The Pap smear for detection of bacterial vaginosis

Cas-based bacterial detection: recent advances and perspectives

Persistent bacterial infections pose a formidable threat to global health, contributing to widespread challenges in areas such as food safety, medical hygiene, and animal husbandry. Addressing this peril demands the urgent implementation of swift and highly sensitive detection methodologies suitable for point-of-care testing and large-scale screening. These methodologies play a pivotal role in the identification of pathogenic bacteria, discerning drug-resistant strains, and managing and treating diseases. Fortunately, new technology, the CRISPR/Cas system, has emerged. The clustered regularly interspaced short joint repeats (CRISPR) system, which is part of bacterial adaptive immunity, has already played a huge role in the field of gene editing. It has been employed as a diagnostic tool for virus detection, featuring high sensitivity, specificity, and single-nucleotide resolution. When applied to bacterial detection, it also surpasses expectations. In this review, we summarise recent advances in the detection of bacteria such as Mycobacterium tuberculosis (MTB), methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli (E. coli), Salmonella and Acinetobacter baumannii (A. baumannii) using the CRISPR/Cas system. We emphasize the significance and benefits of this methodology, showcasing the capability of diverse effector proteins to swiftly and precisely recognize bacterial pathogens. Furthermore, the CRISPR/Cas system exhibits promise in the identification of antibiotic-resistant strains. Nevertheless, this technology is not without challenges that need to be resolved. For example, CRISPR/Cas systems must overcome natural off-target effects and require high-quality nucleic acid samples to improve sensitivity and specificity. In addition, limited applicability due to the protospacer adjacent motif (PAM) needs to be addressed to increase its versatility. Despite the challenges, we are optimistic about the future of bacterial detection using CRISPR/Cas. We have already highlighted its potential in medical microbiology. As research progresses, this technology will revolutionize the detection of bacterial infections.

Reliability of conventional Papanicolaou smear in diagnosing bacterial vaginosis among women with clinical genital infection

OBJECTIVE

Bacterial vaginosis (BV) is a common reproductive tract infection (RTI) reported among Indian women. BV can influence the persistence of high-risk oncogenic human papillomavirus, a causative factor for cervical cancer. BV and cervical cancer are major public health issues in a developing country like India. It becomes important for a resource-constrained country like India with poor healthcare access to implement control measures to screen and treat RTI in an attempt to prevent the risk for cervical cancer. Papanicolaou (Pap) smear is an established screening tool for cervical cancer and the diagnosis of RTIs, forms a part of its evaluation. The present study explores the validity of conventional Pap smear in diagnosing BV.

METHODOLOGY

Pap smear and Gram stain smear were collected for 254 women with clinically evident cervicitis/cervicovaginitis (genital infection). Using the Nugent score on Gram stain as a gold standard, we determined the sensitivity and specificity of Pap smear to diagnose BV.

RESULTS

The overall prevalence of BV in the study population was 44% using the Nugent score. Pap smear showed sensitivity and specificity of 70.9%. (CI- 61.5% - 79.2%) and 56.8% (CI - 48.2%-65.2%), respectively. The positive predictive value of Pap smear to diagnose BV was 56.5% (CI - 47.8%-64.9%), and the negative predictive value was 71.2% (CI - 61.8%-79.4%).

CONCLUSION

In the present study, conventional Pap smear demonstrates good accuracy to detect BV. Pap testing for cervical cancer screening can additionally serve as an effective screening tool for diagnosing BV among women with genital infection in healthcare settings.

Vaginal Microbiota Composition Correlates Between Pap Smear Microscopy and Next Generation Sequencing and Associates to Socioeconomic Status

Recent research on vaginal microbiota relies on high throughput sequencing while microscopic methods have a long history in clinical use. We investigated the correspondence between microscopic findings of Pap smears and the vaginal microbiota composition determined by next generation sequencing among 50 asymptomatic women. Both methods produced coherent results regarding the distinction between Lactobacillus-dominant versus mixed microbiota, reassuring gynaecologists for the use of Pap smear or wet mount microscopy for rapid evaluation of vaginal bacteria as part of diagnosis. Cytologic findings identified women with bacterial vaginosis and revealed that cytolysis of vaginal epithelial cells is associated to Lactobacillus crispatus-dominated microbiota. Education and socio-economic status were associated to the vaginal microbiota variation. Our results highlight the importance of including socio-economic status as a co-factor in future vaginal microbiota studies.

Cannonballs in Pap Smears: Double Whammy of Bacterial Vaginosis and Associated Infections

INTRODUCTION

Cannonballs are structures consisting of neutrophils adherent to epithelial cells, often seen in vaginal Pap smears of patients with trichomoniasis and chlamydiasis. We frequently observed these cannonballs in inflammatory Pap smears showing evidence of bacterial vaginosis.

OBJECTIVE

To study the association between cannonballs and bacterial vaginosis with associated infections in inflammatory Pap smears.

STUDY DESIGN

This was a retrospective study performed over a period of 6 months between April 2014 and September 2014. Three hundred consecutive Pap smears assessed during the study period were retrieved from the archives and studied.

RESULTS

A total of 280 smears were studied. Neutrophilic infiltrates were seen in 83.6%, cannonballs in 82.3%, and bacterial vaginosis in 70.7% of the smears. Cannonballs were found in 84.4% of the smears showing evidence of bacterial vaginosis with associated inflammatory infiltrates. There was a significant association between cannonballs and bacterial vaginosis (p = 0.0001). The odds ratio was 13.8 (95% CI: 7.2-26.2).

CONCLUSION

The present study shows a significant association between cannonballs and bacterial vaginosis and associated vaginal infections.

Vaginal epithelium and microflora characteristics in women with premature ovarian failure under hormone therapy compared to healthy women

PURPOSE

To evaluate some microbiological aspects of the vaginal flora and the vaginal trophism of women with premature ovarian failure (POF) in use of oral hormone therapy.

METHODS

A cross-sectional study with 36 women with POF under the age of 40 years using oral hormonal therapy. They were age matched with 36 women with normal gonadal function (control group). The characteristics of the vaginal epithelium were assessed through the hormonal vaginal cytology, vaginal pH measurement and vaginal health index to identify vaginal disturbances. Vaginal microflora was evaluated by the amine test, bacterioscopy (Nugent score) and culture for fungi to identify vaginal abnormal microflora and fungi infections.

RESULTS

Despite the fact that there were no statistical significant differences related to the cytological aspects and pH measurements, it was found that the vaginal health index was highly superior in the control group than in the POF group (23.4 ± 1.8 vs 20.8 ± 3.5), p < 0.0001 despite both groups had trophic scores. There were no statistical significance differences regarding to vaginal microflora types and fungi infection.

CONCLUSION

Oral hormone therapy for young women with POF seems to be good enough to reestablish the epithelium cells, vaginal pH and microflora.

Dyspareunia and lubrication in premature ovarian failure using hormonal therapy and vaginal health

OBJECTIVE

To evaluate vaginal microbiological and functional aspects in women with and without premature ovarian failure (POF) and the relationship with sexual function.

METHODS

A cross-sectional study of 36 women with POF under hormonal therapy who were age-matched with 36 women with normal gonadal function. The vaginal tropism was assessed through hormonal vaginal cytology, vaginal pH and vaginal health index (VHI). Vaginal flora were assessed by the amine test, bacterioscopy and culture for fungi. Sexual function was evaluated through the questionnaire Female Sexual Function Index (FSFI).

RESULTS

Women in both groups were of similar age and showed similar marital status. The two groups presented vaginal tropic scores according to the VHI but the tropism was worse among women in the POF group. No difference was observed with respect to hormonal cytology and pH. Vaginal flora was similar in both groups. Women with POF showed worse sexual performance with more pain and poorer lubrication than women in the control group. The VHI, the only parameter evaluated showing statistical difference between the groups, did not correlate with the domains of pain and lubrication in the FSFI questionnaire.

CONCLUSION

These findings suggest that the use of systemic estrogen among women with POF is not enough to improve complaints of lubrication and pain despite conferring similar tropism and vaginal flora. Other therapeutic options need to be evaluated.

Accuracy of clinical diagnosis of bacterial vaginosis by human immunodeficiency virus infection status

OBJECTIVE

To assess the accuracy of clinical diagnosis of bacterial vaginosis (BV) by using Amsel criteria, overall and by human immunodeficiency virus (HIV) infection status.

METHODS

Women with HIV, or at risk for HIV, participated in the HIV Epidemiology Research Study, a prospective study conducted in 4 US sites. At enrollment and follow-up visits, scheduled at 6-month intervals for ≤ 5 years, participants received gynecologic examinations, had specimens collected, and underwent standardized interviews. We used McNemar test statistic to evaluate agreement between Amsel criteria and Nugent scoring. Using Nugent scoring as the reference standard, we calculated sensitivity and specificity for Amsel criteria and for 3 other classifications of clinical BV. Our results are based on data collected from 9140 study visits by 862 HIV-infected women and 421 HIV-uninfected women.

RESULTS

Amsel criteria and Nugent scoring did not agree in the classification of BV cases (P < 0.01). Amsel criteria had poor sensitivity (60%; 95% confidence interval, 58%-61%) and specificity (90%; 95% confidence interval, 89%-91%) with wide differences in test properties by study site. We found no differences in diagnosing BV by HIV infection status.

CONCLUSIONS

The under- and overdiagnosing of BV clinically suggests that the accuracy of Amsel criteria for routine screening of asymptomatic women might be lower than previous estimates; that clinicians need more rigorous training to apply subjective Amsel criteria accurately; or that wide heterogeneity in cases might prevent agreement between clinical and laboratory diagnoses, with future research needed to better understand the criteria or morphotypes associated with specific adverse outcomes.

Efficacy of methods used for the diagnosis of bacterial vaginosis

INTRODUCTION

Bacterial vaginosis (BV) has been associated with pelvic inflammatory disease, adverse pregnancy outcomes, increased susceptibility to sexually transmitted infections and infertility. Diagnosis of BV should be rapid, reliable and safe. This is especially vital in pregnant women where intervention may be necessary for the well-being of both the mother and the foetus.

AREAS COVERED

This paper consulted PUBMED, LISTA and Web of Science for point-of-care and laboratory-based tests commonly used for the diagnosis and management of BV in pregnant women. An overview of strengths and weaknesses of the methods used may partially explain why treatment plans have failed. Differences in sampling and detection methods, time of gestation, inter-examiner variability and interpretation of data, and the use of different reference tests, amongst many other factors, complicated a meta-analysis of the data.

EXPERT OPINION

Inconsistencies found in clinical and laboratory detection methods used for the monitoring of treatment have a direct impact on success rates. With current advances in technology, the diagnosis of BV is taking on a new perspective. New information implicating specific vaginal biofilms in adverse pregnancy outcomes through the application of advanced technology promises to change the way we view the aetiology, diagnosis and management of BV.

Comparison of Affirm VPIII and Papanicolaou tests in the detection of infectious vaginitis

To compare the Affirm VPIII molecular test (Becton Dickinson, Burlington, NC) with morphologic identification used in routine Papanicolaou (Pap) test screening in the detection and identification of Candida species, Trichomonas vaginalis, and Gardnerella vaginalis, we identified 431 cases with a concomitant Pap test and Affirm VPIII assay performed from the archives of a large academic institution. The study population consisted of women ranging in age from 17 to 79 years (mean and median ages, 33 and 31 years, respectively). With a routine Pap test, 60 patients (13.9%) were found to have bacterial vaginosis, 60 (13.9%) candidiasis, and 3 (0.7%) Trichomonas infection. With the Affirm VPIII assay, 183 (42.5%) patients tested positive for G vaginalis, 70 (16.2%) positive for Candida species, and 10 (2.3%) positive for T vaginalis. The differences were statistically significant. The results demonstrate that our patient population had a high incidence of bacterial vaginosis/Candida vaginitis; however, the Affirm VPIII was a more sensitive diagnostic test for the detection and identification of all 3 organisms compared with the Pap test.

Diagnosis and management of bacterial vaginosis and other types of abnormal vaginal bacterial flora: a review

Bacterial vaginosis (BV) is a common cause of abnormal vaginal discharge. It is characterised by an overgrowth of predominantly anaerobic organisms (Gardnerella vaginalis, Prevotella spp., Peptostreptocci, Mobiluncus spp.) in the vagina leading to a replacement of lactobacilli and an increase in vaginal pH. BV can arise and remit spontaneously, but often presents as a chronic or recurrent disease. BV is found most often in women of childbearing age, but may also be encountered in menopausal women, and is rather rare in children. The clinical and microscopic features and diagnosis of BV are herein reviewed, and antibiotic and non-antibiotic treatment approaches discussed.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this educational activity, the participant should be better able to analyze bacterial vaginosis clinically, formulate an oral antibiotic treatment regimen for bacterial vaginosis and use vaginal treatments for bacterial vaginosis.

Vaginal flora changes on Pap smears after insertion of levonorgestrel-releasing intrauterine device

BACKGROUND

The levonorgestrel intrauterine system (LNG-IUS) combines a uterine foreign body and the continuous release of low-dose levonorgestrel for contraception. Its influence on the rate of vulvovaginal infections and flora disturbance is insufficiently known, but important for contraceptive advice in women, especially those who develop recurrent vaginosis or Candida vulvovaginitis.

STUDY DESIGN

Slides of 286 women who had a Pap smear taken before and 1 to 2 years after placement of a LNG-IUS were blindly reviewed for the presence of abnormal vaginal flora (AVF), bacterial vaginosis (BV), aerobic vaginitis (AV) and Candida vaginitis (CV).

RESULTS

Prior to insertion, there were no differences in vaginal flora abnormalities between women using different kinds of contraception. LNG-IUS users did not have different rates of AVF, BV, AV or CV, but the general risk to develop any infection was increased. Uterine bleeding after insertion did not seem to predict a different flora type.

CONCLUSION

We found that Pap smears suggested more vaginal infections after 1 year of LNG-IUS use than prior to insertion of the device.