Background: Recent international studies have demonstrated that vaginal microbiota dysbiosis is associated with persistent human papillomavirus (HPV) infection, cervical precancerous lesions, and cervical cancer. In healthy women, Lactobacillus spp. dominate the vaginal microbiota and produce lactic acid and other bioactive compounds, thereby maintaining an acidic vaginal pH and protecting against colonization by pathogenic microorganisms. A reduction in Lactobacillus spp. and overgrowth of pathogenic bacteria, resulting in dysbiosis, has been associated with HPV persistence as well as the progression and recurrence of cervical precancerous lesions. However, no study has compared the prevalence of Lactobacillus spp. and aerobic bacteria, or their associations, among Mongolian women diagnosed with cervical precancerous lesions or cervical cancer. Therefore, this study was conducted to address this gap. Aim: To compare and characterize the composition of selected vaginal microorganisms in women diagnosed with cervical precancerous lesions and cervical cancer. Materials and Methods: This hospital-based, cross-sectional study was conducted from May to October 2026 at the Department of Gynecologic Oncology, National Cancer Center of Mongolia. A total of 275 women with histologically confirmed cervical precancerous lesions or cervical cancer were voluntarily enrolled after providing written informed consent. Prior to initiation, ethical approval was obtained from the Research Ethics Committee of the Mongolian National University of Medical Sciences at its meeting held on April 22, 2026 (Minutes No. 2026/04-28). General information, medical history, and behavioral factors were collected using a structured questionnaire. Three vaginal swabs were collected from the posterior vaginal fornix. Vaginal discharge was examined, and Lactobacillus spp. and aerobic bacteria were cultured. The associations between these microbiological findings and diagnostic groups were compared across five diagnostic categories. Results: Of the 275 women enrolled, the diagnostic distribution was as follows: CIN I, 41 (14.9%); CIN II, 73 (26.5%); CIN III, 80 (29.1%); cervical carcinoma in situ (CIS), 45 (16.4%); and cervical cancer (CC), 36 (13.1%). Vaginal pH was significantly and positively correlated with the cocci count (ρ=0.346, p < 0.001), white blood cell count (ρ=0.283, p < 0.001), and AV score (ρ=0.277, p < 0.001). In contrast, the Lactobacillus count was significantly and negatively correlated with vaginal pH (ρ=−0.238, p < 0.001). When the AV score was compared across diagnostic groups, it was 2.8±1.3 in stage IIB cervical cancer and 3.67±2.3 in stage III cervical cancer (p=0.008). Lactobacillus spp. were isolated from 119 participants (43.3%), while aerobic bacteria were isolated from 103 participants (37.5%). The most frequently identified aerobic bacteria were Escherichia coli (32; 11.6%), Enterococcus faecalis (17; 6.2%), Streptococcus agalactiae (11; 4.0%), and viridans group streptococci (9; 3.3%). However, the detection rates of Lactobacillus spp. and aerobic bacteria did not differ significantly across diagnostic groups (p=0.634 and p=0.221, respectively). Conclusions Among women with cervical precancerous lesions and cervical cancer, an increase in vaginal pH was significantly positively associated with cocci count, white blood cell count, and AV score. The higher AV scores observed in the cervical cancer group suggest that aerobic vaginitis may be associated with the progression of cervical precancerous lesions. Although the prevalence of Lactobacillus spp. and aerobic microorganisms did not differ significantly across diagnostic groups, the CC group showed a trend toward increased prevalence of aerobic microorganisms and decreased prevalence of Lactobacillus spp.

Background: Nucleic acid sequencing is a multi-step process taken place in medical research or diagnostic laboratories. Since the emerge of second generation sequencing technology generally referred as next generation sequencing (NGS), the mass parallel reads covering human genome or transcriptome is achieved by cost cut down over thousand folds. Though the technology made tremendous push forward to various applications, its data analysis time and effort still takes worrisome time and human effort, bringing the emerge of next-step demand: targeted mass sequencing of only desired part from human genome or transcriptome with lower material cost and labor. By targeted sequencing, both run cost and data analysis process can be further cut down, and the read results are more reliable on changes such as determining varied number of repeats, heterozygote alleles, deletions, chromosomal scale abnormality and more. Objective: In this study, we explored the utilization of biotinylated RNA baits on captured sequencing of cancer marker genes functional regions. Method: Targeted NGS was achieved by capturing desired genomic regions using preparatory nucleic acid probes. RNA bait capturing of desired genomic regions has shown to have high specificity and quality.
The study was carried out with informed consent obtained from patients, with the approval №53 in 2018.03.15 by Medical Ethics committee, Ministry of Health, Mongolia. Result: By preparing library of biotinylated RNA baits with 75000 unique sequences, we achieved mass parallel sequencing of human 410 cancer-marker-genes’ exons and UTRs with average read depth ~760, and covered thousands of SNPs on 5 genomic DNA samples. Tissue samples derived from breast cancer and ovary cancer had SNP and deletion on 7 marker genes (BRCA1, BRCA2, ATM, BRIP1, PTEN, TP53, RAD51C) not registered in database. Conclusion Experiments showed RNA baits with up to 117 nucleotide length, produced from ssDNA oligonucleotide stock, can be utilized to capture desired regions of human genome, and bring the cost of captured mass sequencing to 1500 USD, with 93.14-93.33% of Q30 read quality.