Speaker Abstracts - S618


Overview of Antibiotic and Antifungal Interventions

Identification: Balkus, Jennifer

Credits: None available.

Overview of Antibiotic and Antifungal Interventions
Jennifer E. Balkus, PhD, MPH1,2
1University of Washington, USA; 2Fred Hutchinson Cancer Research Center, Seattle, WA, USA
Treatment for vaginal infections, including bacterial vaginosis (BV) and vulvovaginal candidiasis (VVC), have remained relatively consistent over the past two decades. While approved treatments successfully cure these infections in most cases, recurrence levels are high for both conditions. New strategies are needed that successfully treat BV and VVC, reduce recurrence, and in the case of BV, eliminate species associated with an increased risk of adverse reproductive health outcomes. This presentation will review current global treatment recommendations for BV and VVC, discuss alternative treatment approaches (such as suppressive therapy) to reduce recurrence, and highlight promising novel treatment regimens that are currently undergoing evaluation in clinical trials.

Update on Live Biotherapeutic Trials to Prevent Vaginal Dysbiosis and HIV

Identification: Cohen, Craig

Credits: None available.

Update on Live Biotherapeutic Trials to Prevent Vaginal Dysbiosis and HIV
Craig R. Cohen1, Laurel Lagenaur2, Thomas Parks2, Anke Hemmerling1
1Department of Obstetrics, Gynecology & Reproductive Sciences, University of California San Francisco (UCSF), USA; 2Osel, Inc. Mountain View, CA, USA
The vaginal microbiota has long been considered a factor impacting women's risk for acquiring HIV, but the extent of this contribution and the underlying mechanisms have not been well defined. Given the apparent protection from infections afforded by a Lactobacillus-dominant microbiota, and the limited efficacy of antibiotics in establishing such a community, a different intervention strategy may be necessary. A strain of L. crispatus (LACTIN-V) developed as a live biotherapeutic product (LBP) to prevent the recurrence of bacterial vaginosis (BV) has shown excellent safety and tolerability, and close to 80% colonization in early studies. In addition, L. jensenii 1153-1666 genetically modified to produce modified cyanovirin-N, a potent HIV inhibitor has completed preclinical development. Macaques challenged with a repeat challenge of simian/HIV (SHIV) treated with L. jensenii 1153-1666 demonstrated a 63% decrease in infection compared to placebo. Our team at UCSF and Osel, Inc. have recently completed enrollment of a Phase 2b trial of LACTIN-V to prevent BV recurrence and anticipate results in July 2019. In addition, our team is planning a Phase 2 clinical trial of LACTIN-V in Durban, South Africa to determine its effect on genital mucosal immune factors associated with an increased risk of HIV-acquisition in women. In regards to formulated L. jensenii 1153-1666 (MucoCept), we have submitted an investigational new drug (IND) application the U.S. Food and Drug Administration (FDA) to conduct a first-in-human trial. This presentation will provide an update on these LBPs with a focus on their potential to reduce HIV acquisition in women.
Funded by the National Institutes of Health (NIAID U01AI23082) and (DMID HHSN272201300014I)

Partner Treatment Trials

Identification: Bradshaw, Catriona

Credits: None available.


Partner Treatment Trials
Bradshaw CS1-2
1Melbourne Sexual Health Centre, The Alfred Hospital, Victoria, Australia; 2Central Clinical School, Monash University, Melbourne, Victoria, Australia
Bacterial vaginosis is the most common vaginal dysbiosis with the highest burden of disease in women in low income countries and with poor access to healthcare1,2. Current recommended antimicrobial therapy achieves high level short-term cure but post-treatment recurrence exceeds 50% within 6 months3. This presentation will examine why have we made no significant inroads into improving BV cure, and the likely pathogenesis of post-treatment recurrence. Epidemiological studies suggest both reinfection and persistence play a role4. Data on sexual transmission of BV will be discussed and past male partner treatment trials. The rationale for new male partner treatment trials will be presented including discussion of interventions, feasibility, and acceptability5. Many of the difficulties that impacted on past male treatment trials6 are highly relevant and discussion will be encouraged about the logistical constraints faced by clinicians/researchers in undertaking such trials and ensuring successful recruitment and retention in a range of settings. Preliminary data from male partner treatment studies will be presented and discussion on the need for female partner treatment trials. Determining the contribution of reinfection to recurrence is important as if reinfection is a dominant factor in recurrence this will impact on our ability to assess the efficacy of strategies/therapies directed only to women. Time will be made available to discuss strategies and collaborative opportunities to determine how we make substantive progress with couple-specific interventions for BV.
1. Chico, RM et al. JAMA 307; 2079-2086, 2012
2. Allsworth, JE et al. Obstet Gynecol 109; 114-120, 2007
3. Bradshaw, CS et al. J Infect Dis 193; 1478-1489, 2006
4. Unemo M, Bradshaw CS, et al. Lancet Infect Dis 17(8):e235-e279, 2017
5. Plummer EL, et al. PLoS One. 13(1):e0190199, 2018.
6. Mehta, SD. Sex Transm Dis 39; 822-830, 2012
National Health and Medical Research Countil, Project Grant Project Grant APP1138165.  Alfred Research Trust Seeding Grant 2016.


The Vaginal Microbiota and Bacterial Vaginosis

Identification: Fredricks, David

Credits: None available.

The Vaginal Microbiota and Bacterial Vaginosis
David N. Fredricks, MD
Fred Hutchinson Cancer Research Center and University of Washington, Seattle, WA, USA
Bacterial vaginosis (BV) is a highly prevalent condition linked to numerous adverse health outcomes in women.  The application of tools in molecular biology to study the vaginal microbiota has advanced our understanding of this enigmatic condition but has also raised critical questions.  This presentation will focus on understanding the composition and dynamics of the vaginal microbiota, and how changes in the vaginal bacterial microbiota are linked to BV.  Do vaginal Lactobacillus species protect from development of BV?  What are the implications for use of probiotics to prevent or treat BV? What are the microbiological antecedents to incident and relapsing BV? What are the kinetics of disappearance of BV-associated bacteria with antibiotic treatment?  Is there evidence of antibiotic resistance in BV-associated bacteria that is linked to relapse? How are BV-associated bacteria acquired? Do BV-associated bacteria colonize the mouth, rectum, and labia of women, and does their presence predict risk of subsequent BV? How do BV-associated bacteria change the vaginal environment? How does host innate immunity shape risk of BV and colonization with BV-associated bacteria?  What is the connection between BV-associated bacteria and HIV infection risk? How can molecular microbiology data be used to successfully cultivate fastidious BV-associated bacteria in the lab?  I will present data that informs answers to these questions and highlights recent advances in the field.
Supported by NIH grants: R01 AI-061628 and U19 AI-113173

The Microbiome of the Female Reproductive Tract and Pregnancy

Identification: Buck, Gregory

Credits: None available.

The Microbiome of the Female Reproductive Tract and Pregnancy
Gregory A. Buck and the Vaginal Microbiome Consortium at VCU
Department of Microbiology and Immunology and the Center for Microbiome Engineering and Data Analysis, Virginia Commonwealth University, Richmond, Virginia, USA
The microbiome of the the human female reproductive tract is diverse and thought to have a significant impact on women's reproductive health, including but not limited to risk of preterm birth. Preterm birth has a prevalence of ~10%, although some demographic groups (e.g., African Americans) experience even higher incidence. The overall incidence of adverse outcomes in pregnancy and neonatal health has decreased in recent decades, but the risk of preterm birth has not shown commensurate changes. The annual cost of preterm birth in the United States is estimated at over $25 billion. Thus, preterm birth remains a serious issue and it is estimated that 40-50% of preterm birth involves a microbial etiology.
The Vaginal Human Microbiome Consortium at VCU has examined the microbiome profiles of over 6,000 women in a cross-sectional study, and, in collaboration with the Global Alliance to Prevent Preterm Birth and Prematurity, nearly 1600 pregnant women in a longitudinal study. We have collected and banked nearly a quarter million vaginal, rectal, buccal, blood, urine, skin and birth product samples for analysis by 16S taxonomic, metagenomic, metatranscriptomic and cytokine profiling. Analysis of a fraction of these samples has identified modifications in the microbiome during pregnancy, and these modifications vary among demographic groups. We also observed a correlation between microbiome compositions associated with preterm birth and have characterized the genomes of some of the relevant bacterial taxa. The results overall show promise to provide strategies for predicting risk of preterm birth to permit earlier intervention and monitoring to prevent this adverse outcome.
This work is supported by grants from the NIH Common Fund Human Microbiome Project (1UH2/UH3AI08326 and 8U54HD080784 to G. Buck, K. Jefferson and J. Strauss), the Global Alliance to Prevent Prematurity and Stillbirth (PPB Grant 15011), and NIH/NICHD (HD092415). We thank all the members of the Vaginal Microbiome Consortium at VCU (vmc.vcu.edu) for their contributions to this project, and the Global Alliance for the Prevention of Prematurity and Stillbirth (gapps.org) for their participation and support.

Human in vitro Systems to Study Genital Tract Mucosal Defenses

Identification: Herbst-Kralovetz, Melissa

Credits: None available.

Human in vitro Systems to Study Genital Tract Mucosal Defenses
Melissa M. Herbst-Kralovetz1*
1University of Arizona, College of Medicine-Phoenix, AZ, USA
*Corresponding Author
The cervicovaginal microenvironment is home to a diverse array of microbes that contribute to health and disease. These bacteria play a key role in regulating host physiology at this site and profoundly impact reproductive, gynecologic, and obstetric health. In recent years, sequencing technologies have broadened our appreciation for the breadth and diversity of microbes that inhabit the female reproductive tract (FRT) and have associated many of these organisms to women's health outcomes. Unfortunately, tractable, small animal models for studying host-microbe interactions in the lower female reproductive tract are not available. As such, we are limited in our understanding of the functional impact of these organisms on the genital microenvironment and how these mechanisms contribute to homeostasis or disease. Here, we utilize robust, physiologically relevant 3-D human reproductive tract epithelial models to determine the function of these diverse microbes on epithelial cell morphology, cellular integrity, adherence, intercellular interactions and resulting host defense mechanisms. Key modeling topics related to multiplicity of infection, timing, cytotoxicity, site-specificity in the FRT and bacterial species-specific differences in host responsiveness will be discussed. Our findings using these human model systems, coupled with robust clinical translational studies, will aid in better understanding the functional impact of these organisms throughout the female reproductive tract and will provide mechanistic insights into how these bacteria contribute to reproductive and gynecologic health and disease.

Vaginal Microbiota and Biofilms in a Clinical Trial of the NuvaRing® in Rwanda

Identification: Crucitti, Tania

Credits: None available.

Vaginal Microbiota and Biofilms in a Clinical Trial of the NuvaRing® in Rwanda
Crucitti T1, Hardy L1, van de Wijgert J2, Agaba S3, Buyze J1, Kestelyn E2, 3, Delvaux T1, Mwambarangwe L3, De Baetselier I1, Jespers V1, the Ring Plus study group
1 Insititute of Tropical Medicine, Antwerp, Belgium; 2 University of Liverpool, Liverpool, United Kingdom; 3 Rinda Ubuzima, Kigali, Rwanda
The impact of NuvaRing®, a commonly used estrogen/progestin-containing contraceptive vaginal ring, on the vaginal microbiota has been inadequately studied.
We randomized 120 women 1:1 to intermittent use (three rings with one week off between rings) or continuous use (four rings without ring-free weeks) of the NuvaRing® in Kigali, Rwanda. Quantitative PCR was used to assess the vaginal microbiota at baseline and follow-up, as well as the ring deposits at follow-up. Vaginal slides were Nugent scored and cell-adherent bacteria were visualized using fluorescent in situ hybridization (FISH). One-third pieces of the removed rings were assessed for biomass deposit by crystal violet staining and by scanning electron microscopy.  
The baseline prevalence of bacterial vaginosis (BV) by Nugent scoring was high (48%) and BV persisted or recurred during the study in 67% of the cases. The mean Nugent score decreased, and the presence and concentration of lactobacilli in vaginal secretions increased significantly over time. A polymicrobial biofilm containing BV-associated bacteria was detected by FISH in half of the vaginal slides and the presence did not significantly change over time. All ring pieces were coated with an adherent biomass composed of accumulated vaginal epithelial cells covered by either loose or dense structures of bacteria.
NuvaRing® use promoted a lactobacilli-dominated vaginal microbiota in a study population characterized by high BV prevalence. The presence of a polymicrobial vaginal biofilm did not change significantly over time. In addition, biomass deposit on rings, consisting of vaginal epithelial cells covered by vaginal bacteria, was common.
This study was funded by the European and Developing Countries Clinical Trials Partnership (EDCTP) through a project entitled 'Preparing for clinical trials with vaginal rings that protect women from HIV and unintended pregnancy' (grant code SOP.2011.41304.043) with contributions from the Institute of Tropical Medicine in Antwerp and the University of Liverpool.

Using imaging approaches to gain mechanistic insights into HIV transmission and prevention

Identification: Hope, Thomas

Credits: None available.

Using Imaging Approaches to Gain Mechanistic Insights into HIV Transmission and Prevention
Thomas J. Hope
Northwestern University, Feinberg School of Medicine, Department of Cell and Molecular Biology, Chicago, IL
Over the past 20 years my laboratory has developed a series of imaging based tools that allow the imaging of individual HIV particles as they interact with cells and tissues and intact mucosal barriers in the rhesus macaque model. Although these studies defined potential paths of viral penetration through mucosal barriers to encounter would-be target cells, the role of paths for sexual transmission was unclear. Therefore, we developed a single round dual reporter SIV vector system that allows the macroscopic identification of the initial sites of infection after Mucosal challenge.  This system works well in the study of the portal of transmission revealing that Th17 cells and immature dendritic cells (iDC) are the major first targets of vaginal and rectal transmission. Importantly, this reporter system identifies sites of mucosal barrier disfunction and therefore identifies sites of SIV replication in a mixed challenge experiment.  The study of these early foci of transmission reveal a highly dynamic environment where innate host responses to the local SIV replication can be documented as soon as 48 hours after challenge. We have recently adapted our systems using fluorescently tagged virions and antibodies to allow their detection by whole animal Positronic Emission Tomography (PET) to study the distribution of virions and antibodies in the context of the anatomy and physiology of a living macaque.

The role of vaginal microbiota in antiretroviral drug pharmacokinetics

Identification: Klatt, Nichole

Credits: None available.

The Role of Vaginal Microbiota in Antiretroviral Drug Pharmacokinetics
Nichole Klatt
University of Miami, Miami, Florida, USA
More than one million women are infected with HIV annually. However, the biological mechanisms associated with transmission in women are not well understood. One factor that has consistently been associated with increased acquisition of HIV in women is imbalanced vaginal bacteria, i.e. vaginal microbiome dysbiosis. Lack of healthy Lactobacillus bacteria, but increased anaerobic bacteria and higher diversity of the microbiome in the female reproductive tract has been associated with clinical vaginosis, inflammation, and increased HIV infection. We recently demonstrated that dysbiotic vaginal bacteria can also alter the efficacy of topical pre-exposure prophylactic (PrEP) strategies. We found the mechanism by which dysbiotic bacteria decrease efficacy of topical antiretroviral-based PrEP is by direct metabolism of the drugs by bacteria. Here we will summarize what is currently known about vaginal microbial dysbiosis and HIV infection, and the potential mechanisms of how vaginal bacteria may influence HIV transmission in women.

Microbiota of the Female Upper Genital Tract

Identification: Mitchell, Caroline

Credits: None available.

Microbiota of the Female Upper Genital Tract
Caroline Mitchell, MD, MPH
Assistant Professor, Harvard Medical School, Vincent Center for Reproductive Biology, Massachusetts General Hospital, Boston, MA, USA
While dogma in the field of Obstetrics & Gynecology has long asserted that the uterus is sterile, studies spanning five decades have demonstrated the presence of microbes in the upper genital tract of ostensibly healthy women.  Recent application of next-generation sequencing technology to upper genital tract samples has expanded the description of the upper tract microbial community, and has suggested links between upper tract microbiota and reproductive health outcomes ranging from pregnancy implantation to endometrial cancer.  This presentation will review what is known about the origin, composition, and stability of uterine and fallopian tube microbiota, will outline specific challenges associated with evaluation of these sites, and will discuss the potential impact of the upper tract microbiome on reproductive health outcomes.