Objective:b> We analyze the characteristics of Clostridioides difficile (C. difficile) infection among diarrhea patients in Kunming from 2018 to 2020 and provide evidence for follow-up surveillance and prevention. Methods:b> A total of 388 fecal samples of diarrhea patients from four sentinel hospitals in Yunnan Province from 2018 to 2020 were collected. Real-time quantitative PCR was used to detect the fecal toxin genes of C. difficile. The positive fecal samples isolated the bacteria, and isolates were identified by mass spectrometry. The genomic DNA of the strains was extracted for multi-locus sequence typing (MLST). The fecal toxin, strain isolation, and clinical patient characteristics, including co-infection with other pathogens, were analyzed. Results:b> Among the 388 fecal samples, 47 samples with positive reference genes of C. difficile were positive, with a total positive rate of 12.11%. There were 4 (8.51%) non-toxigenic and 43 (91.49%) toxigenic ones. A total of 18 strains C. difficile were isolated from 47 positive specimens, and the isolation rate of positive specimens was 38.30%. Among them, 14 strains were positive for tcdA, tcdB, tcdC, tcdR, and tcdE. All 18 strains of C. difficile were negative for binary toxins. The MLST results showed 10 sequence types (ST), including 5 strains of ST37, accounting for 27.78%; 2 strains of ST129, ST3, ST54, and ST2, respectively; and 1 strain of ST35, ST532, ST48, ST27, and ST39, respectively. Fecal toxin gene positive (tcdB+) results were statistically associated with the patient's age group and with or without fever before the visit; positive isolates were only statistically associated with the patient's age group. In addition, some C. difficile patients have co-infection with other diarrhea-related viruses. Conclusions:b> The infection of C. difficile in diarrhea patients in Kunming is mostly toxigenic strains, and the high diversity of strains was identified using the MLST method. Therefore, the surveillance and prevention of C. difficile should be strengthened.
Humans ; Bacterial Toxins/genetics* ; Enterotoxins/genetics* ; Clostridioides difficile/genetics* ; Multilocus Sequence Typing ; Coinfection ; Bacterial Proteins/genetics* ; China/epidemiology* ; Clostridium Infections/epidemiology* ; Diarrhea/microbiology*

Objective:b> To establish and optimize PCR methods for the gene encoding of Clostridium perfringens β₂ toxin (cpb₂) and atypical-cpb₂ (aty-cpb₂), analyze the epidemiological characteristics and genetic polymorphism of the cpb₂ of Clostridium perfringens in 9 Chinese areas from 2016 to 2021. Methods:b> The cpb₂ of 188 Clostridium perfringens strains were examined by PCR; the cpb₂ sequences were acquired by whole-genome sequencing to analyze the genetic polymorphism. Using Mega 11 and the Makeblastdb tool, a phylogenetic tree, and cpb₂-library based on 110 strains carrying the cpb₂ were produced. Using the Blastn technique, a comparison was made to discover sequence similarity between consensus-cpb₂ (con-cpb₂) and aty-cpb₂. Results:b> The specificity of PCR assay for the cpb₂ and aty-cpb₂ was verified. The PCR results for cpb₂ amplification were highly consistent with the whole-genome sequencing approach (Kappa=0.946, P<0.001). A total of 107 strains from nine regions in China carried cpb₂, 94 types A strains carried aty-cpb₂, 6 types A strains carried con-cpb₂, and 7 types F strains carried aty-cpb₂. The nucleotide sequence similarity between the two coding genes was 68.97%-70.97%, and the similarity between the same coding genes was 98.00%-100.00%. Conclusions:b> In this study, a specific PCR method for cpb₂ toxin was developed, and the previous PCR method for detecting aty-cpb₂ was improved. aty-cpb₂ is the primary gene encoding of β₂ toxin. There is a significant nucleotide sequence variance between the various cpb₂ genotypes.
Humans ; Clostridium perfringens/genetics* ; Clostridium Infections ; Bacterial Toxins/genetics* ; Phylogeny ; Polymerase Chain Reaction ; Polymorphism, Genetic

Intestinal flora and its metabolites are closely related to the progression of type 2 diabetes mellitus(T2DM). Eubacterium is one of the dominant intestinal flora, and its metabolites short-chain fatty acids (SCFAs) play a leading role in regulating intestinal metabolic balance. It has been reported that SCFAs can regulate the secretion of glucagon-like peptide-1, improve the function of pancreatic β cells, participate in bile acids metabolism and regulate the production of inflammatory factors in T2DM. Based on the above research background, this article mainly reviews the relationship between Eubacterium and its metabolite SCFAs and T2DM and its regulatory mechanism.
Humans ; Diabetes Mellitus, Type 2 ; Eubacterium/metabolism* ; Fatty Acids, Volatile/metabolism* ; Gastrointestinal Microbiome

Emerging evidence indicates that the gut microbiome contributes to the host immune response to infectious diseases. Here, to explore the role of the gut microbiome in the host immune responses in COVID-19, we conducted shotgun metagenomic sequencing and immune profiling of 14 severe/critical and 24 mild/moderate COVID-19 cases as well as 31 healthy control samples. We found that the diversity of the gut microbiome was reduced in severe/critical COVID-19 cases compared to mild/moderate ones. We identified the abundance of some gut microbes altered post-SARS-CoV-2 infection and related to disease severity, such as Enterococcus faecium, Coprococcus comes, Roseburia intestinalis, Akkermansia muciniphila, Bacteroides cellulosilyticus and Blautia obeum. We further analyzed the correlation between the abundance of gut microbes and host responses, and obtained a correlation map between clinical features of COVID-19 and 16 severity-related gut microbe, including Coprococcus comes that was positively correlated with CD3⁺/CD4⁺/CD8⁺ lymphocyte counts. In addition, an integrative analysis of gut microbiome and the transcriptome of peripheral blood mononuclear cells (PBMCs) showed that genes related to viral transcription and apoptosis were up-regulated in Coprococcus comes low samples. Moreover, a number of metabolic pathways in gut microbes were also found to be differentially enriched in severe/critical or mild/moderate COVID-19 cases, including the superpathways of polyamine biosynthesis II and sulfur oxidation that were suppressed in severe/critical COVID-19. Together, our study highlighted a potential regulatory role of severity related gut microbes in the immune response of host.
COVID-19 ; Clostridiales ; Gastrointestinal Microbiome ; Humans ; Immunity ; Leukocytes, Mononuclear ; SARS-CoV-2

Clostridium perfringens can produce many kinds of toxins and hydrolase, causing gas gangrene, enteritis and enterotoxemia in both human and animals. It is known that C. perfringens can produce more than 20 toxins and hydrolases. The different toxin types are associated with specific disease types. At present, molecular toxin-typing method by PCR has replaced the traditional serological typing method. In this study, we systematically summarize the types, basic characteristics, pathogenic mechanism and the relationship with disease of C. perfringens toxins to provide evidence for the establishment of rapid detection method, immune antigen screening, antibody preparation and research of related pathogenic mechanism.
Animals ; Humans ; Clostridium perfringens ; Antibodies ; Polymerase Chain Reaction

To analyze a suspected case of Clostridium botulinum food poisoning in Bayingolin Mongolian Autonomous Prefecture, Xinjiang and to help validating the diagnosis and providing technical support for clinical treatment. The basic information and clinical manifestations of food poisoning cases were investigated by using the epidemiological method of food safety accidents. The botulinum toxin genes in the samples were detected by real-time PCR and inoculation of KM mouse. The enriched bacteria were further purified and validated. PFGE and cluster analysis were performed on five isolates. Clostridium botulinum type A was detected in two homemade fermented bean samples and stool lavage fluid samples of three patients from enriched samples by toxin test and real-time PCR, and were further validated after isolation of Clostridium botulinum. PFGE showed 100% homology among five isolates. Five isolates of bacteria isolated from the stool lavage fluid of three patients and two homemade fermented bean curd were identified as the same source through PFGE. The cause of this food poisoning cases is food pollution of Clostridium botulinum type A.
Animals ; Clostridium botulinum/genetics* ; Feces ; Foodborne Diseases/epidemiology* ; Gerbillinae ; Humans ; Mice

Chronic hepatitis B (CHB) is a global epidemic disease caused by hepatitis B virus that can lead to hepatic failure, even liver cirrhosis and hepatocellular carcinoma. The occurrence and development of CHB are closely related to the changes in the gut microbiota communities. To explore the relationship between the structure of gut microbiota and liver biochemical indicators, 14 CHB patients (the CHB group) and 11 healthy people (the CN group) were randomly enrolled in this study. Our results demonstrate that CHB caused changes in the gut microbiota communities and biochemical indicators, such as alanine transaminase, total bilirubin and gamma glutamyl transferase. Furthermore, CHB induced imbalance of the gut microbiota. Prevotella, Blautia, Ruminococcus, Eubacterium eligens group, Bacteroides uniformis and Ruminococcus sp. 5_1_39BFAA were associated with the critical biochemical indicators and liver injury, suggesting a new approach to CHB treatment.
Bacteroides ; Eubacterium ; Gastrointestinal Microbiome ; Hepatitis B virus ; Hepatitis B, Chronic ; Humans ; Liver Cirrhosis ; Liver Neoplasms

Clostridioides ; Clostridioides difficile/isolation & purification* ; Clostridium Infections/epidemiology* ; Guidelines as Topic ; Humans

Clostridia inhabiting in jiupei and pit mud plays key roles in the formation of flavour during the fermentation process of Luzhou-flavour baijiu. However, the differences of Clostridial communities between jiupei and pit mud remains unclear. Here, the species assembly, succession, and metabolic capacity of Clostridial communities between jiupei and pit mud were analysed by high-throughput sequencing and pure culture approaches. The ratio of Clostridial biomass to bacterial biomass in the pit mud was relatively stable (71.5%-91.2%) throughout the fermentation process. However, it varied widely in jiupei (0.9%-36.5%). The dominant Clostridial bacteria in jiupei were Clostridium (19.9%), Sedimentibacter (8.8%), and Hydrogenispora (7.2%), while Hydrogenispora (57.2%), Sedimentibacter (5.4%), and Caproiciproducens (4.9%) dominated in the Clostridial communities in pit mud. The structures of Clostridial community in pit mud and jiupei were significantly different (P=0.001) throughout fermentation. Isolated Clostridial strains showed different metabolic capacities of volatile fatty acids in pure culture. Spatial and temporal heterogeneity of Clostridial communities existed in the baijiu fermentation pit, which was closely related to the main flavour components of Luzhou-flavour baijiu.
Alcoholic Beverages ; microbiology ; Bacteria ; classification ; metabolism ; Clostridium ; physiology ; Fatty Acids, Volatile ; metabolism ; Fermentation ; Food Microbiology

Clostridium acetobutylicum is an important strain for bio-butanol formation. In recent years, gene-editing technology is widely used for developing the hyper-butanol-production strains. In this study, three genes (cac1251, cac2118 and cac2125) encoding cell division proteins (RodA, DivIVA and DivIB) in C. acetobutylicum were knocked out. The cac2118-knockout strain had changed its cell morphology to spherical-shape during the solventogenesis, and obtained a higher butanol yield of 0.19 g/g, increasing by 5.5%, compared with the wild type strain. The glucose utilization and butanol production of cac1251-knockout strain decreased by 33.9% and 56.3%, compared the with wild type strain, reaching to 47.3 g/L and 5.6 g/L. The cac1251-knockout strain and cac2125-knockout strain exhibited poor cell growth with cell optical density decreased by 40.4% and 38.3%, respectively, compared with that of the wild type strain. The results indicate that cell division protein DivIVA made the differences in the regulation of cell morphology and size. Cell division proteins RodA and DivIB played significant roles in the regulation of cell division, and affected cell growth, as well as solventogenesis metabolism.
Butanols ; Cell Division/genetics* ; Clostridium acetobutylicum/genetics* ; Fermentation ; Gene Knockout Techniques ; Solvents