Identification of bacteriophages in the vagina of pregnant women: a descriptive study.

OBJECTIVE: To determine the presence and identity of extracellular bacteriophage (phage) families, genera and species in the vagina of pregnant women. DESIGN: Descriptive, observational cohort study. SETTING: São Paulo, Brazil. POPULATION: Pregnant women at 21-24 weeks' gestation. METHODS: Vaginal samples from 107 women whose vaginal microbiome and pregnancy outcomes were previously determined were analysed for phages by metagenomic sequencing. MAIN OUTCOME MEASURES: Identification of phage families, genera and species. RESULTS: Phages were detected in 96 (89.7%) of the samples. Six different phage families were identified: Siphoviridae in 69.2%, Myoviridae in 49.5%, Microviridae in 37.4%, Podoviridae in 20.6%, Herelleviridae in 10.3% and Inviridae in 1.9% of the women. Four different phage families were present in 14 women (13.1%), three families in 20 women (18.7%), two families in 31 women (29.1%) and one family in 31 women (29.1%). The most common phage species detected were Bacillus phages in 48 (43.6%), Escherichia phages in 45 (40.9%), Staphylococcus phages in 40 (36.4%), Gokushovirus in 33 (30.0%) and Lactobacillus phages in 29 (26.4%) women. In a preliminary exploratory analysis, there were no associations between a particular phage family, the number of phage families present in the vagina or any particular phage species and either gestational age at delivery or the bacterial community state type present in the vagina. CONCLUSIONS: Multiple phages are present in the vagina of most mid-trimester pregnant women. TWEETABLE ABSTRACT: Bacteriophages are present in the vagina of most pregnant women.

Amniotic fluid lactic acid and matrix metalloproteinase-8 levels at the time of fetal surgery for a spine defect: association with subsequent preterm prelabour rupture of membranes.

OBJECTIVE: In utero fetal surgery to correct incomplete closure of the spinal cord lessens the extent of permanent damage but is associated with preterm prelabour rupture of membranes (PPROM). We determined whether compounds in amniotic fluid collected at the time of surgery predicted subsequent development of PPROM. DESIGN: Prospective study. SETTING: Hospitals in Sao Paulo, Brazil. POPULATION: Twenty-four consecutive pregnant women at 24-26 weeks of gestation seen between February and October 2017 with a singleton pregnancy underwent in utero surgery to correct an open spinal defect in their fetus. METHODS: Amniotic fluid was tested for lactic acid, matrix metalloproteinase 2 (MMP-2), MMP-8, MMP-9 and interleukin-6 (IL-6) by enzyme-linked immunosorbent assay. Clinical data were collected after completion of all laboratory studies. MAIN OUTCOME MEASURE: Amniotic fluid concentration of compounds in women with or without PPROM. RESULTS: Preterm prelabour rupture of membranes occurred in seven (29.2%) women. There were no differences in maternal age, gravidity, parity, race, history of caesarean sections or fetal gender between women with or without PPROM. Length of surgery, days of wound healing and length of hospital stay were also indistinguishable. The median concentrations of MMP-8 (1.7 versus 0.6 ng/ml; P = 0.0041) and lactic acid (7.1 versus 5.9 mm; P = 0.0181) were higher in women with PPROM. The amniotic fluid MMP-8 level was also negatively correlated with gestational age at delivery (Spearman r = -0.4217, P = 0.0319). CONCLUSION: Differences in susceptibility to develop PPROM are present before fetal surgery. An increase in anaerobic glycolysis, evidenced by the intra-amniotic lactic acid level, may enhance MMP-8 production and weaken maternal and fetal membranes. TWEETABLE ABSTRACT: Matrix metalloproteinase-8 and lactic acid in amniotic fluid predict preterm prelabour rupture of membranes.

Why do lactobacilli dominate the human vaginal microbiota?

Lactobacilli are the most abundant vaginal bacteria in women. They inhibit binding of other bacteria to epithelial cells and produce lactic acid that kills or inhibits the growth of many other bacteria. Lactic acid blocks histone deacetylases, thereby enhancing gene transcription and DNA repair. Lactic acid induces autophagy in epithelial cells to degrade intracellular microorganisms and promote homeostasis. Lactobacilli are tolerated by vaginal epithelial cells and inhibit induction of pro-inflammatory cytokines. Emotional stress may reduce lactobacilli abundance in the vaginal microbiota and enhance inflammation. The ability of lactobacilli to inhibit infection without inducing inflammation may maximise fecundity and successful pregnancy outcome in women. TWEETABLE ABSTRACT: Lactobacilli prevent infection without inducing inflammation to maximise fertility and pregnancy outcome.

Bacterial vaginosis: a critical analysis of current knowledge.

Bacterial vaginosis (BV), the change from a Lactobacillus-dominant vaginal microbiota to an anaerobic and facultative bacterial dominance, is associated with pathological sequelae. In many BV-positive women their microbiota is in fact normal and unrelated to pathology. Whether or not the dominance of BV-associated bacteria persists depends upon interactions between host and bacterial factors. Inconsistencies in diagnosis and erroneous associations with pathology may be due to a failure to differentiate between sub-populations of women. It is only in those women with a BV diagnosis in which the identified bacteria are atypical and persist that BV may be a clinical problem requiring intervention. TWEETABLE ABSTRACT: Improved diagnosis of bacterial vaginosis is needed to accurately determine its role in pathology.

Maternal immunity and pregnancy outcome: focus on preconception and autophagy.

Modulation of the maternal immune system before conception has a major role in determining subsequent pregnancy outcome. However, this has been a neglected area of investigation. There is a correlation between the length of time a woman is exposed to semen from her male partner and the development of regulatory T cells that limit a maternal antifetal immune response. Similarly, the composition of the vaginal microbiota influences the capacity of microorganisms to bypass the cervical barrier and colonize the uterus before pregnancy. The extent that this preconception colonization influences pre- and post-implantation gestational events depends on the types of microbes present, the genetic make-up of the mother and environmental influences on the magnitude and direction of her immune responses. Prepregnancy uterine and placental colonization with commensal bacteria may be beneficial to the fetus and newborn by generating tolerance to organisms that enhance postnatal well-being. Efforts to prevent or stop the progression of premature myometrial contractions have been limited because of an incomplete understanding of the mechanism(s) that trigger this occurrence. Based on recent studies of autophagy during gestation and parturition, inhibition of autophagy in myometrial cells may be the critical factor leading to a sequence of events culminating in induction of myometrial contractions either prematurely or at term.

The vaginal microbiome, vaginal anti-microbial defence mechanisms and the clinical challenge of reducing infection-related preterm birth.

Ascending bacterial infection is implicated in about 40-50% of preterm births. The human vaginal microbiota in most women is dominated by lactobacilli. In women whose vaginal microbiota is not lactobacilli-dominated anti-bacterial defence mechanisms are reduced. The enhanced proliferation of pathogenic bacteria plus degradation of the cervical barrier increase bacterial passage into the endometrium and amniotic cavity and trigger preterm myometrial contractions. Evaluation of protocols to detect the absence of lactobaciili dominance in pregnant women by self-measuring vaginal pH, coupled with measures to promote growth of lactobacilli are novel prevention strategies that may reduce the occurrence of preterm birth in low-resource areas.

Differential expression of lactic acid isomers, extracellular matrix metalloproteinase inducer, and matrix metalloproteinase-8 in vaginal fluid from women with vaginal disorders.

OBJECTIVE: Do metabolites in vaginal samples vary between women with different vaginal disorders. DESIGN: Cross-sectional study. SETTING: Campinas, Brazil. SAMPLE: Seventy-seven women (39.9%) with no vaginal disorder, 52 women (26.9%) with vulvovaginal candidiasis (VVC), 43 women (22.3%) with bacterial vaginosis (BV), and 21 women (10.9%) with cytolytic vaginosis (CTV). METHOD: Concentrations of D- and L-lactic acid, extracellular matrix metalloproteinase inducer (EMMPRIN), and matrix metalloproteinase-8 (MMP-8), and the influence of Candida albicans on EMMPRIN production by cultured vaginal epithelial cells, were determined by enzyme-linked immunosorbent assay (ELISA). Associations were determined by the Mann-Whitney U-test and by Spearman's rank correlation test. MAIN OUTCOME MEASURES: Metabolite levels and their correlation with diagnoses. RESULTS: Vaginal concentrations of D- and L-lactic acid were reduced from control levels in BV (P < 0.0001); L-lactic acid levels were elevated in CTV (P = 0.0116). EMMPRIN and MMP-8 concentrations were elevated in VVC (P < 0.0001). EMMPRIN and L-lactic acid concentrations (P ≤ 0.008), but not EMMPRIN and D-lactic acid, were correlated in all groups. EMMPRIN also increased in proportion with the ratio of L- to D-lactic acid in controls and in women with BV (P ≤ 0.009). Concentrations of EMMPRIN and MMP-8 were correlated in controls and women with VVC (P ≤ 0.0002). Candida albicans induced EMMPRIN release from vaginal epithelial cells. CONCLUSIONS: Vaginal secretions from women with BV are deficient in D- and L-lactic acid, women with VVC have elevated EMMPRIN and MMP-8 levels, and women with CTV have elevated L-lactic acid levels. These deviations may contribute to the clinical signs, symptoms, and sequelae that are characteristic of these disorders.

Involvement of autophagy in cervical, endometrial and ovarian cancer.

Autophagy is an intracellular molecular pathway that maintains cellular homeostasis. A role for autophagy in the development as well as in the treatment of gynecologic malignancies, while still under-investigated, is receiving increased interest. Depending on concomitant factors, autophagy can either promote or suppress development of cervical, endometrial and ovarian cancer. Moreover, these cancer cells can utilize autophagy to promote its resistance to chemotherapeutic agents or, conversely, autophagy can enhance the efficacy of cytotoxic agents by promoting autophagic cell death. In this review the key autophagy-related mechanisms in development and treatment of cervical, endometrial and ovarian cancer are elucidated and evaluated.

Altered autophagy induction by sera from pregnant women with pre-eclampsia: a case-control study.

OBJECTIVE: Mechanisms leading to pre-eclampsia remain incompletely defined. Autophagy is a conserved process necessary for cell survival under adverse conditions. We hypothesised that sera from women with healthy pregnancies and women with pre-eclampsia differed in autophagy induction. DESIGN: A case-control study. SETTING: Weill Cornell Medical College. POPULATION: Twenty-four normotensive pregnant women and 20 women with pre-eclampsia. METHODS: Sera were incubated with peripheral blood mononuclear cells (PBMCs) from female donors. After 48 hours the PBMCs were lysed and the intracellular concentration of p62 was determined by enzyme-linked immunosorbent assay (ELISA). Its concentration is inversely proportional to the extent of autophagy induction. Serum endoglin, interleukin 13 (IL-13), insulin-like growth factor 1 (IGF-1), and transforming growth factor ß1 (TGF-ß1) levels were quantitated by ELISA. MAIN OUTCOME MEASURES: Differences in autophagy induction and serum mediator levels in the two groups. RESULTS: Autophagy induction increased with gestational age in sera from normotensive women (P = 0.0045), but not in women with pre-eclampsia. In the presence of an autophagy inducer, the capacity for autophagy induction decreased with gestational age in sera from women with pre-eclampsia (P = 0.0235), but not from controls. Endoglin concentrations were positively associated with the extent of autophagy induction in controls only (P = 0.0141). There was no association between autophagy and serum IL-13, IGF-1, or TGF-ß1 levels. CONCLUSIONS: Sera from women with pre-eclampsia differ from normotensive women by their inability to induce autophagy as a function of gestational age.

Autophagy and female genital tract infections: new insights and research directions.

Autophagy is a highly conserved process by which defective organelles, non-functional proteins, and intracellular microorganisms become sequestered within structures called autophagosomes, which fuse with lysosomes and the engulfed components are degraded by lysosomal enzymes. In microbial autophagy degraded peptides are used to induce antigen-specific acquired immunity. Viruses, bacteria, fungi, and protozoa have developed strategies to subvert autophagy and/or to use this process to promote their replication and persistence. This review details the mechanisms by which microorganisms that infect the female genital tract and/or are detrimental to pregnancy interact with this host defence mechanism. Based on an understanding of autophagy-related pathological mechanisms, we propose new avenues for research to more effectively prevent and/or treat these infectious diseases.

Unique alterations in infection-induced immune activation during pregnancy.

BACKGROUND: Immune responses to infection are uniquely regulated during gestation to allow for antimicrobial defence and tissue repair, whilst preventing damage to developing fetal organs or the triggering of preterm labour. OBJECTIVE: A review and analysis of studies delineating gestation-specific immune modulation and intra-amniotic regulation of pro-inflammatory immunity. SEARCH STRATEGY: Identification of the alterations between the fetus/neonate and adult with regard to the endogenous and infection-induced expression of molecules with immune regulatory properties, and the characterisation of intra-amniotic immune mediators that inhibit bacterial-induced pro-inflammatory cytokine production. SELECTION CRITERIA: English and non-English publications from 1985 to the present. DATA COLLECTION AND ANALYSIS: An electronic literature search using MEDLINE, PubMed, articles cited in the primary sources, as well as pregnancy-related immunology research from our laboratory at Weill Medical College of Cornell University. MAIN RESULTS: During fetal development, interleukin (IL)-23, IL-10 and IL-6, as well as T-helper-17 (Th17)-mediated immune responses, are upregulated, whereas tumour necrosis factor-α (TNF-α) and IL-1ß- and Th1-mediated immune responses are downregulated in the intrauterine environment (both the fetal compartment and the amniotic compartment). Infection-related immunity during gestation is preferentially directed towards combating extracellular microbial pathogens. Amniotic fluid and the neonatal circulation contain multiple components that improve the ability of the developing neonate to tolerate microbial-induced immune activation. CONCLUSIONS: The repertoire of immune mechanisms to control infection and inflammation differ between fetal and adult life. The dual mechanisms of resistance to infection and tolerance to infection-induced immune activation prevent damage to the developing fetus and the triggering of premature labour.

Endocervical hyaluronan and ultrasound-indicated cerclage.

OBJECTIVE: To investigate whether, at the time of ultrasound-indicated cerclage, the endocervical concentration of hyaluronan (HA), 27-kDa heat shock protein (HSP-27) and/or interleukin-8 (IL-8) would predict pregnancy outcome. METHODS: Endocervical samples, obtained from 40 women undergoing ultrasound-indicated cerclage at 15 + 3 to 25 + 0 weeks' gestation, were assayed by enzyme-linked immunosorbent assay for HA, HSP-27 and IL-8. All subjects had a cervical length of < 1.5 cm or dramatic cervical length change on serial endovaginal ultrasound, no uterine contractions or tenderness, no fever and intact membranes and underwent a modified Shirodkar cerclage. RESULTS: The median HA level was 10.0 ng/mL in the 12 women who delivered at < 37 weeks' gestation as opposed to 39.7 ng/mL in the 28 women delivering at 37-41 weeks (P = 0.017). Median HSP-27 and IL-8 concentrations were not significantly different in these groups. CONCLUSION: A higher endocervical HA level at the time of ultrasound-indicated cerclage is associated with a longer interval before birth.

Antibody-independent complement activation by myelin via the classical complement pathway.

Murine or rabbit whole brain homogenates were shown to activate human complement via the classical pathway by an antibody-independent reaction. This activity required Ca++ ions. Anticomplementary activity in fractionated murine brain was found to reside in the myelin fraction and in purified myelin. It was absent, however, both from highly purified myelin basic protein (MBP) and from the MBP-free residue. Because purified MBP is a monomer and this protein exists in brain tissue largely as a dimer, the ability of the cross-linked form of MBP to activate complement was investigated. MBP, dimerized with difluorodinitrobenzene, was highly anticomplementary. The murine brain, inactive when taken from the newborn mouse, was shown to first acquire the capacity to activate complement at 7 d after birth. This finding is consistent with the report that the synthesis of myelin protein has been shown to be initiated in murine brain 8 d after birth. Complement activation by MBP could play an important role in the pathological changes observed in neurological disorders.