Within-Host Diversity and Vertical Transmission of Group B Streptococcus Among Mother-infant Dyads in The Gambia

Foster-Nyarko, E.; Senghore, M.; Kwambana-Adams, B. A.; Alikhan, N.-F.; Ravi, A.; Jawneh, K.; Jah, A.; Jarju, M.; Ceesay, F.; Bojang, S.; Jafali, J.; Worwui, A.; Odutola, A.; Ogundare, E.; Pallen, M. J.; Ota, M.; Antonio, M.

doi:10.1101/760512

bioRxiv · 10.1101/760512

Within-Host Diversity and Vertical Transmission of Group B Streptococcus Among Mother-infant Dyads in The Gambia

Foster-Nyarko, E.·Senghore, M.·Kwambana-Adams, B. A.·Alikhan, N.-F.·Ravi, A.·Jawneh, K.·Jah, A.·Jarju, M.·Ceesay, F.·Bojang, S.·Jafali, J.·Worwui, A.·Odutola, A.·Ogundare, E.·Pallen, M. J.·Ota, M.·Antonio, M.

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Abstract

IntroductionUnderstanding mother-to-infant transmission of Group B Streptococcus (GBS) is vital to the prevention and control of GBS disease. We investigated the transmission and phylogenetic relationships of mothers colonised by GBS and their infants in a peri-urban setting in The Gambia.\n\nMethodsWe collected nasopharyngeal swabs from 35 mother-infant dyads at weekly intervals from birth until six weeks post-partum. GBS was isolated by conventional microbiology techniques. Whole-genome sequencing was performed on GBS isolates from one mother-infant dyad (dyad 17).\n\nResultsWe recovered 85 GBS isolates from the 245 nasopharyngeal swabs. GBS was isolated from 16.33% and 18.37% of sampled mothers and infants, respectively. In 87% of cultured swabs, the culture status of an infant agreed with that of the mother (Kappa p-value <0.001). In dyad 17, phylogenetic analysis revealed within-host strain diversity in the mother and clone to her infant.\n\nConclusionGBS colonisation in mothers presents a significant risk of colonisation in their infants. We confirm vertical transmission from mother to child in dyad 17, accompanied by within-host diversity.

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Foster-Nyarko, E., Senghore, M., Kwambana-Adams, B. A., Alikhan, N.-F., Ravi, A., Jawneh, K., Jah, A., Jarju, M., Ceesay, F., Bojang, S., Jafali, J., Worwui, A., Odutola, A., Ogundare, E., Pallen, M. J., Ota, M., Antonio, M.. 2019-09-06. Within-Host Diversity and Vertical Transmission of Group B Streptococcus Among Mother-infant Dyads in The Gambia. https://doi.org/10.1101/760512

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