Association of cervicovaginal infections with increased vaginal fluid phospholipase A2 activity

Phospholipases A and Lysophospholipases in protozoan parasites

Phospholipases (PLs) and Lysophospholipases (LysoPLs) are a diverse group of esterases responsible for phospholipid or lysophospholipid hydrolysis. They are involved in several biological processes, including lipid catabolism, modulation of the immune response and membrane maintenance. PLs are classified depending on their site of hydrolysis as PLA1, PLA2, PLC and PLD. In many pathogenic microorganisms, from bacteria to fungi, PLAs and LysoPLs have been described as critical virulence and/or pathogenicity factors. In protozoan parasites, a group containing major human and animal pathogens, growing literature show that PLAs and LysoPLs are also involved in the host infection. Their ubiquitous presence and role in host-pathogen interactions make them particularly interesting to study. In this review, we summarize the literature on PLAs and LysoPLs in several protozoan parasites of medical relevance, and discuss the growing interest for them as potential drug and vaccine targets.

Isolation and identification of Aspergillus fumigatus from Immunocompromised patients in AL- Najaf Province

The present study was conducted to isolation and identification of Aspergillus fumigatus. Isolated from immunocompromised patients with (Diabetes, Cancer) by different identification methods including direct examination, laboratory culture and electron microscopy. During the period from (July to September 2016), a total of 50 swab were collected from immunocompromised patients with attending to the in AL- Sadder Medical City (the Center for Diabetes and Endocrinology) and (Euphrates middle Center for cancer diseases). In AL-Najaf Governorate, the samples were collected as following: 30 swab from the eyes of cancer patients who were suffering from prostate, leukemia, stomach and intestines cancer, also 20 swabs from the ears of diabetic patients. The percentage of female to male was as following, 29 females (58%) males and 21 (42%). In this study, the results show that the incidence of aspergillosis in women was higher than the male. The results of the present study reveal that the prevalence of aspergillosis from patient with cancer was more than diabetes patients which was 18 (66.66%) and 9 (33.33%), respectively.

Identification and characterization of NanH2 and NanH3, enzymes responsible for sialidase activity in the vaginal bacterium Gardnerella vaginalis

Gardnerella vaginalis is abundant in bacterial vaginosis (BV), a condition associated with adverse reproductive health. Sialidase activity is a diagnostic feature of BV and is produced by a subset of G. vaginalis strains. Although its genetic basis has not been formally identified, sialidase activity is presumed to derive from the sialidase A gene, named here nanH1 In this study, BLAST searches predicted two additional G. vaginalis sialidases, NanH2 and NanH3. When expressed in Escherichia coli, NanH2 and NanH3 both displayed broad abilities to cleave sialic acids from α2-3- and α2-6-linked N- and O-linked sialoglycans, including relevant mucosal substrates. In contrast, recombinant NanH1 had limited activity against synthetic and mucosal substrates under the conditions tested. Recombinant NanH2 was much more effective than NanH3 in cleaving sialic acids bearing a 9-O-acetyl ester. Similarly, G. vaginalis strains encoding NanH2 cleaved and foraged significantly more Neu5,9Ac₂ than strains encoding only NanH3. Among a collection of 34 G. vaginalis isolates, nanH2, nanH3, or both were present in all 15 sialidase-positive strains but absent from all 19 sialidase-negative isolates, including 16 strains that were nanH1-positive. We conclude that NanH2 and NanH3 are the primary sources of sialidase activity in G. vaginalis and that these two enzymes can account for the previously described substrate breadth cleaved by sialidases in human vaginal specimens of women with BV. Finally, PCRs of nanH2 or nanH3 from human vaginal specimens had 81% sensitivity and 78% specificity in distinguishing between Lactobacillus dominance and BV, as determined by Nugent scoring.

Mechanisms of Tritrichomonas foetus Pathogenicity in Cats with Insights from Venereal Trichomonosis

Almost 20 years has passed since trichomonosis was first recognized as a potential cause of diarrhea in domestic cats. Despite progress in confirming disease causation, developing means for diagnosis, and identifying approaches to treatment of the infection, we still know very little about how this parasite causes diarrhea. With increasing recognition of resistance of trichomonosis to treatment with 5‐nitroimidazole drugs, new treatment strategies based on an understanding of disease pathogenesis are needed. In this review, lessons learned from the pathogenesis of venereal trichomonosis in people and cattle are applied to clinical observations of trichomonosis in cats in effort to generate insight into areas where further research may be beneficial.

Biochemical markers predictive of preterm delivery

Preterm delivery is the leading cause of perinatal morbidity and mortality worldwide. Despite a great deal of research into this disease, we still do not understand its pathophysiology. Our treatments for this disease are only marginally effective. Biochemical markers were developed with the hope of giving us new tools to prevent preterm deliveries. Specifically the hope was that they could predict which patients were destined to have a preterm delivery. At the present time these markers perform only satisfactorily at predicting preterm labor. They are expensive and not convenient to use at present. Perhaps more importantly, though, these markers have given us insight into the complexities of preterm delivery. Preterm delivery can arise from many different etiologies. This will lead to research into new treatments as knowledge about preterm delivery is amassed. We know that any number of pathological processes may be involved in any given patient with preterm labor. Biochemical markers have the distinct advantage of being able to determine the specific pathophysiology in a given patient and may allow us to tailor therapy according to the specific problem. In the future it is likely that a careful search for specific pathophysiology will be the only way we can treat this disease effectively. For the present time the biochemical markers will be used only to predict preterm delivery. Ultrasound measurements of the cervix during the pregnancy are likely a faster and less expensive way to accomplish that goal.

Pathogenesis to treatment: preventing preterm birth mediated by infection

Prevention of preterm birth and subsequent newborn immaturity is a primary goal of obstetrical care worldwide. Accumulated evidence shows that 1) as many as 25–50% of preterm births are caused by common genital tract infections and subsequent maternal/fetal inflammatory responses; 2) microbial and maternal host factors (phospholipases, proteases, etc.) play roles in preterm labor and preterm premature rupture of membranes (pPROM); 3) integrated aspects of maternal and fetal host responses (inflammation, altered immune adaptations, endocrine and paracrine mechanisms) play increasingly understood roles in premature activation of parturition; and 4) identification and systemic treatment of common genitourinary infections, most importantly bacterial vaginosis (BV), reduce the risks of preterm delivery and PROM.

Trichomonas vaginalis: diagnosis and clinical characteristics in pregnancy

Objective: The objectives of this study were to 1) determine the prevalance and characterize the symptomatology of Trichomonas vaginalis (TV) infection in pregnant women on entry into prenatal care in an inner-city population; 2) compare conventional microscopic methods vs. culture techniques in diagnosing TV in both symptomatic and asymptomatic pregnant patients; and 3) correlate wet mount microscopic and microbiologic characteristics of varying manifestations of trichomoniasis.

Methods: One thousand two hundred sixty patients in an inner-city population were tested at entry into prenatal care for TV by saline wet mount and culture techniques. Other tests for lower genital tract infection were also performed. Vaginal symptoms were ascertained through standardized questioning prior to examination. Standard microscopic and microbiologic data were also obtained for analysis. Wet mounts were systematically examined and considered negative if no TV was identified in 10 high powerfields (HPFs). Cultures were inspected from days 4 to 7 or until positive results were obtained. Results were analyzed using McNemar's test for correlated proportions, chi-squared test, or Fisher exact test where appropriate.

Results: Culture and wet mount results were available in 1,175 patients. TV infection was documented by one or both techniques in 110/1,175 (9.4%). Culture methods detected 105/110 (94.5%) of all patients while wet mount detected 90/110 (73%) (P <0.001). Vaginal symptoms were present in only 20/110 patents (18.2%). Among asymptomatic patients, culture detected 94% while wet mount detected 70% (P < 0.001). Among symptomatic patients, wet mount and culture were both effective and diagnosed 85% and 95% of infections, respectively (P = not significant). Patients with TV were more likely to have increased vaginal fluid wlaite blood cells (WBCs) and more severe vaginal flora disruption than uninfected controls. Subgroup analysis revealed wet mount-positive/culture-positive patients were more likely to have vaginal flora disruption, as evidenced by decreased lactobacilli and elevated vaginal pH, than wet mount-negative/culture-positive subjects. Coexistent infection rates were similar regardless of wet mount status. Elevated vaginal fluid WBCs were more common among patients with symptoms.

Conclusions: 1) Screening pregnant women for TV based solely on symptomatology is ineffective in this population; 2) culture techniques detected more infections than conventional microscopic evaluation; and 3) significant increases in vaginal fluid WBCs and altered vaginal flora are found in both symptomatic and asymptomatic TV, suggesting that both infestations have the potential to adversely affect pregnancy outcome. Studies on the influence of TV on pregnancy outcomes are ongoing.

Improved cure of bacterial vaginosis with single dose of tinidazole (2 g), Lactobacillus rhamnosus GR-1, and Lactobacillus reuteri RC-14: a randomized, double-blind, placebo-controlled trial

Bacterial vaginosis (BV) is the most prevalent vaginal infection worldwide and is characterized by depletion of the indigenous lactobacilli. Antimicrobial therapy is often ineffective. We hypothesized that probiotic Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14 might provide an adjunct to antimicrobial treatment and improve cure rates. Sixty-four Brazilian women diagnosed with BV were randomly assigned to receive a single dose of tinidazole (2 g) supplemented with either 2 placebo capsules or 2 capsules containing L. rhamnosus GR-1 and L. reuteri RC-14 every morning for the following 4 weeks. At the end of treatment (day 28), the probiotic group had a significantly higher cure rate of BV (87.5%) than the placebo group (50.0%) (p = 0.001). In addition, according to the Gram-stain Nugent score, more women were assessed with "normal" vaginal microbiota in the probiotic group (75.0% vs. 34.4% in the placebo group; p = 0.011). This study shows that probiotic lactobacilli can provide benefits to women being treated with antibiotics for an infectious condition.

Detection of bacteria in placental tissues obtained from extremely low gestational age neonates

OBJECTIVE

The objective of the study was to quantify and identify aerobic and anaerobic bacteria as well as Mycoplasma and Ureaplasma in the chorionic parenchyma.

STUDY DESIGN

A sample of the chorionic parenchyma from neonates delivered between 23-27 completed weeks was cultured and tested by polymerase chain reaction (PCR) methods using universal bacterial primers for the presence of bacteria and mycoplasmas.

RESULTS

The culture positive rate was higher for vaginal deliveries (333/489; 68%) than for cesarean sections (363/876; 41%). Thirty percent of all culture-positive samples had only aerobic bacteria, 21% of the samples had only anaerobic bacteria, and 9% of the samples had only Mycoplasma/Ureaplasma. The mean concentration of Mycoplasma/Ureaplasma (4.00 +/- 1.11 log10 CFU/g) was significantly higher (P < .001) than the total count of either aerobes (3.24 +/- 1.12 log10 CFU/g) or anaerobes (2.89 +/- 0.99 log10 CFU/g). Staphylococcus sp. and Corynebacterium sp. as well as organisms associated with bacterial vaginosis were the most frequently recovered. A PCR product was not detected from either randomly selected or known culture-positive samples.

CONCLUSION

Approximately half of second-trimester placentas harbor organisms within the chorionic plate. The chorion parenchyma appears to harbor constituents that prevent the identification of bacterial deoxyribonucleic acid by PCR methods.

Probiotics for women's health

GOALS

The goals of this research were 2-fold: (1) to determine whether a commercially available probiotic mixture (VSL-3) could survive and grow in a continuous culture system simulating the vaginal environment and (2) to determine whether the probiotic mixture was capable of suppressing the growth of a known vaginal vault pathogen, Gardnerella vaginalis.

BACKGROUND

An abnormal vaginal microflora, such as that associated with bacterial vaginosis (BV) is an important health issue for women. In addition, the association of this condition with preterm labor and delivery suggests that control of BV may impact the number of preterm births. Interventional trials with antibiotics have received mixed reviews and other interventional options, including the use of probiotics, are being considered.

STUDY

A well-documented continuous culture system has been used to determine whether VSL-3 can survive and grow in conditions simulating a vaginal environment. In addition, the ability of VSL-3 to inhibit the growth of a known vaginal vault pathogen, G. vaginalis, has been determined.

RESULTS

The probiotic mixture was shown to survive and maintain itself within the fermentation vessel of the continuous culture system over an extended period of time. This mixture, when challenged with a known pathogen, was also shown to suppress the growth of G. vaginalis.

CONCLUSIONS

It may be feasible to use probiotics as interventional therapy to suppress the growth of pathogens within the vaginal vault associated with BV.

The determination of phospholipase A2 enzyme activity in the vaginal secretions of pregnant and non-pregnant women with bacterial vaginosis-and in culture exudates of its causative organisms

Bacterial vaginosis (BV) is presently being cited as a probable cause of premature labour, where it is thought that an abnormal excess of phospholipase A2 enzyme (PLA2 ), generated by infecting organisms, prematurely liberates prostaglandins, which trigger-off the labour process. PLA levels of pregnant and non-pregnant women, with and without BV infection were compared. The in vitro concentrations of PLA2 in broth cultures of infecting organisms were also measured. Mean PLA2 level in non-infected pregnant women was 777 units per mg but was raised to 1226 U/mg in those with BV ( P= <0.001). Mean level in non-infected normal women was 21 U/mg, but was raised to 97 U/mg in those having BV ( P= <0.001). PLA2 concentrations in broth cultures of the causative organisms showed that most Bacteroides strains produced the enzyme, having a mean concentration of 95 U/mg, but that it was generated by only 34% of Gardnerella vaginalis strains, their mean concentration being 32 U/mg.

Trichomoniasis

Trichomoniasis is perhaps the most common curable sexually transmitted disease worldwide, yet few resources are devoted to its control. It is associated with potentially serious complications such as preterm birth and human immunodeficiency virus acquisition and transmission. The immunology of a related organism, Tritrichomonas foetus, which causes disease in cattle, has been investigated to some extent, but more work is needed for the human strain, Trichomonas vaginalis. In addition, although trichomoniasis is easily treated with oral metronidazole, there is concern that the number of strains resistant to this antibiotic are increasing, and currently no alternative is licensed in the United States. As more is appreciated concerning the important public health implications of this common infection, more work will need to be done in understanding the diagnosis, treatment, and immunology of this organism.

Purification and analysis of a phospholipase A2-like lytic factor of Trichomonas vaginalis

Trichomonas vaginalis produces soluble factors that have been reported to have the ability to damage target cells in vitro, and it has been hypothesized that these factors may play a role in the pathogenesis of human trichomoniasis. A lytic factor (LF) was purified from T. vaginalis, and the molecular characteristics of LF were determined. T. vaginalis extract was subjected to hydrophobic chromatography with a 10 to 60% N-propanol gradient in 0.1 M ammonium acetate, resulting in the elution of LF from the column at 30% N-propanol. Cytotoxicity assays revealed that LF was cytotoxic to WEHI 164 cells and bovine red blood cells, and inactivation of LF by treatment with trypsin suggested that the active component of LF was a protein. Size exclusion chromatography of LF produced two fractions at 144 and 168 kDa, and analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of LF under reducing conditions revealed two subunits of 57 and 60 kDa. Results of a fluorescence assay of LF on carboxyfluorescein-labeled liposomes composed of phosphatidylcholine-cholesterol showed that liposomes were hydrolyzed, suggesting that LF had phospholipase activity. Thin-layer chromatography analysis of BODIPY (4,4-difluoro-3a,4adiaza-s-indacene)-labeled phosphatidylcholine treated with LF demonstrated products that migrated identically to the products produced by treatment with phospholipase A(2) (PLA(2)). These results suggest that LF is a PLA(2) and may be an important virulence factor of T. vaginalis mediating the destruction of host cells and contributing to tissue damage and inflammation in trichomoniasis.

Relationship between periodontal disease in pregnant women and the nutritional condition of their newborns

BACKGROUND

The purpose of this study was to determine whether maternal periodontal disease (PD) could be associated with the nutritional condition of newborns.

METHODS

After controlling for traditional risk factors for premature childbirth and low birth weight, 69 mothers were selected: 13 were periodontally healthy and 56 had varying stages of PD. They and their newborns formed the study population. PD presence and severity were clinically determined using Russell's periodontal index. The nutritional evaluation of the newborns was determined by Lubchenco's modified growth patterns.

RESULTS

A decrease in the average newborn's weight and gestational age was observed as the mother's level of PD increased. Correlation analysis demonstrated a highly significant clinical relationship between more severe PD and lower birth weight (r = -0.49; P < 0.01); a highly significant relationship was also clinically demonstrated between increasing PD severity and decreasing gestational age of the newborn babies (r = -0.59; P < 0.01). There were significant differences in the weight and gestational age of the newborns of mothers with PD.

CONCLUSIONS

These data suggest that PD in pregnant women could be a clinically significant risk factor for preterm deliveries and low birth weight. There was considerable variability in the results, and these preliminary findings need to be confirmed in larger studies.

Infection, antibiotics, and preterm delivery

The relationship between genital tract infection and preterm delivery has been established on the basis of biochemical, microbiological, and clinical evidence. In theory, pathogenic bacteria may ascend from the lower reproductive tract into the uterus, and the resulting inflammation leads to preterm labor, rupture of the membranes, and birth. A growing body of evidence suggests that preterm labor and/rupture of the membranes are triggered by micro-organisms in the genital tract and by the host response to these organisms, ie, elaboration of cytokines and proteolytic enzymes. Epidemiologic and in vitro studies do not prove a cause-and-effect relationship between infection and preterm birth. However, the preponderance of evidence indicates that treatment of asymptomatic bacteriuria and symptomatic lower genital tract infections such as bacterial vaginosis (BV), trichomoniasis, gonorrhea, and chlamydia will lower the risk of preterm delivery. Based on current evidence, pregnant women who note an abnormal vaginal discharge should be tested for BV, trichomonas, gonorrhea, and chlamydia. Those who test positive should be treated appropriately. A 3- to 7-day course of antibiotic treatment for asymptomatic bacteriuria during pregnancy is clinically indicated to reduce the risk of pyelonephritis and preterm delivery. Routine screening for chlamydia and gonorrhea should be performed for women at high risk of acquiring sexually transmitted diseases. The practice of routine screening for BV in asymptomatic women who are at low risk for preterm delivery cannot be supported based on evidence from the literature. Routine screening for asymptomatic bacteriuria during pregnancy is cost-effective, particularly in high-prevalence populations. The results of antibiotic trials for the treatment of preterm labor have been inconsistent. In the absence of reasonable evidence that antimicrobial therapy leads to significant prolongation of pregnancy in the setting of preterm labor, antibiotics should be used only for protecting the neonate from group B streptococci sepsis. They should not be used for the purpose of prolonging pregnancy. Multiple investigations have shown that, in patients with preterm premature rupture of the membranes, prophylactic antibiotics are of value in prolonging the latent period between rupture of the membranes and onset of labor and in reducing the incidence of maternal and neonatal infection. The most extensively tested effective antibiotic regimen for prophylaxis involves erythromycin alone or in combination with ampicilln. Controversy still exists regarding the appropriate length and route of antibiotic prophylaxis.

Bacterial vaginosis in pregnancy

Bacterial vaginosis is a clinical condition caused by replacement of the normal hydrogen peroxide producing Lactobacillus sp. in the vagina with high concentrations of characteristic sets of aerobic and anaerobic bacteria. Bacterial vaginosis is the most prevalent cause of vaginal discharge or malodor, although 50 percent of women who meet the criteria for this condition are asymptomatic. Bacterial vaginosis is reported in 10 to 41 percent of women, and new evidence has shown association with maternal and fetal morbidity. Studies have shown that spontaneous abortion, preterm labor, premature birth, preterm premature rupture of the membranes, amniotic fluid infection, postpartum endometritis, and postcesarean wound infections are increased because of infection with bacterial vaginosis during pregnancy. Clinical trials demonstrated important reductions in many of these adverse events with appropriate screening and antimicrobial treatment protocols. New low-cost, diagnostic, point-of-care screening tools are available for rapid screening of patients, affording the physician the opportunity to potentially make a dramatic clinical and cost impact in preventing preterm birth and the costly sequelae of prematurity. Practicing physicians need to be aware of current guidelines for screening and treating pregnant patients for bacterial vaginosis. The authors recommend that all pregnant women be screened and treated with the Centers for Disease Control and Prevention (CDC-P) recommended oral regimens early in pregnancy. Each treated women should be evaluated for "test of cure" 1 month after treatment. Mothers likely to benefit from "screen and treat" approaches include 1) those with the highest concentrations of genital anaerobes and mycoplasmas, 2) women with prior preterm birth or who have low body mass (BMI < 19.8 kg/m2), 3) those with evidence of endometritis before pregnancy, and 4) those who are treated with oral agents effective for both presumed intrauterine mycoplasmas and other bacterial vaginosis flora (i.e., oral clindamycin or erythromycin and metronidazole).

Biology of trichomonosis

Trichomonas vaginalis is emerging as a major pathogen of men and women and is associated with serious health consequences. Advances in diagnosis and treatment are presented. The complexity of trichomonad pathogenesis is illustrated in the interaction of this parasite with human cells, tissues and the immune system. It is now becoming evident that the interaction of trichomonads with the host is frequently modulated by environmental signals. The molecular biology of trichomonads is still in its infancy, but analysis of genes, genomic structure and transcriptional mechanisms suggest that trichomonads combine both prokaryotic and eukaryotic features. Evidence for the ancient divergence of trichomonads from other eukaryotic lineages is discussed.

Pathogenesis of preterm labor and preterm premature rupture of membranes associated with intraamniotic infection

We have proposed a model in which the initiation of human parturition in the presence of infection is controlled by the host. Systemic maternal infections such as pyelonephritis or localized infections such as deciduitis can trigger parturition by the activation of the monocyte and macrophage system in peripheral blood and human decidua. Preterm labor and preterm PROM can, according to this, be considered events that occur when the intrauterine or maternal environment is hostile and threaten the survival of the fetal-maternal pair. From this point of view, the initiation of preterm labor may have survival value. Why does intrauterine infection result in preterm labor in some cases and PROM in others? It is possible that regulation of different components of the host response has an important role to play in determining clinical presentation. Thus, if preferential activation of the host response leads to the secretion of uterotonic agents (i.e., prostaglandins), preterm labor will result. On the other hand, if the activation of the host response results predominantly in the production of proteases (i.e., leukocyte elastase and MMPs), patients are more likely to experience PROM. Preterm labor and preterm PROM can be considered expressions of the same basic phenomenon: activation of the host-defense macrophage system. Although we have provided evidence that infection is an important factor in the pathogenesis of these conditions, preterm parturition should be considered as a syndrome with multiple causes.

The pathobiology of premature rupture of membranes

Premature rupture of membranes arises from what are likely multifaceted and multistep pathogenic pathways. Pathophysiological processes may involve both endogenous and exogenous fetal and maternal factors. This article reviews and analyzes information regarding, first, the form and function of fetal membranes; second, how membranes physically fail (rupture) at term and preterm gestations; and third, evaluates if we can reduce risks of rupture using physiological understanding and evidence-based clinical studies.

Prevention of premature birth by screening and treatment for common genital tract infections: results of a prospective controlled evaluation

OBJECTIVE

Our purpose was to analyze (1) the effects of prevalent lower reproductive tract infections and (2) the effect of systematic diagnosis and treatment to reduce risks of early pregnancy loss (< 22 weeks), preterm premature rupture of membrances, and overall preterm birth.

STUDY DESIGN

A prospective, controlled treatment trial was conducted on 1260 women. During the first 7 months of the program (observation, phase I), women were examined at initiation of prenatal care for a panel of lower genital tract microorganisms and bacterial vaginosis. Women were followed up with reexaminations at 22 to 29 weeks and after 32 weeks' gestation. The recommended treatments of the Centers for Disease Control (i.e., 300 mg of clindamycin orally twice daily for 7 days for bacterial vaginosis) were used for infected women during the second 8 months of the study (treatment, phase II). Data were analyzed according to intent to treat by means of univariate and multivariate methods.

RESULTS

Overall, presence of bacterial vaginosis (32.5%) at enrollment was associated with pregnancy loss at < 22 weeks' gestation (relative risk 3.1, 95% confidence interval 1.4 to 6.9). Among women in the observation phase bacterial vaginosis was associated with increased risk of both preterm birth (relative risk 1.9, 95% confidence interval 1.2 to 3.0) and preterm premature rupture of membranes (relative risk 3.5, 95% confidence interval 1.4 to 8.9). Within this population (phase I) 21.9% of preterm birth overall (43.8% premature rupture of membranes) is estimated as attributable to bacterial vaginosis. Among women with bacterial vaginosis phase II (treatment) was associated with reduced preterm birth (relative risk 0.5, 95% confidence interval 0.3 to 0.9); there was a similar reduction for women with preterm premature rupture of membranes (relative risk 0.5, 95% confidence interval 0.2 to 1.4). Women with both bacterial vaginosis and trichomoniasis were at highest risk of preterm birth (28%); treatment of both conditions (phase II) reduced preterm birth (17%) but did not eliminate this risk. Earlier patient enrollment and oral antibiotic treatment were associated with reduced preterm birth.

CONCLUSIONS

This prospective, controlled trial confirms that the presence of bacterial vaginosis is associated with increased risks of pregnancy loss at < 22 weeks, preterm premature rupture of membranes, and preterm birth. Orally administered clindamycin treatment is associated with a 50% reduction of bacterial vaginosis-linked preterm birth and preterm premature rupture of membranes. Women at risk for preterm birth or preterm premature rupture of membranes because of bacterial vaginosis or common genital tract infections should be screened, treated, reevaluated for cure, and re-treated if necessary.

Bacterial vaginosis is associated with prematurity and vaginal fluid mucinase and sialidase: results of a controlled trial of topical clindamycin cream

OBJECTIVE

The pathogenesis of preterm birth and other adverse pregnancy outcomes linked with reproductive tract infection remains poorly understood. Mucolytic enzymes, including mucinases and sialidases (neuraminidase), are recognized virulence factors among enteropathogens and bacteria that cause periodontal infection. Perturbation of maternal cervicovaginal mucosa membrane host defenses by such enzyme-producing microorganisms may increase the risk of subclinical intrauterine infection during pregnancy and thus increase risks of preterm birth.

STUDY DESIGN

We prospectively evaluated vaginal fluid mucinase and sialidase and selected cervicovaginal bacteria along with pregnancy outcomes in 271 women. Within this study, women with bacterial vaginosis (16 to 27 week' gestation) were treated with 2% clinadmycin vaginal cream or placebo. Enzyme, microbial findings, treatment effects, and pregnancy outcomes were compared among drug- and placebo-treated women and control women without bacterial vaginosis.

RESULTS

Presence of bacterial vaginosis at intake was associated with increased risk of preterm birth (relative risk 3.3, 95% confidence interval 1.2 to 9.1, p = 0.02), premature rupture of membranes (relative risk 3.8, 95% confidence interval 1.6 to 9.0, p = 0.002), and preterm premature rupture of membranes. Mucinase and sialidase activities were more commonly identified, and they occurred in higher concentrations, if present, in women with bacterial vaginosis (mucinase: 44.3% with bacterial vaginosis vs 27.4% without, p = 0.007; sialidase: 45% with bacterial vaginosis vs 12% without p < 0.001). Sialidase activity was associated with bacterial vaginosis-linked organisms (Gardnerella vaginalis, Mobiluncus spp, and Mycoplasma hominis) and Chlamydia trachomatis and yeast species; mucinase activity was associated only with bacterial vaginosis-linked microorganisms. Clindamycin, 2% cream, was effective treatment for bacterial vaginosis and temporarily reduced mucinase and sialidase activities. Topical treatment of bacterial vaginosis did not reduce risks of perinatal morbidity. Women with persistent or recurrent sialidase 8 weeks after treatment were at increased risk of preterm birth (15.6% vs 7.4%) premature rupture of membranes (30% vs 15%), and low birth weight (20% vs 3%, relative risk 6.8, 95% confidence interval 1.6 to 28.1).

CONCLUSIONS

Persistence of sialidase-producing vaginal microorganisms in numbers sufficient to increase vaginal fluid sialidase activity may be a risk factor for possibly preventable subclinical intrauterine infection and preterm birth. This study confirms and further informs our understanding of the association of bacterial vaginosis and preterm birth; studies to evaluate whether systemic treatment for bacterial vaginosis can effectively reduce vaginal mucolytic enzymes and risks of prematurity and other morbid outcomes are continuing.