Maternal Oral Health Influences Infant Salivary Microbiome.

Oral microbiomes vary in cariogenic potential; these differences may be established early in life. A major concern is whether mothers transmit cariogenic bacteria to their children. Here we characterize early salivary microbiome development and the potential associations of that development with route of delivery, breastfeeding, and mother's oral health, and we evaluate transmission of microbes between mother and child. We analyzed saliva and metadata from the Center for Oral Health Research in Appalachia. For this cohort study, we sequenced the V6 region of the 16S rRNA gene and used quantitative polymerase chain reaction to detect Streptococcus mitis, Streptococcus sobrinus, Streptococcus mutans, Streptococcus oralis, and Candida albicans in the saliva from mothers and their infants, collected at 2, 9, and 12 mo (Pennsylvania site) and 2, 12, and 24 mo (West Virginia site). Breastfed children had lower relative abundances of Prevotella and Veillonella. If mothers had decayed, missing, or filled teeth, children had greater abundances of Veillonella and Actinomyces. There was little evidence of maternal transmission of selected microbes. At 12 mo, children's microbiomes were more similar to other children's than to their mothers'. Infants' salivary microbiomes became more adult-like with age but still differed with mothers' microbiomes at 12 mo. There was little evidence supporting transmission of selected microbes from mothers to children, but risk of colonization was associated with tooth emergence. Children are likely to acquire cariogenic bacteria from a variety of sources, including foods and contact with other children and adults.

Co-colonization by Streptococcus pneumoniae and Staphylococcus aureus in the throat during acute respiratory illnesses.

Pneumonia due to either Streptococcus pneumoniae (Sp) or Staphylococcus aureus (Sa) accounts for most mortality after influenza and acute respiratory illness (ARI). Because carriage precedes infection, we estimated Sp and Sa carriage to examine the co-colonization dynamics between Sp, Sa and respiratory viruses in the presence of ARI in the oropharynx. We tested oropharyngeal specimens of community subjects (aged ⩾2 years) with ARI for the presence of influenza A and B, 11 other common respiratory viruses, Sp and Sa, using real-time PCR. A total of 338 participants reported 519 ARI episodes of which 119 (35%) carried Sp, 52 (13%) carried Sa and 25 (7%) carried both. Thirty-five subjects tested positive for influenza, of which 14 (40%) carried Sp and six (17%) carried Sa, significantly more than in the influenza-negative group (P = 0·03 and P = 0·04, respectively). In subjects infected by any virus compared to those with no virus, Sp carriage (39·2% vs. 27·9%, P = 0·03) but not Sa carriage (11·6% vs. 14%, P = 0·6) was more frequent. For children, when Sa was present, Sp carriage tended to be less frequent than expected given the presence of viral infection, but not significantly [observed relative risk 1·14, 95% confidence interval (CI) 0·4-3·1; with a relative excess risk due to interaction of -0·11]. Independent of age, Sp carriers were more likely to return that season with subsequent ARI (odds ratio 2·14, 95% CI 1·1-4·3, P = 0·03). Both Sp and Sa carriage rates in the oropharynx increase during influenza infection in children. However, no negative interaction between Sp and Sa was observed. Sp carriers are more likely to suffer subsequent ARI episodes than non-carriers.