Children and adolescents in the CoVid-19 pandemic: Schools and daycare centers are to be opened again without restrictions. The protection of teachers, educators, carers and parents and the general hygiene rules do not conflict with this.

In the opinion of the medical societies of hygiene and pediatrics undersigning the present statement, the analyses published to date regarding transmission of SARS-CoV-2 and the course of CoVid-19 show that children play a much less significant role in the spread of the virus than do adults. According to the findings available to date, not only do children and adolescents less frequently fall ill with CoVid-19, they also generally become less severely ill than do adults. The vast majority of infections in children and adolescents are asymptomatic or oligosymptomatic. Even the first analyses from China demonstrated that children and adolescents play a subordinate role in the transmission of the virus - not only to other children and adolescents, but also to adults. Taking into account regional infection rates and available resources, daycare centers, kindergartens and elementary schools promptly should be reopened. For children, this should be possible without excessive restrictions, such as clustering into very small groups, implementation of barrier precautions, maintaining appropriate distance from others or wearing masks. A factor more decisive than individual group size is the issue of sustaining the constancy of respective group members and the avoidance of intermixing. Children can be taught basic rules of hygiene such as handwashing and careful hygiene behavior when coming into contact with others during mealtimes and/or when using sanitary facilities. Independent of the prevention measures implemented for children and adolescents, the protection of teachers, educators and caregivers is crucial, (e.g., the maintenance of appropriate distance from others, use of medical masks, situation-dependent hand disinfection, when necessary, supported by regular pool testing). Children over the age of 10 and adolescents up to school graduation age are more capable of actively understanding and conforming to specific hygiene rules. For this group, maintaining appropriate distance from others (1.5 meters), wearing a mouth-and-nose protection (whenever they are not sitting in their assigned classroom seats) and consistent education regarding the basic rules of infection prevention may provide increased options for normalizing teaching activities. Children and adolescents suspected of infection with SARS-CoV-2 should be tested immediately in order to either confirm or rule out such an infection. Evidence of individual infections in children or students must not automatically lead to the closure of the entire daycare center or school. A detailed analysis of the chain of infection is a prerequisite for a balanced approach to infection control. The opening of schools and children's facilities should be accompanied by specifically structured, model surveillance studies that further clarify outstanding questions about infectious disease events and hygiene control. These prospective, concomitant examinations will be essential for the purpose of evaluating and verifying the effectiveness of the required hygiene measures.

Food-borne enterococci integrate into oral biofilm: an in vivo study.

INTRODUCTION: Enterococci, particularly Enterococcus faecalis, are still a primary concern in endodontic infections. To date, enterococci have been considered to be only transiently present in the oral cavity. The aim of this study was to examine whether different enterococci from food are able to reside in oral biofilm. METHODS: Six healthy volunteers wore dental splints loaded with enamel slabs. After 3 days, the volunteers consumed cheese containing enterococci. The fate of the enterococci was analyzed by culture technique and 16S rRNA gene sequencing. All isolates were characterized genotypically by macrorestriction analysis (SmaI) and pulsed-field gel electrophoresis. E. faecalis was also analyzed by using fluorescent in situ hybridization (FISH). RESULTS: E. faecalis, E. faecium, E. avium, and E. durans were detected in the initial biofilm after 2 hours, as well as in the 5-day-old oral biofilm. E. faecalis, E. faecium, and E. avium isolated from the initial biofilm and from the 5-day-old biofilm, as well as those isolated from cheese, showed genetic homogeneity. E. faecium and E. avium had integrated into a pre-existing 3-day-old biofilm. No genetic similarity between E. durans strains isolated from cheese and those from the initial and 5-day-old oral biofilm was detected. E. faecalis was also detected in the oral biofilm by using FISH. CONCLUSIONS: Food-borne enterococci, particularly E. faecalis, might not only be transient but could also survive in the oral biofilm and become a source for endodontic infections. Moreover, genotypic analysis is required to study the source of oral enterococci.

Endodontic and salivary isolates of Enterococcus faecalis integrate into biofilm from human salivary bacteria cultivated in vitro.

INTRODUCTION: The aim of this study was to examine whether Enterococcus faecalis isolates from endodontic patients (from saliva and from a root canal) are able to prevail against salivary bacteria when grown in coculture in a biofilm reactor. METHODS: Saliva that was tested to be free of E. faecalis was used as the inoculum. The fate of E. faecalis was examined by using culture techniques and fluorescence in situ hybridization (FISH). RESULTS: The root canal isolate accounted for 37.4% of the biofilm and 31.9% of the planktonic phase when examined by the culture technique, whereas the proportions examined by FISH showed 15.3% in the biofilm and 11.7% in the planktonic phase. The saliva isolate (as examined by the culture technique) accounted for 32.4% in the biofilm and 27.1% in the planktonic phase, respectively, compared with 14.1% in the biofilm and 9.5% in the planktonic phase when examined by FISH analysis. CONCLUSIONS: These results led to the suggestion that E. faecalis could persist in the biofilm of the human oral cavity. Because of the ubiquitous presence of E. faecalis, root canal infections may arise from different sources.