Novel allele sequences for each locus identified in our study.

Novel allele sequences for each locus identified in our study.</p

Characteristics of the seven housekeeping loci used in <i>C</i>. <i>albicans</i> MLST.

Characteristics of the seven housekeeping loci used in C. albicans MLST.</p

Demographic, socioeconomic, medical, and dental background of mother-child dyads.

Demographic, socioeconomic, medical, and dental background of mother-child dyads.</p

Oral <i>Candida</i> comparison among mother-child dyads in the first two years of child’s life.

The upper panel demonstrates oral Candida detection status among mother-child dyads. The status is categorized as mother and child both positive of Candida (blue), mother and child both negative of Candida (green), mother negative but child positive of Candida (pink), and mother positive but child negative (purple). Nine percent of the 36 mother-infant dyads had positive Candida detection in their oral cavity at 1 month, whereas 36% of the mother-infant dyads had positive Candida detection at 12 months. The middle panel represents the percentage of mothers and children who share the same type (green) or different type (blue) of Candida species, including C. albicans, C. parapsilosis, C. dubliniensis, C. lusitaniae, C. krusei, C. glabrata, or C. tropicalis. The lower panel indicates the genetic relatedness of C. albicans between mothers and children by MLST nucleotide analysis; genetically related (purple) ≥ 99% similar and genetically different (pink) C.a, C. albicans.</p

Additional description for methods section.

Candida albicans is a pathogenic fungus recently recognized for its role in severe early childhood caries development (S-ECC). C. albicans oral colonization begins at birth, but the extent of the mother’s involvement in yeast transmission to their children is unclear, therefore, this study used a prospective mother-infant cohort to investigate the maternal contribution of C. albicans oral colonization in early life. Oral samples were collected from 160 mother-child dyads during pregnancy and from birth to two years of life. We used whole-genome sequencing to obtain the genetic information of C. albicans isolates and examined the genetic relatedness of C. albicans between mothers and their children using Multilocus Sequence Typing. Multivariate statistical methods were used to identify factors associated with C. albicans’ acquisition (horizontal and vertical transmissions). Overall, 227 C. albicans oral isolates were obtained from 93 (58.1%) of mother-child pairs. eBURST analysis revealed 16 clonal complexes, and UPGMA analysis identified 6 clades, with clade 1 being the most populated 124 isolates (54.6%). Significantly, 94% of mothers and children with oral C. albicans had highly genetically related strains, highlighting a strong maternal influence on children’s C. albicans acquisition. Although factors such as race, ethnicity, delivery method, and feeding behaviors did not show a significant association with C. albicans vertical transmission, the mother’s oral hygiene status reflected by plaque index (PI) emerged as a significant factor; Mothers with higher dental plaque accumulation (PI >=2) had a significantly increased risk of vertically transmitting C. albicans to their infants [odds ratio (95% confidence interval) of 8.02 (1.21, 53.24), p=0.03]. Furthermore, Black infants and those who attended daycare had an elevated risk of acquiring C. albicans through horizontal transmission (p C. albicans during early life. Incorporating screening for maternal fungal oral carriage and implementing oral health education programs during the perinatal stage may prove valuable in preventing fungal transmission in early infancy.</div

Time series transmission rate of <i>C</i>. <i>albicans</i> and the factors associated with its vertical and horizontal transmission.

At one month, 60% of the infants displayed vertical transmission of C. albicans, with the remaining 40% experiencing horizontal transmission. However, by the 18-month visit, the percentage of vertical transmission was 36%, while horizontal transmission was 64%. From the multivariate logistic model, the mother’s plaque index was identified as the significant factor associated with C. albicans’ vertical transmission (OR, 8.02 [95% CI, 1.21-53.24]; p = 0.03) (B). Regarding C. albicans horizontal transmission, the factors associated with increased risk included being of Black race (OR, 3.46 [95% CI, 1.43-8.85]; p = 0.007) and attending daycare (OR, 2.90 [95% CI, 1.18-7.39]; p = 0.02) (C).</p

UPGMA dendrogram of 3000 <i>C</i>. <i>albicans</i> isolates with different DSTs from the database and 227 clinical isolates from our study.

The DSTs of the population isolates were categorized into 19 clades that were previously identified, and a new clade designated as "N". Additionally, there were some singletons present marked as S. To facilitate easy identification, we have highlighted the DSTs of the isolates from our study in green. (XLSX)</p

Snapshot of the 16 clonal clusters identified by eBURST in 227 clinical oral isolates of <i>C</i>. <i>albicans</i>.

The isolates were grouped into 16 clusters and 31 singletons (not shown in the figure). Lines connecting the sequence types (DSTs) indicate a hierarchical relationship between them, with those differing in just two of the seven sequenced fragments being joined. When a putative ancestral DST was identified for a cluster, its number was marked with a red asterisk. The clonal clusters of related isolates are numbered in boldface font. Note that the color of DSTs and the length of the lines connecting the DSTs does not hold any significance. Each DST is accompanied by the subject ID and the child’s age in months. If no age is specified, it signifies a mother isolate. The caries status is visually represented by font color, with black indicating no caries and red indicating the presence of caries.</p

Metadata.

Candida albicans is a pathogenic fungus recently recognized for its role in severe early childhood caries development (S-ECC). C. albicans oral colonization begins at birth, but the extent of the mother’s involvement in yeast transmission to their children is unclear, therefore, this study used a prospective mother-infant cohort to investigate the maternal contribution of C. albicans oral colonization in early life. Oral samples were collected from 160 mother-child dyads during pregnancy and from birth to two years of life. We used whole-genome sequencing to obtain the genetic information of C. albicans isolates and examined the genetic relatedness of C. albicans between mothers and their children using Multilocus Sequence Typing. Multivariate statistical methods were used to identify factors associated with C. albicans’ acquisition (horizontal and vertical transmissions). Overall, 227 C. albicans oral isolates were obtained from 93 (58.1%) of mother-child pairs. eBURST analysis revealed 16 clonal complexes, and UPGMA analysis identified 6 clades, with clade 1 being the most populated 124 isolates (54.6%). Significantly, 94% of mothers and children with oral C. albicans had highly genetically related strains, highlighting a strong maternal influence on children’s C. albicans acquisition. Although factors such as race, ethnicity, delivery method, and feeding behaviors did not show a significant association with C. albicans vertical transmission, the mother’s oral hygiene status reflected by plaque index (PI) emerged as a significant factor; Mothers with higher dental plaque accumulation (PI >=2) had a significantly increased risk of vertically transmitting C. albicans to their infants [odds ratio (95% confidence interval) of 8.02 (1.21, 53.24), p=0.03]. Furthermore, Black infants and those who attended daycare had an elevated risk of acquiring C. albicans through horizontal transmission (p C. albicans during early life. Incorporating screening for maternal fungal oral carriage and implementing oral health education programs during the perinatal stage may prove valuable in preventing fungal transmission in early infancy.</div

Minimum spanning (MS) tree and Neighbor-Joining (NJ) tree of 227 <i>C</i>. <i>albicans</i> clinical oral isolates from our study.

MS tree was generated based on the allelic profiles of the 227 C. albicans strains isolated from our study by PHYLOViZ visualization (A). NJ tree as determined by p-distance of the 227 C. albicans strains isolated from our study (B). The tree is presented in a radial format to illustrate the relative positions of the isolates that are related to each other. Clades are highlighted with colored shading to help with visualization.</p