Vaginal flora and pelvic inflammatory disease

Characterization of Gardnerella vaginalis membrane vesicles reveals a role in inducing cytotoxicity in vaginal epithelial cells

Bacterial vaginosis (BV) is a common polymicrobial infection affecting women in the reproductive age and is associated with adverse obstetric and gynaecological outcomes. Gardnerella vaginalis is the most virulent anaerobic bacterial species predominantly associated with BV. However, a clear understanding of the mechanisms by which it contributes to the pathogenesis and persistence of BV is lacking. In this report, we demonstrate for the first time, the isolation of membrane vesicles (MVs) from G. vaginalis ATCC 14019. These MVs are approximately 120-260 nm in diameter. Proteomic characterization of the MVs by LC-MS/MS led to the identification of 417 proteins, including proteins involved in cellular metabolism as well as molecular chaperones and certain virulence factors. Immunoblot analysis of the MVs confirmed the presence of vaginolysin, the most well-characterized virulence factor of G. vaginalis. The exposure of the vaginal epithelial cells, VK2/E6E7 to the G. vaginalis MVs resulted in the internalization of the MVs. The MVs induced cytotoxicity and an increase in the levels of the pro-inflammatory cytokine, IL-8 in VK2 cells as well lysis of erythrocytes. The results of the study indicate that G. vaginalis MVs may be involved in the delivery of cytotoxic proteins and other virulence factors to the host cells and could thereby contribute towards enhancing the cellular damage associated with pathogenesis of BV.

Genital hygiene behaviors and practices: A cross-sectional descriptive study among antenatal care attendees

The female genital tracts harbor a wide variety of microorganisms’ knowns as microflora mostly constituted by lactobacilli, involved in the healthy state of the vagina without causing infection. Urinary tract infections (UTI) are frequent in pregnant women due to physiological and anatomical changes that occur during pregnancy. These infections can result to disabilities or serious health problems both for the mother and the new-born. Vaginal douching has been reported among risky practices associate with UTIs. However, this remains debatable and contradictory when other studies report the benefit effects of vaginal cleaning in infection prevention. The aim of this study was to assess pregnant women behaviors and practices regarding genital hygiene. This was a cross sectional descriptive study conducted on exhaustive sample of pregnant women coming for antenatal visits in Lafé Sub-divisional Hospital (SDH) and Baleng Catholic Health Center (BCHC) between 16 and 30 September 2013. Data were collected using a paper based standardized questionnaire directly self-administered after obtain a free consent. Overall, 80 pregnant women were enrolled. The majority of them had attended at least primary education (97.5%; n=78/80) and many were lived in couple (81.25%; n=65/80). Almost one on three participants identified antenatal consultation (ANC) as a key element to be taken into account by pregnant women. 70.1% (n=56/80) of women declared wearing undergarments in cotton. Regarding the daily vaginal douching behaviors, the majority (76.3%; n=61/80) of participants used the recommended gynecological measure, while the remaining use self-prescribed measures. Both genital parts (vulva area and vagina) were cleaned and use of water was mostly cited (63.8%; n=51/80). Almost one participant on four (n=29/80) use antiseptic solutions for genital cleaning. Antiseptic solutions were associated with water in 34.5% of cases (n=10/29), and in 65.5% (n=19/29) of cases it was used only for the vagina. Our findings suggest that knowledge and genital hygiene cleaning practices are acceptable among our study population. Risky practices such as use of antiseptic solutions and synthetic underwear’s were reported. Skills of health care providers on good hygiene practices for pregnant should be improved and community-based communication strategies need to be implemented to reach all women of child bearing age.

Smoking, poor nutrition, and sexually transmitted infections associated with pelvic inflammatory disease in remote North Queensland Indigenous communities, 1998-2005

Background

Indigenous women in remote North Queensland have a high prevalence of unhealthy lifestyle behaviors and associated health conditions such as sexual transmitted infections (STI). The association of severe pelvic inflammatory disease (PID) with these factors has not been studied. The purpose of this study is to associate the factors with severe PID, as indicated by hospitalization in a high risk population in North Queensland Indigenous communities.

Methods

A cross-sectional association of 1445 Indigenous women using linked hospital separation and survey data during 1998–2005.

Results

The mean age of participating women was 37.4 years, 60% were of Aboriginal and 40% were Torres Strait Island (TSI) people. More than half of them (52.5%) were smokers, 9.3% had chlamydia and 2.6% had gonorrhoea with the overall prevalence of STI among those less than 25 years of age being 23.9%. Among the 47 participants diagnosed with PID in the study period, 42.5% were under 25 years and 95.7% (45 cases) were under 55 years (OR 2.5, 95% CI 1.2-4.1 among women younger than 25 compared to those 25 years and over). PID was strongly associated with smoking (OR 3.1, 95% CI 1.4-9.2) independent of age, ethnicity, STI and folate status. Low red cell folate increased PID hospitalization by 4 times (95% CI 1.5-13.2 of lowest quartile compared to the highest quartile) regardless of age. Having a STI significantly increased the likelihood of severe PID by 2.2 times (95% CI: 1.03-4.5) in Indigenous women younger than 45 years, independent of smoking and folate level. The risk of PID hospitalization was higher for gonorrheal infections (OR 3.2, 955 CI 1.1-9.6) compared to chlamydial infections (OR 1.5 95% CI 0.7-3.5).

Conclusions

Young Indigenous women in North Queensland communities are at very high risk for STI and PID. Smoking, low folate, and STI are clustered, and are associated with PID hospitalizations. Much of this can be prevented with improved nutrition and access to preventive services, especially tobacco control, regular STI screening and treatment, as well as more investment in sexual health education and awareness.

Electronic supplementary material

The online version of this article (doi:10.1186/s12905-015-0188-z) contains supplementary material, which is available to authorized users.

Maternal vitamin D, folate, and polyunsaturated fatty acid status and bacterial vaginosis during pregnancy

OBJECTIVE

To investigate associations among serum 25-hydroxy-vitamin D (25-OH-D), folate, omega-6/omega-3 fatty acid ratio and bacterial vaginosis (BV) during pregnancy.

METHODS

Biospecimens and data were derived from a random sample (N = 160) of women from the Nashville Birth Cohort. We compared mean plasma nutrient concentrations for women with and without BV during pregnancy (based on Nugent score ≥7) and assessed the odds of BV for those with 25-OH-D <12 ng/mL, folate <5 ug/L, and omega-6/omega-3 ratio >15.

RESULTS

The mean plasma 25-OH-D was significantly lower among women with BV during pregnancy (18.00±8.14 ng/mL versus 24.34±11.97 ng/mL, P = 0.044). The adjusted odds of BV were significantly increased among pregnant women with 25-OH-D <12 ng/mL (aOR 5.11, 95% CI: 1.19-21.97) and folate <5 ug/L (aOR 7.06, 95% CI: 1.07-54.05).

CONCLUSION

Vitamin D and folate deficiencies were strongly associated with BV (Nugent score ≥7) during pregnancy.

The laboratory diagnosis of bacterial vaginosis

Bacterial vaginosis (BV) is an extremely common health problem for women. In addition to the troublesome symptoms often associated with a disruption in the balance of vaginal flora, BV is associated with adverse gynecological and pregnancy outcomes. Although not technically a sexually transmitted infection, BV is a sexually associated condition. Diagnostic tests include real-time clinical/microbiological diagnosis, and the current gold standard, the standardized evaluation of morphotypes on Gram stain analysis. The inappropriate use of vaginal culture can be misleading. Future developments into molecular-based diagnostics will be important to further understand this complex endogenous flora disruption.

Diagnostic evaluation of pelvic inflammatory disease

Pelvic inflammatory disease (PID) is a serious public health and reproductive health problem in the United States. An early and accurate diagnosis of PID is extremely important for the effective management of the acute illness and for the prevention of long-term sequelae. The diagnosis of PID is difficult, with considerable numbers of false-positive and false-negative diagnoses. An abnormal vaginal discharge or evidence of lower genital tract infection is an important and predictive finding that is often underemphasized and overlooked. This paper reviews the clinical diagnosis and supportive laboratory tests for the diagnosis of PID and outlines an appropriate diagnostic plan for the clinician and the researcher.

Postoperative pelvic infections

Infectious morbidity affecting the postoperative course has long been a concern for obstetricians and gynecologists. The incidence of postoperative infections approaches 38%. The third most common nosocomial infection is surgical site infection. The realm of postoperative infections includes obstetric and gynecologic sources. An understanding of the basic fundamentals of the vaginal flora and addressing host and surgical risk factors can aid in prevention of postoperative infections, which result in significant morbidity and mortality.

Prevalence of bacterial vaginosis among young women in low-income populations of coastal Peru

The goal of this study was to determine the prevalence of bacterial vaginosis (BV) in Peruvian women from socioeconomically deprived populations and to determine the association between BV and risk factors for sexually transmitted diseases (STDs). Women were administered an epidemiologic survey to determine sexual risk behaviour and they provided biological samples to test for BV and STDs. The prevalence of BV was high (27%) and was significantly associated with having a bacterial STD or trichomoniasis. Age, marital status, and a history of sex work, but not of sexual experience, frequency of intercourse, and unprotected intercourse, were associated with BV. As BV may be a marker for STDs, screening for STDs should be performed in individuals with BV to promote early detection and treatment of co-infecting sexually transmitted pathogens.

Bacterial vaginosis: many questions--any answers?

PURPOSE OF REVIEW

Bacterial vaginosis, a common disorder among young women, is associated with adverse reproductive health outcomes. This review summarizes our current understanding of bacterial vaginosis and where future research should be focused. Recommendations for prevention, diagnosis, and treatment in both nonpregnant and pregnant populations are discussed.

RECENT FINDINGS

Little progress has been made in understanding the causal factors. The results of several large prospective studies have shown that racial differences persist for rates of bacterial vaginosis even when other known risk factors are controlled for. Studies of the gene-environment interaction that examine the genetic aspects of immune response may explain racial differences and why some but not all women with bacterial vaginosis experience complications. Trials to prevent preterm birth by the treatment of bacterial vaginosis in pregnancy are disappointing. Resistance to clindamycin by bacterial vaginosis-associated anaerobic organisms has also been documented. New technology to provide rapid point-of-care diagnostic testing for bacterial vaginosis has emerged.

SUMMARY

To understand the vaginal ecosystem and its role in reproductive health and disease, we will need to study not only the microflora but also the host-immune response. Currently recommended treatment options for bacterial vaginosis are associated with high rates of recurrence. A new concern is the development of macrolide resistance to vaginal anaerobic flora when clindamycin is used as treatment. Further studies are still needed to determine whether prevention or control of bacterial vaginosis, particularly approaches that rely not on antibiotic treatment but on the maintenance of a healthy vaginal ecosystem, can reduce adverse health outcomes.

Mobiluncus species in gynaecological and obstetric infections: antimicrobial resistance and prevalence in a Turkish population

The purpose of this study was to determine the prevalence and antimicrobial resistance of Mobiluncus species isolated from specimens collected from Turkish women with gynaecological infections. Mobiluncus species were isolated on enriched Schaedler agar and RLK agar plates under anaerobic conditions. The MICs of various antibiotics were evaluated using an agar dilution procedure. The prevalence of Mobiluncus species isolated from vulvo-vaginal abscesses, endometrial smears, salpingitis and bacterial vaginosis was 2%, 4.7%, 3.8% and 49%, respectively. Mobiluncus isolates were only resistant to metronidazole (81% resistance). The isolation rate of M. curtisii was higher than M. mulieris in Turkish women with bacterial vaginosis, vulvo-vaginal abscesses, endometritis or salpingitis.

Bacterial Vaginosis and Risk of Pelvic Inflammatory Disease

BACKGROUND

Bacterial vaginosis commonly is found in women with pelvic inflammatory disease (PID), but it is unclear whether bacterial vaginosis leads to incident PID.

METHODS

Women (n = 1,179) from 5 U.S. centers were evaluated for a median of 3 years. Every 6-12 months, vaginal swabs were obtained for gram stain and culture of microflora. A vaginal microflora gram stain score of 7-10 was categorized as bacterial vaginosis. Pelvic inflammatory disease was diagnosed by presence of either histologic endometritis or pelvic pain and tenderness plus one of the following: oral temperature greater than 38.3 degrees C; sedimentation rate greater than 15 mm/hour; white blood count greater than 10,000; or lower genital tract detection of leukorrhea, mucopus, or Neisseria gonorrhoeae or Chlamydia trachomatis.

RESULTS

After adjustment for relevant demographic and lifestyle factors, baseline bacterial vaginosis was not associated with the development of PID (adjusted hazard ratio 0.89, 95% confidence interval 0.55-1.45). Carriage of bacterial vaginosis in the previous 6 months before a diagnosis (adjusted risk ratio 1.31, 95% confidence interval 0.71-2.42) also was not significantly associated with PID. Similarly, neither absence of hydrogen peroxide-producing Lactobacillus nor high levels of Gardnerella vaginalis significantly increased the risk of PID. Dense growth of pigmented, anaerobic gram-negative rods in the 6 months before diagnosis did significantly increase a woman's risk of PID (P =.04). One subgroup of women, women with 2 or more recent sexual partners, demonstrated associations among bacterial vaginosis, Gardnerella vaginalis, anaerobic gram-negative rods, and PID.

CONCLUSION

In this cohort of high-risk women, after adjustment for confounding factors, we found no overall increased risk of developing incident PID among women with bacterial vaginosis.

LEVEL OF EVIDENCE

II-2

Vaginal douching among adolescent and young women: more challenges than progress

The practice of vaginal douching dates back centuries. Numerous studies have shown that douching is quite prevalent and often begins during adolescence. Motivation for the initiation and maintenance of this practice appears complex, and presents challenges to the intervention efforts. The practice of douching remains controversial. Douching has been implicated in numerous adverse reproductive health outcomes such as increased risk for pelvic inflammatory disease, ectopic pregnancy, reduced fertility, and bacterial vaginosis. However, recent studies in developing countries have suggested that in certain circumstances, douching may actually be beneficial. We summarize key findings from the review of published literature and ongoing research, as well as highlight research challenges to our understanding of the role of vaginal douching in reproductive health.

Preventing Adverse Sequelae of Bacterial Vaginosis

BACKGROUND

The cause of bacterial vaginosis remains poorly understood. Recent evidence strengthens the association between bacterial vaginosis and serious medical complications.

GOAL

To review the evidence linking bacterial vaginosis with adverse pregnancy outcomes, complications after gynecologic procedures, and HIV infection, and to identify prevention strategies.

METHODS

In March 1999, the Centers for Disease Control and Prevention organized a conference to accomplish this goal.

RESULTS

Better understanding is needed concerning the etiology, epidemiology, and natural history of bacterial vaginosis. More efficacious treatment of bacterial vaginosis and strategies to reduce maternal complications associated with bacterial vaginosis, such as premature rupture of the fetal membranes, chorioamnionitis, premature labor and delivery, postdelivery endometritis, and postpartum infant complications should be developed. Recent evidence shows that screening and treatment of bacterial vaginosis before abortion reduces postabortion pelvic inflammatory disease, and that anaerobic coverage during hysterectomy reduces postoperative complications. Better understanding concerning the relation of bacterial vaginosis to acquisition of sexually transmitted diseases and HIV infection are needed as well as possible prevention strategies.

CONCLUSIONS

A national prevention effort should be guided by the results of research that addresses current knowledge gaps.

Identification of a human lactoferrin-binding protein in Gardnerella vaginalis

Previous studies have shown that Gardnerella vaginalis can utilize iron-loaded human lactoferrin as a sole source of iron. In this study, G. vaginalis cells were shown to bind digoxigenin (DIG)-labeled human lactoferrin in a dot blot assay. Using the DIG-labeled human lactoferrin, a 120-kDa human lactoferrin-binding protein was detected by Western blot analysis of G. vaginalis proteins. The lactoferrin-binding activity of this protein was found to be heat stable. Competition studies indicated that this binding activity was specific for human lactoferrin. Treatment of G. vaginalis cells with proteases suggested that this protein was surface exposed. An increase in lactoferrin binding by the 120-kDa protein was observed in G. vaginalis cells grown under iron-restrictive conditions, suggesting that this activity may be iron regulated.

Pelvic inflammatory disease. From diagnosis to prevention

Pelvic inflammatory disease (PID) refers to infection of the uterus, fallopian tubes, and adjacent pelvic structures that is not associated with surgery or pregnancy. PID causes major medical, social, and economic problems worldwide. Long-term sequelae, most notably tubal factor infertility and ectopic pregnancy, are common and extremely costly to the healthcare system. The most important causative micro-organisms are Chlamydia trachomatis, Neisseria gonorrhoeae, and micro-organisms associated with bacterial vaginosis. The clinical spectrum of PID ranges from subclinical endometritis to severe salpingitis, pyosalpinx, tubo-ovarian abscess, pelvic peritonitis, and perihepatitis. Clinical diagnosis of PID has limitations. The clinical diagnostic criteria are insensitive and nonspecific, and false-positive and false-negative diagnosis is common; however, direct visual diagnosis is not always feasible, requires general anesthesia, and is costly. More research is needed of noninvasive diagnosis of PID. Current treatment guidelines call for broad-spectrum antimicrobial coverage. Screening for asymptomatic chlamydial infection is the mainstay of prevention of PID. Emerging evidence from randomized controlled trials provides strong evidence that intervention with selective screening for chlamydial infection effectively reduces the incidence of PID.

Acquisition of iron by Gardnerella vaginalis

Six Gardnerella vaginalis strains were examined for the ability to utilize various iron-containing compounds as iron sources. In a plate bioassay, all six strains acquired iron from ferrous chloride, ferric chloride, ferrous sulfate, ferric ammonium citrate, ferrous ammonium sulfate, bovine and equine hemin, bovine catalase, and equine, bovine, rabbit, and human hemoglobin. All six strains also acquired iron from human lactoferrin, but not from human transferrin, as determined by a liquid broth growth assay. Siderophore production was detected in eight G. vaginalis strains by the chrome azurol S universal chemical assay. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the cytoplasmic membrane proteins isolated from G. vaginalis 594 grown under iron-replete and iron-restricted conditions revealed several iron-regulated proteins ranging in molecular mass from 33 to 94 kDa. These results indicate that G. vaginalis may acquire iron from iron salts and host iron compounds.

Evaluation and management of vaginitis

OBJECTIVE

To evaluate recent advances in our understanding of the clinical relevance, diagnosis, and treatment of vaginal infections, and to determine an efficient and effective method of evaluating this clinical problem in the outpatient setting.

DATA SOURCES

Relevant papers on vaginitis limited to the English language obtained through a MEDLINE search for the years 1985 to 1997 were reviewed.

DATA SYNTHESIS

Techniques that enable the identification of the various strains of candida have helped lead to a better understanding of the mechanisms of recurrent candida infection. From this information a rationale for the treatment of recurrent disease can be developed. Bacterial vaginosis has been associated with complications, including upper genital tract infection, preterm delivery, and wound infection. Women undergoing pelvic surgery, procedures in pregnancy, or pregnant women at risk of preterm delivery should be evaluated for bacterial vaginosis to decrease the rate of complications associated with this condition. New, more standardized criteria for the diagnosis of bacterial vaginosis may improve diagnostic consistency among clinicians and comparability of study results. Use of topical therapies in the treatment of bacterial vaginosis are effective and associated with fewer side effects than systemic medication. Trichomonas vaginalis, although decreasing in incidence, has been associated with upper genital tract infection. Therapy of T. vaginalis infection has been complicated by an increasing incidence of resistance to metronidazole.

CONCLUSIONS

Vaginitis is a common medical problem in women that is associated with significant morbidity and previously unrecognized complications. Research in recent years has improved diagnostic tools as well as treatment modalities for all forms of vaginitis.

Role of bacterial vaginosis-associated microorganisms in endometritis

OBJECTIVE

Our goal was to define the role of bacterial vaginosis and bacterial vaginosis-associated microorganisms in endometritis.

STUDY DESIGN

Endometrial biopsies were obtained for histologic and microbiologic study from 178 consecutive women with suspected pelvic inflammatory disease, and 85 of them underwent laparoscopy to diagnose salpingitis.

RESULTS

Histologic endometritis was confirmed in 117 (65%) of the women. Among women who underwent laparoscopy, salpingitis was present in 68% of those with and 23% of those without endometritis. Some but not all bacterial vaginosis-associated microorganisms were linked with endometritis. By logistic regression analysis, after adjustment for bacterial vaginosis and isolation of Neisseria gonorrhoeae and Chlamydia trachomatis, endometritis was associated with endometrial N. gonorrhoeae (odds ratio 5.7, 95% confidence interval 1.8 to 17.5), C. trachomatis (odds ratio 4.8, 95% confidence interval 1.3 to 18.2), anaerobic gram-negative rods (odds ratio 2.6, 95% confidence interval 1.1 to 5.7), and nonwhite race (odds ratio 2.3, 95% confidence interval 1.1 to 4.8).

CONCLUSIONS

The association of anaerobic gram-negative rods with endometritis, after adjustment for bacterial vaginosis, N. gonorrhoeae, and C. trachomatis, supports the role of these microorganisms in the etiology of histologic endometritis among women with clinically suspected pelvic inflammatory disease.

Detection and identification of amines in bacterial vaginosis

For the purpose of determining an objective indicator of bacterial vaginosis (BV), we tried to detect and to identify amines in the vaginal fluid of patients by using the dansyl method (to detect amine in a solution of water). Bacteria isolated from these patients were also analyzed. 1) In BV (n: 32) 7 kinds of amines were detected; and the positive rate of detection of the dansyl method was 90.6%. No specific bacteria was found in BV. 2) The positive rate was 80.0% for the patients with trichomonas vaginitis (n: 5). 3) The positive rate of detection was 20.0% in the candida group (n: 5), and 28.6% in the control group (n: 14). Those amines detected in other than BV-related vaginitis are presumed not to vaporize. For purposes of diagnosis, it would be better to detect vaporized amines instead of detecting amines dissolved in vaginal fluid.