Abstract
BACKGROUND: Respiratory disease outbreaks frequently occur in settings where individuals are in close contact, for example, schools and factories. However, the transmission patterns of oropharyngeal microbiota among healthy individuals living in clusters are unclear. Therefore, we aimed to investigate the respiratory tract bacteria distribution and transmission patterns among individuals in close contact. METHODS: A total of 36 freshmen from Peking University Medical School participated in the study. We collected pharyngeal swabs on the first day of enrollment, 15, 30, and 60 days after cohabitation. DNA was extracted from the swabs and subjected to high-throughput sequencing to profile the microbial composition. Statistical analyses were performed to assess diversity and significance. RESULTS: Neisseriaceae, Prevotellaceae, and Streptococcaceae were the most abundant bacterial families detected. Over time, changes were observed in the bacterial communities, with a tendency for increased similarity between dormitory room members. By day 60 of cohabitation, the bacterial communities appeared to be more similar compared to the baseline (prior to cohabitation). The transmission patterns included spreading with colonization, spreading without colonization, and non-spreading. Bacteria belonging to the core genera are most likely to spread and colonize easily. CONCLUSION: The risk of healthy cohabitants acquiring respiratory pathogens through close contact may be overestimated in epidemiological studies. Therefore, monitoring the spread of core genera that are easily transmitted and colonized is crucial for effective prevention of respiratory pathogen transmission.