Feto-Maternal Interface Organ-on-Chip: A New Technology to Study Ascending Infection.

Modeling human pregnancy is challenging as two subjects, the mother and fetus, must be evaluated in tandem. To understand pregnancy, parturition, and adverse pregnancy outcomes, the two feto-maternal interfaces (FMi) that form during gestation (i.e., the placenta and fetal membrane) need to be investigated to understand their biological roles, and organ dysfunction can lead to adverse outcomes. Adverse pregnancy outcomes such as preterm rupture of the membranes, spontaneous preterm birth, preeclampsia, intra-uterine growth restriction, and gestational diabetes rates are on the rise worldwide, highlighting the need for future studies and a better understanding of molecular and cellular pathways that contribute to disease onset. Current in vivo animal models nor in vitro cell culture systems can answer these questions as they do not model the function or structure of human FMis. Utilizing microfabrication and soft-lithography techniques, microfluidic organ-on-chip (OOC) devices have been adapted by many fields to model the anatomy and biological function of complex organs and organ systems within small in vitro platforms.These techniques have been adapted to recreate the fetal membrane FMi (FMi-OOC) using immortalized cells and collagen derived from patient samples. The FMi-OOC is a four-cell culture chamber, concentric circle system, that contains both fetal (amniochorion) and maternal (decidua) cellular layers and has been validated to model physiological and pathological states of pregnancy (i.e., ascending infection, systemic oxidative stress, and maternal toxicant exposure). This platform is fully compatible with various analytical methods such as microscopy and biochemical analysis. This protocol will outline this device's fabrication, cell loading, and utility to model ascending infection-related adverse pregnancy outcomes.

Intrauterine Detection of Ureaplasma Species after Vaginal Colonization in Pregnancy and Neonatal Outcome.

INTRODUCTION: Intrauterine infection with Ureaplasma species (U.spp.) is mostly a result of vaginal colonization with subsequent ascending infection and is associated with adverse pregnancy outcome. Little is known about rates and risk factors for ascending infection. Aim of the current study was to analyse the frequency of ascending U.spp. infection in vaginally colonized pregnant women delivering preterm and subsequent short- and long-term outcome of infants. METHODS: Women delivering ≤32 weeks of gestation with available data on vaginal U.spp. colonization in early pregnancy as well as amniotic and placental colonization screening during caesarean section were included. Neonatal short- and long-term outcome was analysed depending on vaginal and intrauterine colonization. RESULTS: Seventy-two women giving birth to 104 preterm infants were included. Intrauterine microbial invasion was found in 23/72 (31.9%) pregnancies. The most commonly detected organisms were U.spp. (52.2%), followed by E. coli (21.7%) and Enterococcus faecalis (17.4%). Intrauterine growth of U.spp. occurred exclusively after previous vaginal colonization in early pregnancy (42/72; 58.3%) and was found in 12/42 (28.6%) cases. Ascending U.spp. infection mainly occurred in pregnancies delivering <28 weeks after preterm rupture of membranes or preterm labour (9/17, 52.3%). Intrauterine detection of U.spp., but not vaginal colonization, was associated with a significantly higher rate of severe intraventricular haemorrhage, retinopathy of prematurity, bronchopulmonary dysplasia, and unfavourable psychomotor outcome. CONCLUSION: Ascending U.spp. infection after previous vaginal colonization occurred in almost one-third of pregnancies delivering ≤32 weeks, with particularly high rates in those <28 weeks, and was associated with adverse outcome of preterm infants.

Characterization of fetal microchimeric immune cells in mouse maternal hearts during physiologic and pathologic pregnancies.

Introduction: During pregnancy, fetal cells can be incorporated into maternal tissues (fetal microchimerism), where they can persist postpartum. Whether these fetal cells are beneficial or detrimental to maternal health is unknown. This study aimed to characterize fetal microchimeric immune cells in the maternal heart during pregnancy and postpartum, and to identify differences in these fetal microchimeric subpopulations between normal and pregnancies complicated by spontaneous preterm induced by ascending infection. Methods: A Cre reporter mouse model, which when mated with wild-type C57BL/6J females resulted in cells and tissues of progeny expressing red fluorescent protein tandem dimer Tomato (mT+), was used to detect fetal microchimeric cells. On embryonic day (E)15, 104 colony-forming units (CFU) E. coli was administered intravaginally to mimic ascending infection, with delivery on or before E18.5 considered as preterm delivery. A subset of pregnant mice was sacrificed at E16 and postpartum day 28 to harvest maternal hearts. Heart tissues were processed for immunofluorescence microscopy and high-dimensional mass cytometry by time-of-flight (CyTOF) using an antibody panel of immune cell markers. Changes in cardiac physiologic parameters were measured up to 60 days postpartum via two-dimensional echocardiography. Results: Intravaginal E. coli administration resulted in preterm delivery of live pups in 70% of the cases. mT + expressing cells were detected in maternal uterus and heart, implying that fetal cells can migrate to different maternal compartments. During ascending infection, more fetal antigen-presenting cells (APCs) and less fetal hematopoietic stem cells (HSCs) and fetal double-positive (DP) thymocytes were observed in maternal hearts at E16 compared to normal pregnancy. These HSCs were cleared while DP thymocytes persisted 28 days postpartum following an ascending infection. No significant changes in cardiac physiologic parameters were observed postpartum except a trend in lowering the ejection fraction rate in preterm delivered mothers. Conclusion: Both normal pregnancy and ascending infection revealed distinct compositions of fetal microchimeric immune cells within the maternal heart, which could potentially influence the maternal cardiac microenvironment via (1) modulation of cardiac reverse modeling processes by fetal stem cells, and (2) differential responses to recognition of fetal APCs by maternal T cells.

Vaginal Drain to Prevent Ascending Infection in Preterm Premature Rupture of Membranes: A Novel Method.

BACKGROUND: Not to delay delivery for more than 24 hours after rupture of the membrane is the thumb rule in obstetrics. Ascending infection from the vagina results in dangerous chorioamnionitis, which threatens the lives of the baby and mother. We developed a novel method to prevent ascending infection by using a vaginal drain, which helps to continue pregnancies if the leak stops and buys some time for antenatal steroids to act if the leak doesn't stop. METHOD: In this study, 20 uncomplicated singleton pregnant women with spontaneous preterm premature rupture of membranes at gestational ages <35 weeks were recruited. Under the speculum, vaginal epithelial debris and secretions were cleared by a saline wash. The tip of the Nelaton Catheter was kept in the posterior fornix and then strapped to the thigh. The outer end was connected to the collection bag system and allowed to hang down to the ground. The foot end of the cot was raised. Leaked amniotic fluid and amniotic fluid index (AFI) were measured daily. A daily AFOD estimation was done for leaked AF. Uterine activity was controlled with low-dose Isoxsuprine Hydrochloride rapid infusion tocolysis. Antenatal steroids (ANS) were given. The spread of infection was monitored by maternal pulse rate, fetal heart rate, TC, and CRP. Pregnancies were terminated when leaks didn't stop, AFI didn't raise, or mature AFOD was observed. The number of women in whom leaks stopped, the number of days pregnancies continued, neonatal respiratory distress (NRD), birth weights, and perinatal deaths were recorded.  Results: Leaks stopped in eight (40%) women. Pregnancy continuation ranged from 7 to 74 days. In 12 women, the leak did not stop, but we could buy 2-5 days' time for ANS to act. All parameters of the infection were within normal limits. Thirteen babies developed mild NRD, and we lost one baby. CONCLUSION: By using a vaginal drain for P(P)ROM, ascending infection can be prevented, leaks can be stopped in 40% of women, and can buy time for ANS to act.

Extracellular Vesicles-mediated recombinant IL-10 protects against ascending infection-associated preterm birth by reducing fetal inflammatory response.

Background: Fetal inflammatory response mediated by the influx of immune cells and activation of pro-inflammatory transcription factor NF-κB in feto-maternal uterine tissues is the major determinant of infection-associated preterm birth (PTB, live births < 37 weeks of gestation). Objective: To reduce the incidence of PTB by minimizing inflammation, extracellular vesicles (EVs) were electroporetically engineered to contain anti-inflammatory cytokine interleukin (IL)-10 (eIL-10), and their efficacy was tested in an ascending model of infection (vaginal administration of E. coli) induced PTB in mouse models. Study design: EVs (size: 30-170 nm) derived from HEK293T cells were electroporated with recombinant IL-10 at 500 volts and 125 Ω, and 6 pulses to generate eIL-10. eIL-10 structural characters (electron microscopy, nanoparticle tracking analysis, ExoView [size and cargo content] and functional properties (co-treatment of macrophage cells with LPS and eIL-10) were assessed. To test efficacy, CD1 mice were vaginally inoculated with E. coli (1010CFU) and subsequently treated with either PBS, eIL-10 (500ng) or Gentamicin (10mg/kg) or a combination of eIL-10+gentamicin. Fetal inflammatory response in maternal and fetal tissues after the infection or treatment were conducted by suspension Cytometer Time of Flight (CyTOF) using a transgenic mouse model that express red fluorescent TdTomato (mT+) in fetal cells. Results: Engineered EVs were structurally and functionally stable and showed reduced proinflammatory cytokine production from LPS challenged macrophage cells in vitro. Maternal administration of eIL-10 (10 µg/kg body weight) crossed feto-maternal barriers to delay E. coli-induced PTB to deliver live pups at term. Delay in PTB was associated with reduced feto-maternal uterine inflammation (immune cell infiltration and histologic chorioamnionitis, NF-κB activation, and proinflammatory cytokine production). Conclusions: eIL-10 administration was safe, stable, specific, delayed PTB by over 72 hrs and delivered live pups. The delivery of drugs using EVs overcomes the limitations of in-utero fetal interventions. Protecting IL-10 in EVs eliminates the need for the amniotic administration of recombinant IL-10 for its efficacy.

Life After Amsterdam: Placental Pathology Consensus Recommendations and Beyond.

The Amsterdam Placental Workshop Group Consensus Statement on Sampling and Definitions of Placental Lesions has become widely accepted and is increasingly used as the universal language to describe the most common pathologic lesions found in the placenta. This review summarizes the most salient aspects of this seminal publication and the subsequent emerging literature based on Amsterdam definitions and criteria, with emphasis on publications relating to diagnosis, grading, and staging of placental pathologic conditions. We also provide an overview of the recent expert recommendations on the pathologic grading of placenta accreta spectrum, with insights on their clinical context. Finally, we discuss the emerging entity of SARS-CoV2 placentitis.

Recurrent Paravaginal Abscess: An Unusual Presentation of a Distal Ectopic Ureteral Remnant.

Introduction: Obstructed hemivagina ipsilateral renal agenesis (OHVIRA) is a rare syndrome with limited data on both treatment and postoperative sequelae, specifically of ectopic ureters to the vagina. Case Description: This case study describes a 22-year-old patient with OHVIRA syndrome presenting with pelvic pain and drainage from a chronic vaginal abscess secondary to a remnant distal ectopic ureter after nephrectomy and proximal ureterectomy. Imaging was significant for a right paravaginal abscess. Previously, the patient was treated with conservative therapy and on presentation her evaluation confirmed a right paravaginal abscess. She subsequently underwent a robot-assisted incision and drainage of the paravaginal abscess and excision of the remnant distal ectopic ureter. She did well postoperatively without recurrence. Discussion: We discuss the successful surgical technique used to identify and excise a paravaginal abscess. We also highlight the unique anatomy of a patient with OHVIRA syndrome. Lastly, we underline the importance of a complete resection of an ectopic ureter to the vagina at the time of nephrectomy, given the potential risk of ascending chronic infection and recurrent abscess formation.

Gardnerella vaginalis promotes group B Streptococcus vaginal colonization, enabling ascending uteroplacental infection in pregnant mice.

BACKGROUND: Group B Streptococcus is a common vaginal bacterium and the leading cause of invasive fetoplacental infections. Group B Streptococcus in the vagina can invade through the cervix to cause ascending uteroplacental infections or can be transmitted to the neonate during vaginal delivery. Some studies have found that women with a "dysbiotic" polymicrobial or Lactobacillus-depleted vaginal microbiota are more likely to harbor group B Streptococcus. Gardnerella vaginalis is often the most abundant bacteria in the vaginas of women with dysbiosis, while being detected at lower levels in most other women, and has been linked with several adverse pregnancy outcomes. Mouse models of group B Streptococcus and Gardnerella vaginalis colonization have been reported but, to the best of our knowledge, the two have not been studied together. The overarching idea driving this study is that certain members of the dysbiotic vaginal microbiota, such as Gardnerella vaginalis, may directly contribute to the increased rate of group B Streptococcus vaginal colonization observed in women with vaginal dysbiosis. OBJECTIVE: We used a mouse model to test the hypothesis that vaginal exposure to Gardnerella vaginalis may facilitate colonization and/or invasive infection of the upper reproductive tract by group B Streptococcus during pregnancy. STUDY DESIGN: Timed-pregnant mice were generated using an allogeneic mating strategy with BALB/c males and C57Bl/6 females. Dams were vaginally inoculated at gestational day 14 with group B Streptococcus alone (using a 10-fold lower dose than previously reported models) or coinoculated with group B Streptococcus and Gardnerella vaginalis. Bacterial titers were enumerated in vaginal, uterine horn, and placental tissues at gestational day 17. The presence (Fisher exact tests) and levels (Mann-Whitney U tests) of bacterial titers were compared between mono- and coinoculated dams in each compartment. Relative risks were calculated for outcomes that occurred in both groups. Tissue samples were also examined for evidence of pathophysiology. RESULTS: Inoculation of pregnant mice with 107 group B Streptococcus alone did not result in vaginal colonization or ascending infection. In contrast, coinoculation of group B Streptococcus with Gardnerella vaginalis in pregnant mice resulted in a 10-fold higher risk of group B Streptococcus vaginal colonization (relative risk, 10.31; 95% confidence interval, 2.710-59.04; P=.0006 [Fisher exact test]). Ascending group B Streptococcus infection of the uterus and placenta occurred in approximately 40% of coinoculated animals, whereas none of those receiving group B Streptococcus alone developed uterine or placental infections. Immunofluorescence microscopy revealed group B Streptococcus in both the maternal and fetal sides of the placenta. Histologic inflammation and increased proinflammatory cytokines were evident in the setting of group B Streptococcus placental infection. Interestingly, placentas from dams exposed to group B Streptococcus and Gardnerella vaginalis, but without recoverable vaginal or placental bacteria, displayed distinct histopathologic features and cytokine signatures. CONCLUSION: These data suggest that Gardnerella vaginalis vaginal exposure can promote group B Streptococcus vaginal colonization, resulting in a greater likelihood of invasive perinatal group B Streptococcus infections. These findings suggest that future clinical studies should examine whether the presence of Gardnerella vaginalis is a risk factor for group B Streptococcus vaginal colonization in women. Because Gardnerella vaginalis can also be present in women without bacterial vaginosis, these findings may be relevant both inside and outside of the context of vaginal dysbiosis.

Members of Prevotella Genus Distinctively Modulate Innate Immune and Barrier Functions in a Human Three-Dimensional Endometrial Epithelial Cell Model.

BACKGROUND: Prevotella species are commonly isolated from the reproductive tract of women with obstetric/gynecologic health complications. However, contributions of this genus to changes in local microenvironment are not well characterized. Our objective was to evaluate species-specific effects of Prevotella on the human endometrial epithelium. METHODS: Thirteen Prevotella strains, originally isolated from the human oral cavity, amniotic fluid, endometrium, or vagina (including women with bacterial vaginosis), were obtained from BEI and ATCC resources. Bacteria were evaluated in silico and in vitro using human endometrial epithelial cells (EEC) grown as monolayers or a 3-dimensional (3D) model. RESULTS: Genomic characterization illustrated metabolic and phylogenetic diversity of Prevotella genus. Among tested species, P. disiens exhibited cytotoxicity. Scanning electron microscopy analysis of the 3D EEC model revealed species-specific colonization patterns and alterations of ultracellular structures. Infection with sialidase-producing P. timonensis resulted in elongated microvilli, and increased MUC3 and MUC4 expression. Infections with Prevotella species, including P. bivia, did not result in significant proinflammatory activation of EEC. CONCLUSIONS: Collectively, findings indicate that Prevotella species are metabolically diverse and overall not cytotoxic or overtly inflammatory in EEC; however, these bacteria can form biofilms, alter barrier properties of the endometrial epithelium, and ultimately impact colonization of secondary colonizers.

Coronavirus disease 2019 in pregnant women: a report based on 116 cases.

BACKGROUND: The coronavirus disease 2019, caused by severe acute respiratory syndrome coronavirus 2, is a global public health emergency. Data on the effect of coronavirus disease 2019 in pregnancy are limited to small case series. OBJECTIVE: To evaluate the clinical characteristics and outcomes in pregnancy and the vertical transmission potential of severe acute respiratory syndrome coronavirus 2 infection. STUDY DESIGN: Clinical records were retrospectively reviewed for 116 pregnant women with coronavirus disease 2019 pneumonia from 25 hospitals in China between January 20, 2020, and March 24, 2020. Evidence of vertical transmission was assessed by testing for severe acute respiratory syndrome coronavirus 2 in amniotic fluid, cord blood, and neonatal pharyngeal swab samples. RESULTS: The median gestational age on admission was 38+0 (interquartile range, 36+0-39+1) weeks. The most common symptoms were fever (50.9%, 59/116) and cough (28.4%, 33/116); 23.3% (27/116) patients presented without symptoms. Abnormal radiologic findings were found in 96.3% (104/108) of cases. Of the 116 cases, there were 8 cases (6.9%) of severe pneumonia but no maternal deaths. One of 8 patients who presented in the first trimester and early second trimester had a missed spontaneous abortion. Of 99 patients, 21 (21.2%) who delivered had preterm birth, including 6 with preterm premature rupture of membranes. The rate of spontaneous preterm birth before 37 weeks' gestation was 6.1% (6/99). One case of severe neonatal asphyxia resulted in neonatal death. Furthermore, 86 of the 100 neonates tested for severe acute respiratory syndrome coronavirus 2 had negative results; of these, paired amniotic fluid and cord blood samples from 10 neonates used to test for severe acute respiratory syndrome coronavirus 2 had negative results. CONCLUSION: Severe acute respiratory syndrome coronavirus 2 infection during pregnancy is not associated with an increased risk of spontaneous abortion and spontaneous preterm birth. There is no evidence of vertical transmission of severe acute respiratory syndrome coronavirus 2 infection when the infection manifests during the third trimester of pregnancy.

Cervical Gene Delivery of the Antimicrobial Peptide, Human ß-Defensin (HBD)-3, in a Mouse Model of Ascending Infection-Related Preterm Birth.

Approximately 40% of preterm births are preceded by microbial invasion of the intrauterine space; ascent from the vagina being the most common pathway. Within the cervical canal, antimicrobial peptides and proteins (AMPs) are important components of the cervical barrier which help to prevent ascending vaginal infection. We investigated whether expression of the AMP, human ß-defensin-3 (HBD3), in the cervical mucosa of pregnant mice could prevent bacterial ascent from the vagina into the uterine cavity. An adeno-associated virus vector containing both the HBD3 gene and GFP transgene (AAV8 HBD3.GFP) or control AAV8 GFP, was administered intravaginally into E13.5 pregnant mice. Ascending infection was induced at E16.5 using bioluminescent Escherichia coli (E. coli K1 A192PP-lux2). Bioluminescence imaging showed bacterial ascent into the uterine cavity, inflammatory events that led to premature delivery and a reduction in pups born alive, compared with uninfected controls. Interestingly, a significant reduction in uterine bioluminescence in the AAV8 HBD3.GFP-treated mice was observed 24 h post-E. coli infection, compared to AAV8 GFP treated mice, signifying reduced bacterial ascent in AAV8 HBD3.GFP-treated mice. Furthermore, there was a significant increase in the number of living pups in AAV HBD3.GFP-treated mice. We propose that HBD3 may be a potential candidate for augmenting cervical innate immunity to prevent ascending infection-related preterm birth and its associated neonatal consequences.

¿Se puede prevenir el parto prematuro por infección bacteriana ascendente y sus resultados adversos en los hospitales públicos de Chile? / Can preterm birth be prevented from ascending bacterial infection and its adverse results in the public hospitals of Chile?

Resumen El parto prematuro (PP) es el principal contribuyente de la morbilidad/mortalidad perinatal. A pesar del conocimiento de los factores de riesgo y de la introducción de intervenciones médicas destinadas a la prevención del nacimiento prematuro, su frecuencia ha aumentado. La infección bacteriana ascendente (IBA) es la condición obstétrica más frecuente asociada al PP ocasionando un importante resultado perinatal adverso en un hospital público de Chile. Esta revisión muestra la asociación entre PP e IBA, analiza la fisiopatología y la inmunología de las infecciones vaginales en la mujer embarazada susceptible, como asimismo la aplicación en este grupo de medidas con evidencia clínica que han demostrado ser eficientes, tales como la pesquisa rutinaria y el tratamiento de las infecciones genitourinarias (IGU), el cerclaje profiláctico o terapéutico, uso de probióticos, de progesterona vaginal, control metabólico de la diabetes mellitus y del peso de la obesa. El tratamiento de las IGU, conjuntamente con el uso de intervenciones que mejoran la inmunidad vaginal en la población de riesgo, permiten predecir una reducción del PP por IBA, de sus consecuencias inmediatas y de largo plazo y costos asociados elevados, con el consiguiente beneficio de la salud pública de Chile.

Preterm birth (PB) is the main contributor to the perinatal morbidity/mortality. In spite of the knowledge of the risk factors and the introduction of medical interventions intended to prevent PB, its frequency has increased. Ascending bacterial infection (ABI) is the obstetric condition most frequently associated to PB causing an important adverse perinatal outcome in a public hospital in Chile. This review shows the association between PB and ABI, analyzes the physiopathology and immunology of vaginal infections in the susceptible pregnant woman., as well as their application in this group of effective measures demonstrated by evidence, such as routine control, treatment of genitourinary tract infections (GTI), prophylactic or therapeutic cerclage, use of probiotics, use of vaginal progesterone, metabolic control of diabetes mellitus and weight of the obese woman. Treatment GTI together with the use of medical interventions that improve the vaginal immunity in the risk population allow to predict a reduction of PB by ABI and of its immediate consequences, long term sequels and high associated costs, with the consequent benefit of the public health in Chile.

Cervical hyaluronan biology in pregnancy, parturition and preterm birth.

Cervical hyaluronan (HA) synthesis is robustly induced in late pregnancy in numerous species including women and mice. Recent evidence highlights the diverse and dynamic functions of HA in cervical biology that stem from its expression in the cervical stroma, epithelia and immune cells, changes in HA molecular weight and cell specific expression of HA binding partners. Mice deficient in HA in the lower reproductive tract confirm a structural role of HA to increase spacing and disorganization of fibrillar collagen, though this function is not critical for pregnancy and parturition. In addition, cervical HA depletion via targeted deletion of HA synthase genes, disrupts cell signaling required for the differentiation of epithelia and their mucosal and junctional barrier, resulting in increased susceptibility to ascending infection-mediated preterm birth. Finally the generation of HA disaccharides by bacterial hyaluronidases as made by Group B streptococcus can ligate toll like receptors TLR2/4 thus preventing appropriate inflammatory responses as needed to fight ascending infection and preterm birth. This review summarizes our current understanding of HA's novel and unique roles in cervical remodeling in the process of birth.

Pasteurella multocida multiple intrapelvic abscesses in a young woman with uterine cervical cancer.

Pasteurella multocida, a zoonotic pathogen in humans, is known to be associated with skin and soft tissue infections following animal bites, but rarely causes visceral infections. We report a case of P. multocida-associated multiple intrapelvic abscesses in a young woman with uterine cervical cancer. A 29-year-old unmarried woman was referred to us because of prolonged high fever accompanying abdominal pain with muscular guarding. She had a domestic cat but denied of any bites or scratches before that. Computed tomography demonstrated ascites and multiple abscesses around her uterus. Her condition did not improve with an initial treatment with flomoxef, clindamycin, and azithromycin. Further, we performed percutaneous pus drainage and switched the antimicrobial therapy to a combination of piperacillin/tazobactam and minocycline for 10 days. Although P. multocida was isolated from vaginal culture, no organisms were isolated from the pus culture. However, further investigation with specimen-direct 16S rDNA analysis diagnosed P. multocida as possibly a single pathogen responsible for the intrapelvic infection. After taking oral levofloxacin for two weeks, no recurrence was reported. Although P. multocida is known as an animal-related pathogen, it can transmit to humans without apparent bites or scratches. The present case illustrates that P. multocida can cause intrapelvic abscess as a result of ascending genital infection.

Chlamydia muridarum plasmid induces mouse oviduct pathology by promoting chlamydial survival and ascending infection and triggering host inflammation.

BACKGROUND: Infection with plasmid-free Chlamydia trachomatis and Chlamydia muridarum fails to induce severe pathology, however, the mechanisms underlying this phenotype are unclear. OBJECTIVES: To elucidate the mechanisms of chlamydial plasmid-mediated pathology in mouse oviducts. MATERIALS & METHODS: BALB/c mice were intravaginally infected with either plasmid-competent or plasmid-free C. muridarum strains. To compare the survival and ascending infection of these strains, vaginal swabs and genital tract tissues were collected and cultured with HeLa cells to monitor the recovery of live organisms. In addition, Chlamydia strains were intrabursally inoculated into the oviducts of mice to assess pathogenicity. Cytokine levels in the vaginal swabs collected from both the plasmid-competent and plasmid-free C. muridarum-infected mice were detected using Bio-Plex Pro Mouse Cytokine, Chemokine, and Growth Factor Assays. RESULTS: The plasmid-competent C. muridarum strain induced hydrosalpinx formation in mouse oviducts following intravaginal inoculation, however, this was not the case for the plasmid-free C. muridarum strain. The lack of hydrosalpinges in response to the plasmid-free C. muridarum strain correlated with its significantly reduced ability to survive and disseminate to the upper genital tract. Furthermore, the plasmid-free C. muridarum failed to induce hydrosalpinx formation in mice, even when the strain was intrabursally injected into oviducts. A comparison of the cytokine levels in mouse vaginal secretions showed that the plasmid-free C. muridarum strain induced less IL-15, LIF, MIP-2, IL-1α, IL-1ß, TNF-α, and RANTES. CONCLUSION: C. muridarum plasmid contributes to oviduct pathology by promoting bacterial survival and ascending infection, and triggering host inflammatory responses.

Characterization of pelvic and cervical microbiotas from patients with pelvic inflammatory disease.

PURPOSE: The aims of this work were: (i) to profile and compare pelvic and cervical microbiota from patients with pelvic inflammatory disease (PID); (ii) to test the ascending infection hypothesis that the microbes in the vagina or cervix spread to the upper genital tract and cause PID. METHODOLOGY: Thirty-eight PID patients and 19 control patients were enrolled in this study and received salpingectomy or salpingo-oophorectomy. Both pelvic and cervical samples were collected during surgery, which were subject to culture diagnosis and next-generation sequencing (NGS)-based 16S rRNA profiling. RESULTS: For the PID group, the NGS-based method revealed that half of the pelvic samples were dominated by a single organism while the other half exhibited a polymicrobial infection. The pelvic and cervical microbiota were similar in terms of both taxonomic richness and evenness. Pelvic microbiota was dominated by Acinetobacter, Escherichia, Sneathia and Streptococcus whereas cervical microbiota was dominated by Lactobacillus and Gardnerella. Only six pelvic samples were positive by culture diagnosis, three of which matched the NGS-based results. The PID group was further divided into 23 hydrosalpinx and 15 pyosalpinx samples according to the pelvic mass collected during surgery, the former showing a richer bacterial composition than the latter. CONCLUSION: The NGS-based method provides a more informative profile of pelvic microbiota than the culture method. The pelvic and cervical microbiota from the same patient were inconsistent with each other, and thus therapeutic decisions based on cervical microbiota may lead to antimicrobial misuse.

Progress in pathogenesis of adverse pregnancy outcomes induced by group B Streptococcus / 中华微生物学和免疫学杂志

Group B Streptococcus ( GBS) is a leading infectious cause of adverse pregnancy out-comes such as preterm birth. GBS colonizes the vagina during pregnancy and can ascend into the uterus and then infect the fetus. It encodes a series of virulence factors such as adhesion and invasion factors, hemolytic pigments and hyaluronidase, which are important to vaginal colonization and immune evasion. Immune re-sponses to GBS cause the release of a multiple of inflammatory mediators, leading to the premature rupture of membranes, preterm birth and fetal injury. This paper reviews the pathogenesis of GBS vaginal colonization and ascending infection causing adverse pregnancy outcomes.

IL-6-mediated signaling pathways limit Chlamydia muridarum infection and exacerbate its pathogenicity in the mouse genital tract.

Chlamydia muridarum induction of mouse hydrosalpinx, depending on both tubal infection and inflammation, has been used for investigating Chlamydia trachomatis pathogenesis. We now report that IL-6 both inhibits C. muridarum infection and exacerbates pathogenicity in the mouse genital tract. When intravaginally inoculated with a high dose of C. muridarum, IL-6-deficient mice developed more extensive genital tract infection with severe hydrosalpinx, suggesting that IL-6 is required for controlling the high dose infection but not essential for C. muridarum-induced pathology. However, at a low dose, IL-6-deficient mice still developed more extensive infection in the genital tract but no longer with significant pathology, suggesting that IL-6 is required for both controlling the low dose infection and exacerbating the low dose infection-induced pathology. The lack of hydrosalpinx in IL-6-deficient mice correlated with significantly reduced inflammatory infiltration in the oviduct tissue and decreased spleen CD4+ and CD8+ T cells that produce TNFα. Thus, IL-6-dependent pathways are important for both limiting chlamydial colonization in the genital tract mucosal tissues regardless of the infection doses and exacerbating chlamydial pathogenicity in the upper genital tract when IL-6-independent pathogenic mechanisms are not yet activated with a low infection dose.