Profiling of vaginal Lactobacillus jensenii isolated from preterm and full-term pregnancies reveals strain-specific factors relating to host interaction

• DOI: 10.1099/mgen.0.001137
• Publication Date: 2023-11-27T16:17:20Z
• Authors: Sai Ravi Chandra ...; Tara K. McGuire; Elaine M. Lawton; Fionnuala M. McAu...; Douwe Van Sinderen; Calum J. Walsh; Paul D. Cotter; Conor Feehily
• Keywords: Lactobacillus; 0303 health sciences; 03 medical and health sciences; Bacteria; Pregnancy; Vagina; Infant, Newborn; Humans; Premature Birth; Female; Child; Research Articles

Each year, 15 million infants are born preterm (<37 weeks gestation), representing the leading cause of mortality for children under the age of five. Whilst there is no single cause, factors such as maternal genetics, environmental interactions, and the vaginal microbiome have been associated with an increased risk of preterm birth. Previous studies show that a vaginal microbiota dominated by

Lactobacillus

is, in contrast to communities containing a mixture of genera, associated with full-term birth. However, this binary principle does not fully consider more nuanced interactions between bacterial strains and the host. Here, through a combination of analyses involving genome-sequenced isolates and strain-resolved metagenomics, we identify that

L. jensenii

strains from preterm pregnancies are phylogenetically distinct from strains from full-term pregnancies. Detailed analysis reveals several genetic signatures that distinguish preterm birth strains, including genes predicted to be involved in cell wall synthesis, and lactate and acetate metabolism. Notably, we identify a distinct gene cluster involved in cell surface protein synthesis in our preterm strains, and profiling the prevalence of this gene cluster in publicly available genomes revealed it to be predominantly present in the preterm-associated clade. This study contributes to the ongoing search for molecular biomarkers linked to preterm birth and opens up new avenues for exploring strain-level variations and mechanisms that may contribute to preterm birth.