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The Journal of Infectious Diseases Sep 2019Bacterial vaginosis (BV) is the most common cause of vaginal discharge. It is associated with an increased risk of preterm delivery, pelvic inflammatory disease, and an... (Review)
Review
Bacterial vaginosis (BV) is the most common cause of vaginal discharge. It is associated with an increased risk of preterm delivery, pelvic inflammatory disease, and an increased risk of acquisition of sexually transmitted infections including human immunodeficiency virus (HIV). The epidemiology of BV supports sexual transmission. However, its etiology remains unknown. At the center of the debate is whether BV is caused by a primary pathogen or a polymicrobial consortium of microorganisms that are sexually transmitted. We previously published a conceptual model hypothesizing that BV is initiated by sexual transmission of Gardnerella vaginalis. Critics of this model have iterated that G. vaginalis is found in virginal women and in sexually active women with a normal vaginal microbiota. In addition, colonization does not always lead to BV. However, recent advances in BV pathogenesis research have determined the existence of 13 different species within the genus Gardnerella. It may be that healthy women are colonized by nonpathogenic Gardnerella species, whereas virulent strains are involved in BV development. Based on our results from a recent prospective study, in addition to an extensive literature review, we present an updated conceptual model for the pathogenesis of BV that centers on the roles of virulent strains of G. vaginalis, as well as Prevotella bivia and Atopobium vaginae.
Topics: Actinobacteria; Female; Gardnerella vaginalis; Humans; Models, Biological; Prevotella; Vagina; Vaginosis, Bacterial; Virulence
PubMed: 31369673
DOI: 10.1093/infdis/jiz342 -
MSphere Jun 2022Bacterial vaginosis (BV) is a dysbiosis of the vaginal microbiome, characterized by low levels of lactobacilli and overgrowth of a diverse group of bacteria, associated...
Bacterial vaginosis (BV) is a dysbiosis of the vaginal microbiome, characterized by low levels of lactobacilli and overgrowth of a diverse group of bacteria, associated with higher risk of a variety of infections, surgical complications, cancer, and preterm birth (PTB). Despite the lack of a consistently applicable etiology, spp. are often associated with both BV and PTB, and has known symbiotic relationships with both Peptostreptococcus anaerobius and Gardnerella vaginalis. Higher risk of PTB can also be predicted by a composite of metabolites linked to bacterial metabolism, but their specific bacterial source remains poorly understood. Here, we characterize diversity of metabolic strategies among BV-associated bacteria and lactobacilli and the symbiotic metabolic relationships between and its partners and show how these influence the availability of metabolites associated with BV/PTB and/or pro- or anti-inflammatory immune responses. We confirm a commensal relationship between and , refining its mechanism, which sustains a substantial increase in acetate production. In contrast, the relationship between and strains, with sequence variant G2, is mutualistic, with outcome dependent on the metabolic strategy of the strain. Taken together, our data show how knowledge of inter- and intraspecies metabolic diversity and the effects of symbiosis may refine our understanding of the mechanism and approach to risk prediction in BV and/or PTB. Bacterial vaginosis (BV) is the most common vaginal infection for women of childbearing age. Although 50% of women with BV do not have any symptoms, it approximately doubles the risk of catching a sexually transmitted infection and also increases the risk of preterm delivery in pregnant women. Recent studies of the vaginal microbiota have suggested that variation between species in the same genus or between strains of the same species explain better or poorer outcomes or at least some coexistence patterns for bacteria of concern. We tested whether such variation is manifested in how vaginal bacteria grow in the laboratory and whether and how they may share nutrients. We then showed that this affected the overall cocktail of chemicals they produce, including bacterially derived chemicals that we have previously shown are linked to a higher risk of preterm delivery.
Topics: Bacteria; Female; Humans; Infant, Newborn; Lactobacillus; Magnetic Resonance Spectroscopy; Pregnancy; Premature Birth; Symbiosis; Vaginosis, Bacterial
PubMed: 35491843
DOI: 10.1128/msphere.00166-22 -
Frontiers in Cellular and Infection... 2020The aetiology of bacterial vaginosis (BV) is not well-understood, and prevalence appears to be higher among women living in sub-Saharan Africa. A recent conceptual model...
The aetiology of bacterial vaginosis (BV) is not well-understood, and prevalence appears to be higher among women living in sub-Saharan Africa. A recent conceptual model implicates three main bacteria ( and ), sexual activity, sialidase activity, and biofilm formation in the pathogenesis of BV. We describe the vaginal microbiota, presence of the putative sialidase A gene of , and biofilm among 386 adolescent girls aged 17 and 18 years in a cross-sectional study in Mwanza, Tanzania around the time of expected sexual debut. Vaginal swabs were collected and tested by quantitative polymerase chain reaction (qPCR) for five species, , the sialidase A gene of , and by fluorescence hybridisation (FISH) for evidence of and biofilm. We conducted a risk factor analysis of and , and explored the associations between biofilm, the presence of the sialidase A gene, and non-optimal vaginal microbiota (Nugent 4-7) and were detected in 69 and 82% of girls, respectively. The prevalence of was higher than previously reported in earlier studies among East and Southern African women. were independently associated with reported penile-vaginal sex. Samples with all three BV-associated bacteria made up the highest proportion of samples with Nugent-BV compared to samples with each bacterium alone or together in pairs. Of the 238 girls with , 63% had the sialidase A gene detected, though there was no difference by reported sexual activity ( = 0.197). Of the 191 girls with results for sialidase A gene and FISH, there was strong evidence for an increased presence of sialidase A gene among those with evidence of a biofilm ( < 0.001). There was a strong association between biofilm and non-optimal microbiota (aOR67.00; 95% CI 26.72-190.53). These results support several of the steps outlined in the conceptual model, although the role of sexual activity is less clear. We recommend longitudinal studies to better understand changes in vaginal microbiota and biofilm formation around the time of sexual debut.
Topics: Actinobacteria; Adolescent; Cross-Sectional Studies; Female; Humans; Microbiota; Prevotella; Sexual Behavior; Tanzania; Vagina
PubMed: 32670894
DOI: 10.3389/fcimb.2020.00305 -
European Journal of Clinical... Aug 2020Diagnosis of bacterial vaginosis (BV) in resource-poor settings relies on semiquantitative microscopy algorithm such as the Nugent score (NS). We evaluated a...
Diagnosis of bacterial vaginosis (BV) in resource-poor settings relies on semiquantitative microscopy algorithm such as the Nugent score (NS). We evaluated a quantitative real-time PCR (qPCR) assay to detect and quantify individual BV-associated bacterial communities. Vaginal swabs from 247 South African women attending an STI clinic were evaluated for BV using NS. We used qPCR to analyze DNA from vaginal swabs for eight BV-associated bacteria, Gardnerella vaginalis (GV), Prevotella bivia (PB), BV-associated bacteria 2 (BVAB2), Megasphaera-1 (M-1), Atopobium vaginae (AV), Lactobacillus crispatus (LC), Lactobacillus jensenii (LJ), and Lactobacillus iners (LI). Sensitivities and specificities were generated for each qPCR assay. Using a ROC analysis, cutoffs were calculated for each bacterial species. A logistic regression model was used to determine the strongest predictors of BV status. Nugent scores indicated 35.6% of patients harbor BV-associated flora (NS 7-10). AV, GV, GAMB (GV + AV + M-1 + BVAB2), and LC + LJ showed the highest AUC, sensitivities, and specificities (listed respectively): AV (0.96; 96%; 93%), GV (0.88; 78%; 79%), GAMB (0.9; 87%; 82%), and LC + LJ (0.84; 82%; 72%) (all p < 0.05). Increased GAMB copies (effect = 0.15, p = 0.01) and decreased LC + LJ copies (effect = - 0.26, p < 0.0001) demonstrated the strongest association with higher BV scoring. Scoring of BV did not differ across our qPCR assay when compared to the commercial BD MAX® and the gold standard Nugent scores. We developed an accurate assay, which has the potential to be used as a BV diagnosis tool that is cost-effective and has the potential to be utilized in a resource limited setting.
Topics: Actinobacteria; Adult; Area Under Curve; DNA, Bacterial; Female; Gardnerella vaginalis; Humans; Lactobacillus; Predictive Value of Tests; Prevotella; Real-Time Polymerase Chain Reaction; Specimen Handling; Vaginosis, Bacterial; Young Adult
PubMed: 32193689
DOI: 10.1007/s10096-020-03862-3 -
A Review on Microbial Species for Forensic Body Fluid Identification in Healthy and Diseased Humans.Current Microbiology Jul 2023Microbial communities present in body fluids can assist in distinguishing between types of body fluids. Metagenomic studies have reported bacterial genera which are core... (Review)
Review
Microbial communities present in body fluids can assist in distinguishing between types of body fluids. Metagenomic studies have reported bacterial genera which are core to specific body fluids and are greatly influenced by geographical location and ethnicity. Bacteria in body fluids could also be due to bacterial infection; hence, it would be worthwhile taking into consideration bacterial species associated with diseases. The present review reports bacterial species characteristic of diseased and healthy body fluids across geographical locations, and bacteria described in forensic studies, with the aim of collating a set of bacteria to serve as the core species-specific markers for forensic body fluid identification. The most widely reported saliva-specific bacterial species are Streptococcus salivarius, Prevotella melaninogenica, Neisseria flavescens, with Fusobacterium nucleatum associated with increased diseased state. Lactobacillus crispatus and Lactobacillus iners are frequently dominant in the vaginal microbiome of healthy women. Atopobium vaginae, Prevotella bivia, and Gardnerella vaginalis are more prevalent in women with bacterial vaginosis. Semen and urine-specific bacteria at species level have not been reported, and menstrual blood bacteria are indistinguishable from vaginal fluid. Targeting more than one bacterial species is recommended for accurate body fluid identification. Although metagenomic sequencing provides information of a broad microbial profile, the specific bacterial species could be used to design biosensors for rapid body fluid identification. Validation of microbial typing methods and its application in identifying body fluids in a mixed sample would allow regular use of microbial profiling in a forensic workflow.
Topics: Humans; Female; Vaginosis, Bacterial; Vagina; Body Fluids; Gardnerella vaginalis; Saliva; Bacteria
PubMed: 37491404
DOI: 10.1007/s00284-023-03413-x -
Cancer Management and Research 2019
PubMed: 31576164
DOI: 10.2147/CMAR.S217362 -
BMJ Case Reports Jun 2022A man in his 20s, with irritation, pain and photophobia in the left eye, was clinically diagnosed with herpes simplex virus nummular keratitis at our institute and...
A man in his 20s, with irritation, pain and photophobia in the left eye, was clinically diagnosed with herpes simplex virus nummular keratitis at our institute and advised topical antivirals and corticosteroids, causing resolution of active infiltrates. The infection recurred after 7 months and the patient did not respond to the previous regimen, so corneal scraping was sent for microbiological evaluation. Gram-positive bacilli grew on culture, which were identified as using VITEK 2 Compact system (bioMérieux, Marcy l'Etoile, France). Gatifloxacin eye drops were added based on antibiotic sensitivity patterns. Infiltrates resolved completely, leaving behind residual scars without any recurrences. This is the first reported case of corneal infection caused by , a bacterium known to reside in the urogenital tract. It caused secondary corneal infection in a case of recurrent herpes simplex keratitis. Species identification systems like VITEK 2 Compact can help identify such rare bacteria with great accuracy.
Topics: Actinobacteria; Anti-Bacterial Agents; Humans; Keratitis, Herpetic; Male; Neoplasm Recurrence, Local
PubMed: 35760507
DOI: 10.1136/bcr-2022-248988 -
Frontiers in Cellular and Infection... 2022Bacterial colonization and associations with bacterial vaginosis (BV) signs and symptoms (Amsel criteria) may vary between populations. We assessed relationships between...
BACKGROUND
Bacterial colonization and associations with bacterial vaginosis (BV) signs and symptoms (Amsel criteria) may vary between populations. We assessed relationships between vaginal bacteria and Amsel criteria among two populations.
METHODS
Kenyan participants from the placebo arm of the Preventing Vaginal Infections (PVI) trial and participants from a Seattle-based cross-sectional BV study were included. Amsel criteria were recorded at study visits, and the vaginal microbiota was characterized using 16S rRNA gene sequencing. Logistic regression models, accounting for repeat visits as appropriate, were fit to evaluate associations between bacterial relative abundance and each Amsel criterion.
RESULTS
Among 84 PVI participants (496 observations) and 220 Seattle participants, the prevalence of amine odor was 25% and 40%, clue cells 16% and 37%, vaginal discharge 10% and 52%, elevated vaginal pH 69% and 67%, and BV 13% and 44%, respectively. BV-associated bacterium 1 (BVAB1) was positively associated with all Amsel criteria in both populations. type 1, (, spp., , and were positively associated with all Amsel criteria in the Seattle study, and all but discharge in the PVI trial.
CONCLUSIONS
Core vaginal bacteria are consistently associated with BV signs and symptoms across two distinct populations of women.
Topics: Bacteria; Cross-Sectional Studies; Female; Humans; Kenya; RNA, Ribosomal, 16S; United States; Vagina; Vaginosis, Bacterial
PubMed: 35310847
DOI: 10.3389/fcimb.2022.801770 -
Microbiology Spectrum Oct 2022Bacterial vaginosis (BV) is the most common cause of abnormal vaginal discharge. BV represents a dysbiosis with the acquisition of a diverse community of anaerobic...
Bacterial vaginosis (BV) is the most common cause of abnormal vaginal discharge. BV represents a dysbiosis with the acquisition of a diverse community of anaerobic bacteria and a reduction in lactobacilli burden. Our objective was to evaluate the Aptima BV assay kit for the diagnosis of BV. From May to August 2019, we enrolled outpatients and inpatients, including nonpregnant women above 18 with vaginosis symptoms, consulting at Nantes University hospital. The Aptima BV assay measures the loads of Gardnerella vaginalis, Atopobium vaginae, and species in relation to overall bacterial load. The Aptima BV assay was compared to Nugent scoring (NS). A total of 456 women were enrolled, and 347 patients met the inclusion criteria with data available for the analysis. NS was used to classify the samples and 144 (41.5%) samples were classified as normal (NS = 0-3), 45 (13%) as BV (NS = 7-10), 38 (11%) presented an intermediate vaginal microbiota (3 < NS < 7), 79 (22.7%) had various bacteria (excluding vaginal flora), 29 (8.3%) had insufficient bacterial density, and 12 (3.5%) had a predominance of yeasts. The Aptima BV kit displayed a sensitivity of 91.1% and specificity of 94.4% with a positive predictive value (PPV) of 83.7% and a negative predictive (NPV) value of 97.1%. The results of this monocentric retrospective study show that Aptima BV kit has a good diagnostic correlation compared to standard of care for dysbiotic diagnosis cases. The possibility exists of the involvement of a new molecular test in the routine algorithm of bacterial vaginosis diagnosis in microbiology laboratories. This manuscript reports on our experience, and we propose an organization combining Nugent scoring and molecular testing, especially for intermediate Nugent scores.
Topics: Humans; Female; Vaginosis, Bacterial; Retrospective Studies; Gardnerella vaginalis; Vagina; Lactobacillus; Bacteria; Hospitals
PubMed: 35980223
DOI: 10.1128/spectrum.01301-22 -
Access Microbiology 2023Skin flora bacteria, such as , are the predominant contaminants of blood products used for transfusion. Platelet concentrates (PCs), a therapeutic product used to treat...
Skin flora bacteria, such as , are the predominant contaminants of blood products used for transfusion. Platelet concentrates (PCs), a therapeutic product used to treat patients with platelet deficiencies, are stored at ambient temperature under agitation, providing ideal conditions for bacterial proliferation. At Canadian Blood Services, PCs are screened for microbial contamination using the automated BACT/ALERT culture system. Positive cultures are processed and contaminating organisms are identified using the VITEK 2 system. Over a period of approximately 2 years, several PC isolates were identified as to a high level of confidence. However, since is associated with bacterial vaginosis and is not a common PC contaminant, a retrospective investigation revealed that in all cases was misidentified as . Our investigation demonstrated that the media type used to grow PC bacterial isolates can have a significant impact on the results obtained on the VITEK 2 system. Furthermore, other identification methods such as matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALD-TOF MS) and PCR amplification of the 16S RNA gene were only partially successful in the identification of . Therefore, our findings support a multiphasic approach when PC isolates are identified as by the VITEK 2 system for proper identification of using macroscopic, microscopic and other biochemical analyses.
PubMed: 37424557
DOI: 10.1099/acmi.0.000539.v3