Background: Outbreaks of respiratory diseases tend to occur in individuals who live in communities, such as students, factory workers, troops, and prisons, because they are in close contact with each other. However, little is known about the transmission mode of nasopharyngeal microbiota in healthy people living in clusters. Therefore, the aim of this study is to explore the distribution of transmission patterns of respiratory tract flora in individuals who have close contact over time to provide a basis for the prevention and control of respiratory diseases.
Result: Thirty-six freshmen in Peking University Medical School volunteered for this study. Throat swab samples were collected on the first day of enrollment and on the 15th, 30th, and 60th day of living together. Streptococcaceae , Bacillaceae , and Neisseriaceae were the most abundant bacterial groups in the cohort. The bacterial community was found to change with time, and the similarity in bacterial community between dormitory members also changed with time. When the dormitory members had lived together for 15 days, the bacterial community had the highest similarity, but it declined thereafter. However, on the 60th day, it was still higher than the similarity on the first day (before they started living together). The transmission patterns of respiratory tract bacteria were spreading with colonization, spreading without colonization, and non-spreading. The bacteria that spread and colonized easily mainly belonged to core genuses (It was defined as that detected in more than 90% of the samples). Bacteria that could spread easily but did not colonize mainly belonged to soft-core genuses (It was defined as that detected in 10%–90% of the samples). The non-spreading bacteria mainly belonged to rare genuses (It was defined as that found in less than 10% of the samples).
Conclusions: These findings indicate that it is important to monitor the incidence and spread of bacteria belonging to the core genuses in order to prevent the spread of bacterial respiratory pathogens.