由Handelsman et al(1998)提出的宏基因组(metagenome)泛指特定环境样品(例如:人类和动物的肠道、母乳、土壤、湖泊、冰川和海洋等环境)中微生物群落所有物种的基因组。宏基因组技术起源于环境微生物学研究,而新一代高通量测序技术使其...由Handelsman et al(1998)提出的宏基因组(metagenome)泛指特定环境样品(例如:人类和动物的肠道、母乳、土壤、湖泊、冰川和海洋等环境)中微生物群落所有物种的基因组。宏基因组技术起源于环境微生物学研究,而新一代高通量测序技术使其广泛应用成为可能。与基因组学研究相类似,目前宏基因组学发展的瓶颈在于如何高效分析高通量测序产生的海量数据,因此,相关的生物信息学分析方法和平台是宏基因组学研究的关键。该文介绍了目前宏基因组研究领域中主要的生物信息学软件及工具;鉴于目前宏基因组研究所采用的"全基因组测序"(whole genome sequencing)和"扩增子测序"(amplicon sequencing)两大测序方法所获得的数据和相应分析方法有较大差异,文中分别对相应软件平台进行了介绍。展开更多
Many viruses can cause respiratory diseases in humans.Although great advances have been achieved in methods of diagnosis,it remains challenging to identify pathogens in unexplained pneumonia(UP) cases.In this study,we...Many viruses can cause respiratory diseases in humans.Although great advances have been achieved in methods of diagnosis,it remains challenging to identify pathogens in unexplained pneumonia(UP) cases.In this study,we applied next-generation sequencing(NGS) technology and a metagenomic approach to detect and characterize respiratory viruses in UP cases from Guizhou Province,China.A total of 33 oropharyngeal swabs were obtained from hospitalized UP patients and subjected to NGS.An unbiased metagenomic analysis pipeline identified 13 virus species in 16 samples.Human rhinovirus C was the virus most frequently detected and was identified in seven samples.Human measles virus,adenovirus B 55 and coxsackievirus A10 were also identified.Metagenomic sequencing also provided virus genomic sequences,which enabled genotype characterization and phylogenetic analysis.For cases of multiple infection,metagenomic sequencing afforded information regarding the quantity of each virus in the sample,which could be used to evaluate each viruses' role in the disease.Our study highlights the potential of metagenomic sequencing for pathogen identification in UP cases.展开更多
BACKGROUND Rifaximin has been shown to reduce the incidence of hepatic encephalopathy and other complications in patients with cirrhosis.However,few studies have investigated the effect of rifaximin in cirrhotic patie...BACKGROUND Rifaximin has been shown to reduce the incidence of hepatic encephalopathy and other complications in patients with cirrhosis.However,few studies have investigated the effect of rifaximin in cirrhotic patients with refractory ascites.AIM To evaluate the effects of rifaximin in the treatment of refractory ascites and to preliminarily explore its possible mechanism.METHODS A total of 75 cirrhotic patients with refractory ascites were enrolled in the study(50 in a rifaximin and 25 in a control group).Patients in the rifaximin group were divided into two subgroups according to the presence of spontaneous bacterial peritonitis and treatment with or without other antibiotics(19 patients treated with rifaximin and 31 patients treated with rifaximin plus intravenous antibiotics).All patients received conventional treatment for refractory ascites,while patients in the rifaximin group received oral rifaximin-α200 mg four times daily for at least 2 wk.The ascites grade,fasting weight,liver and kidney function,and inflammatory factors in the plasma were evaluated before and after treatment.In addition,the gut microbiota was determined by metagenomics sequencing to analyse the changes in the characteristics of the gut microbiota before and after rifaximin treatment.The patients were followed for 6 mo.RESULTS Compared with the control group,the fasting weight of patients significantly decreased and the ascites significantly subsided after treatment with rifaximin(P=0.011 and 0.009,respectively).The 6-mo survival rate of patients in the rifaximin group was significantly higher than that in the control group(P=0.048).The concentration of interferon-inducible protein 10 decreased significantly in the rifaximin group compared with that in the control group(P=0.024).The abundance of Roseburia,Haemophilus,and Prevotella was significantly reduced after rifaximin treatment,while the abundance of Lachnospiraceae_noname,Subdoligranulum,and Dorea decreased and the abundance of Coprobacillus increased after treatment with rifa展开更多
East Lake(Lake Donghu),located in Wuhan,China,is a typical city freshwater lake that has been experiencing eutrophic conditions and algal blooming during recent years.Marine and fresh water are considered to contain a...East Lake(Lake Donghu),located in Wuhan,China,is a typical city freshwater lake that has been experiencing eutrophic conditions and algal blooming during recent years.Marine and fresh water are considered to contain a large number of viruses.However,little is known about their genetic diversity because of the limited techniques for culturing viruses.In this study,we conducted a viral metagenomic analysis using a high-throughput sequencing technique with samples collected from East Lake in Spring,Summer,Autumn,and Winter.The libraries from four samples each generated 234,669,71,837,12,820,and 34,236 contigs(>90 bp each),respectively.The genetic structure of the viral community revealed a high genetic diversity covering 23 viral families,with the majority of contigs homologous to DNA viruses,including members of Myoviridae,Podoviridae,Siphoviridae,Phycodnaviridae,and Microviridae,which infect bacteria or algae,and members of Circoviridae,which infect invertebrates and vertebrates.The highest viral genetic diversity occurred in samples collected in August,then December and June,and the least diversity in March.Most contigs have low-sequence identities with known viruses.PCR detection targeting the conserved sequences of genes(g20,psbA,psbD,and DNApol)of cyanophages further confirmed that there are novel cyanophages in the East Lake.Our viral metagenomic data provide the first preliminary understanding of the virome in one freshwater lake in China and would be helpful for novel virus discovery and the control of algal blooming in the future.展开更多
Infectious diseases are a great threat to human health.Rapid and accurate detection of pathogens is important in the diagnosis and treatment of infectious diseases.Metagenomics next-generation sequencing(mNGS)is an un...Infectious diseases are a great threat to human health.Rapid and accurate detection of pathogens is important in the diagnosis and treatment of infectious diseases.Metagenomics next-generation sequencing(mNGS)is an unbiased and comprehensive approach for detecting all RNA and DNA in a sample.With the development of sequencing and bioinformatics technologies,mNGS is moving from research to clinical application,which opens a new avenue for pathogen detection.Numerous studies have revealed good potential for the clinical application of mNGS in infectious diseases,especially in difficult-to-detect,rare,and novel pathogens.However,there are several hurdles in the clinical application of mNGS,such as:(1)lack of universal workflow validation and quality assurance;(2)insensitivity to high-host background and low-biomass samples;and(3)lack of standardized instructions for mass data analysis and report interpretation.Therefore,a complete understanding of this new technology will help promote the clinical application of mNGS to infectious diseases.This review briefly introduces the history of next-generation sequencing,mainstream sequencing platforms,and mNGS workflow,and discusses the clinical applications of mNGS to infectious diseases and its advantages and disadvantages.展开更多
Background:Accurate diagnosis of Pneumocystis jirovecii pneumonia(PJP)is challenging,and the delayed diagnosis of PJP is associated with high mortality in patients with connective tissue disease(CTD).Metagenomic next-...Background:Accurate diagnosis of Pneumocystis jirovecii pneumonia(PJP)is challenging,and the delayed diagnosis of PJP is associated with high mortality in patients with connective tissue disease(CTD).Metagenomic next-generation sequencing(mNGS)technology facilitates etiological diagnosis of various infectious diseases,with promising application in diagnosing PJP.This study aimed to investigate the value of mNGS using bronchoalveolar lavage fluid(BALF)for diagnosing PJP infection.Methods:Data from 55 patients with CTD and suspected pulmonary infection was retrospectively collected and analysed.A PJP group and non-PJP group were formed.The clinical manifestations,laboratory test results,treatment methods,and outcomes were summarized.BALF mNGS results were compared with traditional pathogen tests(TPT)and serum 1,3-beta-D-glucan(BDG)testing.Results:The mean age of PJP patients was 54 years,and 59%(10/17)of the patients were female.A significant difference was found between the average daily dose of prednisone administered to the PJP group and non-PJP group(25 mg vs.16 mg,P<0.001).The PJP group had a significantly higher incidence of dyspnoea(88%[15/17]vs.16%[6/38],P<0.001)and elevated serum BDG level(167.73 vs.30.67 pg/mL,P<0.001).BALF mNGS was more sensitive than both TPT(100%[95%confidence interval{CI}:77.1%-100%]vs.11.8%[95%CI:2.1%-37.7%],P<0.001)and serum BDG(100%[95%CI:77.1%-100%]vs.85.7%[95%CI:42%-99.2%],P<0.001).BALF mNGS was more specific than serum BDG(89.5%[95%CI:74.3%-96.6%]vs.46.7%[95%CI:22.3%-72.6%],P=0.493).Co-infection with cytomegalovirus(CMV)was more common in the PJP patients than in the non-PJP patients(59%[10/17]vs.11%[4/38],respectively,P<0.001).Conclusion:BALF mNGS technology is highly effective for diagnosing PJP in patients with CTD and identifying co-infections.展开更多
基金supported by the National Mega-projects for Infectious Diseases(2014ZX10004002)Beijing Municipal Science and Technology Commission grant(D151100002115003)
文摘Many viruses can cause respiratory diseases in humans.Although great advances have been achieved in methods of diagnosis,it remains challenging to identify pathogens in unexplained pneumonia(UP) cases.In this study,we applied next-generation sequencing(NGS) technology and a metagenomic approach to detect and characterize respiratory viruses in UP cases from Guizhou Province,China.A total of 33 oropharyngeal swabs were obtained from hospitalized UP patients and subjected to NGS.An unbiased metagenomic analysis pipeline identified 13 virus species in 16 samples.Human rhinovirus C was the virus most frequently detected and was identified in seven samples.Human measles virus,adenovirus B 55 and coxsackievirus A10 were also identified.Metagenomic sequencing also provided virus genomic sequences,which enabled genotype characterization and phylogenetic analysis.For cases of multiple infection,metagenomic sequencing afforded information regarding the quantity of each virus in the sample,which could be used to evaluate each viruses' role in the disease.Our study highlights the potential of metagenomic sequencing for pathogen identification in UP cases.
基金Supported by the State Key Projects Specialized on Infectious Diseases,No.2017ZX10203202-004 and No.2017ZX10203202003008the Digestive Medical Coordinated Development Centre of the Beijing Municipal Administration of Hospitals,No.XXZ0303+1 种基金Beijing High-level Health Technicians,No.2013-03-073Beijing Municipal Administration of Hospitals’Ascent Plan,No.DFL20151602
文摘BACKGROUND Rifaximin has been shown to reduce the incidence of hepatic encephalopathy and other complications in patients with cirrhosis.However,few studies have investigated the effect of rifaximin in cirrhotic patients with refractory ascites.AIM To evaluate the effects of rifaximin in the treatment of refractory ascites and to preliminarily explore its possible mechanism.METHODS A total of 75 cirrhotic patients with refractory ascites were enrolled in the study(50 in a rifaximin and 25 in a control group).Patients in the rifaximin group were divided into two subgroups according to the presence of spontaneous bacterial peritonitis and treatment with or without other antibiotics(19 patients treated with rifaximin and 31 patients treated with rifaximin plus intravenous antibiotics).All patients received conventional treatment for refractory ascites,while patients in the rifaximin group received oral rifaximin-α200 mg four times daily for at least 2 wk.The ascites grade,fasting weight,liver and kidney function,and inflammatory factors in the plasma were evaluated before and after treatment.In addition,the gut microbiota was determined by metagenomics sequencing to analyse the changes in the characteristics of the gut microbiota before and after rifaximin treatment.The patients were followed for 6 mo.RESULTS Compared with the control group,the fasting weight of patients significantly decreased and the ascites significantly subsided after treatment with rifaximin(P=0.011 and 0.009,respectively).The 6-mo survival rate of patients in the rifaximin group was significantly higher than that in the control group(P=0.048).The concentration of interferon-inducible protein 10 decreased significantly in the rifaximin group compared with that in the control group(P=0.024).The abundance of Roseburia,Haemophilus,and Prevotella was significantly reduced after rifaximin treatment,while the abundance of Lachnospiraceae_noname,Subdoligranulum,and Dorea decreased and the abundance of Coprobacillus increased after treatment with rifa
文摘East Lake(Lake Donghu),located in Wuhan,China,is a typical city freshwater lake that has been experiencing eutrophic conditions and algal blooming during recent years.Marine and fresh water are considered to contain a large number of viruses.However,little is known about their genetic diversity because of the limited techniques for culturing viruses.In this study,we conducted a viral metagenomic analysis using a high-throughput sequencing technique with samples collected from East Lake in Spring,Summer,Autumn,and Winter.The libraries from four samples each generated 234,669,71,837,12,820,and 34,236 contigs(>90 bp each),respectively.The genetic structure of the viral community revealed a high genetic diversity covering 23 viral families,with the majority of contigs homologous to DNA viruses,including members of Myoviridae,Podoviridae,Siphoviridae,Phycodnaviridae,and Microviridae,which infect bacteria or algae,and members of Circoviridae,which infect invertebrates and vertebrates.The highest viral genetic diversity occurred in samples collected in August,then December and June,and the least diversity in March.Most contigs have low-sequence identities with known viruses.PCR detection targeting the conserved sequences of genes(g20,psbA,psbD,and DNApol)of cyanophages further confirmed that there are novel cyanophages in the East Lake.Our viral metagenomic data provide the first preliminary understanding of the virome in one freshwater lake in China and would be helpful for novel virus discovery and the control of algal blooming in the future.
基金supported by the Medicine and Health,Science and Technology Plan Project of Zhejiang(Nos.2020KY1009 and 2021KY387)the Jinhua Science and Technology Planning Project Social Development Key Project(No.2021-3-072),China.
文摘Infectious diseases are a great threat to human health.Rapid and accurate detection of pathogens is important in the diagnosis and treatment of infectious diseases.Metagenomics next-generation sequencing(mNGS)is an unbiased and comprehensive approach for detecting all RNA and DNA in a sample.With the development of sequencing and bioinformatics technologies,mNGS is moving from research to clinical application,which opens a new avenue for pathogen detection.Numerous studies have revealed good potential for the clinical application of mNGS in infectious diseases,especially in difficult-to-detect,rare,and novel pathogens.However,there are several hurdles in the clinical application of mNGS,such as:(1)lack of universal workflow validation and quality assurance;(2)insensitivity to high-host background and low-biomass samples;and(3)lack of standardized instructions for mass data analysis and report interpretation.Therefore,a complete understanding of this new technology will help promote the clinical application of mNGS to infectious diseases.This review briefly introduces the history of next-generation sequencing,mainstream sequencing platforms,and mNGS workflow,and discusses the clinical applications of mNGS to infectious diseases and its advantages and disadvantages.
基金Foundation of Fujian Medical University,Grant/Award Number:2019QH1161。
文摘Background:Accurate diagnosis of Pneumocystis jirovecii pneumonia(PJP)is challenging,and the delayed diagnosis of PJP is associated with high mortality in patients with connective tissue disease(CTD).Metagenomic next-generation sequencing(mNGS)technology facilitates etiological diagnosis of various infectious diseases,with promising application in diagnosing PJP.This study aimed to investigate the value of mNGS using bronchoalveolar lavage fluid(BALF)for diagnosing PJP infection.Methods:Data from 55 patients with CTD and suspected pulmonary infection was retrospectively collected and analysed.A PJP group and non-PJP group were formed.The clinical manifestations,laboratory test results,treatment methods,and outcomes were summarized.BALF mNGS results were compared with traditional pathogen tests(TPT)and serum 1,3-beta-D-glucan(BDG)testing.Results:The mean age of PJP patients was 54 years,and 59%(10/17)of the patients were female.A significant difference was found between the average daily dose of prednisone administered to the PJP group and non-PJP group(25 mg vs.16 mg,P<0.001).The PJP group had a significantly higher incidence of dyspnoea(88%[15/17]vs.16%[6/38],P<0.001)and elevated serum BDG level(167.73 vs.30.67 pg/mL,P<0.001).BALF mNGS was more sensitive than both TPT(100%[95%confidence interval{CI}:77.1%-100%]vs.11.8%[95%CI:2.1%-37.7%],P<0.001)and serum BDG(100%[95%CI:77.1%-100%]vs.85.7%[95%CI:42%-99.2%],P<0.001).BALF mNGS was more specific than serum BDG(89.5%[95%CI:74.3%-96.6%]vs.46.7%[95%CI:22.3%-72.6%],P=0.493).Co-infection with cytomegalovirus(CMV)was more common in the PJP patients than in the non-PJP patients(59%[10/17]vs.11%[4/38],respectively,P<0.001).Conclusion:BALF mNGS technology is highly effective for diagnosing PJP in patients with CTD and identifying co-infections.
