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Friberg M, Woeller K, Iberi V, Mancheno PP, Riedeman J, Bohman L, Davis CC. Development of in vitro methods to model the impact of vaginal lactobacilli on Staphylococcus aureus biofilm formation on menstrual cups as well as validation of recommended cleaning directions. FRONTIERS IN REPRODUCTIVE HEALTH 2023; 5:1162746. [PMID: 37671283 PMCID: PMC10475951 DOI: 10.3389/frph.2023.1162746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 07/25/2023] [Indexed: 09/07/2023] Open
Abstract
Introduction Menstrual cups (MC) are a reusable feminine hygiene product. A recent publication suggested that Staphylococcus aureus (S. aureus) biofilms can form on MCs which may lead to increased risk of menstrual Toxic Shock Syndrome (mTSS). Additionally, there is concern that buildup of residual menses may contribute to microbial growth and biofilm formation further increasing mTSS risk. Quantitative and qualitative analysis of in vitro tests were utilized to determine if S. aureus biofilm could form on MC in the presence of the keystone species Lactobacillus after 12 h of incubation. The methodology was based on a modification of an anaerobic in vitro method that harnesses the keystone species hypothesis by including a representative of vaginal lactic acid bacteria. Methods MCs were incubated anaerobically for 12 h in Vaginal Defined Media (VDM) with the two morphologically distinct bacteria, Lactobacillus gasseri (L. gasseri) and S. aureus. Colony Forming Units (CFU) for each organism from the VDM broth and sonicated MC were estimated. In addition, a separate experiment was conducted where S. aureus was grown for 12 h in the absence of L. gasseri. Qualitative analysis for biofilm formation utilized micro-CT (µ-CT) and cryogenic scanning electron microscopy (Cryo-SEM). Results Samples collected from the media control had expected growth of both organisms after 12 h of incubation. Samples collected from VDM broth were similar to media control at the end of the 12-h study. Total S. aureus cell density on MC following sonication/rinsing was minimal. Results when using a monoculture of S. aureus demonstrated that there was a significant growth of the organism in the media control and broth as well as the sonicated cups indicating that the presence of L. gasseri was important for controlling growth and adherence of S. aureus. Few rod-shaped bacteria (L. gasseri) and cocci (S. aureus) could be identified on the MCs when grown in a dual species culture inoculum and no biofilm was noted via µ-CT and cryo-SEM. Additionally, efforts to model and understand the validity of the current labeled recommendations for MC cleaning in-between uses are supported. Discussion The data support continued safe use of the Tampax® cup when used and maintained as recommended.
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Affiliation(s)
- Maria Friberg
- Baby, Feminine and Family Care Microbiology, The Procter & Gamble Company, Mason, OH, United States
| | - Kara Woeller
- Baby, Feminine and Family Care, Global Product Stewardship, The Procter & Gamble Company, Cincinnati, OH, United States
| | - Vighter Iberi
- Corporate Functions Analytical, The Procter & Gamble Company, Mason, OH, United States
| | | | - James Riedeman
- Baby, Family and Feminine Care Analytical Chemistry, The Procter & Gamble Company, Cincinnati, OH, United States
| | - Lisa Bohman
- Data Modeling and Sciences, The Procter & Gamble Company, Mason, OH, United States
| | - Catherine C. Davis
- Department of Medical Microbiology and Immunology, School of Medicine, Creighton University, Omaha, NE, United States
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O'Hanlon DE, Come RA, Moench TR. Vaginal pH measured in vivo: lactobacilli determine pH and lactic acid concentration. BMC Microbiol 2019; 19:13. [PMID: 30642259 PMCID: PMC6332693 DOI: 10.1186/s12866-019-1388-8] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 01/04/2019] [Indexed: 12/04/2022] Open
Abstract
Background Lactic acid (protonated lactate) has broad antimicrobial activity. Vaginal lactobacilli produce lactic acid, and are known to confer protection against reproductive tract infections when they are predominant in the vaginal microbiota. Using novel ex vivo methods, we showed that cervicovaginal fluid (CVF) from women with a predominantly lactobacilli-morphotype microbiota contains significantly more lactic acid than previously thought, sufficient to inactivate reproductive tract pathogens. Here, we measured vaginal pH in vivo in 20 women with a predominantly lactobacilli-morphotype (low Nugent score) microbiota. We also investigated the in vitro production of protons (as hydrogen ions) and lactate by vaginal lactobacilli. Results The average vaginal pH in these women was 3.80 ± 0.20, and the average lactate concentration was 0.79% ± 0.22% w/v, with pH and lactate concentration tightly correlated for each sample. In vitro, lactobacilli cultured from these CVF samples reached an average pH of 3.92 ± 0.22, but the average lactate concentration was only 0.14% ± 0.06% w/v, approximately five-fold less than in the corresponding CVF samples. When the pH of the cultures was raised, lactate and hydrogen ion production resumed, indicating that production of lactate and hydrogen ions by vaginal lactobacilli is limited primarily by their sensitivity to hydrogen ion concentration (low pH) not lactate concentration. Conclusions Some vaginal lactobacilli cultures have a lower limiting pH than others, and limiting pHs in vitro showed good correlation with pHs measured in vivo. The limiting pH of the lactobacilli predominant in a woman’s vaginal microbiota seems critical in determining the concentration of antimicrobial lactic acid protecting her.
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Affiliation(s)
- Deirdre Elizabeth O'Hanlon
- Institute for Genomic Sciences, University of Maryland School of Medicine, 801 West Baltimore Street, Baltimore, MD, USA.
| | - Richard A Come
- Thomas C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, Maryland, USA
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Tachedjian G, O’Hanlon DE, Ravel J. The implausible "in vivo" role of hydrogen peroxide as an antimicrobial factor produced by vaginal microbiota. MICROBIOME 2018; 6:29. [PMID: 29409534 PMCID: PMC5801833 DOI: 10.1186/s40168-018-0418-3] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 01/30/2018] [Indexed: 05/29/2023]
Abstract
In the cervicovaginal environment, the production of hydrogen peroxide (H2O2) by vaginal Lactobacillus spp. is often mentioned as a critical factor to the in vivo vaginal microbiota antimicrobial properties. We present several lines of evidence that support the implausibility of H2O2 as an "in vivo" contributor to the cervicovaginal milieu antimicrobial properties. An alternative explanation is proposed, supported by previous reports ascribing protective and antimicrobial properties to other factors produced by Lactobacillus spp. capable of generating H2O2. Under this proposal, lactic acid rather than H2O2 plays an important role in the antimicrobial properties of protective vaginal Lactobacillus spp. We hope this commentary will help future research focus on more plausible mechanisms by which vaginal Lactobacillus spp. exert their antimicrobial and beneficial properties, and which have in vivo and translational relevance.
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Affiliation(s)
- Gilda Tachedjian
- Disease Elimination Program, Life Sciences Discipline, Burnet Institute, 85 Commercial Rd, Melbourne, Victoria 3004 Australia
- Department of Microbiology, Monash University, Clayton, VIC 3168 Australia
- Department of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Melbourne, VIC 3010 Australia
- School of Science, College of Science, Engineering and Health, RMIT University, Melbourne, Victoria 3000 Australia
| | - Deirdre E. O’Hanlon
- Institute for Genome Sciences, University of Maryland School of Medicine, 801 West Baltimore Street, Baltimore, MD 21201 USA
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Jacques Ravel
- Institute for Genome Sciences, University of Maryland School of Medicine, 801 West Baltimore Street, Baltimore, MD 21201 USA
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD 21201 USA
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O’Hanlon DE, Moench TR, Cone RA. Vaginal pH and microbicidal lactic acid when lactobacilli dominate the microbiota. PLoS One 2013; 8:e80074. [PMID: 24223212 PMCID: PMC3819307 DOI: 10.1371/journal.pone.0080074] [Citation(s) in RCA: 298] [Impact Index Per Article: 27.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 10/08/2013] [Indexed: 12/27/2022] Open
Abstract
Lactic acid at sufficiently acidic pH is a potent microbicide, and lactic acid produced by vaginal lactobacilli may help protect against reproductive tract infections. However, previous observations likely underestimated healthy vaginal acidity and total lactate concentration since they failed to exclude women without a lactobacillus-dominated vaginal microbiota, and also did not account for the high carbon dioxide, low oxygen environment of the vagina. Fifty-six women with low (0-3) Nugent scores (indicating a lactobacillus-dominated vaginal microbiota) and no symptoms of reproductive tract disease or infection, provided a total of 64 cervicovaginal fluid samples using a collection method that avoided the need for sample dilution and rigorously minimized aerobic exposure. The pH of samples was measured by microelectrode immediately after collection and under a physiological vaginal concentration of CO2. Commercial enzymatic assays of total lactate and total acetate concentrations were validated for use in CVF, and compared to the more usual HPLC method. The average pH of the CVF samples was 3.5 ± 0.3 (mean ± SD), range 2.8-4.2, and the average total lactate was 1.0% ± 0.2% w/v; this is a five-fold higher average hydrogen ion concentration (lower pH) and a fivefold higher total lactate concentration than in the prior literature. The microbicidal form of lactic acid (protonated lactic acid) was therefore eleven-fold more concentrated, and a markedly more potent microbicide, than indicated by prior research. This suggests that when lactobacilli dominate the vaginal microbiota, women have significantly more lactic acid-mediated protection against infections than currently believed. Our results invite further evaluations of the prophylactic and therapeutic actions of vaginal lactic acid, whether provided in situ by endogenous lactobacilli, by probiotic lactobacilli, or by products that reinforce vaginal lactic acid.
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Affiliation(s)
- Deirdre E. O’Hanlon
- Thomas C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, Maryland, United States of America
| | | | - Richard A. Cone
- Thomas C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, Maryland, United States of America
- ReProtect Inc., Baltimore, Maryland, United States of America
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Watson ME, Nielsen HV, Hultgren SJ, Caparon MG. Murine vaginal colonization model for investigating asymptomatic mucosal carriage of Streptococcus pyogenes. Infect Immun 2013; 81:1606-17. [PMID: 23460515 PMCID: PMC3648019 DOI: 10.1128/iai.00021-13] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Accepted: 02/21/2013] [Indexed: 11/20/2022] Open
Abstract
While many virulence factors promoting Streptococcus pyogenes invasive disease have been described, specific streptococcal factors and host properties influencing asymptomatic mucosal carriage remain uncertain. To address the need for a refined model of prolonged S. pyogenes asymptomatic mucosal colonization, we have adapted a preestrogenized murine vaginal colonization model for S. pyogenes. In this model, derivatives of strains HSC5, SF370, JRS4, NZ131, and MEW123 established a reproducible, asymptomatic colonization of the vaginal mucosa over a period of typically 3 to 4 weeks' duration at a relatively high colonization efficiency. Prior treatment with estradiol prolonged streptococcal colonization and was associated with reduced inflammation in the colonized vaginal epithelium as well as a decreased leukocyte presence in vaginal fluid compared to the levels of inflammation and leukocyte presence in non-estradiol-treated control mice. The utility of our model for investigating S. pyogenes factors contributing to mucosal carriage was verified, as a mutant with a mutation in the transcriptional regulator catabolite control protein A (CcpA) demonstrated significant impairment in vaginal colonization. An assessment of in vivo transcriptional activity in the CcpA(-) strain for several known CcpA-regulated genes identified significantly elevated transcription of lactate oxidase (lctO) correlating with excessive generation of hydrogen peroxide to self-lethal levels. Deletion of lctO did not impair colonization, but deletion of lctO in a CcpA(-) strain prolonged carriage, exceeding even that of the wild-type strain. Thus, while LctO is not essential for vaginal colonization, its dysregulation is deleterious, highlighting the critical role of CcpA in promoting mucosal colonization. The vaginal colonization model should prove effective for future analyses of S. pyogenes mucosal colonization.
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Affiliation(s)
- Michael E. Watson
- Divison of Pediatric Infectious Diseases, Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Hailyn V. Nielsen
- Department of Molecular Microbiology, Washington University Medical School, St. Louis, Missouri, USA
| | - Scott J. Hultgren
- Department of Molecular Microbiology, Washington University Medical School, St. Louis, Missouri, USA
- Center for Women's Infectious Disease Research, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Michael G. Caparon
- Department of Molecular Microbiology, Washington University Medical School, St. Louis, Missouri, USA
- Center for Women's Infectious Disease Research, Washington University School of Medicine, St. Louis, Missouri, USA
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O'Hanlon DE, Lanier BR, Moench TR, Cone RA. Cervicovaginal fluid and semen block the microbicidal activity of hydrogen peroxide produced by vaginal lactobacilli. BMC Infect Dis 2010; 10:120. [PMID: 20482854 PMCID: PMC2887447 DOI: 10.1186/1471-2334-10-120] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2009] [Accepted: 05/19/2010] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND H2O2 produced by vaginal lactobacilli is believed to protect against infection, and H2O2-producing lactobacilli inactivate pathogens in vitro in protein-free salt solution. However, cervicovaginal fluid (CVF) and semen have significant H2O2-blocking activity. METHODS We measured the H2O2 concentration of CVF and the H2O2-blocking activity of CVF and semen using fluorescence and in vitro bacterial-exposure experiments. RESULTS The mean H2O2 measured in fully aerobic CVF was 23 +/- 5 microM; however, 50 microM H2O2 in salt solution showed no in vitro inactivation of HSV-2, Neisseria gonorrhoeae, Hemophilus ducreyii, or any of six BV-associated bacteria. CVF reduced 1 mM added H2O2 to an undetectable level, while semen reduced 10 mM added H2O2 to undetectable. Moreover, the addition of just 1% CVF supernatant abolished in vitro pathogen-inactivation by H2O2-producing lactobacilli. CONCLUSIONS Given the H2O2-blocking activity of CVF and semen, it is implausible that H2O2-production by vaginal lactobacilli is a significant mechanism of protection in vivo.
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Affiliation(s)
- Deirdre E O'Hanlon
- Mucosal Protection Laboratory, Thomas C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Blair R Lanier
- Mucosal Protection Laboratory, Thomas C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, MD 21218, USA
| | | | - Richard A Cone
- Mucosal Protection Laboratory, Thomas C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, MD 21218, USA
- ReProtect, Inc., Baltimore, MD 21286, USA
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Schlievert PM, Case LC, Strandberg KL, Tripp TJ, Lin YC, Peterson ML. Vaginal Staphylococcus aureus superantigen profile shift from 1980 and 1981 to 2003, 2004, and 2005. J Clin Microbiol 2007; 45:2704-7. [PMID: 17537948 PMCID: PMC1951268 DOI: 10.1128/jcm.02295-06] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We determined vaginal Staphylococcus aureus superantigens. Staphylococci were quantified from tampons/diaphragms in 2003 to 2005, with counts compared to those determined in 1980 and 1981. In 2003 to 2005, more women were colonized than in 1980 and 1981 (23 versus 12%). Enterotoxins G and I and enterotoxin-like superantigens M and N declined, but enterotoxin-like superantigens K, L, and Q increased.
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Affiliation(s)
- Patrick M Schlievert
- Department of Microbiology, University of Minnesota Medical School, 420 Delaware Street S.E., Room 960, Minneapolis, MN 55455, USA.
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Abstract
This account describes studies from the Institute of Medical Physiology in the University of Copenhagen, starting in the mid 1970's, which included some of the earliest European laboratory investigations on human female genital function. The measurements involved vaginal pH, pO2, blood flow, motility, fluid and its ionic concentrations, amino-acid concentrations and electrical activity (transvaginal potential difference) usually in both the basal and sexual aroused states. The blood flow monitoring pioneered the use of the heated oxygen electrode. Other studies examined the effects of arousal to orgasm on cervical secretion, on the heart rate as an objective indicator of orgasmic excitement and investigated the actions of TRH and the cholinergic antagonist atropine on a number of vaginal parameters. The work was part of the scientific watershed that divided the previous descriptive era of human genital mechanisms from the now prevalent quantitative assessments.
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Affiliation(s)
- R J Levin
- Department of Biomedical Science, University of Sheffield, Western Bank, Yorkshire, UK.
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