Objective: 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: 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: 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: 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: 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: 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: 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: 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

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

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

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

PURPOSE: The roles of gut microbiota on the natural course of atopic dermatitis (AD) are not yet fully understood. We investigated whether the composition and function of gut microbiota and short-chain fatty acids (SCFAs) at 6 months of age could affect the natural course of AD up to 24 months in early childhood.METHODS: Fecal samples from 132 infants were analyzed using pyrosequencing, including 84 healthy controls, 22 transient AD and 26 persistent AD subjects from the Cohort for Childhood Origin of Asthma and Allergic Diseases (COCOA) birth cohort. The functional profile of the gut microbiome was analyzed by whole-metagenome sequencing. SCFAs were measured using gas chromatography-mass spectrometry.RESULTS: Low levels of Streptococcus and high amounts of Akkermansia were evident in transient AD cases, and low Clostridium, Akkermansia and high Streptococcus were found in children with persistent AD. The relative abundance of Streptococcus positively correlated with scoring of AD (SCORAD) score, whereas that of Clostridium negatively correlated with SCORAD score. The persistent AD group showed decreased gut microbial functional genes related to oxidative phosphorylation compared with healthy controls. Butyrate and valerate levels were lower in transient AD infants compared with healthy and persistent AD infants.CONCLUSIONS: Compositions, functions and metabolites of the early gut microbiome are related to natural courses of AD in infants.
Asthma ; Butyrates ; Child ; Clostridium ; Cohort Studies ; Dermatitis, Atopic ; Fatty Acids, Volatile ; Gas Chromatography-Mass Spectrometry ; Gastrointestinal Microbiome ; Humans ; Infant ; Metabolomics ; Metagenome ; Oxidative Phosphorylation ; Parturition ; Streptococcus

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

OBJECTIVE: To describe the profile, management, and outcome of adult patients admitted for tetanus. METHODOLOGY: A search of the hospital and department database was conducted for patients with admitting or final diagnosis of tetanus. Patients below 19 years old, with alternative diagnosis, incomplete or unavailable records, transferred to another institution, and went home against medical advice were excluded. Data on patient demographics, source of infection, symptom severity, and management were obtained. Data was described using proportions and averages. RESULTS: Thirty-two patients were included in the study. Twenty-seven were male with a mean age of 45.63 ± 13.39. All cases had no history of tetanus vaccination. The most common focus of infection was acute injuries. More than half of patients would be diagnosed within 72 hours of symptom onset. The most common symptoms on presentation were trismus, rigidity, dysphagia, and spasms. On admission, Cole severity for 11 (34.4%) cases was mild, 17 (53.1%) moderate, and 4 (12.5%) severe. Prophylactic tracheostomy was performed in 31 patients and 19 (59.4%) were placed on assisted ventilation. All cases were treated with metronidazole. A benzodiazepine was started in all cases for spasm control. Baclofen, magnesium sulfate, and antiepileptic drugs such as carbamazepine were also used. Twenty (62.5%) patients suffered from complications, the most common of which was nosocomial pneumonia, which resulted in longer ICU and hospital stays. Eleven patients exhibited progression in Cole severity: 8.6% at stage 1, 57.1% at stage 2, and 34.3% cases were at stage 3. Mortality rate was 19% with the proportion increasing with Cole severity. CONCLUSION We describe the presentation and course of patients admitted for tetanus in our institution. Most cases were males and all cases had no vaccination history. Trismus was the most common presenting symptom. Metronidazole was the antibiotic of choice and benzodiazepines were the mainstay for spasm control. Majority of cases were mild to moderate in severity on presentation. Advanced disease stages were associated with higher fatality rates. Complications were associated with longer ICU and hospital stay. These findings suggest that prevention of progression of disease severity and complications must be the focus of tetanus protocols to shorten hospital stay and decrease mortality rate. Promoting vaccination of at-risk adults is recommended to lower the incidence of tetanus.
Tetanus ; Clostridium tetani ; Clostridium Infections

The most common cause of antibiotic-associated diarrhea is Clostridium difficile infection (CDI). Recurrent C. difficile infection (rCDI) often occurs after successful treatment of CDI. Due to the increased incidence and the difficulty in treating rCDI, it is becoming an important clinical issue. Identifying risk factors is helpful for early detection, treatment, and prevention of rCDI. Advanced age, use of antibiotics, gastric acid suppression, and infection with a hypervirulent strain are currently regarded as the major risk factors for rCDI. Several treatment modalities, including vancomycin, fidaxomicin, and fecal microbiota transplant (FMT), are suggested for rCDI treatment. However, there is currently no definitive treatment method with sufficient evidence for rCDI. Recent studies have focused on FMT and have shown positive results for rCDI. Prevention of rCDI by measures such as hand washing and isolation of patients is very important. However, these preventive measures are often overlooked in clinical practice. Here, we review the risk factors, treatment, and prevention of rCDI.
Anti-Bacterial Agents ; Clostridium difficile* ; Clostridium* ; Diarrhea ; Gastric Acid ; Hand Disinfection ; Humans ; Incidence ; Methods ; Microbiota ; Recurrence ; Risk Factors* ; Vancomycin