The oral-gut axis: Salivary and fecal microbiome dysbiosis in patients with inflammatory bowel disease.

Inflammatory bowel disease (IBD) is a group of chronic inflammatory disorders that fall into two main categories: Crohn's disease (CD) and ulcerative colitis (UC). The gastrointestinal tract extends from the mouth to the anus and harbors diverse bacterial communities. Several sequencing-based studies have identified an intestinal enrichment of oral-associated bacteria and demonstrated their ability to induce intestinal inflammation in mice, suggesting that intestinal pathobionts originate from the oral cavity, particularly members of the genus Streptococcus. This study aimed to investigate the composition of the salivary and fecal microbiome of IBD patients (n = 14) compared to healthy controls (n = 12) and to determine the abundance of common bacterial taxa in both niches. Metagenomic DNA was extracted from saliva and fecal samples, and the 16S rRNA gene was targeted for sequencing. Our results revealed that the overall microbial composition of saliva was significantly altered in the IBD patients compared to the control subjects (p = 0.038). At the genus level, Veillonella and Prevotella were highly abundant in IBD (median: 25.4% and 22.2%, respectively) compared to the control group (17.9% and 13.4%, respectively). In contrast, Neisseria, Streptococcus, Haemophilus, and Fusobacterium were associated with a healthy gut state. Regarding the fecal microbiome, the IBD group had a significantly higher abundance of Clostridium sensu stricto 1 and Escherichia-Shigella (both comprising pathogenic bacteria) compared with the control group. Members of both bacterial groups have previously been shown to positively correlate with intestinal inflammation and high expression of pro-inflammatory cytokines that disrupt intestinal barrier integrity. In addition, we demonstrate that the increased abundance of Clostridium sensu stricto 1 and Escherichia-Shigella has also been associated with significant upregulation of certain metabolic pathways in the feces of the IBD group, including bacterial invasion of epithelial cells. Streptococcus was the only common genus detected in both the salivary and fecal microbiome and represented the oral-gut axis in our study. Using culture-based methods, we isolated 57 and 91 Streptococcus strains from saliva as well as 40 and 31 strains from fecal samples of the controls and IBD patients, respectively. The phylogenetic tree of streptococci based on sodA sequences revealed several patient-specific clusters comprising salivary and fecal streptococcal isolates from the same patient and belonging to the same species, suggesting that the oral cavity is an endogenous reservoir for intestinal strains.

Management of a Hospital-Wide COVID-19 Outbreak Affecting Patients and Healthcare Workers.

To the best of our knowledge, here, we describe the first hospital-wide outbreak of SARS-CoV-2 that occurred in Germany in April 2020. We aim to share our experience in order to facilitate the management of nosocomial COVID-19 outbreaks in healthcare facilities. All patients and hospital workers were screened for SARS-CoV-2 repeatedly. An infection control team on the side was installed. Strict spatial separation of patients and intensified hygiene training of healthcare workers (HCW) were initiated. By the time of reporting, 26 patients and 21 hospital workers were infected with a cluster of cases in the geriatric department. Fourteen patients developed COVID-19 consistent symptoms and five patients with severe pre-existing medical conditions died. The outbreak was successfully contained after intensified infection control measures were implemented and no further cases among patients were detected over a period of 14 days. Strict application of standard infection control measures proved to be successful in the management of nosocomial SARS-CoV-2 outbreaks.

Factors affecting DNA synthesis in an in vitro system.

Mononucleated striated muscle cells and one type of endoderm can be isolated from anthomedusae and cultivated in artificial sea-water. In the cultivated muscle the differentiated state is maintained. In the cultivated endoderm flagella are formed, but no new cell types differentiate and DNA synthesis or mitosis is not observed. When isolated muscle is grafted upon endoderm, regeneration or formation of new cell types is not observed. Following treatingment with bacterial collagenase DNA synthesis and flagellum formation are initiated in the isolated muscle; in the isolated endoderm, collagenase treatment has no effect. When striated muscle treated with collagenase is grafted upon endoderm, DNA synthesis is observed in the endoderm, and a regenerate is formed involving transdifferentiation. Although desmosomal contact between collagenase treated muslce and the endoderm is established, it is not sufficient to induce DNA synthesis; complete covering of the endoderm by the muscle is required.