Adventitious agents,comprising unintentionally introduced microorganisms in the production of biological products,pose a significant challenge in ensuring the safety of gene therapy products.The revised International ...Adventitious agents,comprising unintentionally introduced microorganisms in the production of biological products,pose a significant challenge in ensuring the safety of gene therapy products.The revised International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use(ICH)guildline Q5A(R2)from September 2022 highlights the inclusion of viral vector-based gene therapy products in safety discussions,emphasizing controls in material sourcing,testing,and viral clearance[1].Detecting adventitious virus contamination is complex due to the unique characteristics of gene therapy products and the limitations of routine testing methods.The US Food and Drug Administration(FDA)recommends incorporating routine and specific virus detection methods,including those outlined in various pharmacopeias.Existing control methods have limitations,prompting the need for highly sensitive and broad-spectrum detection approaches.Unlike traditional biological products,gene therapy products primarily consist of live viruses,necessitating methods that distinguish between the main virus and adventitious viruses.Current virus detection techniques,such as polymerase chain reaction(PCR),sequencing,mass spectrometry,and DNA microarrays[2e4],have their drawbacks.展开更多
Purpose: The genus Pseudomonas is a ubiquitous microorganism frequently detected from immunocompromised patients. The inherent resistance to numerous antimicrobial agents contributes to the opportunistic character of ...Purpose: The genus Pseudomonas is a ubiquitous microorganism frequently detected from immunocompromised patients. The inherent resistance to numerous antimicrobial agents contributes to the opportunistic character of this pathogen exhaustive monitoring of this pathogen is considered of critical importance to public health organizations. The reliable identification method able to distinguish genetic close Pseudomonas species is needed, because these organisms are difficult to differentiate by phenotypic or biochemical methods. The purpose of the present study was to design species-specific primers in order to identify and detect four Pseudomonas species which are frequently detected from the human oral cavities, and to investigate the distribution of these organisms in the living environment using a multiplex PCR. Methods: Polymerase chain reaction (PCR) primers were designed based on partial sequences of the rpoD gene of four Pseudomonas species. Swab samples were collected from fifty washstands, and the distribution of Pseudomonas species was investigated using a conventional PCR at genus level and a multiplex PCR at species level. Results: Multiplex PCR method developed in this study was able to distinguish four Pseudomonas species clearly. The genus Pseudomonas was detected from all samples (100%), whereas P. putida, P, aeruginosa, P. stutzeri and P. fluorescens were detected at 44%, 8%, 4% and 2% in fifty swab samples, respectively. Conclusion: Our developed one-step multiplex PCR method is accurate, specific, cost-effective, time-saving, and works without requiring DNA extraction. It was indicated that washstands were the uninhabitable environment for P. putida, P, aeruginosa, P. stutzeri and P. fluorescens.展开更多
为了满足乳制品中食源性致病菌精确、高效和高通量检测需求,文章以典型食源性致病菌大肠埃希氏菌O157、金黄色葡萄球菌、单核细胞增生李斯特氏菌和沙门氏菌作为目的菌,建立1种灵敏稳定的多重芯片式数字PCR(Multiplex digital chip PCR)...为了满足乳制品中食源性致病菌精确、高效和高通量检测需求,文章以典型食源性致病菌大肠埃希氏菌O157、金黄色葡萄球菌、单核细胞增生李斯特氏菌和沙门氏菌作为目的菌,建立1种灵敏稳定的多重芯片式数字PCR(Multiplex digital chip PCR)反应体系。针对4种致病菌的靶向基因,设计特异性引物,优化多重反应引物组合和反应条件,并验证其特异性和灵敏度。结果表明,该四重反应体系具有良好的特异性且未出现交叉反应。体系对4种菌株最低检出限分别达0.38、1.03、0.69 copies/μL和0.24 copies/μL,与单重反应体系检测灵敏度相当,未发生混合引物抑制反应。方法对模拟阳性样品、生乳和市售乳制品检测结果证明了其在乳原料及乳制品质量安全控制中的应用前景,文章构建的四重反应体系可为乳制品的检测与监管提供技术支持。展开更多
基金financially supported by Beijing Municipal Science&Technology Commission,China(Grant No.:Z221100007922015)Youth Development Research Foundation of National Institutes for Food and Drug Control,China(Grant No.:2020B1).
文摘Adventitious agents,comprising unintentionally introduced microorganisms in the production of biological products,pose a significant challenge in ensuring the safety of gene therapy products.The revised International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use(ICH)guildline Q5A(R2)from September 2022 highlights the inclusion of viral vector-based gene therapy products in safety discussions,emphasizing controls in material sourcing,testing,and viral clearance[1].Detecting adventitious virus contamination is complex due to the unique characteristics of gene therapy products and the limitations of routine testing methods.The US Food and Drug Administration(FDA)recommends incorporating routine and specific virus detection methods,including those outlined in various pharmacopeias.Existing control methods have limitations,prompting the need for highly sensitive and broad-spectrum detection approaches.Unlike traditional biological products,gene therapy products primarily consist of live viruses,necessitating methods that distinguish between the main virus and adventitious viruses.Current virus detection techniques,such as polymerase chain reaction(PCR),sequencing,mass spectrometry,and DNA microarrays[2e4],have their drawbacks.
文摘Purpose: The genus Pseudomonas is a ubiquitous microorganism frequently detected from immunocompromised patients. The inherent resistance to numerous antimicrobial agents contributes to the opportunistic character of this pathogen exhaustive monitoring of this pathogen is considered of critical importance to public health organizations. The reliable identification method able to distinguish genetic close Pseudomonas species is needed, because these organisms are difficult to differentiate by phenotypic or biochemical methods. The purpose of the present study was to design species-specific primers in order to identify and detect four Pseudomonas species which are frequently detected from the human oral cavities, and to investigate the distribution of these organisms in the living environment using a multiplex PCR. Methods: Polymerase chain reaction (PCR) primers were designed based on partial sequences of the rpoD gene of four Pseudomonas species. Swab samples were collected from fifty washstands, and the distribution of Pseudomonas species was investigated using a conventional PCR at genus level and a multiplex PCR at species level. Results: Multiplex PCR method developed in this study was able to distinguish four Pseudomonas species clearly. The genus Pseudomonas was detected from all samples (100%), whereas P. putida, P, aeruginosa, P. stutzeri and P. fluorescens were detected at 44%, 8%, 4% and 2% in fifty swab samples, respectively. Conclusion: Our developed one-step multiplex PCR method is accurate, specific, cost-effective, time-saving, and works without requiring DNA extraction. It was indicated that washstands were the uninhabitable environment for P. putida, P, aeruginosa, P. stutzeri and P. fluorescens.
