Evaluation of DNA extraction protocols from liquid-based cytology specimens for studying cervical microbiota

Evaluation of silica spin‑column and magnetic bead formats for rapid DNA methylation analysis in clinical and point‑of‑care settings

Late-stage cancers lack effective treatment, underscoring the need for early diagnosis to improve prognosis and decrease mortality rates. Molecular markers, such as DNA methylation, offer promise in early cancer detection. The present study compared commercial kits for analyzing DNA from cervical liquid cytology samples in cancer screening. Rapid bisulfite conversion kits using silica spin-columns and magnetic beads were assessed against standard DNA extraction and bisulfite conversion methods for profiling DNA methylation using quantitative methylation-specific PCR. β-actin amplification indicated the suitability of small sample volumes for methylation studies using either the pellet or supernatant (cell-free DNA) parts. Comparison of Bisulfite Conversion Kit-Whole Cell (Abcam), Methylamp Bisulfite Modification (Epigentek), EpiTect Fast LyseAll Bisulfite Kit (Qiagen GmbH) and EZ DNA Methylation-Direct Kit (Zymo Research Corp.) showed no significant differences in β-actin cycle threshold values. EZ-96 DNA Methylation-Lightning MagPrep (Zymo Research Corp.), a hybrid kit in a 96-well plate format, exhibited swift turnaround time and similar amplification efficiency. Automation with magnetic bead kits increased throughput without compromising amplification efficiency in open PCR systems. Cost analysis favored direct kits over the gold standard manual protocol. This comparison aids in selecting cost-effective DNA methylation diagnostic tests. The present study confirmed comparable kit performance in methylation-based analysis, highlighting the adequacy of cytology samples and the potential of bodily fluids as alternatives for liquid biopsy.

Pragmatic Considerations When Extracting DNA for Metagenomics Analyses of Clinical Samples

Microbiome analyses are essential for understanding microorganism composition and diversity, but interpretation is often challenging due to biological and technical variables. DNA extraction is a critical step that can significantly bias results, particularly in samples containing a high abundance of challenging-to-lyse microorganisms. Taking into consideration the distinctive microenvironments observed in different bodily locations, our study sought to assess the extent of bias introduced by suboptimal bead-beating during DNA extraction across diverse clinical sample types. The question was whether complex targeted extraction methods are always necessary for reliable taxonomic abundance estimation through amplicon sequencing or if simpler alternatives are effective for some sample types. Hence, for four different clinical sample types (stool, cervical swab, skin swab, and hospital surface swab samples), we compared the results achieved from extracting targeted manual protocols routinely used in our research lab for each sample type with automated protocols specifically not designed for that purpose. Unsurprisingly, we found that for the stool samples, manual extraction protocols with vigorous bead-beating were necessary in order to avoid erroneous taxa proportions on all investigated taxonomic levels and, in particular, false under- or overrepresentation of important genera such as Blautia, Faecalibacterium, and Parabacteroides. However, interestingly, we found that the skin and cervical swab samples had similar results with all tested protocols. Our results suggest that the level of practical automation largely depends on the expected microenvironment, with skin and cervical swabs being much easier to process than stool samples. Prudent consideration is necessary when extending the conclusions of this study to applications beyond rough estimations of taxonomic abundance.

Effect of Probiotics on Host-Microbiota in Bacterial Infections

Diseases caused by bacteria cause millions of deaths every year. In addition, the problem of resistance to antibiotics is so serious that it threatens the achievements of modern medicine. This is a very important global problem as some bacteria can also develop persistence. Indeed, the persistence of pathogenic bacteria has evolved as a potent survival strategy to overcome host organisms’ defense mechanisms. Additionally, chronic or persistent infections may be caused by persisters which could facilitate antibiotic resistance. Probiotics are considered good bacteria. It has been described that the modulation of gut microbiota by probiotics could have a great potential to counteract the deleterious impact and/or regulate gut microbiota after bacterial infection. Probiotics might provide health benefits through the inhibition of pathogen growth or the replacement of pathogenic bacteria. Bearing in mind that current strategies to avoid bacterial persistence and prevent antibiotic resistance are not effective, other strategies need to be assessed. We have carried out a comprehensive review, which included the reported literature between 2016 and 2021, highlighting the clinical trials that reported the probiotics’ potential to regulate gut microbiota after bacterial infection and focusing in particular on the context of antibiotic resistance and persister cells.

Human Papillomavirus Types Associated with Cervical Dysplasia among HIV- and Non-HIV-Infected Women Attending Reproductive Health Clinics in Eastern Kenya

Background

Human papillomavirus (HPV) causes over 99% of all cervical cancer globally. In 2019, it was responsible for 3286 deaths in Kenya. Data on the epidemiological distribution of HPV genotypes by cervical dysplasia and HIV-infected women which is important in designing prevention strategy monitoring treatment and management of cervical cancer is lacking in Eastern Kenya.

Objective

To determine HPV genotype prevalence and their association with cervical dysplasia among HIV-infected (cases) and noninfected (control) women aged 18-48 years seeking reproductive healthcare.

Methods

A cervical broom was softly rotated 360 degrees five times to exfoliate cells from the region of the transformation zone, squamocolumnar junction, and endocervical canal for HPV genotyping. Social-demographic and risk factors responsible for HPV acquisition were collected using a questionnaire. Laboratory outcome and questionnaire data statistical relationships were computed using Pearson chi-square test.

Results

317 women (cases: 161 (50.8%), control 156 (49.2%), mean age: 34.3,SD ± 10.4, range 18-46 years) were recruited from Embu (85/317 (26.8%)), Isiolo (64/317 (20.2%)), Kirinyaga (56/317 (17.7%)), Meru (81/317 (25.6%)), and Tharaka-Nithi (31/317 (9.8%)). The frequency HPV genotypes detected by cervical dysplasia were CIN1 (cases: HPV81 (12/317 (3.8%)), HPV11 (2/317 (0.6%)); control: HPV53 and 66 coinfection (1/317 (0.3%)), CIN2 (cases: HPV11, HPV16, HPV66 ((1/317 (0.3%) each), HPV81 (6/317 (1.9%)), and single case (1/317 (0.3%)) of HPV11 and 66, HPV81 and 44, HPV81 and 88, HPV9 and 53, and HPV16 and 58 coinfection; control: HPV81 (2/317 (0.6%)) and invasive cervical cancer (cases: HPV16 (1/317 (0.3%)) and HPV81 (3/317 (0.9%)); control: HPV16 and 66 (1/317 (0.3%))).

Conclusions

There was a higher frequency of both high-risk and low-risk HPV genotypes associated with cervical dysplasia among HIV-infected than HIV-uninfected women seeking reproductive health care. This study provides epidemiological data on the existence of nonvaccine HPV types associated with cervical dysplasia in the region.