IARC 60th Anniversary - 19-21 May 2026
Session : 19/05/26 - Posters
IDENTIFICATION OF CERVICOVAGINAL MICROBIAL SIGNATURES IN DISEASE-FREE INDIAN WOMEN
ANANTHARAMAN D. 1, KELLY J. 2, SANKARAN S. 1, MALVI S. 3, PULIKOTTIL E. 4, JOSHI S. 5, LUCAS E. 6, MUWONGE R. 6, PILLAI R. 1, BASU P. 6, GAFFNEY P. 2
1 BRIC-Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, India; 2 Oklahoma Medical Research Foundation’s Clinical Genomics Centre , Oklahoma City, United States; 3 Tata Memorial Centre Rural Cancer Project, Nargis Dutt Memorial Cancer Hospital, Barshi, India; 4 Christian Fellowship Community Health Centre, Ambillikai, India; 5 Jehangir Clinical Development Centre, Jehangir Hospital , Pune, India; 6 International Agency for Research on Cancer, Lyon, France
Background
Bacterial populations that exist symbiotically in the cervical/ vaginal mucosal epithelial linings play a a protective role in women’s reproductive and gynaecological health. Unlike other mucosal sites of the body, health in the female reproductive tract is associated with low species diversity. Increase in species diversity, particularly with anaerobic bacterial species are often indicative of pathological states. While studies have examined cervicovaginal microbial composition in relation to cervical intraepithelial neoplasia (CIN) or cervical cancer, and a few with respect to high-risk HPV infection, few longitudinal studies exist.
Objectives
The primary aim was to determine the core cervicovaginal microbiome composition and diversity in healthy, disease-free Indian women. The study also aimed to identify microbial populations associated with high risk HPV acquisition, clearance and persistence in healthy, disease-free cervix.
Methods
The current analysis was nested within the IARC-India multi-centre HPV vaccination study, a cluster-randomized HPV vaccination trial in India to evaluate the effectiveness of varying doses of quadrivalent HPV vaccine in preventing cervical neoplasia. Ninety-six individuals (50 vaccinated, 46 unvaccinated), who contributed three consecutive endocervical brushing samples were included. Following DNA extraction, sequencing of the hyper variable region of 16S ribosomal RNA genes were completed on the Illumina NovaSeq 6000 platform. The microbial populations were identified using QIIME2 metagenomic analysis with an NB classifier against SILVA 138 database. Alpha and beta diversities were measured by the Shannon diversity index and Jaccard index respectively.
Results
This analysis identified a total of 495 taxa with ≥0.9 confidence score. We observed that majority of the microbial species were shared across timepoints for the same individual indicating intraindividual microbial composition was stable over time. Lactobacillus was the top-ranking genus with predominance of L. hominis and L. iners. Limited variability was seen with vaccination status or HPV positivity; C. massiliense, L. gallinarum, L. equicursoris, L. reuteri were unique to the vaccinated cohort while G. vaginalis was associated with persistent HPV16/31 infection.
Conclusions
We found that the cervix/ vagina was associated with a core microbial signature dominated by Lactobacillae.