The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Mario Vaneechoutte - One of the best experts on this subject based on the ideXlab platform.
-
Gardnerella vaginalis enhances atopobium vaginae viability in an in vitro model
Frontiers in Cellular and Infection Microbiology, 2020Co-Authors: Joana Castro, Mario Vaneechoutte, Piet Cools, Nuno Cerca, A Rosca, Joana Castro, Nuno CercaAbstract:Bacterial vaginosis (BV) is the most common vaginal infection among women of reproductive age. A hallmark of BV is the presence of a highly structured polymicrobial biofilm on the vaginal epithelium, presumably initiated by facultative anaerobes of the genus Gardnerella, which then becomes a scaffold for other species to adhere to. One of the species often found incorporated in Gardnerella mediated biofilms is Atopobium vaginae. Interestingly, A. vaginae is very rarely found without the presence of Gardnerella. However, not much is known regarding the interactions between A. vaginae and Gardnerella species. This study assessed biological interactions between Gardnerella vaginalis and A. vaginae. In our in vitro model, by using specific Gardnerella and A. vaginae Peptide Nucleic Acid (PNA)-Fluorescence In Situ Hybridization (FISH) probes, we confirmed that A. vaginae was able to incorporate a pre-formed G. vaginalis biofilm, accounting for up to 20% of the total number of biofilm cells. However, our findings showed that almost 92% of A. vaginae cells lost viability after 48 h of mono-species planktonic growth, but were able to maintain viability when co-cultured with Gardnerella or after pre-conditioning with cell-free supernatant of Gardnerella cultures. While the in vitro conditions are very different from the in vivo microenvironment, this study contributes to a better understanding of why A. vaginae vaginal colonization rarely occurs in the absence of Gardnerella. Overall, this highlights the importance of microbial interactions between BV-associated bacteria and demands more studies focused on the polymicrobial bacterial communities found in BV.
-
emended description of Gardnerella vaginalis and description of Gardnerella leopoldii sp nov Gardnerella piotii sp nov and Gardnerella swidsinskii sp nov with delineation of 13 genomic species within the genus Gardnerella
International Journal of Systematic and Evolutionary Microbiology, 2019Co-Authors: Mario Vaneechoutte, Alexandr Guschin, Leen Van Simaey, Yannick Gansemans, Filip Van Nieuwerburgh, Piet CoolsAbstract:Whole genome sequence analysis (digital DNA–DNA hybridization and average nucleotide identity) was carried out for 81 sequenced full genomes of the genus Gardnerella , including ten determined in this study, and indicated the existence of 13 genomic species, of which five consist of only one strain and of which only five contain more than four sequenced genomes. Furthermore, a collection of ten Gardnerella strains, representing the emended species G. vaginalis and the newly described species Gardnerella leopoldii, Gardnerella piotii and Gardnerella swidsinskii, was studied. Matrix-assisted laser desorption ionization time-of-flight MS analysis of the protein signatures identified specific peaks that can be used to differentiate these four species. Only strains of G. vaginalis produce β-galactosidase. We emend the description of G. vaginalis (type strain ATCC 14018T=LMG 7832T=CCUG 3717T) and describe the novel species Gardnerella leopoldii sp. nov. (UGent 06.41T=LMG 30814T=CCUG 72425T), Gardnerella piotii sp. nov. (UGent 18.01T=LMG 30818T=CCUG 72427T) and Gardnerella swidsinskii sp. nov. (GS 9838-1T=LMG 30812T=CCUG 72429T).
-
Gardnerella vaginalis enhances Atopobium vaginae viability in vitro
2019Co-Authors: Castro Joana, Mario Vaneechoutte, Piet Cools, Rosca A., Cerca NunoAbstract:Background: Bacterial vaginosis (BV) is a clinical condition characterized by a dramatic shift in the vaginal microflora from the beneficial lactobacilli to a polymicrobial flora, consisting of strictly and facultatively anaerobic bacteria. It is noteworthy that a hallmark of BV is the presence of a highly structured polymicrobial biofilm on the vaginal epithelium, presumably initiated by a facultative anaerobe, Gardnerella vaginalis, which then become a scaffold for other species to adhere. While not much is known about multi- species interactions within BV biofilms, Atopobium vaginae is often associated with G. vaginalis biofilms and is rarely detected without G. vaginalis.This study was supported by the Portuguese Foundation for Science and Technology (FCT) by the funded project PTDC/BIA-MIC/28271/2017, under the scope of COMPETE2020 (POCI-01-0145- FEDER-028271) and by the strategic funding of unit UID/BIO/04469/2019.info:eu-repo/semantics/publishedVersio
-
unravelling the bacterial vaginosis associated biofilm a multiplex Gardnerella vaginalis and atopobium vaginae fluorescence in situ hybridization assay using peptide nucleic acid probes
PLOS ONE, 2015Co-Authors: Liselotte Hardy, Vicky Jespers, Nassira Dahchour, Lambert Mwambarangwe, Viateur Musengamana, Mario Vaneechoutte, Tania CrucittiAbstract:Bacterial vaginosis (BV), a condition defined by increased vaginal discharge without significant inflammation, is characterized by a change in the bacterial composition of the vagina. Lactobacillus spp., associated with a healthy vaginal microbiome, are outnumbered by BV-associated organisms. These bacteria could form a polymicrobial biofilm which allows them to persist in spite of antibiotic treatment. In this study, we examined the presence of Gardnerella vaginalis and Atopobium vaginae in vaginal biofilms using Peptide Nucleic Acid (PNA) probes targeting these bacteria. For this purpose, we developed three new PNA probes for A. vaginae. The most specific A. vaginae probe, AtoITM1, was selected and then used in an assay with two existing probes, Gard162 and BacUni-1, to evaluate multiplex FISH on clinical samples. Using quantitative polymerase chain reaction (qPCR) as the gold standard, we demonstrated a sensitivity of 66.7% (95% confidence interval: 54.5% - 77.1%) and a specificity of 89.4% (95% confidence interval: 76.1% - 96%) of the new AtoITM1 probe. FISH enabled us to show the presence of a polymicrobial biofilm in bacterial vaginosis, in which Atopobium vaginae is part of a Gardnerella vaginalis-dominated biofilm. We showed that the presence of this biofilm is associated with high bacterial loads of A. vaginae and G. vaginalis.
-
Gardnerella biofilm involves females and males and is transmitted sexually
Gynecologic and Obstetric Investigation, 2010Co-Authors: Alexander Swidsinski, Mario Vaneechoutte, Hans Verstraelen, Vera Loeningbaucke, Johannes Schilling, Sonja Swidsinski, Yvonne Doerffel, Vesna Lemm, Werner MendlingAbstract:Objective: To study the incidence and distribution of adherent Gardnerella vaginalis. Methods: Bacteria adherent to desquamated epithelial cells in the urine were detected using fluorescence in situ hybridization (FISH). Urine from patients with bacterial vaginosis (BV, n = 20), their partners (n = 10) and different control populations (n = 344) including pregnant women and their partners, randomly selected populations of hospitalized man, women and children as also healthy controls was investigated. Results:Gardnerella was found in two different forms: cohesive and dispersed. In the cohesive form, Gardnerella were attached to the epithelial cells in groups of highly concentrated bacteria. In the dispersed form, solitary Gardnerella were intermixed with other bacterial groups. Cohesive Gardnerella was present in all patients with proven BV and their partners, in 7% of men and 13% of women hospitalized for reasons other than BV, in 16% of pregnant women and 12% of their male partners, and in none of the healthy laboratory staff or children. In sexual partners, occurrence of cohesive Gardnerella was clearly linked. Dispersed Gardnerella were found in 10–18% of randomly selected females, 3–4% of males and 10% of children and not sexually linked. In daily longitudinal investigations over 4 weeks no transition between cohesive and dispersed Gardnerella and vice versa was observed. Transmission of a cohesive Gardnerella strain could be followed retrospectively over 15 years using molecular genetic methods. Conclusions: Cohesive Gardnerella biofilm is a distinct, clearly definable entity which involves both genders and is sexually transmitted. The correct name distinguishing it from symptom-defined conditions like BV should be gardnerellosis and for the bacterium Gardnerella genitalis.
Janet E Hill - One of the best experts on this subject based on the ideXlab platform.
-
A Generalist Lifestyle Allows Rare Gardnerella spp. to Persist at Low Levels in the Vaginal Microbiome
Microbial Ecology, 2020Co-Authors: Salahuddin Khan, Sarah J. Vancuren, Janet E HillAbstract:Gardnerella spp. are considered a hallmark of bacterial vaginosis, a dysbiosis of the vaginal microbiome. There are four cpn60 sequence-based subgroups within the genus (A, B, C and D), and thirteen genome species have been defined recently. Gardnerella spp. co-occur in the vaginal microbiome with varying abundance, and these patterns are shaped by a resource-dependent, exploitative competition, which affects the growth rate of subgroups A, B and C negatively. The growth rate of rarely abundant subgroup D, however, increases with the increasing number of competitors, negatively affecting the growth rate of others. We hypothesized that a nutritional generalist lifestyle and minimal niche overlap with the other more abundant Gardnerella spp. facilitate the maintenance of subgroup D in the vaginal microbiome through negative frequency-dependent selection. Using 40 whole-genome sequences from isolates representing all four subgroups, we found that they could be distinguished based on the content of their predicted proteomes. Proteins associated with carbohydrate and amino acid uptake and metabolism were significant contributors to the separation of subgroups. Subgroup D isolates had significantly more of their proteins assigned to amino acid metabolism than the other subgroups. Subgroup D isolates were also significantly different from others in terms of number and type of carbon sources utilized in a phenotypic assay, while the other three could not be distinguished. Overall, the results suggest that a generalist lifestyle and lack of niche overlap with other Gardnerella spp. leads to subgroup D being favoured by negative frequency-dependent selection in the vaginal microbiome.
-
a generalist lifestyle allows rare Gardnerella spp to persist at low levels in the vaginal microbiome
bioRxiv, 2020Co-Authors: Salahuddin Khan, Sarah J. Vancuren, Janet E HillAbstract:Gardnerella spp. are considered a hallmark of bacterial vaginosis, a dysbiosis of the vaginal microbiome. There are four cpn60 sequence-based subgroups within the genus (A, B, C, and D), and thirteen genome species have been defined recently. Gardnerella spp. co-occur in the vaginal microbiome with varying abundance, and these patterns are shaped by a resource-dependent, exploitative competition, which affects the growth rate of subgroup A, B, and C negatively. The growth rate of rarely abundant subgroup D, however, increases with the increasing number of competitors, negatively affecting the growth rate of others. We hypothesized that a nutritional generalist lifestyle and minimal niche overlap with the other, more abundant Gardnerella spp. facilitate the maintenance of subgroup D in the vaginal microbiome through negative-frequency dependent selection. Using 40 whole genome sequences from isolates representing all four subgroups we found that they could be distinguished based on content of their predicted proteomes. Proteins associated with carbohydrate and amino acid uptake and metabolism were significant contributors to the separation of subgroups. Subgroup D isolates had significantly more of their proteins assigned to amino acid metabolism than the other subgroups. Subgroup D isolates were also significantly different from others in terms of number and type of carbon sources utilized in a phenotypic assay, while the other three could not be distinguished. Overall, the results suggest that a generalist lifestyle and lack of niche overlap with other Gardnerella spp. leads to subgroup D being favoured by negative-frequency dependent selection in the vaginal microbiome.
-
resolution and cooccurrence patterns of Gardnerella leopoldii g swidsinskii g piotii and g vaginalis within the vaginal microbiome
Infection and Immunity, 2019Co-Authors: Janet E Hill, Arianne AlbertAbstract:Gardnerella vaginalis is a hallmark of vaginal dysbiosis, but it is found in the microbiomes of women with and without vaginal symptoms and those who do not have microbiologically defined dysbiosis. G. vaginalis encompasses diverse taxa differing in attributes that are potentially important for virulence, and there is evidence that clades or subgroups within the species are differentially associated with clinical outcomes. The G. vaginalis species description was recently emended, and three new species within the genus were defined (G. leopoldii, G. swidsinskii, and G. piotii). 16S rRNA sequences for the four Gardnerella species are all >98.5% identical, and no signature sequences differentiate them. We demonstrated that Gardnerella species can be resolved using partial chaperonin 60 (cpn60) sequences, with pairwise percent identities of 87.1 to 97.8% among the type strains. Pairwise cooccurrence patterns of Gardnerella spp. in the vaginal microbiomes of 413 reproductive aged Canadian women were investigated, and several significant cooccurrences of species were identified. Abundance of G. vaginalis and G. swidsinskii was associated with vaginal symptoms of abnormal odor and discharge. cpn60 barcode sequencing can provide a rapid assessment of the relative abundance of Gardnerella spp. in microbiome samples, providing a powerful method of elucidating associations between these diverse organisms and clinical outcomes. Researchers should consider using cpn60 instead of 16S RNA for better resolution of these important organisms.
-
competition among Gardnerella subgroups from the human vaginal microbiome
Frontiers in Cellular and Infection Microbiology, 2019Co-Authors: Salahuddin Khan, Maarten J Voordouw, Janet E HillAbstract:Gardnerella spp. are hallmarks of bacterial vaginosis, a clinically significant dysbiosis of the vaginal microbiome. Gardnerella has four subgroups (A, B, C and D) based on cpn60 sequences. Multiple subgroups are often detected in individual women, and interactions between these subgroups are expected to influence their population dynamics and associated signs and symptoms of bacterial vaginosis. In the present study, contact-independent and contact-dependent interactions between the four Gardnerella subgroups were investigated in vitro. The cell free supernatants of mono- and co-cultures had no effect on growth rates of the Gardnerella subgroups suggesting that there are no contact-independent interactions (and no contest competition). For contact-dependent interactions, mixed communities of 2, 3 or 4 subgroups were created and the initial (0 h) and final population sizes (48 h) were quantified using subgroup-specific PCR. Compared to the null hypothesis of additive interactions, most (69.3%) of the mixed communities exhibited competition (p < 0.0001). Competition reduced the growth rates of subgroups A, B and C. In contrast, the growth rate of subgroup D increased in the presence of the other subgroups (p < 0.0001). All subgroups were able to form biofilm alone and in mixed communities. Our study suggests that there is scramble competition among Gardnerella subgroups, which likely contributes to the observed distributions of Gardnerella spp. in vaginal microbiomes and the formation of the multispecies biofilms characteristic of bacterial vaginosis.
-
resolution and cooccurrence patterns of Gardnerella leopoldii g swidsinskii g piotii and g vaginalis within the vaginal microbiome
Infection and Immunity, 2019Co-Authors: Janet E Hill, Arianne AlbertAbstract:BackgroundGardnerella vaginalis is a hallmark of vaginal dysbiosis, but is found in the microbiomes of women with and without vaginal symptoms, and those who do not have microbiologically-defined dysbiosis. G. vaginalis encompasses diverse taxa differing in attributes that are potentially important for virulence, and there is evidence that ‘clades’ or ‘subgroups’ within the species are differentially associated with clinical outcomes. The G. vaginalis species description was recently emended, and three new species within the genus were defined (leopoldii, swidsinskii, piotii). 16S rRNA sequences for the four Gardnerella species are all > 98.5% identical and no signature sequences differentiate them. Results We demonstrated that Gardnerella species can be resolved using partial chaperonin-60 (cpn60) sequences, with pairwise percent identities of 87.1-97.8% among the type strains. Pairwise co-occurrence patterns of Gardnerella spp. in the vaginal microbiomes of 413 reproductive aged Canadian women were investigated, and several significant co-occurrences of species were identified. Abundance of G. vaginalis, and G. swidsinskii was associated with vaginal symptoms of abnormal odour and discharge. Conclusions cpn60 barcode sequencing can provide a rapid assessment of the relative abundance of Gardnerella spp. in microbiome samples, providing a powerful method of elucidating associations between these diverse organisms and clinical outcomes. Researchers should consider using cpn60 instead of 16S RNA for better resolution of these important organisms.
Nuno Cerca - One of the best experts on this subject based on the ideXlab platform.
-
Gardnerella vaginalis enhances atopobium vaginae viability in an in vitro model
Frontiers in Cellular and Infection Microbiology, 2020Co-Authors: Joana Castro, Mario Vaneechoutte, Piet Cools, Nuno Cerca, A Rosca, Joana Castro, Nuno CercaAbstract:Bacterial vaginosis (BV) is the most common vaginal infection among women of reproductive age. A hallmark of BV is the presence of a highly structured polymicrobial biofilm on the vaginal epithelium, presumably initiated by facultative anaerobes of the genus Gardnerella, which then becomes a scaffold for other species to adhere to. One of the species often found incorporated in Gardnerella mediated biofilms is Atopobium vaginae. Interestingly, A. vaginae is very rarely found without the presence of Gardnerella. However, not much is known regarding the interactions between A. vaginae and Gardnerella species. This study assessed biological interactions between Gardnerella vaginalis and A. vaginae. In our in vitro model, by using specific Gardnerella and A. vaginae Peptide Nucleic Acid (PNA)-Fluorescence In Situ Hybridization (FISH) probes, we confirmed that A. vaginae was able to incorporate a pre-formed G. vaginalis biofilm, accounting for up to 20% of the total number of biofilm cells. However, our findings showed that almost 92% of A. vaginae cells lost viability after 48 h of mono-species planktonic growth, but were able to maintain viability when co-cultured with Gardnerella or after pre-conditioning with cell-free supernatant of Gardnerella cultures. While the in vitro conditions are very different from the in vivo microenvironment, this study contributes to a better understanding of why A. vaginae vaginal colonization rarely occurs in the absence of Gardnerella. Overall, this highlights the importance of microbial interactions between BV-associated bacteria and demands more studies focused on the polymicrobial bacterial communities found in BV.
-
genetic heterogeneity and taxonomic diversity among Gardnerella species
Trends in Microbiology, 2020Co-Authors: Joana Castro, Kimberly K Jefferson, Nuno CercaAbstract:Gardnerella vaginalis has been considered a pivotal player in the progression of bacterial vaginosis (BV), a condition associated with serious health complications. However, G. vaginalis is also commonly found in asymptomatic or BV-negative women. This has generated interest in the question of whether genetic differences among isolates might distinguish pathogenic from commensal isolates. G. vaginalis was the only recognized species in its genus for four decades, but recently an emended description of G. vaginalis and descriptions of three new species – Gardnerella leopoldii, Gardnerella piotii, and Gardnerella swidsinskii – have been proposed. This review provides background on the heterogeneity and diversity within the genus Gardnerella, highlighting the main features that distinguish species and clades, and how these features may impact BV development.
-
lactobacillus crispatus represses vaginolysin expression by bv associated Gardnerella vaginalis and reduces cell cytotoxicity
Anaerobe, 2018Co-Authors: Joana Castro, Ana Paula Loucao Martins, Maria Elisa Rodrigues, Nuno CercaAbstract:Abstract Using a chemically-defined medium simulating genital tract secretions, we have shown that pre-adhering Lactobacillus crispatus to Hela epithelial cells reduced cytotoxicity caused by Gardnerella vaginalis. This effect was associated to the expression of vaginolysin and was specific to L. crispatus interference, as other vaginal facultative anaerobes had no protective effect.
Amanda L Lewis - One of the best experts on this subject based on the ideXlab platform.
-
Gardnerella vaginalis promotes group b streptococcus vaginal colonization enabling ascending uteroplacental infection in pregnant mice
American Journal of Obstetrics and Gynecology, 2021Co-Authors: Nicole M Gilbert, Lynne Foster, Bin Cao, Yin Yin, Indira U Mysorekar, Amanda L LewisAbstract:Background Group B Streptococcus is a common vaginal bacterium and the leading cause of invasive fetoplacental infections. Group B Streptococcus in the vagina can invade through the cervix to cause ascending uteroplacental infections or can be transmitted to the neonate during vaginal delivery. Some studies have found that women with a “dysbiotic” polymicrobial or Lactobacillus-depleted vaginal microbiota are more likely to harbor group B Streptococcus. Gardnerella vaginalis is often the most abundant bacteria in the vaginas of women with dysbiosis, while being detected at lower levels in most other women, and has been linked with several adverse pregnancy outcomes. Mouse models of group B Streptococcus and Gardnerella vaginalis colonization have been reported but, to the best of our knowledge, the two have not been studied together. The overarching idea driving this study is that certain members of the dysbiotic vaginal microbiota, such as Gardnerella vaginalis, may directly contribute to the increased rate of group B Streptococcus vaginal colonization observed in women with vaginal dysbiosis. Objective We used a mouse model to test the hypothesis that vaginal exposure to Gardnerella vaginalis may facilitate colonization and/or invasive infection of the upper reproductive tract by group B Streptococcus during pregnancy. Study Design Timed-pregnant mice were generated using an allogeneic mating strategy with BALB/c males and C57Bl/6 females. Dams were vaginally inoculated at gestational day 14 with group B Streptococcus alone (using a 10-fold lower dose than previously reported models) or coinoculated with group B Streptococcus and Gardnerella vaginalis. Bacterial titers were enumerated in vaginal, uterine horn, and placental tissues at gestational day 17. The presence (Fisher exact tests) and levels (Mann-Whitney U tests) of bacterial titers were compared between mono- and coinoculated dams in each compartment. Relative risks were calculated for outcomes that occurred in both groups. Tissue samples were also examined for evidence of pathophysiology. Results Inoculation of pregnant mice with 107 group B Streptococcus alone did not result in vaginal colonization or ascending infection. In contrast, coinoculation of group B Streptococcus with Gardnerella vaginalis in pregnant mice resulted in a 10-fold higher risk of group B Streptococcus vaginal colonization (relative risk, 10.31; 95% confidence interval, 2.710–59.04; P=.0006 [Fisher exact test]). Ascending group B Streptococcus infection of the uterus and placenta occurred in approximately 40% of coinoculated animals, whereas none of those receiving group B Streptococcus alone developed uterine or placental infections. Immunofluorescence microscopy revealed group B Streptococcus in both the maternal and fetal sides of the placenta. Histologic inflammation and increased proinflammatory cytokines were evident in the setting of group B Streptococcus placental infection. Interestingly, placentas from dams exposed to group B Streptococcus and Gardnerella vaginalis, but without recoverable vaginal or placental bacteria, displayed distinct histopathologic features and cytokine signatures. Conclusion These data suggest that Gardnerella vaginalis vaginal exposure can promote group B Streptococcus vaginal colonization, resulting in a greater likelihood of invasive perinatal group B Streptococcus infections. These findings suggest that future clinical studies should examine whether the presence of Gardnerella vaginalis is a risk factor for group B Streptococcus vaginal colonization in women. Because Gardnerella vaginalis can also be present in women without bacterial vaginosis, these findings may be relevant both inside and outside of the context of vaginal dysbiosis.
-
vaginal sialoglycan foraging by Gardnerella vaginalis mucus barriers as a meal for unwelcome guests
Glycobiology, 2021Co-Authors: Kavita Agarwal, Amanda L LewisAbstract:Bacterial vaginosis (BV) is a condition of the vaginal microbiome in which there are few lactobacilli and abundant anaerobic bacteria. Members of the genus Gardnerella are often one of the most abundant bacteria in BV. BV is associated with a wide variety of poor health outcomes for women. It has been recognized since the 1980s that women with BV have detectable and sometimes markedly elevated levels of sialidase activity in vaginal fluids and that bacteria associated with this condition produce this activity in culture. Mounting evidence collected using diverse methodologies points to the conclusion that BV is associated with a reduction in intact sialoglycans in cervico-vaginal secretions. Here we review evidence for the contributions of vaginal bacteria, especially Gardnerella, in the processes of mucosal sialoglycan degradation, uptake, metabolism, and depletion. Our understanding of the impacts of vaginal sialoglycan degradation is still limited. However, the potential implications of sialic acid depletion are discussed in light of our current understanding of the roles played by sialoglycans in vaginal physiology.
-
Gardnerella vaginalis as a cause of bacterial vaginosis appraisal of the evidence from in vivo models
Frontiers in Cellular and Infection Microbiology, 2020Co-Authors: Sydney Morrill, Nicole M Gilbert, Amanda L LewisAbstract:: Koch's postulates dictate the use of experimental models to illustrate features of human disease and provide evidence for a singular organism as the cause. The underlying cause(s) of bacterial vaginosis (BV) has been debated in the literature for over half a century. In 1955, it was first reported that a bacterium now known as Gardnerella vaginalis may be the cause of a condition (BV) resulting in higher vaginal pH, thin discharge, a fishy odor, and the presence of epithelial cells covered in bacteria. Here we review contemporary and historical studies on BV with a focus on reports of experimental infections in human or animal models using Gardnerella vaginalis. We evaluate experimental evidence for the hypothesis that G. vaginalis is sufficient to trigger clinical features of BV or relevant health complications associated with the condition. Additionally, we evaluate in vivo models of co-infection employing G. vaginalis together with other bacterial species to investigate evidence for the hypothesis that G. vaginalis may encourage colonization or virulence of other potential pathogens. Together, these studies paint a complex picture in which G. vaginalis has both direct and indirect roles in the features, health complications, and co-infections associated with BV. We briefly review the current taxonomic landscape and genetic diversity pertinent to Gardnerella and note the limitations of sequence-based studies using different marker genes and priming sites. Although much more study is needed to refine our understanding of how BV develops and persists within the human host, applications of the experimental aspects of Koch's postulates have provided an important glimpse into some of the causal relationships that may govern this condition in vivo.
-
Gardnerella vaginalis is a covert pathogen in the bladder.
2019Co-Authors: Nicole M Gilbert, Amanda L LewisAbstract:(Left panel) A schematic representation of Escherichia coli reservoirs, which become established within bladder epithelial cells during infection in mice. (Right panel) Schematic illustration of what happens when the bladder tissue is exposed to Gardnerella vaginalis, namely, that epithelial cells are exfoliated and E. coli emerges from the epithelium to cause another UTI. Host neutrophils enter the tissue only upon E. coli emergence, illustrating the concept that E. coli is “caught red-handed” whereas G. vaginalis is no longer detectable at the time of a recurrent UTI. UTI, urinary tract infection.
-
genome sequences of 15 Gardnerella vaginalis strains isolated from the vaginas of women with and without bacterial vaginosis
Genome Announcements, 2016Co-Authors: Lloyd S Robinson, Justin Perry, Aye Wollam, Warren G Lewis, Erica Sodergren, George M Weinstock, Amanda L LewisAbstract:ABSTRACT Gardnerella vaginalis is a predominant species in bacterial vaginosis, a dysbiosis of the vagina that is associated with adverse health outcomes, including preterm birth. Here, we present the draft genome sequences of 15 Gardnerella vaginalis strains (now available through BEI Resources) isolated from women with and without bacterial vaginosis.
Haywood L Brown - One of the best experts on this subject based on the ideXlab platform.
-
clinical evaluation of affirm vpiii in the detection and identification of trichomonas vaginalis Gardnerella vaginalis and candida species in vaginitis vaginosis
Infectious Diseases in Obstetrics & Gynecology, 2004Co-Authors: Haywood L Brown, Deanna D Fuller, Thomas E Davis, Lori T Jasper, Justin D WrightAbstract:collection tube for Affirm VPIII testing based on previously demonstrated methods. Results: The Affirm assay was significantly more likely to identify Gardnerella and Candida than wet mount. 190 (45%) were positive for Gardnerella by Affirm compared to 58 (14%) by wet mount; 45 (11%) were positive for Candida by Affirm compared to 31 (7%) by wet mount; and 30 (7%) were positive for Trichomonas by Affirm compared to 23 (5%) by wet mount. Symptomatic women were significantly more likely to be positive by Affirm only (23% vs. 10%), wet mount only (3% vs. 2%) or Affirm and wet mount (15% vs. 1%). Asymptomatic women were significantly more likely to be negative for Affirm and wet mount (43% vs. 5%). Conclusions: The Affirm VPIII test is a more sensitive diagnostic test for detection and identification of symptomatic vaginitis/vaginosis than conventional clinical examination and wet mount testing.
-
evaluation of the affirm ambient temperature transport system for the detection and identification of trichomonas vaginalis Gardnerella vaginalis and candida species from vaginal fluid specimens
Journal of Clinical Microbiology, 2001Co-Authors: Haywood L Brown, Jane R. Schwebke, Deanna D Fuller, Thomas E Davis, Sharon L HillierAbstract:The objective of this study was to measure the performance of the Affirm Ambient Temperature Transport System (ATTS) over time and to estimate the length of time the system can preserve a vaginal specimen containing the three common organisms causing vaginitis: Trichomonas vaginalis, Candida species, and Gardnerella vaginalis (one of the causative agents of bacterial vaginosis). Women with symptoms of vaginitis presenting to one of three clinical centers were evaluated over a 4- to 8-week period. Four simultaneously obtained swabs were collected and tested by the Affirm VPIII assay at time zero with and without a preservative reagent, at 24 h with reagent, and at either 48 or 72 h with reagent. For each of the three organisms, Trichomonas, Gardnerella, and Candida, positivity at each time point was evaluated and compared to that at reference time zero with and without the ATTS. A total of 940 specimens were obtained from the three clinical sites. Eight hundred three were positive for one or more of the three organisms. Gardnerella had the highest overall positive rate (62%), followed by Candida with 18% and Trichomonas at 9%. The percent sensitivity versus control for Trichomonas ranged from 100% at time zero with and without reagent to 91% by 72 h. Gardnerella and Candida sensitivity remained at 100% for each time period. The Affirm VPIII ATTS system performed within 10% of the control swab (no transport reagent) at all four time points (0, 24, 48, and 72 h) for Trichomonas, Gardnerella, and Candida.
