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Neonatal Oral Flora — NDEB AFK MCQ

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ModerateBiomedical SciencesNeonatal Oral FloraNDEB AFK

Which organism is the predominant normal flora of the oral cavity in healthy newborns?

Educational content. Not a substitute for clinical judgement or local policy.

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Correct answer: BStreptococcus salivarius

Streptococcus salivarius is typically the first organism to colonise the oral cavity of newborns (within hours of birth), establishing on the tongue and buccal mucosa. S. mutans does not colonise until tooth surfaces are available for adhesion (after tooth eruption, typically 6-31 months — the 'window of infectivity'). The timing of S. mutans acquisition is influenced by maternal transmission (vertical transmission via saliva sharing) and correlates with subsequent caries risk. Delayed acquisition of S. mutans is associated with lower caries experience.

Reference: Lamont – Oral Microbiology and Immunology, 3rd ed., 2019