Detection of co-infection of Gardnerella vaginalis and Atopobium vaginae using qualitative PCR: A better predictor of bacterial vaginosis

The microbiome in recurrent pregnancy loss - A scoping review

Recurrent pregnancy loss (RPL) is a troubling condition that affects couples worldwide. Despite extensive research efforts, many RPL cases remain unexplained, highlighting the need for novel approaches to unravel its underlying mechanisms. Recent advances in microbiome research have shed light on the potential role of the microbiome in reproductive health and outcomes. Based on a systematic literature research, this review aims to comprehensively explore the current understanding of the microbiome's involvement in RPL, focusing on the vaginal, endometrial, and gut microbiomes. Evidence from the available studies is examined to explain the relationship between the microbiome and RPL. Furthermore, we discuss the diagnostic potential of the microbiome, therapeutic interventions, and future directions in microbiome research for RPL. Understanding the complex interactions between the microbiome and reproductive health holds promise for developing targeted interventions to help patients today diagnosed as unexplained.

Development of a Prevotella bivia PNA probe and a multiplex approach to detect three relevant species in bacterial vaginosis-associated biofilms

Bacterial vaginosis (BV) is the most common vaginal infection worldwide. We developed a peptide nucleic acid (PNA) probe targeting Prevotella bivia, a common BV-associated bacteria, and optimized a multiplex approach for detection of Gardnerella spp., P. bivia and Fannyhessea vaginae. Our P. bivia PNA probe specifically detected the target species, and the optimized multiplex approach was able to detect the presence of the three species in multi-species BV biofilms.

A New PNA-FISH Probe Targeting Fannyhessea vaginae

Bacterial vaginosis (BV) is the most common vaginal infection in women of reproductive age and has been associated with serious health complications, mainly in pregnant women. It is characterized by a decrease in the number of Lactobacillus species in the healthy vaginal microbiota and an overgrowth of strict and facultative anaerobic bacteria that develop a polymicrobial biofilm. Despite over 60 years of research investigating BV, its etiology is not fully understood. Gardnerella spp. is a crucial microorganism that contributes to the formation of the biofilm and the development of BV, but the role of other BV-associated bacteria is not clear. Nevertheless, Fannyhessea vaginae (previously known as Atopobium vaginae) is a highly specific species for BV, and co-colonization with Gardnerella is thought to be a very specific diagnostic marker. The diagnosis of BV still presents some limitations, since currently used methods often fail to accurately detect BV. This work aims to develop a novel peptide nucleic acid (PNA) probe targeting F. vaginae. This probe was further validated in a multiplex assay, which included a Gardnerella-specific PNA probe, as a possible method for diagnosis of BV, and was compared with quantification by qPCR. The new PNA probe showed excellent sensitivity and specificity and could discriminate F. vaginae-Gardnerella biofilms, confirming the potential to be used for the detection of BV-associated pathogens.

Gardnerella vaginalis in urinary tract infections, are men spared?

Gardnerella vaginalis in association with anaerobes has been linked to bacterial vaginosis in women, while urinary tract infections (UTIs) in men have rarely been reported. The aim of the review was to reveal the significance of G. vaginalis UTIs in men. Prevalence of G. vaginalis UTIs in men varied from 0.5 to >27% according to patients' groups. Most patients had comorbidity such as urolithiasis or stents, transplants, tumors and diabetes, however, infections can also affect immunocompetent patients. We observed G. vaginalis-associated bacteriuria and leukocyturia in a kidney transplant man. Complications of the UTIs such as bacteremia (in 9/11 cases), hydronephrosis (4/11) and abscesses or septic emboli have been reported. Bacterial vaginosis in female partners has been a risk factor for UTIs in males. In women, biofilm Gardnerella phenotype, stabilized by Atopobium vaginae and Prevotella bivia was linked to ≥6-fold higher antibiotic resistance rates compared with the planktonic phenotype. Non-susceptibility to metronidazole and levofloxacin was found also in males. Therefore, if aerobic urine cultures are negative, urine and blood samples from male patients with predisposing factors and clinical signs of UTIs and bacteremia, can be taken. Plates should be incubated for 2-4 days in capnophilic/microaerophilic conditions, however only anaerobic incubation can help with detecting G. vaginalis strains which grow only anaerobically. Susceptibility testing of the isolates is highly important. Briefly, adherent G. vaginalis phenotype can be sexually transmissible. Despite the infrequency of G. vaginalis UTIs in men, the infections should be considered since they are often linked to severe complications.

Molecular Study of Gardnerella vaginalis Isolated from Vaginal Discharge of Women Referring to Gynecology Clinics in Chaharmahal and Bakhtiari, Iran, in 2017

Background: vaginal infections are common among women referring to gynecological clinics worldwide, but treatment modalities cannot provide complete remission of the disease. Laboratory diagnosis of vaginal infections using more sensitive and specific methods is essential for the best treatment options. Objectives: In this study, diagnosis of bacterial vaginosis (BV) using the polymerase chain reaction (PCR) method was investigated. Methods: vaginal samples were collected from 635 symptomatic women referring to gynecology clinics in Chaharmahal and Bakhtiari, Iran, in 2017. All samples were then diagnosed using microscopy, culture, and PCR methods. Results: Of 635 symptomatic women, 200 cases (31.4%) were diagnosed with BV according to the culture method using the PCR method. However, 3.9% of samples who were negative based on the culture method, were diagnosed to have BV based on PCR results. Conclusions: PCR is more sensitive than culture and microscopy methods for the diagnosis of BV.

Diagnosis of bacterial vaginosis: Clinical or microscopic? A cross-sectional study

OBJECTIVE

To compare the performance of the Amsel criteria, culture of Gardnerella spp., and wet mount microscopy (WMM) in the diagnosis of bacterial vaginosis.

METHODS

A cross-sectional cohort study was conducted, consisting of evaluating 749 consecutive women, regardless of symptoms. The Amsel criteria were evaluated, WMM microscopy and Gram staining were performed, and a swab was collected for culture. The gold standard for diagnosis was the Nugent score.

RESULTS

The sensitivity and specificity for the different approaches were: Amsel criteria 41.3% (95% confidence interval [CI] 33.76-49.18) and 97.8% (95% CI 96.21-98.81); cultures 59.9% (95% CI 51.47-67.85) and 99.0% (95% CI 97.76-99.69); WMM 82.6% (95% CI 76.02-88.05) and 92.4% (95% CI 89.98-94.45), respectively. WMM performed equally well in symptomatic and asymptomatic women. Amsel criteria in scenarios where there is no use of a microscope had very poor sensitivity (22.8% [CI 16.63-29.87%]).

CONCLUSION

The Amsel criteria have a poor performance for the diagnosis of bacterial vaginosis. WMM performs well but is not routinely used and should be the first approach for the diagnosis of vaginitis.