دانلود رایگان ترجمه مقاله ارزیابی تشخیصی سنجش PCR ریل تایم کمی multiplex برای واژینوز باکتریال (نشریه Omicsonline 2016)

ارزیابی تشخیصی سنجش PCR ریل تایم کمی multiplex برای واژینوز باکتریال

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

Abstract

Background: Quantitative multiplex PCR assay for Bacterial Vaginosis (BV) based on the detection of the predominant contributory targets was evaluated against the conventional Nugent Score that is laborious and subjective due to morphological assessment bias of BV-associated bacteria.

Methods: 125 dual vaginal specimens were collected from patients aged ≥18 years at the time of presentation at the provider office to perform real time PCR and Nugent Testing. PCR assessment of BV was performed by quantitation of DNA amounts of Gardnerella vaginalis, Atopobium vaginae, Lactobacillus spp., and total amount of bacterial DNA using a multiplex RT-PCR kit (ATRiDA, Netherlands). Discordant results were resolved by the Amsel criteria or ancillary testing such as BD Affirm, when available.

Results: Nugent score classified 36.36% of the patients in BV and 15.45% in transitional BV categories. In contrast, the PCR method called 48.18% as BV and 12.72% as transitional BV or BV of unspecified origin categories. The overall concordance between the two methods was 81.81%. None of the BV positives by Nugent method were missed by the PCR. There were only 2 intermediates by Nugent that were called normal by PCR. PCR method was more sensitive than the Nugent and picked an additional 11% positives.

Conclusions: PCR based molecular BV diagnosis can standardize women health testing by removing the bias due to subjective interpretation of Nugent scoring. Our study shows that PCR method is more sensitive than conventional testing and may be a promising replacement for laborious Nugent scoring method in an era of shrinking microbiology expertise.

1 Introduction

Bacterial vaginosis (BV) is a complex polymicrobial syndrome characterized by alterations of the vaginal flora with acquisition of diverse communities of anaerobic and facultative bacteria and depletion of the usually dominant Lactobacillus flora. BV is a cause of malodorous vaginal discharge, vulvovaginal irritation, and/or dysuria. Recurrent and/or untreated infections are associated with several obstetric and gynecologic complications, including preterm rupture of membranes, chorioamnionitis, puerperal endometritis, pelvic inflammatory disease, urinary tract infection, postoperative cellulitis, cervical dysplasia, and human immunodeficiency virus acquisition. The current diagnostic gold standard Nugent Score is based on morphological assessment of BV associated bacteria. The technique is laborious and subjective as some morphologically similar non-contributory bacteria can skew the results. As a consequence, the use of molecular techniques to detect predominant contributory targets is desirable to make the BV diagnosis. Molecular methods that solely depend on the detection of a single target such as Gardnerella vaginalis have limited utility due to low sensitivity and specificity [1]. Quantitative ratios of specific anaerobic microflora such as G vaginalis and Atopobium vaginae in relation to Lactobacillus spp. are highly sensitive and specific for the diagnosis of BV and is associated with disease recurrence. Since A. vaginae have advanced resistance to metronidazole, its identification can play an important role in helping to change therapy decisions [2,3].

The aim of the study was to evaluate the diagnostic value of a multiplex quantitative real-time PCR assay (AmpliSens® Florocenosis/ Bacterial vaginosis-FRT PCR kit, ATRiDA, Netherlands) for Bacterial Vaginosis. A combination of Amsel critera and Nugent Graded gram stain (used as a gold standard) was used as the reference method.