Objective: To observe the dynamic changes of oral microflora early colonized in infants.
Methods: The oral swab samples for the study were taken in 1 day, 1, 3, 6, 9, 12 months after birth from 12 healthy neonates. By choosing suitable diluted concentration, the samples were incubated aerobically, facultative anaerobically and anaerobically. The strains were identified by observing colony characteristics, Gram staining and biochemical tests.
Results: S. salivarius was the most frequent microflora, followed by S. mitis, S. sanguis, S. gordonii and S. mutans occurred in oral cavity after tooth eruption. Veillonella spp. can be detected in oral cavity of 1-month-old babies, A. odontolyticus was isolated from 8.3% infants of more than 3 months old. L. acidophilus maintained the lower prevalence in oral cavity of babies. Leptotrichia buccalis and Capnocytophaga spp. occurred in oral cavity of some dentate infants.
Conclusion: S. solivarius and S. mitis are predominant species in oral cavity of the infants, Veillonella spp. is the first and the most anaerobic species appeared in oral cavity of healthy babies. A. odontolyticus is the first actinomyces detected in oral cavity. With the increasing months, kind and amount of microflora increase dramatically.