Identification and enumeration of Clostridium spp. In sufu

In this study, Clostridium spp. was counted in 49 Chinese commercial sufu samples, and 25 samples were detected Clostridium in all samples: the detection rate was 51.02%. About 93.87% of the samples contained Clostridium at low levels (log CFU/g＜3.0) and one sample had over 4.12lg CFU/g indicating potential hazard to consumers. The 16S rDNA identification was carried out on the genus Clostridium, and the isolates were confirmed as Clostridium botulinum, Clostridium sporogenes, Clostridium beijerinckii and Clostridium bifermentans, while Clostridium butyricum, Clostridium botulinum, Clostridium perfringens and Clostridium bifermentans were the species detected in the sufu samples by high-throughput sequencing. Based on these results, the research on the number and distribution of clostridium and the possible risks of biotoxins in fermented food needs to be strengthened. To our knowledge, this is the first study to isolate and identify Clostridium spp. in sufu.

Infection of a prosthetic knee joint with Clostridium bifermentans

ABSTRACT We present the first reported case of prosthetic joint infection caused by Clostridium bifermentans, which was treated with total joint washout and debridement allowing for the patient to retain his prosthesis and achieve full recovery. Clostridium bifermentans is a gram-positive, anaerobic, spore-forming bacterium. This organism was once considered to be non-pathogenic, but has recently been associated with cases of septic arthritis, empyema, osteomyelitis, soft tissue infection, brain abscess, bacteremia and endocarditis.

The mechanisms of in vivo commensal control of Clostridioides difficile virulence

We define multiple mechanisms by which commensals protect against or worsen Clostridioides difficile infection. Using a systems-level approach we show how two species of Clostridia with distinct metabolic capabilities modulate the pathogen’s virulence to impact host survival. Gnotobiotic mice colonized with the amino acid fermenter Clostridium bifermentans survived infection, while colonization with the butyrate-producer, Clostridium sardiniense, more rapidly succumbed. Systematic in vivo analyses revealed how each commensal altered the pathogen’s carbon source metabolism, cellular machinery, stress responses, and toxin production. Protective effects were replicated in infected conventional mice receiving C. bifermentans as an oral bacteriotherapeutic that prevented lethal infection. Leveraging a systematic and organism-level approach to host-commensal-pathogen interactions in vivo, we lay the groundwork for mechanistically-informed therapies to treat and prevent this disease.

Periodontal microbiota and microorganisms isolated from heart valves in patients undergoing valve replacement surgery in a clinic in Cali, Colombia

Introducción. La periodontitis es una enfermedad infecciosa que afecta los tejidos de soporte del diente y se asocia con diferentes enfermedades sistémicas, incluida la enfermedad cardiovascular. Los estudios microbiológicos permiten detectar microorganismos a partir de muestras subgingivales y cardiovasculares.Objetivo. Describir la microbiota periodontal cultivable y la presencia de microorganismos en válvulas cardiacas de pacientes sometidos a cirugía de reemplazo valvular en una clínica de Cali.Materiales y métodos. Se analizaron 30 muestras subgingivales y de tejidos valvulares mediante cultivo en medio bifásico, agar de sangre con suplemento y agar tripticasa de soya con antibiótico. Las muestras de las válvulas se analizaron mediante reacción en cadena de la polimerasa (PCR) convencional.Resultados. Los patógenos periodontales aislados de bolsas periodontales fueron Fusobacterium (50 %), Prevotella intermedia/nigrescens (40 %), Campilobacter rectus (40 %), Eikenella corrodens (36,7 %), bacilos entéricos Gram negativos (36,7 %), Porphyromonas gingivalis (33,3 %) y Eubacterium (33,3 %). Los agentes patógenos aislados de la válvula aórtica fueron Propionibacterium acnes (12 %), bacilos entéricos Gram negativos (8 %), Bacteroides merdae (4 %) y Clostridium bifermentans (4 %), y de la válvula mitral, P. acnes y Clostridium beijerinckii. La PCR convencional no arrojó resultados positivos para agentes patógenos orales y solo se detectó ADN bacteriano en dos muestras.Conclusiones. La microbiota periodontal de pacientes sometidos a cirugía de reemplazo valvular estaba conformada por especies Gram negativas que han sido relacionadas con infecciones en tejidos extraorales; sin embargo, no se encontraron agentes patógenos periodontales en los tejidos de las válvulas. Aunque hubo muestras de estos tejidos y subgingivales, positivas para bacilos entéricos Gram negativos, no es posible asegurar que tuvieran el mismo origen filogenético.