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Rigmor E Persson - One of the best experts on this subject based on the ideXlab platform.
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tannerella forsythia and pseudomonas aeruginosa in subgingival bacterial samples from parous women
Journal of Periodontology, 2008Co-Authors: Rutger G Persson, Katie Paul, Regula Hirschi, Marianne Weibel, Marilynn Rothen, Rigmor E Persson, Jane HittiAbstract:BACKGROUND: Information on the subgingival microbiota in parous women is limited. The present study assessed 74 bacterial species at periodontal sites. METHODS: Subgingival bacterial plaque was collected from women > or =6 months after delivery. Bacteria were assessed by the checkerboard DNA-DNA hybridization method. Gingivitis was defined as > or =20% of sites with bleeding on probing (BOP), and periodontitis was defined as radiographic evidence of bone loss and probing depths > or =5.0 mm. RESULTS: A total of 197 women (mean age: 29.4 +/- 6.8 years; range: 18 to 46 years) were included in the study. Gingivitis was identified in 82 of 138 subjects without evidence of periodontitis (59.4%). Periodontitis was found in 59 women (32%). Higher bacterial levels in subjects with gingivitis compared to those without evidence of gingivitis were observed for Actinomyces neuii, Bifidobacterium bifidum, Corynebacterium pseudogenitalis, Porphyromonas endodontalis, Prevotella bivia, and Pseudomonas aeruginosa (P or =1 x 10(5) in the sample and periodontitis was 3.1 (95% confidence interval: 1.6 to 5.9; P <0.001). CONCLUSION: In addition to P. gingivalis and T. forsythia, a diverse microbiota, including P. aeruginosa, P. endodontalis, P. bivia, and S. aureus, can be found in subgingival plaque samples from women of child-bearing age with periodontitis.
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tannerella forsythia and pseudomonas aeruginosa in subgingival bacterial samples from parous women
Journal of Periodontology, 2008Co-Authors: Rutger G Persson, Katie Paul, Regula Hirschi, Marianne Weibel, Marilynn Rothen, Rigmor E Persson, Jane HittiAbstract:Background: Information on the subgingival microbiota in parous women is limited. The present study assessed 74 bacterial species at periodontal sites.Methods: Subgingival bacterial plaque was collected from women ≥6 months after delivery. Bacteria were assessed by the checkerboard DNA-DNA hybridization method. Gingivitis was defined as ≥20% of sites with bleeding on probing (BOP), and periodontitis was defined as radiographic evidence of bone loss and probing depths ≥5.0 mm.Results: A total of 197 women (mean age: 29.4 ± 6.8 years; range: 18 to 46 years) were included in the study. Gingivitis was identified in 82 of 138 subjects without evidence of periodontitis (59.4%). Periodontitis was found in 59 women (32%). Higher bacterial levels in subjects with gingivitis compared to those without evidence of gingivitis were observed for Actinomyces neuii, Bifidobacterium bifidum, Corynebacterium pseudogenitalis, Porphyromonas endodontalis, Prevotella bivia, and Pseudomonas aeruginosa (P <0.001 for each). Higher...
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tannerella forsythia and pseudomonas aeruginosa in subgingival bacterial samples from parous women
Journal of Periodontology, 2008Co-Authors: Rutger G Persson, Katie Paul, Regula Hirschi, Marianne Weibel, Marilynn Rothen, Rigmor E Persson, Jane HittiAbstract:BACKGROUND: Information on the subgingival microbiota in parous women is limited. The present study assessed 74 bacterial species at periodontal sites. METHODS: Subgingival bacterial plaque was collected from women > or =6 months after delivery. Bacteria were assessed by the checkerboard DNA-DNA hybridization method. Gingivitis was defined as > or =20% of sites with bleeding on probing (BOP), and periodontitis was defined as radiographic evidence of bone loss and probing depths > or =5.0 mm. RESULTS: A total of 197 women (mean age: 29.4 +/- 6.8 years; range: 18 to 46 years) were included in the study. Gingivitis was identified in 82 of 138 subjects without evidence of periodontitis (59.4%). Periodontitis was found in 59 women (32%). Higher bacterial levels in subjects with gingivitis compared to those without evidence of gingivitis were observed for Actinomyces neuii, Bifidobacterium bifidum, Corynebacterium pseudogenitalis, Porphyromonas endodontalis, Prevotella bivia, and Pseudomonas aeruginosa (P or =1 x 10(5) in the sample and periodontitis was 3.1 (95% confidence interval: 1.6 to 5.9; P <0.001). CONCLUSION: In addition to P. gingivalis and T. forsythia, a diverse microbiota, including P. aeruginosa, P. endodontalis, P. bivia, and S. aureus, can be found in subgingival plaque samples from women of child-bearing age with periodontitis.
Nuno Cerca - One of the best experts on this subject based on the ideXlab platform.
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atopobium vaginae and Prevotella bivia are able to incorporate and influence gene expression in a pre formed gardnerella vaginalis biofilm
Pathogenetics, 2021Co-Authors: Joana Vaz De Castro, A Rosca, Christina A Muzny, Nuno CercaAbstract:Bacterial vaginosis (BV) is associated with a highly structured polymicrobial biofilm on the vaginal epithelium where Gardnerella species presumably play a pivotal role. Gardnerella vaginalis, Atopobium vaginae, and Prevotella bivia are vaginal pathogens detected during the early stages of incident BV. Herein, we aimed to analyze the impact of A. vaginae and P. bivia on a pre-established G. vaginalis biofilm using a novel in vitro triple-species biofilm model. Total biofilm biomass was determined by the crystal violet method. We also discriminated the bacterial populations in the biofilm and in its planktonic fraction by using PNA FISH. We further analyzed the influence of A. vaginae and P. bivia on the expression of key virulence genes of G. vaginalis by quantitative PCR. In our tested conditions, A. vaginae and P. bivia were able to incorporate into pre-established G. vaginalis biofilms but did not induce an increase in total biofilm biomass, when compared with 48-h G. vaginalis biofilms. However, they were able to significantly influence the expression of HMPREF0424_0821, a gene suggested to be associated with biofilm maintenance in G. vaginalis. This study suggests that microbial relationships between co-infecting bacteria can deeply affect the G. vaginalis biofilm, a crucial marker of BV.
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influence of biofilm formation by gardnerella vaginalis and other anaerobes on bacterial vaginosis
The Journal of Infectious Diseases, 2015Co-Authors: Antonio Machado, Nuno CercaAbstract:Bacterial vaginosis (BV) is the worldwide leading vaginal disorder among women of reproductive age. BV is characterized by the replacement of beneficial lactobacilli and the augmentation of anaerobic bacteria. Gardnerella vaginalis is a predominant bacterial species, but BV is also associated with other numerous anaerobes, such as Atopobium vaginae, Mobiluncus mulieris, Prevotella bivia, Fusobacterium nucleatum, and Peptoniphilus species. Currently, the role of G. vaginalis in the etiology of BV remains a matter of controversy. However, it is known that, in patients with BV, a biofilm is usually formed on the vaginal epithelium and that G. vaginalis is typically the predominant species. So, the current paradigm is that the establishment of a biofilm plays a key role in the pathogenesis of BV. This review provides background on the influence of biofilm formation by G. vaginalis and other anaerobes, from the time of their initial adhesion until biofilm formation, in the polymicrobial etiology of BV and discusses the commensal and synergic interactions established between them to understand the phenotypic shift of G. vaginalis biofilm formation to BV establishment.
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interactions between lactobacillus crispatus and bacterial vaginosis bv associated bacterial species in initial attachment and biofilm formation
International Journal of Molecular Sciences, 2013Co-Authors: Antonio Machado, Kimberly Kay Jefferson, Nuno CercaAbstract:Certain anaerobic bacterial species tend to predominate the vaginal flora during bacterial vaginosis (BV), with Gardnerella vaginalis being the most common. However, the exact role of G. vaginalis in BV has not yet been determined. The main goal of this study was to test the hypothesis that G. vaginalis is an early colonizer, paving the way for intermediate (e.g., Fusobacterium nucleatum) and late colonizers (e.g., Prevotella bivia). Theoretically, in order to function as an early colonizer, species would need to be able to adhere to vaginal epithelium, even in the presence of vaginal lactobacilli. Therefore, we quantified adherence of G. vaginalis and other BV-associated bacteria to an inert surface pre-coated with Lactobacillus crispatus using a new Peptide Nucleic Acid (PNA) Fluorescence In Situ Hybridization (FISH) methodology. We found that G. vaginalis had the greatest capacity to adhere in the presence of L. crispatus. Theoretically, an early colonizer would contribute to the adherence and/or growth of additional species, so we next quantified the effect of G. vaginalis biofilms on the adherence and growth of other BV-associated species by quantitative Polymerase Chain Reaction (qPCR) technique. Interestingly, G. vaginalis derived a growth benefit from the addition of a second species, regardless of the species. Conversely, G. vaginalis biofilms enhanced the growth of P. bivia, and to a minor extent of F. nucleatum. These results contribute to our understanding of BV biofilm formation and the progression of the disorder.
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Interactions between Lactobacillus crispatus and Bacterial Vaginosis (BV)-Associated Bacterial Species in Initial Attachment and Biofilm Formation
2013Co-Authors: Antonio Machado, Kimberly Kay Jefferson, Nuno CercaAbstract:Abstract: Certain anaerobic bacterial species tend to predominate the vaginal flora during bacterial vaginosis (BV), with Gardnerella vaginalis being the most common. However, the exact role of G. vaginalis in BV has not yet been determined. The main goal of this study was to test the hypothesis that G. vaginalis is an early colonizer, paving the way for intermediate (e.g., Fusobacterium nucleatum) and late colonizers (e.g., Prevotella bivia). Theoretically, in order to function as an early colonizer, species would need to be able to adhere to vaginal epithelium, even in the presence of vaginal lactobacilli. Therefore, we quantified adherence of G. vaginalis and other BV-associated bacteria to an inert surface pre-coated with Lactobacillus crispatus using a new Peptide Nucleic Acid (PNA) Fluorescence In Situ Hybridization (FISH) methodology. We found that G. vaginalis had the greatest capacity to adhere in the presence of L. crispatus. Theoretically, an early colonizer would contribute to the adherence and/or growth of additional species, so we next quantified the effect of G. vaginalis biofilms on the adherence and growth of other BV-associated species by quantitative Polymerase Chain Reaction (qPCR) technique. Interestingly, G. vaginalis derived a growth benefit from th
Andrew B. Onderdonk - One of the best experts on this subject based on the ideXlab platform.
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characterization of chorioamnionitis in 2nd trimester c section placentas and correlation with microorganism recovery from subamniotic tissues
Pediatric and Developmental Pathology, 2006Co-Authors: Jonathan L Hecht, Andrew B. Onderdonk, Mary L Delaney, Elizabeth N Allred, Harvey J Kliman, Eduardo Zambrano, Solveig M V Pflueger, Chad A Livasy, Ina Bhan, Alan LevitonAbstract:Prolonged exposure to infection appears to influence fetal/neonatal development. We characterize the relationship between histologic patterns of inflammation and microorganism recovery from the placentas of live born infants delivered before the 28th postmenstrual week. The subamniotic parenchyma of 835 placentas delivered by cesarean section were cultured and evaluated for specific histologic patterns of inflammation in a blinded fashion. Cases with prolonged membrane rupture were excluded. Microorganisms were recovered from 41% of placentas. Microorganisms found more frequently in placentas with high-grade chorionic plate inflammation include Actinomyces, Prevotella bivia, Corynebacterium sp., Escherichia coli, Peptostreptococcus magnus, multiple species of Streptococci, and Mycoplasma sp., including Ureaplasma urealyticum. These microorganisms were also associated with fetal vasculitis (neutrophilic infiltration of chorionic plate stem vessels or umbilical cord). Recovery of microorganisms from placental parenchyma is associated with histologic inflammation. The same microorganisms responsible for inciting high-grade chorionic plate inflammation are also most likely to promote fetal inflammation.
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a commensal symbiosis between Prevotella bivia and peptostreptococcus anaerobius involves amino acids potential significance to the pathogenesis of bacterial vaginosis
Fems Immunology and Medical Microbiology, 1998Co-Authors: Vivien Pybus, Andrew B. OnderdonkAbstract:In both batch and continuous culture, Peptostreptococcus anaerobius was able to grow in vaginal defined medium with Prevotella bivia, but not in pure culture. Growth of P. anaerobius was increased by 238% (P<0.001) in peptone-supplemented vaginal defined medium conditioned by prior growth of P. bivia. Analysis of P. bivia culture supernatants showed a net accumulation of amino acids and subsequent growth of P. anaerobius in the conditioned supernatants resulted generally in amino acid utilization. Supplementation of peptone-supplemented vaginal defined medium with amino acids in concentrations similar to those available after prior growth with P. bivia were growth-stimulatory (246%, P=0.006) for P. anaerobius. Increased availability of amino acids by P. bivia is proposed as a mechanism to support the observed in vitro commensal symbiosis between P. bivia and P. anaerobius.
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evidence for a commensal symbiotic relationship between gardnerella vaginalis and Prevotella bivia involving ammonia potential significance for bacterial vaginosis
The Journal of Infectious Diseases, 1997Co-Authors: Vivien Pybus, Andrew B. OnderdonkAbstract:Six strains of Prevotella biviaand 4 of Gardnerella vaginalis were examined for nutrient substrate utilization as part of ongoing studies on the pathogenesis of bacterial vaginosis. Addition of single amino acids to vaginal defined medium (VDM) was stimulatory to the growth of P. bivia but not to G. vaginalis. However, peptides significantly promoted the growth of both organisms. Growth of P. bivia in VDM and VDM supplemented with either amino acids or peptone was accompanied by net ammonia production, while growth of G. vaginalis under the same conditions resulted in net ammonia utilization. Ammonia-enriched supernatants from the growth of P. bivia in peptone supplemented VDM were stimulatory to G. vaginalis growth. However, ammonia-reduced superna tants from G. vaginalis growth in peptone-supplemented VDM had a neutral effect on P. bivia growth. A commensal relationship between P. biviato G. vaginalis is proposed, with ammonia flow as a mechanism to support this hypothesis. Bacterial vaginosis (BV) is the most common vaginal tract infection seen in women of reproductive age in primary health care [1, 2]. Clinical diagnosis of BV is based on the presence of three ofthe following four criteria: an elevated (>4.5) vagi nal pH, release of a fishy odor on addition of 10% KOH to the vaginal fluid, an abnormal discharge that is thin and homog enous, and clue cells in the vaginal fluid [1]. During BV, clini cal signs ofinflammation are not apparent [3, 4]. While BV is a distinct clinical entity, coinfection with other vaginal (Candida albicans or Trichomonas vaginalis) or cervical (Neisseria go norrhoeae, Chlamydia trachomatis, or herpes simplex virus) pathogens can occur [5]. Bacterial vaginosis has a complex microbiology. Lactobacil lus populations, which are usually dominant in healthy women, are replaced by a polymicrobial group of organisms that in cludes Gardnerella vaginalis, anaerobic gram-negative rods such as Prevotella species, Peptostreptococcus species, Myco plasma hominis, Ureaplasma urealyticum, and often Mobilun cus species [6]. Overall, concentrations are 100- and IOOO-foid greater for aerobes and anaerobes, respectively, than levels measured in women without BV [7]. However, the factor(s), either endogenous or exogenous, that initiate the shift in the ecology of the vagina and result in the massive overgrowth of these microbial populations are incompletely understood [5, 6].
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evidence for a commensal symbiotic relationship between gardnerella vaginalis and Prevotella bivia involving ammonia potential significance for bacterial vaginosis
The Journal of Infectious Diseases, 1997Co-Authors: Vivien Pybus, Andrew B. OnderdonkAbstract:Six strains of Prevotella bivia and 4 of Gardnerella vaginalis were examined for nutrient substrate utilization as part of ongoing studies on the pathogenesis of bacterial vaginosis. Addition of single amino acids to vaginal defined medium (VDM) was stimulatory to the growth of P. bivia but not to G. vaginalis. However, peptides significantly promoted the growth of both organisms. Growth of P. bivia in VDM and VDM supplemented with either amino acids or peptone was accompanied by net ammonia production, while growth of G. vaginalis under the same conditions resulted in net ammonia utilization. Ammonia-enriched supernatants from the growth of P. bivia in peptone-supplemented VDM were stimulatory to G. vaginalis growth. However, ammonia-reduced supernatants from G. vaginalis growth in peptone-supplemented VDM had a neutral effect on P. bivia growth. A commensal relationship between P. bivia to G. vaginalis is proposed, with ammonia flow as a mechanism to support this hypothesis.
Fabrice Atassi - One of the best experts on this subject based on the ideXlab platform.
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diverse expression of antimicrobial activities against bacterial vaginosis and urinary tract infection pathogens by cervicovaginal microbiota strains of lactobacillus gasseri and lactobacillus crispatus
Frontiers in Microbiology, 2019Co-Authors: Fabrice Atassi, Diane Pho Viet L Ahn, Vanessa Lievinle MoalAbstract:We aimed to analyze the strain-by-strain expression of a large panel of antimicrobial activities counteracting the virulence mechanisms of bacterial vaginosis-associated Prevotella bivia CI-1 and Gardnerella vaginalis 594, pyelonephritis-associated Escherichia coli CFT073, and recurrent cystitis- and preterm labor-associated IH11128 E. coli by Lactobacillus gasseri and Lactobacillus crispatus clinical strains, and L. gasseri ATCC 9857 and KS 120.1, and L. crispatus CTV-05 strains isolated from the cervicovaginal microbiota of healthy women. All L. gasseri and L. crispatus strains exerted antimicrobial activity by secreted lactic acid, which killed the microbial pathogens by direct contact. Potent bactericidal activity was exerted by a very limited number of resident L. gasseri and L. crispatus strains showing the specific ability to a strain to produce and release antibiotic-like compounds. These compounds eradicated the microbial pathogens pre-associated with the surface of cervix epithelial cells, providing efficient protection of the cells against the deleterious effects triggered by toxin-producing G. vaginalis and uropathogenic E. coli. Furthermore, these compounds crossed the cell membrane to kill the pre-internalized microbial pathogens. In addition, all L. gasseri and L. crispatus cells exhibited another non-strain specific activity which inhibited the association of microbial pathogens with cervix epithelial cells with varying efficiency, partially protecting the cells against lysis and detachment triggered by toxin-producing G. vaginalis and uropathogenic E. coli. Our results provide evidence of strain-level specificity for certain antimicrobial properties among cervicovaginal L. gasseri and L. crispatus strains, indicating that the presence of a particular species in the vaginal microbiota is not sufficient to determine its benefit to the host. A full repertory of antimicrobial properties should be evaluated in choosing vaginal microbiota-associated Lactobacillus isolates for the development of live biotherapeutic strategies.
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lactobacillus strains isolated from the vaginal microbiota of healthy women inhibit Prevotella bivia and gardnerella vaginalis in coculture and cell culture
Fems Immunology and Medical Microbiology, 2006Co-Authors: Fabrice Atassi, Dominique Brassart, Philipp Grob, Federico Graf, Alain L ServinAbstract:The purpose of this study was to investigate how human vaginal isolates of Lactobacillus acidophilus, Lactobacillus jensenii, Lactobacillus gasseri and Lactobacillus crispatus inhibit the vaginosis-associated pathogens Gardnerella vaginalis and Prevotella bivia. Results show that all the strains in coculture condition reduced the viability of G. vaginalis and P. bivia, but with differing degrees of efficacy. The treatment of G. vaginalis- and P. bivia-infected cultured human cervix epithelial HeLa cells with L. gasseri strain KS120.1 culture or cell-free culture supernatant (CFCS) results in the killing of the pathogens that are adhering to the cells. The mechanism of the killing activity is not attributable to low pH and the presence of lactic acid alone, but rather to the presence of hydrogen peroxide and proteolytic enzyme-resistant compound(s) present in the CFCSs. In addition, coculture of G. vaginalis or P. bivia with L. gasseri KS120.1 culture or KS120.1 bacteria results in inhibition of the adhesion of the pathogens onto HeLa cells.
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In vitro antibacterial activity of Lactobacillus helveticus strain KS300 against diarrhoeagenic, uropathogenic and vaginosis-associated bacteria.
Journal of Applied Microbiology, 2006Co-Authors: Fabrice Atassi, Dominique Brassart, Philipp Grob, Federico Graf, Alain ServinAbstract:AIMS: The purpose of this study was to investigate in vitro the antibacterial activity of the Lactobacillus helveticus strain KS300 against vaginosis-associated bacteria including Gardnerella vaginalis and Prevotella bivia, uropathogenic Escherichia coli, and diarrhoeagenic Salmonella enterica serovar Typhimurium. METHODS AND RESULTS: The KS300 strain inhibited the growth of G. vaginalis, P. bivia, S. typhimurium, and pathogenic E. coli. After direct co-culture, data show that the Lactobacillus strain decreased the viability of G. vaginalis, P. bivia, S. typhimurium, and pathogenic E. coli. The adhering KS300 strain inhibited the adhesion of G. vaginalis DSM 4944 and uropathogenic Dr-positive E. coli IH11128 onto HeLa cells. Moreover, the KS300 strain inhibited the internalization of uropathogenic Dr-positive E. coli IH11128 within HeLa cells and S. typhimurium SL1344 within Caco-2/TC7 cells. CONCLUSIONS: The findings demonstrate that L. helveticus strain KS300 is adhesive onto cultured human cells and has antagonistic activities against vaginosis-associated, uropathogenic and diarrhoeagenic pathogens. SIGNIFICANCE AND IMPACT OF THE STUDY: Adhering L. helveticus strain KS300 is a potential probiotic strain displaying a strain-specific array of in vitro antibacterial activities.
Vivien Pybus - One of the best experts on this subject based on the ideXlab platform.
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a commensal symbiosis between Prevotella bivia and peptostreptococcus anaerobius involves amino acids potential significance to the pathogenesis of bacterial vaginosis
Fems Immunology and Medical Microbiology, 1998Co-Authors: Vivien Pybus, Andrew B. OnderdonkAbstract:In both batch and continuous culture, Peptostreptococcus anaerobius was able to grow in vaginal defined medium with Prevotella bivia, but not in pure culture. Growth of P. anaerobius was increased by 238% (P<0.001) in peptone-supplemented vaginal defined medium conditioned by prior growth of P. bivia. Analysis of P. bivia culture supernatants showed a net accumulation of amino acids and subsequent growth of P. anaerobius in the conditioned supernatants resulted generally in amino acid utilization. Supplementation of peptone-supplemented vaginal defined medium with amino acids in concentrations similar to those available after prior growth with P. bivia were growth-stimulatory (246%, P=0.006) for P. anaerobius. Increased availability of amino acids by P. bivia is proposed as a mechanism to support the observed in vitro commensal symbiosis between P. bivia and P. anaerobius.
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evidence for a commensal symbiotic relationship between gardnerella vaginalis and Prevotella bivia involving ammonia potential significance for bacterial vaginosis
The Journal of Infectious Diseases, 1997Co-Authors: Vivien Pybus, Andrew B. OnderdonkAbstract:Six strains of Prevotella biviaand 4 of Gardnerella vaginalis were examined for nutrient substrate utilization as part of ongoing studies on the pathogenesis of bacterial vaginosis. Addition of single amino acids to vaginal defined medium (VDM) was stimulatory to the growth of P. bivia but not to G. vaginalis. However, peptides significantly promoted the growth of both organisms. Growth of P. bivia in VDM and VDM supplemented with either amino acids or peptone was accompanied by net ammonia production, while growth of G. vaginalis under the same conditions resulted in net ammonia utilization. Ammonia-enriched supernatants from the growth of P. bivia in peptone supplemented VDM were stimulatory to G. vaginalis growth. However, ammonia-reduced superna tants from G. vaginalis growth in peptone-supplemented VDM had a neutral effect on P. bivia growth. A commensal relationship between P. biviato G. vaginalis is proposed, with ammonia flow as a mechanism to support this hypothesis. Bacterial vaginosis (BV) is the most common vaginal tract infection seen in women of reproductive age in primary health care [1, 2]. Clinical diagnosis of BV is based on the presence of three ofthe following four criteria: an elevated (>4.5) vagi nal pH, release of a fishy odor on addition of 10% KOH to the vaginal fluid, an abnormal discharge that is thin and homog enous, and clue cells in the vaginal fluid [1]. During BV, clini cal signs ofinflammation are not apparent [3, 4]. While BV is a distinct clinical entity, coinfection with other vaginal (Candida albicans or Trichomonas vaginalis) or cervical (Neisseria go norrhoeae, Chlamydia trachomatis, or herpes simplex virus) pathogens can occur [5]. Bacterial vaginosis has a complex microbiology. Lactobacil lus populations, which are usually dominant in healthy women, are replaced by a polymicrobial group of organisms that in cludes Gardnerella vaginalis, anaerobic gram-negative rods such as Prevotella species, Peptostreptococcus species, Myco plasma hominis, Ureaplasma urealyticum, and often Mobilun cus species [6]. Overall, concentrations are 100- and IOOO-foid greater for aerobes and anaerobes, respectively, than levels measured in women without BV [7]. However, the factor(s), either endogenous or exogenous, that initiate the shift in the ecology of the vagina and result in the massive overgrowth of these microbial populations are incompletely understood [5, 6].
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evidence for a commensal symbiotic relationship between gardnerella vaginalis and Prevotella bivia involving ammonia potential significance for bacterial vaginosis
The Journal of Infectious Diseases, 1997Co-Authors: Vivien Pybus, Andrew B. OnderdonkAbstract:Six strains of Prevotella bivia and 4 of Gardnerella vaginalis were examined for nutrient substrate utilization as part of ongoing studies on the pathogenesis of bacterial vaginosis. Addition of single amino acids to vaginal defined medium (VDM) was stimulatory to the growth of P. bivia but not to G. vaginalis. However, peptides significantly promoted the growth of both organisms. Growth of P. bivia in VDM and VDM supplemented with either amino acids or peptone was accompanied by net ammonia production, while growth of G. vaginalis under the same conditions resulted in net ammonia utilization. Ammonia-enriched supernatants from the growth of P. bivia in peptone-supplemented VDM were stimulatory to G. vaginalis growth. However, ammonia-reduced supernatants from G. vaginalis growth in peptone-supplemented VDM had a neutral effect on P. bivia growth. A commensal relationship between P. bivia to G. vaginalis is proposed, with ammonia flow as a mechanism to support this hypothesis.