Bacterial Vaginosis Diagnosed by Analysis of First-Void-Urine Specimens

Abstract

e Bacterial vaginosis (BV) is traditionally diagnosed using vaginal samples. The aim of this study was to investigate whether BV can be diagnosed from first-void urine (FVU). Self-collected vaginal smears, vaginal swabs, and FVU were obtained from 176 women. BV was diagnosed by Nugent's criteria. The FVU and vaginal swabs were analyzed by quantitative PCRs (qPCRs) for selected vaginal bacteria (Atopobium vaginae, Prevotella spp., Gardnerella vaginalis, bacterial vaginosis-associated bacterium 2, Eggerthella-like bacterium, "Leptotrichia amnionii," Megasphaera type 1), and all had an area under the receiver operating characteristic (ROC) curve of >85%, suggesting good prediction of BV according to the Nugent score. All seven bacteria in FVU were significantly associated with BV in univariate analysis. An accurate diagnosis of BV from urine was obtained in this population by a combination of qPCRs for Megasphaera type 1 and Prevotella spp. The same two bacteria remained significantly associated with BV in a multivariate model after adjusting for the other five species. There was no statistically significant difference between the sensitivities and specificities of BV diagnosis by molecular methods performed on swabs and FVU samples. A linear regression analysis showed good agreement between bacterial loads from swabs and FVU, but Prevotella spp. could be detected in high numbers in a few FVU samples without being present in swabs. This method will allow diagnosis of BV in studies where only urine has been collected and where detection of BV is considered relevant. Bacterial vaginosis (BV) is an alteration of the normal Lactobacillus sp.-dominated vaginal flora toward a more diverse bacterial flora with overgrowth of facultative and strict anaerobic microorganisms. The BV flora includes anaerobes such as Gardnerella vaginalis, Prevotella spp., Peptostreptococcus spp., Mobiluncus spp., and several uncultured species, e.g., bacterial vaginosis-associated bacteria (BVAB) 1, 2, 3, and TM7, Megasphaera spp., and Eggerthella-like uncultured bacteria (1, 2).The classical and most commonly used algorithms for diagnosing BV are represented by clinical and microscopic classification criteria. The former were established by Amsel et al. (3) and consist of a set of four characteristics, including a homogenous, white vaginal discharge, a fishy odor of the vaginal discharge before or after addition of 10% potassium hydroxide, pH of the vaginal fluid elevated above 4.5, and the presence of clue cells (squamous epithelial cells covered with adherent bacteria). At least three of the four criteria must be present to diagnose BV. Different microscopy scores to diagnose BV have been established, some of them based on Gram-stained vaginal smears (4-6) and others based on wet-smear microscopy (7,8). Among these, the criteria published by Nugent et al. (5) are the most widely used and are considered the gold standard for diagnosing BV.Several studies on the diagnosis of BV using PCR have been published recently (9-13), but all these have...

Diagnostic Evaluation of a Multiplex Quantitative Real-Time PCR Assay for Bacterial Vaginosis

“…Normal vaginal microbiome is dominated by specific Lactobacillus spp. and its quantification relative to G. vaginalis and A. vaginae has been shown consistently as highly specific marker for diagnosing BV [6][7][8][9]. Standard antibiotic therapy for BV offers temporary relief with about 30-40% recurrence within months.…”

Reproductive outcome of patients undergoing in vitro fertilisation treatment and diagnosed with bacterial vaginosis or abnormal vaginal microbiota: a systematic PRISMA review and meta‐analysis

“…3 Recently, a variety of molecular-based techniques have been suggested which may prove superior to Gram-stained diagnostic approaches, as they dichotomise abnormal vaginal microbiota; in addition, some tests allow subclassification of BV based on a quantitative assessment of bacterial species pathognomonic for BV. 4,5 Evidence suggests that the microbiota of the female reproductive tract are found not only in the vaginal compartment but also in the uterus, which has been found to harbour a distinct microbiota both before and during pregnancy. [6][7][8][9] Although the endometrial microbiota might comprise unique species, it seems that the vaginal microbiota is an important source of ascending bacterial colonisation, at least in the preconception state.…”

Investigating the effect of an abnormal cervico‐vaginal and endometrial microbiome on assisted reproductive technologies: A systematic review

“…However, it is now known that many organisms cannot be identified by culture‐based technologies, resulting in a failure to identify potential pathogenic organisms, as well as underestimating the diversity of the ecosystem overall . It is also reported that Nugent BV is not a single entity, as it classifies bacterial communities according to their morphology on gram staining . Some vaginal communities, such as L. iners are difficult to distinguish from G. vaginalis using gram staining, which could lead to a false positive .…”

“…Some vaginal communities, such as L. iners are difficult to distinguish from G. vaginalis using gram staining, which could lead to a false positive . Studies have reported inter‐rater variability between laboratory technicians using the Nugent score, primarily in specimens dominated by L. iners . Therefore, while still interesting, studies using culture‐based data should be interpreted with caution given the limitation of the technology.…”