Objective This study aimed to understand the epidemic status and phylogenetic relationships of rotavirus group A(RVA)in the Pearl River Delta region of Guangdong Province,China.Methods This study included individuals ...Objective This study aimed to understand the epidemic status and phylogenetic relationships of rotavirus group A(RVA)in the Pearl River Delta region of Guangdong Province,China.Methods This study included individuals aged 28 days–85 years.A total of 706 stool samples from patients with acute gastroenteritis collected between January 2019 and January 2020 were analyzed for 17 causative pathogens,including RVA,using a Gastrointestinal Pathogen Panel,followed by genotyping,virus isolation,and complete sequencing to assess the genetic diversity of RVA.Results The overall RVA infection rate was 14.59%(103/706),with an irregular epidemiological pattern.The proportion of co-infection with RVA and other pathogens was 39.81%(41/103).Acute gastroenteritis is highly prevalent in young children aged 0–1 year,and RVA is the key pathogen circulating in patients 6–10 months of age with diarrhea.G9P[8](58.25%,60/103)was found to be the predominant genotype in the RVA strains,and the 41 RVA-positive strains that were successfully sequenced belonged to three different RVA genotypes in the phylogenetic analysis.Recombination analysis showed that gene reassortment events,selection pressure,codon usage bias,gene polymorphism,and post-translational modifications(PTMs)occurred in the G9P[8]and G3P[8]strains.Conclusion This study provides molecular evidence of RVA prevalence in the Pearl River Delta region of China,further enriching the existing information on its genetics and evolutionary characteristics and suggesting the emergence of genetic diversity.Strengthening the surveillance of genotypic changes and gene reassortment in RVA strains is essential for further research and a better understanding of strain variations for further vaccine development.展开更多
Brucellosis is a bacterial anthropozoonosis usually caused by Brucella abortus, Brucella melitensis, Brucella suis and Brucella canis. Brucella suis, the causative agent of swine brucellosis, is classified into five b...Brucellosis is a bacterial anthropozoonosis usually caused by Brucella abortus, Brucella melitensis, Brucella suis and Brucella canis. Brucella suis, the causative agent of swine brucellosis, is classified into five biovars and preferentially infects different animal hostsIll. In China, brucellosis is a national notifiable communicable disease both in animals and in human. In 2009, 35 816 brucellosis cases were reported. The annual incidence was 2.7 per 100 000 population.展开更多
The first imported Middle East respiratory syndrome (MERS) case in China was identified in May 2015. We determined the kinetics of antibody (IgG and IgM) and neutralizing antibodies against MERS-coronavirus (MERS...The first imported Middle East respiratory syndrome (MERS) case in China was identified in May 2015. We determined the kinetics of antibody (IgG and IgM) and neutralizing antibodies against MERS-coronavirus (MERS-CoV) in this case before discharge. Moreover, no seroconversion was found among 53 close contacts by anti-MERS IgG antibody enzyme-linked immunosorbent assay (ELISA) of paired serum samples. These findings suggest that neither community nor nosocomial transmission of MERS-CoV occurred in China.展开更多
Objective The pandemic of severe acute respiratory syndrome coronavirus 2(SARS-Co V-2) has been engendering enormous hazards to the world. We obtained the complete genome sequences of SARSCo V-2 from imported cases ad...Objective The pandemic of severe acute respiratory syndrome coronavirus 2(SARS-Co V-2) has been engendering enormous hazards to the world. We obtained the complete genome sequences of SARSCo V-2 from imported cases admitted to the Guangzhou Eighth People’s Hospital, which was appointed by the Guangdong provincial government to treat coronavirus disease 2019(COVID-19). The SARS-Co V-2 diversity was analyzed, and the mutation characteristics, time, and regional trend of variant emergence were evaluated.Methods In total, 177 throat swab samples were obtained from COVID-19 patients(from October2020 to May 2021). High-throughput sequencing technology was used to detect the viral sequences of patients infected with SARS-Co V-2. Phylogenetic and molecular evolutionary analyses were used to evaluate the mutation characteristics and the time and regional trends of variants.Results We observed that the imported cases mainly occurred after January 2021, peaking in May2021, with the highest proportion observed from cases originating from the United States. The main lineages were found in Europe, Africa, and North America, and B.1.1.7 and B.1.351 were the two major sublineages. Sublineage B.1.618 was the Asian lineage(Indian) found in this study, and B.1.1.228 was not included in the lineage list of the Pangolin web. A reasonably high homology was observed among all samples. The total frequency of mutations showed that the open reading frame 1 a(ORF1 a) protein had the highest mutation density at the nucleotide level, and the D614 G mutation in the spike protein was the commonest at the amino acid level. Most importantly, we identified some amino acid mutations in positions S, ORF7 b, and ORF9 b, and they have neither been reported on the Global Initiative of Sharing All Influenza Data nor published in Pub Med among all missense mutations.Conclusion These results suggested the diversity of lineages and sublineages and the high homology at the amino acid level among imported cases infected with SARS-Co V-2 in Guangdong Province, China.展开更多
Objective The coronavirus disease 2019(COVID-19) pandemic continues to present a major challenge to public health. Vaccine development requires an understanding of the kinetics of neutralizing antibody(NAb) responses ...Objective The coronavirus disease 2019(COVID-19) pandemic continues to present a major challenge to public health. Vaccine development requires an understanding of the kinetics of neutralizing antibody(NAb) responses to severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).Methods In total, 605 serum samples from 125 COVID-19 patients(from January 1 to March 14, 2020)varying in age, sex, severity of symptoms, and presence of underlying diseases were collected, and antibody titers were measured using a micro-neutralization assay with wild-type SARS-CoV-2.Results NAbs were detectable approximately 10 days post-onset(dpo) of symptoms and peaked at approximately 20 dpo. The NAb levels were slightly higher in young males and severe cases, while no significant difference was observed for the other classifications. In follow-up cases, the NAb titer had increased or stabilized in 18 cases, whereas it had decreased in 26 cases, and in one case NAbs were undetectable at the end of our observation. Although a decreasing trend in NAb titer was observed in many cases, the NAb level was generally still protective.Conclusion We demonstrated that NAb levels vary among all categories of COVID-19 patients. Longterm studies are needed to determine the longevity and protective efficiency of NAbs induced by SARS-CoV-2.展开更多
基金funded by the grant National Key R&D Program of China(2017ZX10103011-004 and 2018YFC1603804)the Science and Technology Program of Guangdong Province(2018B020207013 and 2019B030316013).
文摘Objective This study aimed to understand the epidemic status and phylogenetic relationships of rotavirus group A(RVA)in the Pearl River Delta region of Guangdong Province,China.Methods This study included individuals aged 28 days–85 years.A total of 706 stool samples from patients with acute gastroenteritis collected between January 2019 and January 2020 were analyzed for 17 causative pathogens,including RVA,using a Gastrointestinal Pathogen Panel,followed by genotyping,virus isolation,and complete sequencing to assess the genetic diversity of RVA.Results The overall RVA infection rate was 14.59%(103/706),with an irregular epidemiological pattern.The proportion of co-infection with RVA and other pathogens was 39.81%(41/103).Acute gastroenteritis is highly prevalent in young children aged 0–1 year,and RVA is the key pathogen circulating in patients 6–10 months of age with diarrhea.G9P[8](58.25%,60/103)was found to be the predominant genotype in the RVA strains,and the 41 RVA-positive strains that were successfully sequenced belonged to three different RVA genotypes in the phylogenetic analysis.Recombination analysis showed that gene reassortment events,selection pressure,codon usage bias,gene polymorphism,and post-translational modifications(PTMs)occurred in the G9P[8]and G3P[8]strains.Conclusion This study provides molecular evidence of RVA prevalence in the Pearl River Delta region of China,further enriching the existing information on its genetics and evolutionary characteristics and suggesting the emergence of genetic diversity.Strengthening the surveillance of genotypic changes and gene reassortment in RVA strains is essential for further research and a better understanding of strain variations for further vaccine development.
文摘Brucellosis is a bacterial anthropozoonosis usually caused by Brucella abortus, Brucella melitensis, Brucella suis and Brucella canis. Brucella suis, the causative agent of swine brucellosis, is classified into five biovars and preferentially infects different animal hostsIll. In China, brucellosis is a national notifiable communicable disease both in animals and in human. In 2009, 35 816 brucellosis cases were reported. The annual incidence was 2.7 per 100 000 population.
基金Funds from the Nationl Health and Family Planning Commission of China:grants 2014ZX10004-001 and 2013ZX10004601
文摘The first imported Middle East respiratory syndrome (MERS) case in China was identified in May 2015. We determined the kinetics of antibody (IgG and IgM) and neutralizing antibodies against MERS-coronavirus (MERS-CoV) in this case before discharge. Moreover, no seroconversion was found among 53 close contacts by anti-MERS IgG antibody enzyme-linked immunosorbent assay (ELISA) of paired serum samples. These findings suggest that neither community nor nosocomial transmission of MERS-CoV occurred in China.
基金supported by the grant National Key Research and Development Program of China[2018YFC1603804 and 2021YFC0863300]Emergency Key Program of Guangzhou Laboratory[EKPG21-27]and Sino-German Center for Research Promotion(SGC)’s Rapid Response Funding Call for Bilateral Collaborative Proposals Between China and Germany in COVID-19 Related Research[C-0032].
文摘Objective The pandemic of severe acute respiratory syndrome coronavirus 2(SARS-Co V-2) has been engendering enormous hazards to the world. We obtained the complete genome sequences of SARSCo V-2 from imported cases admitted to the Guangzhou Eighth People’s Hospital, which was appointed by the Guangdong provincial government to treat coronavirus disease 2019(COVID-19). The SARS-Co V-2 diversity was analyzed, and the mutation characteristics, time, and regional trend of variant emergence were evaluated.Methods In total, 177 throat swab samples were obtained from COVID-19 patients(from October2020 to May 2021). High-throughput sequencing technology was used to detect the viral sequences of patients infected with SARS-Co V-2. Phylogenetic and molecular evolutionary analyses were used to evaluate the mutation characteristics and the time and regional trends of variants.Results We observed that the imported cases mainly occurred after January 2021, peaking in May2021, with the highest proportion observed from cases originating from the United States. The main lineages were found in Europe, Africa, and North America, and B.1.1.7 and B.1.351 were the two major sublineages. Sublineage B.1.618 was the Asian lineage(Indian) found in this study, and B.1.1.228 was not included in the lineage list of the Pangolin web. A reasonably high homology was observed among all samples. The total frequency of mutations showed that the open reading frame 1 a(ORF1 a) protein had the highest mutation density at the nucleotide level, and the D614 G mutation in the spike protein was the commonest at the amino acid level. Most importantly, we identified some amino acid mutations in positions S, ORF7 b, and ORF9 b, and they have neither been reported on the Global Initiative of Sharing All Influenza Data nor published in Pub Med among all missense mutations.Conclusion These results suggested the diversity of lineages and sublineages and the high homology at the amino acid level among imported cases infected with SARS-Co V-2 in Guangdong Province, China.
基金the Guangdong Provincial Novel Coronavirus Scientific and Technological Project[2020111107001 and202008040004]the National Key Research and Development Program of China[2020YFC0846900]+1 种基金the Guangzhou Basic Research Program on People’s Livelihood Science and Technology[202002020005]the National Natural Science Foundation of China[82003487 and 82072265]。
文摘Objective The coronavirus disease 2019(COVID-19) pandemic continues to present a major challenge to public health. Vaccine development requires an understanding of the kinetics of neutralizing antibody(NAb) responses to severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).Methods In total, 605 serum samples from 125 COVID-19 patients(from January 1 to March 14, 2020)varying in age, sex, severity of symptoms, and presence of underlying diseases were collected, and antibody titers were measured using a micro-neutralization assay with wild-type SARS-CoV-2.Results NAbs were detectable approximately 10 days post-onset(dpo) of symptoms and peaked at approximately 20 dpo. The NAb levels were slightly higher in young males and severe cases, while no significant difference was observed for the other classifications. In follow-up cases, the NAb titer had increased or stabilized in 18 cases, whereas it had decreased in 26 cases, and in one case NAbs were undetectable at the end of our observation. Although a decreasing trend in NAb titer was observed in many cases, the NAb level was generally still protective.Conclusion We demonstrated that NAb levels vary among all categories of COVID-19 patients. Longterm studies are needed to determine the longevity and protective efficiency of NAbs induced by SARS-CoV-2.