Prevalence and Abundance of Uncultivated
            <i>Megasphaera</i>
            -Like Bacteria in the Human Vaginal Environment

Zozaya-Hinchliffe, Marcela; Martín, David H.; Ferris, Michael J.

doi:10.1128/aem.02127-07

Cited by 51 publications

(36 citation statements)

References 26 publications

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“…Other studies have used taxon-directed conventional PCR assays to describe the prevalences of various bacterial species in vaginal samples, and while this method is much more sensitive at detecting minority bacterial species than broad-range PCR, it is also not reliably quantitative (7,21). There are few published studies that have used targeted qPCR methods to describe levels of vaginal bacteria, but most such studies were cross-sectional (22,23,27,28); even fewer studies have examined how vaginal bacterial concentrations change with antibiotic therapy (2). Ferris at al.…”

Section: Discussionmentioning

confidence: 99%

Changes in Vaginal Bacterial Concentrations with Intravaginal Metronidazole Therapy for Bacterial Vaginosis as Assessed by Quantitative PCR

et al. 2009

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Several fastidious bacteria have been associated with bacterial vaginosis (BV) using broad-range bacterial PCR methods such as consensus sequence 16S rRNA gene PCR, but their role in BV remains poorly defined. We describe changes in vaginal bacterial concentrations following metronidazole therapy for BV. Vaginal swabs were collected from women with BV diagnosed using Amsel clinical criteria, and vaginal fluid was assessed by Gram stain to generate Nugent scores. Follow-up swabs were collected 1 month after a 5-day course of vaginal 0.75% metronidazole gel and analyzed for 24 subjects with cured BV and 24 subjects with persistent BV. Changes in bacterial concentrations were measured using eight bacterium-specific 16S rRNA gene quantitative PCR assays. DNA from several fastidious BV-associated bacteria (BVAB) were present at high concentrations in the vagina prior to treatment. Successful antibiotic therapy resulted in 3-to 4-log reductions in median bacterial loads of BVAB1 (P ‫؍‬ 0.02), BVAB2 (P ‫؍‬ 0.0004), BVAB3 (P ‫؍‬ 0.03), a Megasphaera-like bacterium (P < 0.0001), Atopobium species (P < 0.0001), Leptotrichia/Sneathia species (P ‫؍‬ 0.0002), and Gardnerella vaginalis (P < 0.0001). Median posttreatment bacterial levels did not change significantly in subjects with persistent BV except for a decline in levels of BVAB3. The presence or absence of BV is reflected by vaginal concentrations of BV-associated bacteria such as BVAB1, BVAB2, Leptotrichia/Sneathia species, Atopobium species, Gardnerella vaginalis, and a Megasphaera-like bacterium, suggesting that these bacteria play an important role in BV pathogenesis and may be suitable markers of disease and treatment response.Bacterial vaginosis (BV) is a very common condition, affecting 10 to 37% of women (24), with particularly high prevalences reported in areas of sub-Saharan Africa (3, 25) and among African-American women (51%) (15). BV is the most common cause of vaginitis and vaginal discharge and has been linked to several adverse health outcomes including preterm labor, pelvic inflammatory disease, and human immunodeficiency virus acquisition (12,18,19).Women with BV experience a loss of vaginal Lactobacillus species that produce hydrogen peroxide (primarily Lactobacillus crispatus) and the acquisition of several facultative or anaerobic bacteria, but no single cultivated bacterium has been conclusively demonstrated to cause BV. The profound shifts in vaginal microbiota that characterize BV and the clinical response to antibiotics such as metronidazole or clindamycin suggest that anaerobic bacteria play a key role. The recent use of cultivation-independent methods (e.g., broad-range 16S rRNA gene PCR) to characterize the vaginal microbiota (5, 26) has identified novel fastidious bacteria that appear to be highly associated with BV, including three bacteria of the order Clostridiales that are not closely related to any previously identified bacteria and that we have designated BV-associated bacterium 1 (BVAB1), BVAB2, and BVAB3 (6). Other fastidious bacteri...

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Section: Discussionmentioning

confidence: 99%

Changes in Vaginal Bacterial Concentrations with Intravaginal Metronidazole Therapy for Bacterial Vaginosis as Assessed by Quantitative PCR

et al. 2009

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“…These phylotypes have been detected in both women with and those without BV, with significantly higher concentrations in women with BV (14,20,92).…”

Section: Anaerobic Coccimentioning

confidence: 95%

The Human Microbiome during Bacterial Vaginosis

2016

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SUMMARYBacterial vaginosis (BV) is the most commonly reported microbiological syndrome among women of childbearing age. BV is characterized by a shift in the vaginal flora from the dominantLactobacillusto a polymicrobial flora. BV has been associated with a wide array of health issues, including preterm births, pelvic inflammatory disease, increased susceptibility to HIV infection, and other chronic health problems. A number of potential microbial pathogens, singly and in combinations, have been implicated in the disease process. The list of possible agents continues to expand and includes members of a number of genera, includingGardnerella,Atopobium,Prevotella,Peptostreptococcus,Mobiluncus,Sneathia,Leptotrichia,Mycoplasma, and BV-associated bacterium 1 (BVAB1) to BVAB3. Efforts to characterize BV using epidemiological, microscopic, microbiological culture, and sequenced-based methods have all failed to reveal an etiology that can be consistently documented in all women with BV. A careful analysis of the available data suggests that what we term BV is, in fact, a set of common clinical signs and symptoms that can be provoked by a plethora of bacterial species with proinflammatory characteristics, coupled to an immune response driven by variability in host immune function.

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“…Our choice of bacterial targets was based on a literature survey of isolates that have been cultured from the vaginal microbiota. Given the increasing amount of information regarding the composition of the vaginal microbiota accruing from cultureindependent approaches (16,19,40,42,46), the first-generation vaginal Luminex array described here could easily be improved upon to yield more information regarding the composition of a vaginal sample. We have successfully developed a 46-plex Luminex instrument-based test for the detection of human papillomaviruses (V. Goleski and A. Severini, unpublished data), and it is theoretically possible to include up to 99 different probes in each well of a Luminex array.…”

Section: Discussionmentioning

confidence: 99%

Multiplex Detection of Bacteria Associated with Normal Microbiota and with Bacterial Vaginosis in Vaginal Swabs by Use of Oligonucleotide-Coupled Fluorescent Microspheres

et al. 2009

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Bacterial vaginosis (BV) is a recurrent condition that is associated with a range of negative outcomes, including the acquisition of human immunodeficiency virus and other sexually transmitted diseases, preterm births, and pelvic inflammatory disease. In contrast to the Lactobacillus-dominated normal vaginal microbiota, BV is characterized by a lack of lactobacilli and an abundance of anaerobic and gram-negative organisms, including Gardnerella vaginalis and Atopobium vaginae. To date, the laboratory diagnosis of BV has relied upon the fulfillment of criteria determined by microscopic observation of Gram-stained vaginal swabs. We describe a molecular-based method for the easy determination of the species profile within the vaginal microbiota based on the amplification of the chaperonin-60 genes of all bacteria present in the swab and hybridization of the amplicon to species-specific oligonucleotide-coupled fluorescent beads that are identified by flow cytometry with a Luminex instrument. We designed a nineplex Luminex array for characterization of the vaginal microbiota and applied it to the analysis of vaginal swabs from individuals from Africa and North America. Using the presence of A. vaginae or G. vaginalis, or both, as the defining criterion for BV, we found that the method was highly specific and sensitive for the diagnosis of BV using microscopy as a gold standard.Bacterial vaginosis (BV), which is defined by a reduction in the vaginal Lactobacillus populations and an increase in the number of microbial species present, including Gardnerella spp., Atopobium spp., and others, is increasingly recognized as an important risk factor for adverse reproductive health outcomes, such as miscarriage and premature birth, and sexually transmitted diseases, including human immunodeficiency virus infection (25). Despite intense investigation, the etiology and clinical course of BV have not been well defined, probably because the normal variation of the vaginal microbial communities between individuals and their dynamics over time are complex and poorly understood. Consequently, the accurate diagnosis of BV, as well as the elaboration of effective prevention and treatment strategies, remains a major challenge (26, 44).The current "gold standard" for the diagnosis of BV in the laboratory setting relies on microscopic profiling of microbial types in Gram-stained vaginal swab smears by using the criteria of Nugent et al. (29) or Ison and Hay (20). These scoring systems are based on the relative abundance of Lactobacillus morphotypes (large gram-positive rods) compared to the abundance of the bacterial morphotypes suggestive of BV (gramnegative or gram-variable coccobacilli and curved rods and gram-positive cocci). Although this method provides reliable information and is particularly well suited for use in resourcepoor settings, it requires well-trained, highly experienced individuals to interpret the results and is simplistic in its reflection of the variety of organisms present in the microbial communities present in he...

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Prevalence and Abundance of Uncultivated Megasphaera -Like Bacteria in the Human Vaginal Environment

Cited by 51 publications

References 26 publications

Changes in Vaginal Bacterial Concentrations with Intravaginal Metronidazole Therapy for Bacterial Vaginosis as Assessed by Quantitative PCR

Changes in Vaginal Bacterial Concentrations with Intravaginal Metronidazole Therapy for Bacterial Vaginosis as Assessed by Quantitative PCR

The Human Microbiome during Bacterial Vaginosis

Multiplex Detection of Bacteria Associated with Normal Microbiota and with Bacterial Vaginosis in Vaginal Swabs by Use of Oligonucleotide-Coupled Fluorescent Microspheres

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