenerative disease,which is characterized by the most obvious symptoms of movement dysfunction,including shaking,rigidity,slowness of movement and difficulty in walking and gait.This disease can not be clearly identified through laboratory tests at present,thus application of high-throughput technique in studying展开更多
In August 2021,three students with diarrhea from the same school visited a local hospital in the S district of Beijing.An epidemic investigation showed that there were more students with diarrhea in the same school an...In August 2021,three students with diarrhea from the same school visited a local hospital in the S district of Beijing.An epidemic investigation showed that there were more students with diarrhea in the same school and they had one meal together.Campylobacter jejuni was isolated from both patients with diarrhea and asymptomatic food handlers;however,the latter also carried Campylobacter coli.Phylogenomic analysis showed that there was a campylobacteriosis outbreak among the students,and the asymptomatic food handler may have been the source of the infection.Routine inspection and surveillance for Campylobacter is needed for the food producing staff,particularly those cooking in the cafeteria in schools or other public food services.展开更多
Objective This study aimed to investigate whether the VCA0560 gene acts as an active diguanylate cyclase(DGC)in Vibrio cholerae and how its transcription is regulated by Fur and Hap R.Methods The roles of VCA0560 was ...Objective This study aimed to investigate whether the VCA0560 gene acts as an active diguanylate cyclase(DGC)in Vibrio cholerae and how its transcription is regulated by Fur and Hap R.Methods The roles of VCA0560 was investigated by utilizing various phenotypic assays,including colony morphological characterization,crystal violet staining,Cyclic di-GMP(c-di-GMP)quantification,and swimming motility assay.The regulation of the VCA0560 gene by Fur and Hap R was analyzed by luminescence assay,electrophoretic mobility shift assay,and DNase I footprinting.Results VCA0560 gene mutation did not affect biofilm formation,motility,and c-di-GMP synthesis in V.cholerae,and its overexpression remarkably enhanced biofilm formation and intracellular c-di-GMP level but reduced motility capacity.The transcription of the VCA0560 gene was directly repressed by Fur and the master quorum sensing regulator Hap R.Conclusion Overexpressed VCA0560 functions as an active DGC in V.cholerae,and its transcription is repressed by Fur and Hap R.展开更多
Widespread species that inhabit diverse environments possess large population sizes and exhibit a high capacity for environmental adaptation,thus enabling range expansion.In contrast,narrow-range species are confined ...Widespread species that inhabit diverse environments possess large population sizes and exhibit a high capacity for environmental adaptation,thus enabling range expansion.In contrast,narrow-range species are confined to restricted geographical areas and are ecologically adapted to narrow environmental conditions,thus limiting their ability to expand into novel environments.However,the genomic mechanisms underlying the differentiation between closely related species with varying distribution ranges remain poorly understood.The Niviventer niviventer species complex(NNSC),consisting of highly abundant wild rats in Southeast Asia and China,offers an excellent opportunity to investigate these questions due to the presence of both widespread and narrow-range species that are phylogenetically closely related.In the present study,we combined ecological niche modeling with phylogenetic analysis,which suggested that sister species cannot be both widespread and dominant within the same geographical region.Moreover,by assessing heterozygosity,linkage disequilibrium decay,and Tajima's D analysis,we found that widespread species exhibited higher genetic diversity than narrow-range species.In addition,by exploring the“genomic islands of speciation”,we identified 13 genes in highly divergent regions that were shared by the two widespread species,distinguishing them from their narrow-range counterparts.Functional annotation analysis indicated that these genes are involved in nervous system development and regulation.The adaptive evolution of these genes likely played an important role in the speciation of these widespread species.展开更多
Due to the limitations of existing approaches,a rapid,sensitive,accurate,comprehensive,and generally applicable strategy to diagnose and treat bacterial and fungal infections remains a major challenge.Here,based on th...Due to the limitations of existing approaches,a rapid,sensitive,accurate,comprehensive,and generally applicable strategy to diagnose and treat bacterial and fungal infections remains a major challenge.Here,based on the ramanome technology platform,we propose a culture‐free,one cell resolution,phenome‐genome‐combined strategy called single‐cell identification,viability and vitality tests and source tracking(SCIVVS).For each cell directly extracted from a clinical specimen,the fingerprint region of the D2O‐probed single cell Raman spectrum(SCRS)enables species‐level identification based on a reference SCRS database of pathogen species,whereas the C‐D band accurately quantifies viability,metabolic vitality,phenotypic susceptibility to antimicrobials,and their intercellular heterogeneity.Moreover,to source track a cell,Raman‐activated cell sorting followed by sequencing or cultivation proceeds,producinging an indexed,high coverage genome assembly or a pure culture from precisely one pathogenic cell.Finally,an integrated SCIVVS workflow that features automated profiling and sorting of metabolic and morphological phenomes can complete the entire process in only a few hours.Because it resolves heterogeneity for both the metabolic phenome and genome,targets functions,can be automated,and is orders‐of‐magnitude faster while cost‐effective,SCIVVS is a new technological and data framework to diagnose and treat bacterial and fungal infections in various clinical and disease control settings.展开更多
Objective Western blotting (WB;immunoblotting) is a widely used tool for the serodiagnosis of Lyme borreliosis (LB),but so far,no generally accepted criteria for its performance and interpretation have been establishe...Objective Western blotting (WB;immunoblotting) is a widely used tool for the serodiagnosis of Lyme borreliosis (LB),but so far,no generally accepted criteria for its performance and interpretation have been established in China.The present study was designed to determine the criteria for standardized Western blot for the predominant species of Borrelia burgdorferi sensu lato in China,in which WB was produced with strain PD91 as the representative strain attributed to predominant genospecies Borrelia garinii of Borrelia burgdorferi sensu lato.Methods Approximately 13 bands between 14 and 100 kD were differentiated for strain PD91 by using Gel-Pro analysis software.In a study with 631 serum samples (taken from 127 patients with Lyme borreliosis and 504 controls),all observed bands were documented.To establish criteria for a positive WB result for strain PD91,receiver operating characteristic (ROC) curves were used.Results The following interpretation criteria were recommended:for IgG,at least one band of P83/100,P58,P39,P30,OspC,P17,P66,and OspA;for IgM,at least one band of P83/100,P58,OspA,P30,OspC,P17 or P41.In addition,syphilis,leptospirosis and other related diseases should be excluded when the positive band is P41 in IgM.For IgG criteria,the sensitivity is 73.2%,the specificity is 99.4% and Youden index is 0.726;for IgM criteria,the sensitivity is 50.6%,the specificity is 93.1% and Youden index is 0.437.Conclusion Standardization of WB assays is necessary for comparison of results from different laboratories.Moreover,the criteria of other genospecies of Borrelia burgdorferi sensu lato should be determined in the future to complete the criteria of WB for the diagnosis of the Lyme disease in China.展开更多
Objective To study the types of subspecies of Francisella tularensis from China and to investigate the genetic relationships between F.tularensis strains from China and from other countries.Methods Ten strains of F.tu...Objective To study the types of subspecies of Francisella tularensis from China and to investigate the genetic relationships between F.tularensis strains from China and from other countries.Methods Ten strains of F.tularensis isolated from China were amplified by using typing primers C1/C4 and RD1.On the basis of the lengths of the polymerase chain reaction (PCR) products,it was concluded that these strains of F.tularensis belonged to the same subspecies.At the same time,the fopA,tul4,and 16S rRNA genes of the 10 strains were amplified,and a three‐gene based phylogenetic analysis was performed using the Molecular Evolutionary Genetics Analysis software version 4.0.Results The 10 strains of F.tularensis from China were all identified as belonging to subspecies holarctica (type B).We found no direct relationship between the genotypes of F.tularensis subsp.holarctica and the geographical area from where they were isolated.Conclusion The F.tularensis strains isolated from North China mainly belong to subspecies holarctica (type B).The strains of F.tularensis subsp.holarctica from China may have evolved earlier than those from Europe and North America.展开更多
Objective To study the technique of Western blot for the diagnosis of Lyme disease caused by Borrelia afzelii in China and to establish the standard criteria by operational procedure. Methods FP1, which is the represe...Objective To study the technique of Western blot for the diagnosis of Lyme disease caused by Borrelia afzelii in China and to establish the standard criteria by operational procedure. Methods FP1, which is the representative strain of B. afzelii in China, was analyzed by SDS‐PAGE, electro transfer and immunoblotting assays. The molecular weights of the protein bands of FP1 were analyzed by Gel‐Pro analysis software. In a study using 451 serum samples (159 patients with Lyme disease and 292 controls), all observed bands were recorded. The accuracy of the WB as a diagnostic test was established by using the ROC curve and Youden index. Results Criteria for a positive diagnosis of Lyme disease were established as at least one band of P83/100, P58, P39, OspB, OspA, P30, P28, OspC, P17, and P14 in the IgG test and at least one band of P83/100, P58, P39, OspA, P30, P28, OspC, P17, and P41 in the IgM test. For IgG criteria, the sensitivity, specificity and Youden index were 69.8%, 98.3%, and 0.681, respectively; for IgM criteria, the sensitivity, specificity and Youden index were 47%, 94.2%, and 0.412, respectively. Conclusion Establishment of WB criteria for B. afzelii is important in validating the diagnostic assays for Lyme disease in China.展开更多
Objective To characterize the meningococcal strains isolated from cases and close contacts with meningococcal disease associated with an outbreak in a jail in May 2010 by investigating the national distribution of hyp...Objective To characterize the meningococcal strains isolated from cases and close contacts with meningococcal disease associated with an outbreak in a jail in May 2010 by investigating the national distribution of hyperinvasive ST-4821 serogroup C clone associated with this outbreak. Methods The cases were described based on the clinical symptoms and laboratory results. Pharyngeal swabs were cultured for N. meningitidis from men in the jail. Meningococcal isolates were identified by serogrouping, pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST), respectively. Four hundred and sixteen serogroup C N. meningitidis strains were collected from 27 provinces between 2003 and 2010 for a nationwide survey and analyzed by PFGE and MLST. Results Three persons in a jail system were infected with invasive N. meningitidis serogroup C. All isolates tested had matching PFGE patterns and belonged to the multilocus sequence type (ST) 4821 clonal complex. All 47 N. meningitidis strains were identified from the pharyngeal swabs of 166 peoples in the jail, and 26 of them belonged to ST-4821 serogroup C clone, and 90.14% (375/416) serogroup C strains identified in the nationwide survey belonged to the ST-4821 complex. The ST-4821 serogroup C clone was spread nationwide, distributed in 24 provinces, especially in eastern provinces between 2003 and 2010. Conclusion Endemic transmission and carriage rate of ST-4821 serogroup C clone are high in this jail system. The ST-4821 serogroup C clone is spreading in China and nationwide distributed despite the existence of some effective vaccines.展开更多
Objective To investigate the genotypic diversity of Methicillin-resistant Staphylococcus aureus(MRSA) isolated from pigs and retail foods from different geographical areas in China and further to study the routes and ...Objective To investigate the genotypic diversity of Methicillin-resistant Staphylococcus aureus(MRSA) isolated from pigs and retail foods from different geographical areas in China and further to study the routes and rates of transmission of this pathogen from animals to food. Methods Seventy-one MRSA isolates were obtained from pigs and retail foods and then characterized by multi-locus sequencing typing(MLST), spa typing, multiple-locus variable number of tandem repeat analysis(MLVA), pulsed-field gel electrophoresis(PFGE), and antimicrobial susceptibility testing. Results All isolated MRSA exhibited multi-drug resistance(MDR). Greater diversity was found in food-associated MRSA(7 STs, 8 spa types, and 10 MLVA patterns) compared to pig-associated MRSA(3 STs, 1 spa type, and 6 MLVA patterns). PFGE patterns were more diverse for pig-associated MRSA than those of food-associated isolates(40 vs. 11 pulse types). Among the pig-associated isolates, CC9-ST9-t899-MC2236 was the most prevalent clone(96.4%), and CC9-ST9-t437-MC621(20.0%) was the predominant clone among the food-associated isolates. The CC9-ST9 isolates showed significantly higher antimicrobial resistance than other clones. Interestingly, CC398-ST398-t034 clone was identified from both pig-and food-associated isolates. Of note, some community-and hospital-associated MRSA strains(t030, t172, t1244, and t4549) were also identified as food-associated isolates. Conclusion CC9-ST9-t899-MC2236-MDR was the most predominant clone in pigs, but significant genetic diversity was observed in food-associated MRSA. Our results demonstrate the great need for improved surveillance of MRSA in livestock and food and effective prevention strategies to limit MDR-MRSA infections in China.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.
基金supported by Natural Science Foundation of Shandong ProvinceChina[ZR2022MH115]the National Natural Science Foundation of China[81301479,82202593]。
文摘Objective This study explored the potentially modifiable factors for depression and major depressive disorder(MDD)from the MR-Base database and further evaluated the associations between drug targets with MDD.Methods We analyzed two-sample of Mendelian randomization(2SMR)using genetic variant depression(n=113,154)and MDD(n=208,811)from Genome-Wide Association Studies(GWAS).Separate calculations were performed with modifiable risk factors from MR-Base for 1,001 genomes.The MR analysis was performed by screening drug targets with MDD in the DrugBank database to explore the therapeutic targets for MDD.Inverse variance weighted(IVW),fixed-effect inverse variance weighted(FE-IVW),MR-Egger,weighted median,and weighted mode were used for complementary calculation.Results The potential causal relationship between modifiable risk factors and depression contained 459 results for depression and 424 for MDD.Also,the associations between drug targets and MDD showed that SLC6A4,GRIN2A,GRIN2C,SCN10A,and IL1B expression are associated with an increased risk of depression.In contrast,ADRB1,CHRNA3,HTR3A,GSTP1,and GABRG2 genes are candidate protective factors against depression.Conclusion This study identified the risk factors causally associated with depression and MDD,and estimated 10 drug targets with significant impact on MDD,providing essential information for formulating strategies to prevent and treat depression.
文摘By the end of 2005,the estimated number of HIV infected people in China was 650,000. The seriousness of the epidemic calls for effective control measures to tackle the problems in order to avoid the tragedy in Africa from happening in China. "Prevention First" is the cornerstone of the country's health policy. On 2003 World AIDS Day,Premier Jiabao Wen announced a new national AIDS control policy,"Four Frees and One Care". This policy clearly shows that the Chinese government has once again taken full responsibility to solve public health problems and has profound impact far beyond the AIDS field. In early 2006,the central government put scientific and technology innovation as a national priority and set the target to build an innovative China by year 2020. Since then,the government has been increasing investment in science and technology with major emphasis on both infectious diseases control and new drug research and development. For the first time,development of 100 new drugs and control of major infectious diseases (AIDS,HBV,TB and other emerging infectious diseases) have been selected as national key scientific projects. China's best minds in related fields will be pooled to work together in order to remove the technical barriers blocking efficient control of the major infectious disease in China. Knowledge on molecular epidemiology,immunology,pathogenesis,HAART,as well as HIVDR strains will certainly provide urgently needed scientific information for China's AIDS control program. Only evidence-based strategy from good research will provide long-term effective control of AIDS.
基金supported by grants from the Priority Project on Infectious Disease Control and Prevention(2012ZX10004215,2013ZX10004610)from Ministry of Health,China,and the Science Foundation for the State Key Laboratory for Infectious Disease Prevention and Control from China(Grant No.2015SKLID508)the National Natural Science Foundation of China(Grant No.81671985)and(Grant No.81170009)
文摘Objective Lower respiratory tract infections continue to pose a significant threat to human health. It is important to accurately and rapidly detect respiratory bacteria. To compensate for the limits of current respiratory bacteria detection methods, we developed a combination of multiplex polymerase chain reaction(PCR) and capillary electrophoresis(MPCE) assay to detect thirteen bacterial pathogens responsible for lower respiratory tract infections, including Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus, Mycoplasma pneumoniae, Legionella spp., Bordetella pertussis, Mycobacterium tuberculosis complex, Corynebacterium diphtheriae, and Streptococcus pyogenes. Methods Three multiplex PCR reactions were built, and the products were analyzed by capillary electrophoresis using the high-throughput DNA analyzer. The specificity of the MPCE assay was examined and the detection limit was evaluated using DNA samples from each bacterial strain and the simulative samples of each strain. This assay was further evaluated using 152 clinical specimens and compared with real-time PCR reactions. For this assay, three nested-multiplex-PCRs were used to detect these clinical specimens. Results The detection limits of the MPCE assay for the 13 pathogens were very low and ranged from 10^(-7) to 10^(-2) ng/μL. Furthermore, analysis of the 152 clinical specimens yielded a specificity ranging from 96.5%-100.0%, and a sensitivity of 100.0% for the 13 pathogens. Conclusion This study revealed that the MPCE assay is a rapid, reliable, and high-throughput method with high specificity and sensitivity. This assay has great potential in the molecular epidemiological survey of respiratory pathogens.
基金supported by the 12th Five-Year Major National Science and Technology Projects of China (No. 2012ZX10004219-007) and ( No. 2013ZX10004001)
文摘Objective Lyme disease and Human granulocytic anaplasmosis are tick‐borne diseases caused by Borrelia burgdorferi and Anaplasma phagocytophilum respectively. We have investigated infection and co-infection of the two diseases in the population of forest areas of eight provinces in China by measuring seroprevalence of antibodies against B. burgdorferi and A. phagocytophilum. Methods Forest areas in 8 provinces were chosen for investigation using whole sampling and questionnaire survey methods. 3 669 serum samples from people in the forest areas were tested for the presence of antibodies by indirect immunofluorescent assay (IFA). Results Seroprevalence against B. burgdorferi was 3% to 15% and against A. phagocytophilum was 2% to 18% in the study sites in the 8 provinces in China. We also found co-infection of B. burgdorferi and A. phagocytophilum in 7 of the 8 provinces (the exception being the Miyun area in Beijing). The seroprevalence for both B. burgdorferi and A. phagocytophilum was significantly higher among people exposed to ticks than among people who were not exposed to ticks. Conclusion We conclude that both pathogens are endemic in the forest areas in the eight provinces, but the prevalence of B. burgdorferi and A. phagocytophilum differs between the provinces.
基金supported by the National Natural Science Foundation of China[No.81401734,81472007]the National Key Research and Development Program of China[No.2016YFC1306300]。
文摘Objective In the present study,the ABCA1 was used as a label to capture specific exosomes,the level of ABCA1-labeled exosomal microRNA-135 a(miR-135 a)was evaluated for the diagnosis of Alzheimer’s disease(AD),especially in patients with early stages of AD.Methods This is a preliminary research focused on the levels of ABCA1 in WBCs,RBCs,HT-22 cells,and neuron cells.The diagnostic value of ABCA1-labeled exosomal miR-135 a was examined using the CSF and serum of APP/PS1 double transgenic mice,and 152 patients with SCD,131 patients with MCI,198 patients with DAT,and 30 control subjects.Results The level of ABCA1 exosomes harvested from HT-22 cells and neuron culture medium was significantly higher compared to that of RBCs and WBCs(P<0.05).The levels of ABCA1-labeled exosomal miR-135 a increased in the CSF of MCI and DAT group compared to those of control group(P<0.05),slightly increased(P>0.05)in the serum of SCD patient group,and significantly increased in MCI and DAT patient groups compared to those of the control group(P<0.05).Conclusion This study outlines a method to capture specific exosomes and detect them using immunological methods,which is more efficient for early diagnosis of AD.
基金supported by grants from the State Council Three Gorges Project Construction Committee Executive Office(No.SX[98]-05KHB/JSSX[2004]-018+3 种基金SX[2006]-003SX[2007]-002SX[2009]-020)JJ[2011]-030)
文摘Objective To investigate the impact of impoundment and active public health interventions on rodent populations and rodent-borne diseases in the Three Gorges reservoir region from 1997 to 2012. Methods Surveillance data from 1997 to 2012 were extracted from the Public Health Surveillance System of The Three Gorges established in 1997. Temporal changes in the incidences of hemorrhagic fever with renal syndrome(HFRS) and leptospirosis, rodent density, pathogen-carrying rates, and their correlations were analyzed. Results The average indoor and outdoor rodent densities decreased overall from 1997 to 2012. The average densities decreased by 47.72%(from 4.38% to 2.29%) and 39.68%(from 4.41% to 2.66%), respectively, after impoundment(2003-2012) compared with before impoundment(1997-2002). The average annual incidence rates of HFRS and leptospirosis were 0.29/100,000 and 0.52/100,000, respectively, and decreased by 85.74%(from 0.68/100,000 to 0.10/100,000) and 95.73%(from 1.47/100,000 to 0.065/100,000), respectively, after impoundment compared with before impoundment. Incidences of HFRS and leptospirosis appear to be positively correlated with rodent density in the reservoir area. Conclusion This study demonstrated that rodent density and incidences of rodent-borne diseases decreased and were maintained at low levels during construction of the Three Gorges dam. Measures that reduce rodent population densities could be effective in controlling rodent-borne diseases during large-scale hydraulic engineering construction.
基金sponsored by National Science and Technology Major Project No. 2016ZX10004222-001。
文摘Objective We aimed to assess the features of notifiable infectious diseases found commonly in foreign nationals in China between 2004 and 2017 to improve public health policy and responses for infectious diseases.Methods We performed a descriptive study of notifiable infectious diseases among foreigners reported from 2004 to 2017 in China using data from the Chinese National Notifiable Infectious Disease Reporting System(NNIDRIS). Demographic, temporal-spatial distribution were described and analyzed.Results A total of 67,939 cases of 33 different infectious diseases were reported among foreigners.These diseases were seen in 31 provinces of China and originated from 146 countries of the world. The infectious diseases with the highest incidence number were human immunodeficiency virus(HIV) of18,713 cases, hepatitis B(6,461 cases), hand, foot, and mouth disease(6,327 cases). Yunnan province had the highest number of notifiable infectious diseases in foreigners. There were different trends of the major infectious diseases among foreign cases seen in China and varied among provinces.Conclusions This is the first description of the epidemiological characteristic of notifiable infectious diseases among foreigners in China from 2004 to 2017. These data can be used to better inform policymakers about national health priorities for future research and control strategies.
基金supported by a China Mega-Project for Infectious Disease(2011ZX10004-101,2012ZX10004215)Major Program of the National Natural Science Foundation of China(81590763)a SKLID Development Grant(2012SKLID102)
文摘Ebola virus disease reemerged in Western Africa in 2014.Chinese Center for Disease Control and Prevention dispatched the first Ebola virus(EBOV)detection team to run newly established Sierra Leone-China Friendship Biological Safety Laboratory.The aims of study were to understand epidemiology,clinical manifestations and survival time of EBOV in patient’s blood.A total of 913specimens were tested between March 11 and
基金supported by grants from the China Mega-Projects for Infectious Disease [2017ZX10302301-004-002,2018ZX10711001,2017ZX10104001,2018ZX10713-002]IVDC [2019HYDQNJJ03]
文摘West Nile virus(WNV)causes West Nile fever and West Nile encephalitis.Because infection by WNV creates serious public health problems,its simple,rapid,and visual detection is very important in clinical practice,especially in resource-limited laboratories.We have developed a rapid,specific,and highly sensitive internally controlled reverse transcription recombinase-aided amplification(RTRAA)assay to detect WNV,using both real-timefluoresce nee and the lateral flow dipstick(LFD)at39.0°C for 30 min.The analytical sensitivity of theRT-RAA assay was 10 plasmid copies and 1.6 pfu perreacti on with real-time fluoresce nee,and 1,000plasmid copies per reaction with the LFD.No crossreactionwith other control viruses was observed.Compared with the RT-qPCR assay,the RT-RAA assaydemonstrated 100%sensitivity and 100%specificityfor WNV.
基金supported by the National Natural Science Foundation of China(81101302,31270185)SKLID Development Grant(2014,SKLID201)
文摘Parkinson’s disease(PD)is a typical degenerative disease,which is characterized by the most obvious symptoms of movement dysfunction,including shaking,rigidity,slowness of movement and difficulty in walking and gait.This disease can not be clearly identified through laboratory tests at present,thus application of high-throughput technique in studying
基金supported by the National Key Research and Development Program of China[2021YFC2301000].
文摘In August 2021,three students with diarrhea from the same school visited a local hospital in the S district of Beijing.An epidemic investigation showed that there were more students with diarrhea in the same school and they had one meal together.Campylobacter jejuni was isolated from both patients with diarrhea and asymptomatic food handlers;however,the latter also carried Campylobacter coli.Phylogenomic analysis showed that there was a campylobacteriosis outbreak among the students,and the asymptomatic food handler may have been the source of the infection.Routine inspection and surveillance for Campylobacter is needed for the food producing staff,particularly those cooking in the cafeteria in schools or other public food services.
基金supported by grants from the National Natural Science Foundation of China[Grant No.81471917]the National Basic Research Priorities Program[Grant 2015CB554201]the Science Foundation for the State Key Laboratory for Infectious Disease Prevention and Control of China[Grant No.2015SKLID509]
文摘Objective This study aimed to investigate whether the VCA0560 gene acts as an active diguanylate cyclase(DGC)in Vibrio cholerae and how its transcription is regulated by Fur and Hap R.Methods The roles of VCA0560 was investigated by utilizing various phenotypic assays,including colony morphological characterization,crystal violet staining,Cyclic di-GMP(c-di-GMP)quantification,and swimming motility assay.The regulation of the VCA0560 gene by Fur and Hap R was analyzed by luminescence assay,electrophoretic mobility shift assay,and DNase I footprinting.Results VCA0560 gene mutation did not affect biofilm formation,motility,and c-di-GMP synthesis in V.cholerae,and its overexpression remarkably enhanced biofilm formation and intracellular c-di-GMP level but reduced motility capacity.The transcription of the VCA0560 gene was directly repressed by Fur and the master quorum sensing regulator Hap R.Conclusion Overexpressed VCA0560 functions as an active DGC in V.cholerae,and its transcription is repressed by Fur and Hap R.
基金supported by the Guangdong Provincial Key R&D Program (2022B1111040001)the Second Tibetan Plateau Scientific Expedition and Research Program (2019QZKK0402/2019QZKK0501)National Natural Science Foundation of China (32170426)。
文摘Widespread species that inhabit diverse environments possess large population sizes and exhibit a high capacity for environmental adaptation,thus enabling range expansion.In contrast,narrow-range species are confined to restricted geographical areas and are ecologically adapted to narrow environmental conditions,thus limiting their ability to expand into novel environments.However,the genomic mechanisms underlying the differentiation between closely related species with varying distribution ranges remain poorly understood.The Niviventer niviventer species complex(NNSC),consisting of highly abundant wild rats in Southeast Asia and China,offers an excellent opportunity to investigate these questions due to the presence of both widespread and narrow-range species that are phylogenetically closely related.In the present study,we combined ecological niche modeling with phylogenetic analysis,which suggested that sister species cannot be both widespread and dominant within the same geographical region.Moreover,by assessing heterozygosity,linkage disequilibrium decay,and Tajima's D analysis,we found that widespread species exhibited higher genetic diversity than narrow-range species.In addition,by exploring the“genomic islands of speciation”,we identified 13 genes in highly divergent regions that were shared by the two widespread species,distinguishing them from their narrow-range counterparts.Functional annotation analysis indicated that these genes are involved in nervous system development and regulation.The adaptive evolution of these genes likely played an important role in the speciation of these widespread species.
基金National Key R&D Program of China,Grant/Award Number:2022YFA1304101CAS,Grant/Award Number:XDB29050400+1 种基金National Natural Science Foundation of China,Grant/Award Number:32030003Shenzhen‐Hong Kong Innovation Circle Plan,Grant/Award Number:SGDX2019081623060946。
文摘Due to the limitations of existing approaches,a rapid,sensitive,accurate,comprehensive,and generally applicable strategy to diagnose and treat bacterial and fungal infections remains a major challenge.Here,based on the ramanome technology platform,we propose a culture‐free,one cell resolution,phenome‐genome‐combined strategy called single‐cell identification,viability and vitality tests and source tracking(SCIVVS).For each cell directly extracted from a clinical specimen,the fingerprint region of the D2O‐probed single cell Raman spectrum(SCRS)enables species‐level identification based on a reference SCRS database of pathogen species,whereas the C‐D band accurately quantifies viability,metabolic vitality,phenotypic susceptibility to antimicrobials,and their intercellular heterogeneity.Moreover,to source track a cell,Raman‐activated cell sorting followed by sequencing or cultivation proceeds,producinging an indexed,high coverage genome assembly or a pure culture from precisely one pathogenic cell.Finally,an integrated SCIVVS workflow that features automated profiling and sorting of metabolic and morphological phenomes can complete the entire process in only a few hours.Because it resolves heterogeneity for both the metabolic phenome and genome,targets functions,can be automated,and is orders‐of‐magnitude faster while cost‐effective,SCIVVS is a new technological and data framework to diagnose and treat bacterial and fungal infections in various clinical and disease control settings.
基金supported by the "Tenth Five-Year Plan" project of research on the specific diagnosis method for the Lyme disease. 2001BA705B07
文摘Objective Western blotting (WB;immunoblotting) is a widely used tool for the serodiagnosis of Lyme borreliosis (LB),but so far,no generally accepted criteria for its performance and interpretation have been established in China.The present study was designed to determine the criteria for standardized Western blot for the predominant species of Borrelia burgdorferi sensu lato in China,in which WB was produced with strain PD91 as the representative strain attributed to predominant genospecies Borrelia garinii of Borrelia burgdorferi sensu lato.Methods Approximately 13 bands between 14 and 100 kD were differentiated for strain PD91 by using Gel-Pro analysis software.In a study with 631 serum samples (taken from 127 patients with Lyme borreliosis and 504 controls),all observed bands were documented.To establish criteria for a positive WB result for strain PD91,receiver operating characteristic (ROC) curves were used.Results The following interpretation criteria were recommended:for IgG,at least one band of P83/100,P58,P39,P30,OspC,P17,P66,and OspA;for IgM,at least one band of P83/100,P58,OspA,P30,OspC,P17 or P41.In addition,syphilis,leptospirosis and other related diseases should be excluded when the positive band is P41 in IgM.For IgG criteria,the sensitivity is 73.2%,the specificity is 99.4% and Youden index is 0.726;for IgM criteria,the sensitivity is 50.6%,the specificity is 93.1% and Youden index is 0.437.Conclusion Standardization of WB assays is necessary for comparison of results from different laboratories.Moreover,the criteria of other genospecies of Borrelia burgdorferi sensu lato should be determined in the future to complete the criteria of WB for the diagnosis of the Lyme disease in China.
基金supported by the National Technology Key Special Study Program of the Eleventh Five‐year Plan (No. 2008ZX10004‐010)
文摘Objective To study the types of subspecies of Francisella tularensis from China and to investigate the genetic relationships between F.tularensis strains from China and from other countries.Methods Ten strains of F.tularensis isolated from China were amplified by using typing primers C1/C4 and RD1.On the basis of the lengths of the polymerase chain reaction (PCR) products,it was concluded that these strains of F.tularensis belonged to the same subspecies.At the same time,the fopA,tul4,and 16S rRNA genes of the 10 strains were amplified,and a three‐gene based phylogenetic analysis was performed using the Molecular Evolutionary Genetics Analysis software version 4.0.Results The 10 strains of F.tularensis from China were all identified as belonging to subspecies holarctica (type B).We found no direct relationship between the genotypes of F.tularensis subsp.holarctica and the geographical area from where they were isolated.Conclusion The F.tularensis strains isolated from North China mainly belong to subspecies holarctica (type B).The strains of F.tularensis subsp.holarctica from China may have evolved earlier than those from Europe and North America.
基金supported by the 12th Five-Year Major National Science and Technology Projects of China (No.2011ZX10004-001)Natural Science Foundation of China (31100105)
文摘Objective To study the technique of Western blot for the diagnosis of Lyme disease caused by Borrelia afzelii in China and to establish the standard criteria by operational procedure. Methods FP1, which is the representative strain of B. afzelii in China, was analyzed by SDS‐PAGE, electro transfer and immunoblotting assays. The molecular weights of the protein bands of FP1 were analyzed by Gel‐Pro analysis software. In a study using 451 serum samples (159 patients with Lyme disease and 292 controls), all observed bands were recorded. The accuracy of the WB as a diagnostic test was established by using the ROC curve and Youden index. Results Criteria for a positive diagnosis of Lyme disease were established as at least one band of P83/100, P58, P39, OspB, OspA, P30, P28, OspC, P17, and P14 in the IgG test and at least one band of P83/100, P58, P39, OspA, P30, P28, OspC, P17, and P41 in the IgM test. For IgG criteria, the sensitivity, specificity and Youden index were 69.8%, 98.3%, and 0.681, respectively; for IgM criteria, the sensitivity, specificity and Youden index were 47%, 94.2%, and 0.412, respectively. Conclusion Establishment of WB criteria for B. afzelii is important in validating the diagnostic assays for Lyme disease in China.
基金supported by Research Fund from Ministry of Health and Ministry of Science and Technology of the People’s Republic of China,2013ZX10004221,2012ZX10004215,and 2011CB504900
文摘Objective To characterize the meningococcal strains isolated from cases and close contacts with meningococcal disease associated with an outbreak in a jail in May 2010 by investigating the national distribution of hyperinvasive ST-4821 serogroup C clone associated with this outbreak. Methods The cases were described based on the clinical symptoms and laboratory results. Pharyngeal swabs were cultured for N. meningitidis from men in the jail. Meningococcal isolates were identified by serogrouping, pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST), respectively. Four hundred and sixteen serogroup C N. meningitidis strains were collected from 27 provinces between 2003 and 2010 for a nationwide survey and analyzed by PFGE and MLST. Results Three persons in a jail system were infected with invasive N. meningitidis serogroup C. All isolates tested had matching PFGE patterns and belonged to the multilocus sequence type (ST) 4821 clonal complex. All 47 N. meningitidis strains were identified from the pharyngeal swabs of 166 peoples in the jail, and 26 of them belonged to ST-4821 serogroup C clone, and 90.14% (375/416) serogroup C strains identified in the nationwide survey belonged to the ST-4821 complex. The ST-4821 serogroup C clone was spread nationwide, distributed in 24 provinces, especially in eastern provinces between 2003 and 2010. Conclusion Endemic transmission and carriage rate of ST-4821 serogroup C clone are high in this jail system. The ST-4821 serogroup C clone is spreading in China and nationwide distributed despite the existence of some effective vaccines.
基金funded by the National Key R&D Program of China(2016YFD0401102)(the National Key Research and Development Program of China,the Ministry of Science and Technology of China)China Food Safety Talent Competency Development Initiative:CFSA 523 Program(1311613106702)
文摘Objective To investigate the genotypic diversity of Methicillin-resistant Staphylococcus aureus(MRSA) isolated from pigs and retail foods from different geographical areas in China and further to study the routes and rates of transmission of this pathogen from animals to food. Methods Seventy-one MRSA isolates were obtained from pigs and retail foods and then characterized by multi-locus sequencing typing(MLST), spa typing, multiple-locus variable number of tandem repeat analysis(MLVA), pulsed-field gel electrophoresis(PFGE), and antimicrobial susceptibility testing. Results All isolated MRSA exhibited multi-drug resistance(MDR). Greater diversity was found in food-associated MRSA(7 STs, 8 spa types, and 10 MLVA patterns) compared to pig-associated MRSA(3 STs, 1 spa type, and 6 MLVA patterns). PFGE patterns were more diverse for pig-associated MRSA than those of food-associated isolates(40 vs. 11 pulse types). Among the pig-associated isolates, CC9-ST9-t899-MC2236 was the most prevalent clone(96.4%), and CC9-ST9-t437-MC621(20.0%) was the predominant clone among the food-associated isolates. The CC9-ST9 isolates showed significantly higher antimicrobial resistance than other clones. Interestingly, CC398-ST398-t034 clone was identified from both pig-and food-associated isolates. Of note, some community-and hospital-associated MRSA strains(t030, t172, t1244, and t4549) were also identified as food-associated isolates. Conclusion CC9-ST9-t899-MC2236-MDR was the most predominant clone in pigs, but significant genetic diversity was observed in food-associated MRSA. Our results demonstrate the great need for improved surveillance of MRSA in livestock and food and effective prevention strategies to limit MDR-MRSA infections in China.
