Comparison of detection methods for vaginal lactobacilli

Developing diagnostic tools for canine periodontitis: combining molecular techniques and machine learning models

BACKGROUND

Dental plaque microbes play a key role in the development of periodontal disease. Numerous high-throughput sequencing studies have generated understanding of the bacterial species associated with both canine periodontal health and disease. Opportunities therefore exist to utilise these bacterial biomarkers to improve disease diagnosis in conscious-based veterinary oral health checks. Here, we demonstrate that molecular techniques, specifically quantitative polymerase chain reaction (qPCR) can be utilised for the detection of microbial biomarkers associated with canine periodontal health and disease.

RESULTS

Over 40 qPCR assays targeting single microbial species associated with canine periodontal health, gingivitis and early periodontitis were developed and validated. These were used to quantify levels of the respective taxa in canine subgingival plaque samples collected across periodontal health (PD0), gingivitis (PD1) and early periodontitis (PD2). When qPCR outputs were compared to the corresponding high-throughput sequencing data there were strong correlations, including a periodontal health associated taxa, Capnocytophaga sp. COT-339 (rs =0.805), and two periodontal disease associated taxa, Peptostreptococcaceae XI [G-4] sp. COT-019 (rs=0.902) and Clostridiales sp. COT-028 (rs=0.802). The best performing models, from five machine learning approaches applied to the qPCR data for these taxa, estimated 85.7% sensitivity and 27.5% specificity for Capnocytophaga sp. COT-339, 74.3% sensitivity and 67.5% specificity for Peptostreptococcaceae XI [G-4] sp. COT-019, and 60.0% sensitivity and 80.0% specificity for Clostridiales sp. COT-028.

CONCLUSIONS

A qPCR-based approach is an accurate, sensitive, and cost-effective method for detection of microbial biomarkers associated with periodontal health and disease. Taken together, the correlation between qPCR and high-throughput sequencing outputs, and early accuracy insights, indicate the strategy offers a prospective route to the development of diagnostic tools for canine periodontal disease.

Etiology of recurrent cystitis in postmenopausal women based on vaginal microbiota and the role of Lactobacillus vaginal suppository

Background

The vaginal microbiota can be altered by uropathogenic bacteria associated with recurrent cystitis (RC), and the vaginal administration of Lactobacillus have suggested certain effects to prevent RC. The relationship between vaginal microbiota and the development of RC has not been elucidated. We aimed to clarify the etiology of RC from vaginal microbiota and importance of vaginal Lactobacillus.

Methods

Vaginal samples obtained from 39 postmenopausal women were classified into four groups: healthy controls; uncomplicated cystitis; RC; and prevention (prevented RC by Lactobacillus crispatus-containing vaginal suppositories). Principal coordinate analysis and beta-diversity analysis was used to assess 16S rRNA gene sequencing data from the vaginal microbiome.

Results

Cluster analysis divided the vaginal bacterial communities among 129 vaginal samples into three clusters (A, B, and C). Fourteen of 14 (100%) samples from the RC group and 51 of 53 (96%) samples from the prevention group were in clusters B and C, while 29 of 38 (76%) samples from the healthy group and 14 of 24 (58%) samples from the uncomplicated cystitis group were in cluster A. The principal coordinate analysis showed that plots in the uncomplicated cystitis group were similar to the healthy group, indicating a large separation between the RC group and the uncomplicated cystitis group. On beta-diversity analysis, there were significant differences between the healthy group and the uncomplicated cystitis group (p = 0.045), and between the RC group and the uncomplicated cystitis group or the healthy group (p = 0.001, p = 0.001, respectively). There were no significant differences between the RC group and the prevention group (p = 0.446). The top six taxa were as follows: Prevotella, Lactobacillus, Streptococcus, Enterobacteriaceae, Anaerococcus, and Bifidobacterium. Among patients with RC, Lactobacillus was undetectable before administration of suppositories, while the median relative abundance of Lactobacillus was 19% during administration of suppositories (p = 0.0211), reducing the average cystitis episodes per year (6.3 vs. 2.4, p = 0.0015).

Conclusion

The vaginal microbiota of postmenopausal women with RC is differed from healthy controls and uncomplicated cystitis in terms of lack of Lactobacillus and relatively dominant of Enterobacteriaceae. Vaginal administration of Lactobacillus-containing suppositories can prevent RC by stabilizing vaginal dysbiosis and causing a loss of pathogenic bacteria virulence.

Interplay of the microbiome and antifungal therapy in recurrent vulvovaginal candidiasis (RVVC): A narrative review

Recurrent vulvovaginal candidiasis (RVVC) is a microbial, immune and sexual health disorder impacting up to 10 % of the adult female population. Fluconazole is a well-established antifungal drug commonly utilized for acute and long-term RVVC treatment. This insight review provides an overview of known vaginal and gastrointestinal microbiota characteristics in RVVC, presents the potential impacts of fluconazole therapy on multi-microbiome relationships and discusses implications for future research and clinical practice. Next-generation sequencing (NGS) and molecular methods to accurately define vaginal microbiota trends in RVVC are not comprehensively available, limiting understanding of microbiota roles in RVVC. Inconsistencies and variances in Lactobacillus profiles in RVVC women suggest poorly understood disease implications on the bacterial and fungal microbiomes. Investigations of environmental conditions like vaginal pH, drug therapy's impact, especially fluconazole maintenance therapy, and the elucidation of multi-microbiome relationships in RVVC are required to further investigate disease pathogenesis and responsible antimicrobial prescribing.

Impact of Lactobacillus crispatus-containing oral and vaginal probiotics on vaginal health: a randomised double-blind placebo controlled clinical trial

Health of reproductive tract is tightly associated with balance of microbial communities in this area. Bacterial vaginosis (BV) and vulvovaginal candidiasis (VVC) represent common disturbances of vaginal communities. Vaginal discharge due to BV or VVC is a very frequent reason for visiting gynaecologist. We aimed to evaluate the impact of the novel evidence-based probiotics on BV and VVC patients. The study group included 89 BV and 93 VVC patients (aged 18-50 years) who were recruited into randomised double-blind placebo-controlled two-arm parallel trial. The patients of each diagnosis group received oral or vaginal probiotic capsules, or placebo capsules during 3 months. A probiotic capsule contained two (DSM32717 and DSM32720, in case of BV) or three (DSM32720, DSM32718 and DSM32716, in case of VVC) Lactobacillus crispatus strains. Vaginal, intestinal and general health was monitored weekly by questionnaire. Blood analyses were done in the beginning and at the end of trial. Vaginal samples were collected monthly, microscopic and molecular analyses were performed. The study revealed that both oral and vaginal capsules reduced the signs and symptoms in BV patients. Remarkable improvement was noted in Nugent score, amount and smell of discharge, but also in itching/irritation. Consumption of vaginal probiotics significantly increased the lactobacilli counts in their vagina while mean proportion of some BV-related bacteria decreased. In VVC patients, both oral and vaginal capsules lowered the combined score of two most important symptoms, amount of discharge and itching/irritation. In conclusion, the novel formulations of evidence-based well-focused probiotic L. crispatus strains are effective against BV and VVC being suitable for both vaginal and oral administration. Clinical trial registration: ISRCTN34840624, BioMed Central.

Estimating the time since deposition (TsD) in saliva stains using temporal changes in microbial markers

Determining the time since deposition (TsD) of traces could be helpful in the investigation of criminal offenses. However, there are no reliable markers and models available for the inference of short-term TsD. The goal of this study was to investigate the potential of the succession pattern of human salivary microbial communities to serve as an efficiency TsD prediction tool in the resolution of the forensic cases. Saliva stains exposed to indoor conditions up to 20 days were collected and analyzed by 16S rRNA profiling using high-throughput sequencing technique. Noticeable differences in microbial composition were observed between different time points, and the indoor exposure time of saliva stains were inversely correlated with alpha diversity estimates across the measured time period. The sequencing results were used to identify TsD-dependent bacterial indicators to regress a generalized random forest model, resulting in a mean absolute deviation (MAD) of 1.41 days. Furthermore, a simplified TsD predictive model was also developed utilizing Enhydrobacter, Paenisporosarcina, and Janthinobacterium by quantitative PCR (qPCR) with a MAD of 1.32 days, and then forensic practice assessment were also performed by using mock samples with a MAD of 3.53 days. In conclusion, this study revealed significant changes in salivary microbial abundance as the prolongation of TsD. It demonstrated that the microbial biomarkers could be invoked as a "clock" for TsD estimation in human dried saliva stains.

Exploring of probiotic potential vaginal Lactobacillus isolates from healthy women against Gardnerella vaginalis and Caenorhabditis elegans model testing

AIM

Lactobacillus species are the dominant microorganisms in the vaginal microbiota of healthy women and play an important role in the defense against pathogens. This study aimed to evaluate probiotic potential of Lactiplantibacillus plantarum strain P1 isolated from healthy woman's vaginal discharge for its further utilization as a promising candidate strain in the treatment of bacterial vaginosis caused by Gardnerella vaginalis.

METHODS AND RESULTS

Ten lactobacilli strains from a woman's vaginal discharge were evaluated for their probiotic potential, including growth capacity at different pH levels (pH3.5~4.5), acid production, hydrogen peroxide production capacity, antibacterial activity, susceptibility to antibiotics. Moreover In vitro safety assay hemolytic activity and mutagenicity were investigated for safety assessment. In vivo Caenorhabditis elegans infection model was used to investigate the anti-infection effect of selected isolates. We found that lactobacilli strain P1 showed strong growth ability in low acid environment, produced acid, hydrogen peroxide, had the strongest antibacterial activity against G. vaginalis and was highly susceptible to the tested antibiotics. When assayed for the safety, strain P1 showed no hemolytic activity and had no effect of mutagenicity. Moreover, P1 significantly increased the lifespan of C. elegans against G. vaginalis infection. Combined with the results of 16S rRNA gene sequencing, morphological and physiological characteristic, the strain was identified as Lactiplantibacillus plantarum.

CONCLUSION

Lactiplantibacillus plantarum strain P1 proves to be a promising candidate strain in the treatment of bacterial vaginosis caused by G. vaginalis.

SIGNIFICANCE AND IMPACT OF THE STUDY

Conventional antibiotic therapy for bacterial vaginosis has led to the accelerated process of bacterial drug resistance. Probiotics are potentially an alternative method for bacterial vaginosis therapy. This finding provides bacterial resources for keeping pathogens away from the vagina. We believe L. plantarum P1 may be used as vaginal probiotics and be useful to prevent or treat bacterial vaginitis.

Maternal breast milk microbiota and immune markers in relation to subsequent development of celiac disease in offspring

The potential impact of the composition of maternal breast milk is poorly known in children who develop celiac disease (CD). The aim of our study was to compare the microbiota composition and the concentrations of immune markers in breast milk from mothers whose offspring carried the genetic predisposition to CD, and whether they did or did not develop CD during follow-up for the first 3 years of life. Maternal breast milk samples [CD children (n = 6) and healthy children (n = 18)] were collected 3 months after delivery. Enzyme-linked immunosorbent assays were used to measure TGF-β1, TGF-β2, sIgA, MFG-E8 and sCD14. For microbiota analysis, next generation (Illumina) sequencing, real-time PCR and denaturing gradient gel electrophoresis were used. Phylotype abundance and the Shannon ‘H’ diversity index were significantly higher in breast milk samples in the CD group. There was higher prevalence of the phyla Bacteroidetes and Fusobacteria, the classes Clostridia and Fusobacteriia, and the genera Leptotrichia, Anaerococcus, Sphingomonas, Actynomyces and Akkermansia in the CD group. The immunological markers were differently associated with some Gram-negative bacterial genera and species (Chryseobacterium, Sphingobium) as well as Gram-positive species (Lactobacillusreuteri, Bifidobacteriumanimalis). In conclusion, the microbiota in breast milk from mothers of genetically predisposed offspring who presented CD showed a higher bacterial phylotype abundance and diversity, as well as a different bacterial composition, as compared with the mothers of unaffected offspring. These immune markers showed some associations with bacterial composition and may influence the risk for development of CD beyond early childhood.

Lactobacillus spp. create a protective micro-ecological environment through regulating the core fucosylation of vaginal epithelial cells against cervical cancer

Vaginal dysbiosis often occurs in patients with cervical cancer. The fucosylation of mucosal epithelial cells is closely related to microbial colonization, and play an important role in protecting the vaginal mucosal epithelial cells. However, no reports on the relationship between vaginal dysbiosis and abnormal mucosal epithelial cell fucosylation, and their roles in the occurrence and development of cervical cancer are unavailable. Here we report that core fucosylation levels were significantly lower in the serum, exfoliated cervical cells and tumor tissue of cervical cancer patients. Core fucosyltransferase gene (Fut8) knockout promoted the proliferation and migration of cervical cancer cells. In patients with cervical cancer, the vaginal dysbiosis, and the abundance of Lactobacillus, especially L. iners, was significantly reduced. Meanwhile, the abundance of L.iners was positively correlated with core fucosylation levels. The L. iners metabolite lactate can activate the Wnt pathway through the lactate-Gpr81 complex, which increases the level of core fucosylation in epidermal cells, inhibiting the proliferation and migration of cervical cancer cells, and have application prospects in regulating the vaginal microecology and preventing cervical cancer.

Analysis of the Vaginal Microbiome by Next-Generation Sequencing and Evaluation of its Performance as a Clinical Diagnostic Tool in Vaginitis

Background

Next-generation sequencing (NGS) can detect many more microorganisms of a microbiome than traditional methods. This study aimed to analyze the vaginal microbiomes of Korean women by using NGS that included bacteria and other microorganisms. The NGS results were compared with the results of other assays, and NGS was evaluated for its feasibility for predicting vaginitis.

Methods

In total, 89 vaginal swab specimens were collected. Microscopic examinations of Gram staining and microbiological cultures were conducted on 67 specimens. NGS was performed with GS junior system on all of the vaginal specimens for the 16S rRNA, internal transcribed spacer (ITS), and Tvk genes to detect bacteria, fungi, and Trichomonas vaginalis. In addition, DNA probe assays of the Candida spp., Gardnerella vaginalis, and Trichomonas vaginalis were performed. Various predictors of diversity that were obtained from the NGS data were analyzed to predict vaginitis.

Results

ITS sequences were obtained in most of the specimens (56.2%). The compositions of the intermediate and vaginitis Nugent score groups were similar to each other but differed from the composition of the normal score group. The fraction of the Lactobacillus spp. showed the highest area under the curve value (0.8559) in ROC curve analysis. The NGS and DNA probe assay results showed good agreement (range, 86.2-89.7%).

Conclusions

Fungi as well as bacteria should be considered for the investigation of vaginal microbiome. The intermediate and vaginitis Nugent score groups were indistinguishable in NGS. NGS is a promising diagnostic tool of the vaginal microbiome and vaginitis, although some problems need to be resolved.

Characterisation of probiotic properties in human vaginal lactobacilli strains

BACKGROUND

Vaginal lactobacilli offer protection against recurrent urinary infections, bacterial vaginosis, and vaginal candidiasis.

OBJECTIVE

To characterise the isolated vaginal lactobacilli strains for their probiotic properties and to compare their probiotic potential.

METHODS

The Lactobacillus strains were isolated from vaginal samples by conventional culturing and identified by sequencing of the 16S rDNA fragment. Several functional properties were detected (production of hydrogen peroxide and lactic acid; antagonistic activity against Escherichia coli, Candida albicans, Candida glabrata, and Gardnerella vaginalis; auto-aggregation and adhesiveness) as well as safety (haemolytic activity, antibiotic susceptibility, presence of transferrable resistance genes).

RESULTS

A total of 135 vaginal lactobacilli strains of three species, Lactobacillus crispatus (56%), Lactobacillus jensenii (26%), and Lactobacillus gasseri (18%) were characterised using several functional and safety tests. Most of L. crispatus (89%) and L. jensenii (86%) strains produced H2O2. The best lactic acid producers were L. gasseri (18.2±2.2 mg/ml) compared to L. crispatus (15.6±2.8 mg/ml) and L. jensenii (11.6±2.6 mg/ml) (p<0.0001; p<0.0001, respectively). L. crispatus strains showed significantly higher anti-E. coli activity compared to L. jensenii. L. gasseri strains expressed significantly lower anticandidal activity compared to L. crispatus and L. jensenii (p<0.0001). There was no significant difference between the species in antagonistic activity against G. vaginalis. Nearly a third of the strains were able to auto-aggregate while all the tested strains showed a good ability to adhere to HeLa cells. None of the tested lactobacilli caused haemolysis. Although phenotypical resistance was not found to ampicillin, chloramphenicol, erythromycin, gentamycin, tetracycline, and vancomycin, the erm(B), tet(M), and tet(K) were detected in some strains. All strains were resistant to metronidazole, trimethoprim/sulfamethoxazole, and kanamycin.

CONCLUSIONS

Our study revealed that the production of different antimicrobial metabolites is highly strain-specific and that the metabolites are not correlated with each other. L. crispatus displays better antagonistic activity against E. coli and Candida spp. than L. gasseri and L. jensenii; therefore; a potential probiotic candidate could be found among L. crispatus strains.