Clostridium difficile infection (CDI) was generally considered as a hospital-associated disease;however, recent community-acquired CDI has raised the concerns regarding the transmission of the pathogen through environ...Clostridium difficile infection (CDI) was generally considered as a hospital-associated disease;however, recent community-acquired CDI has raised the concerns regarding the transmission of the pathogen through environmental sources. Limited data are available regarding the presence of C. difficile in food and water. In this study, oysters (Crassostrea virginica) and the harvest water collected from the commercial harvesting areas along the Louisiana Gulf Coast as well as the influent and effluent of a municipal treatment plant in New Orleans, LA were analyzed for toxigenic C. difficile. The bacterium was isolated from 47.37% (9/19) of oysters and 37.5% (3/8) of harvest water samples. Toxigenic C. difficile were also detected in all the wastewater influent and effluent samples. All the isolates harbored the gene tcdB encoding the virulence factor toxin B. Further PCR-ribotyping showed that the C. difficile isolated from the oysters and harvest water differed from the wastewater isolates. However, similar ribotypes were found in oysters and the surrounding harvest water. We found that oysters growing in contaminated water could bioaccumulate toxigenic C. difficile and pose a health risks by serving as a vehicle for the transmission of the pathogen to humans.展开更多
Clostridium difficile is a grossly Gram-positive anaerobic bacterium that has been a key factor in inducing imbalances in the gut microbiota in recent years, leading to intestinal-associated inflammation. The main pat...Clostridium difficile is a grossly Gram-positive anaerobic bacterium that has been a key factor in inducing imbalances in the gut microbiota in recent years, leading to intestinal-associated inflammation. The main pathogenic toxins of Clostridium difficile are toxin A (TcdA) and toxin B (TcdB). TcdB is the main pathogenic factor of Clostridium difficile infection. This review revealed the pathogenic mechanism of Clostridium difficile toxin B, expounded the impact of Clostridium difficile on the intestinal system, and predicted the genes on which TcdB may act, thereby providing a new therapeutic target for Clostridium difficile infection, offering theoretical basis and new strategies for clinical prevention and control.展开更多
Clostridioides difficile is a leading cause of healthcare-associated infections,causing billions of economic losses every year.Its symptoms range from mild diarrhea to life-threatening damage to the colon.Transmission...Clostridioides difficile is a leading cause of healthcare-associated infections,causing billions of economic losses every year.Its symptoms range from mild diarrhea to life-threatening damage to the colon.Transmission and recurrence of c.difficile infection(CDl)are mediated by the metabolically dormant spores,while the virulence of C.difficile is mainly due to the two large clostridial toxins,TcdA and TcdB.Producing toxins or forming spores are two different strategies for C.difficile to cope with harsh environmental conditions.It is of great significance to understand the molecular mechanisms for C.difficile to skew to either of the cellular processes.Here,we summarize the current understanding of the regulation and connections between toxin production and sporulation in C.difficile and further discuss the potential solutions for yet-to-be-answered questions.展开更多
基金Supported by National Key Technology Research and Development Program of the Ministry of Science and Technology of China(No.2012BAI11B05)the National Science and Technology Major Project during the"12th Five-Year Plan"(No.2013ZX10004221)~~
文摘Clostridium difficile infection (CDI) was generally considered as a hospital-associated disease;however, recent community-acquired CDI has raised the concerns regarding the transmission of the pathogen through environmental sources. Limited data are available regarding the presence of C. difficile in food and water. In this study, oysters (Crassostrea virginica) and the harvest water collected from the commercial harvesting areas along the Louisiana Gulf Coast as well as the influent and effluent of a municipal treatment plant in New Orleans, LA were analyzed for toxigenic C. difficile. The bacterium was isolated from 47.37% (9/19) of oysters and 37.5% (3/8) of harvest water samples. Toxigenic C. difficile were also detected in all the wastewater influent and effluent samples. All the isolates harbored the gene tcdB encoding the virulence factor toxin B. Further PCR-ribotyping showed that the C. difficile isolated from the oysters and harvest water differed from the wastewater isolates. However, similar ribotypes were found in oysters and the surrounding harvest water. We found that oysters growing in contaminated water could bioaccumulate toxigenic C. difficile and pose a health risks by serving as a vehicle for the transmission of the pathogen to humans.
文摘Clostridium difficile is a grossly Gram-positive anaerobic bacterium that has been a key factor in inducing imbalances in the gut microbiota in recent years, leading to intestinal-associated inflammation. The main pathogenic toxins of Clostridium difficile are toxin A (TcdA) and toxin B (TcdB). TcdB is the main pathogenic factor of Clostridium difficile infection. This review revealed the pathogenic mechanism of Clostridium difficile toxin B, expounded the impact of Clostridium difficile on the intestinal system, and predicted the genes on which TcdB may act, thereby providing a new therapeutic target for Clostridium difficile infection, offering theoretical basis and new strategies for clinical prevention and control.
文摘Clostridioides difficile is a leading cause of healthcare-associated infections,causing billions of economic losses every year.Its symptoms range from mild diarrhea to life-threatening damage to the colon.Transmission and recurrence of c.difficile infection(CDl)are mediated by the metabolically dormant spores,while the virulence of C.difficile is mainly due to the two large clostridial toxins,TcdA and TcdB.Producing toxins or forming spores are two different strategies for C.difficile to cope with harsh environmental conditions.It is of great significance to understand the molecular mechanisms for C.difficile to skew to either of the cellular processes.Here,we summarize the current understanding of the regulation and connections between toxin production and sporulation in C.difficile and further discuss the potential solutions for yet-to-be-answered questions.
