Increased intrauterine frequency of Ureaplasma urealyticum in women with preterm labor and preterm premature rupture of the membranes and subsequent cesarean delivery

Ureaplasma infections: update on epidemiology, antimicrobial resistance, and pathogenesis

Human Ureaplasma species are being increasingly recognized as opportunistic pathogens in human genitourinary tract infections, infertility, adverse pregnancy, neonatal morbidities, and other adult invasive infections. Although some general reviews have focused on the detection and clinical manifestations of Ureaplasma spp., the molecular epidemiology, antimicrobial resistance, and pathogenesis of Ureaplasma spp. have not been adequately explained. The purpose of this review is to offer valuable insights into the current understanding and future research perspectives of the molecular epidemiology, antimicrobial resistance, and pathogenesis of human Ureaplasma infections. This review summarizes the conventional culture and detection methods and the latest molecular identification technologies for Ureaplasma spp. We also reviewed the global prevalence and mechanisms of antibiotic resistance for Ureaplasma spp. Aside from regular antibiotics, novel antibiotics with outstanding in vitro antimicrobial activity against Ureaplasma spp. are described. Furthermore, we discussed the pathogenic mechanisms of Ureaplasma spp., including adhesion, proinflammatory effects, cytotoxicity, and immune escape effects, from the perspectives of pathology, related molecules, and genetics.

Clinical chorioamnionitis at term: definition, pathogenesis, microbiology, diagnosis, and treatment

Clinical chorioamnionitis, the most common infection-related diagnosis in labor and delivery units, is an antecedent of puerperal infection and neonatal sepsis. The condition is suspected when intrapartum fever is associated with two other maternal and fetal signs of local or systemic inflammation (eg, maternal tachycardia, uterine tenderness, maternal leukocytosis, malodorous vaginal discharge or amniotic fluid, and fetal tachycardia). Clinical chorioamnionitis is a syndrome caused by intraamniotic infection, sterile intraamniotic inflammation (inflammation without bacteria), or systemic maternal inflammation induced by epidural analgesia. In cases of uncertainty, a definitive diagnosis can be made by analyzing amniotic fluid with methods to detect bacteria (Gram stain, culture, or microbial nucleic acid) and inflammation (white blood cell count, glucose concentration, interleukin-6, interleukin-8, matrix metalloproteinase-8). The most common microorganisms are Ureaplasma species, and polymicrobial infections occur in 70% of cases. The fetal attack rate is low, and the rate of positive neonatal blood cultures ranges between 0.2% and 4%. Intrapartum antibiotic administration is the standard treatment to reduce neonatal sepsis. Treatment with ampicillin and gentamicin have been recommended by professional societies, although other antibiotic regimens, eg, cephalosporins, have been used. Given the importance of Ureaplasma species as a cause of intraamniotic infection, consideration needs to be given to the administration of antimicrobial agents effective against these microorganisms such as azithromycin or clarithromycin. We have used the combination of ceftriaxone, clarithromycin, and metronidazole, which has been shown to eradicate intraamniotic infection with microbiologic studies. Routine testing of neonates born to affected mothers for genital mycoplasmas could improve the detection of neonatal sepsis. Clinical chorioamnionitis is associated with decreased uterine activity, failure to progress in labor, and postpartum hemorrhage; however, clinical chorioamnionitis by itself is not an indication for cesarean delivery. Oxytocin is often administered for labor augmentation, and it is prudent to have uterotonic agents at hand to manage postpartum hemorrhage. Infants born to mothers with clinical chorioamnionitis near term are at risk for early-onset neonatal sepsis and for long-term disability such as cerebral palsy. A frontier is the noninvasive assessment of amniotic fluid to diagnose intraamniotic inflammation with a transcervical amniotic fluid collector and a rapid bedside test for IL-8 for patients with ruptured membranes. This approach promises to improve diagnostic accuracy and to provide a basis for antimicrobial administration.

Mycoplasma DnaK increases DNA copy number variants in vivo

The human microbiota affects critical cellular functions, although the responsible mechanism(s) is still poorly understood. In this regard, we previously showed that Mycoplasma fermentans DnaK, an HSP70 chaperone protein, hampers the activity of important cellular proteins responsible for DNA integrity. Here, we describe a novel DnaK knock-in mouse model generated in our laboratory to study the effect of M. fermentans DnaK expression in vivo. By using an array-based comparative genomic hybridization assay, we demonstrate that exposure to DnaK was associated with a higher number of DNA copy number variants (CNVs) indicative of unbalanced chromosomal alterations, together with reduced fertility and a high rate of fetal abnormalities. Consistent with their implication in genetic disorders, one of these CNVs caused a homozygous Grid2 deletion, resulting in an aberrant ataxic phenotype that recapitulates the extensive biallelic deletion in the Grid2 gene classified in humans as autosomal recessive spinocerebellar ataxia 18. Our data highlight a connection between components of the human urogenital tract microbiota, namely Mycoplasmas, and genetic abnormalities in the form of DNA CNVs, with obvious relevant medical, diagnostic, and therapeutic implications.

Adverse pregnancy and birth outcomes associated with Mycoplasma hominis, Ureaplasma urealyticum and Ureaplasma parvum: a systematic review and meta-analysis

OBJECTIVES

Mycoplasma hominis, Ureaplasma urealyticum and Ureaplasma parvum (genital mycoplasmas) commonly colonise the urogenital tract in pregnant women. This systematic review aims to investigate their role in adverse pregnancy and birth outcomes, alone or in combination with bacterial vaginosis (BV).

METHODS

We searched Embase, Medline and CINAHL databases from January 1971 to February 2021. Eligible studies tested for any of the three genital mycoplasmas during pregnancy and reported on the primary outcome, preterm birth (PTB) and/or secondary outcomes low birth weight (LBW), premature rupture of membranes (PROM), spontaneous abortion (SA) and/or perinatal or neonatal death (PND).Two reviewers independently screened titles and abstracts, read potentially eligible full texts and extracted data. Two reviewers independently assessed risks of bias using published checklists. Random effects meta-analysis was used to estimate summary ORs (with 95% CIs and prediction intervals). Multivariable and stratified analyses were synthesised descriptively.

RESULTS

Of 57/1194 included studies, 39 were from high-income countries. In meta-analysis of unadjusted ORs, M. hominis was associated with PTB (OR 1.87, 95% CI 1.49 to 2.34), PROM, LBW and PND but not SA. U. urealyticum was associated with PTB (OR 1.84, 95% CI 1.34 to 2.55), PROM, LBW, SA and PND. U. parvum was associated with PTB (1.60, 95% CI 1.12 to 2.30), PROM and SA. Nine of 57 studies reported any multivariable analysis. In two studies, analyses stratified by BV status showed that M. hominis and U. parvum were more strongly associated with PTB in the presence than in the absence of BV. The most frequent source of bias was a failure to control for confounding.

CONCLUSIONS

The currently available literature does not allow conclusions about the role of mycoplasmas in adverse pregnancy and birth outcomes, alone or with coexisting BV. Future studies that consider genital mycoplasmas in the context of the vaginal microbiome are needed.

PROSPERO REGISTRATION NUMBER

CRD42016050962.

Bacteria in the amniotic fluid without inflammation: early colonization vs. contamination

OBJECTIVES

Intra-amniotic infection, defined by the presence of microorganisms in the amniotic cavity, is often accompanied by intra-amniotic inflammation. Occasionally, laboratories report the growth of bacteria or the presence of microbial nucleic acids in amniotic fluid in the absence of intra-amniotic inflammation. This study was conducted to determine the clinical significance of the presence of bacteria in amniotic fluid samples in the absence of intra-amniotic inflammation.

METHODS

A retrospective cross-sectional study included 360 patients with preterm labor and intact membranes who underwent transabdominal amniocentesis for evaluation of the microbial state of the amniotic cavity as well as intra-amniotic inflammation. Cultivation techniques were used to isolate microorganisms, and broad-range polymerase chain reaction coupled with electrospray ionization mass spectrometry (PCR/ESI-MS) was utilized to detect the nucleic acids of bacteria, viruses, and fungi.

RESULTS

Patients whose amniotic fluid samples evinced microorganisms but did not indicate inflammation had a similar perinatal outcome to those without microorganisms or inflammation [amniocentesis-to-delivery interval (p=0.31), spontaneous preterm birth before 34 weeks (p=0.83), acute placental inflammatory lesions (p=1), and composite neonatal morbidity (p=0.8)].

CONCLUSIONS

The isolation of microorganisms from a sample of amniotic fluid in the absence of intra-amniotic inflammation is indicative of a benign condition, which most likely represents contamination of the specimen during the collection procedure or laboratory processing rather than early colonization or infection.

'Mycoplasma hominis does not share common risk factors with other genital pathogens': Findings from a South African pregnant cohort

Background

The role of Mycoplasma hominis (M. hominis) as a genital tract pathogen was still debatable. This study identified the risk factors associated with the prevalence of M. hominis in South African pregnant women.

Methods

This was a cross-sectional analysis of n = 221 prenatal patients attending a Durban hospital during November 2017 to April 2018. M. hominis was detected from urine samples using the quantitative polymerase chain reaction. The population characteristics were described using frequencies stratified by the infection status of M. hominis. In addition, a univariate analysis was used to assess the relationship between each risk factor and infection status. The analysis further considered logistic regression to assess the influence of these risk factors univariately and in the presence of other factors. The coinfection rate between M. hominis and bacterial vaginosis (BV), Trichomonas vaginalis (T. vaginalis), Mycoplasma genitalium (M. genitalium) and Candida species was also determined. All the tests were conducted at 5% level of significance.

Results

The prevalence of M. hominis in this study population was 48% (106/221). In the univariate analysis, factors significantly associated with M. hominis positivity included having past abnormal vaginal discharge (p = 0.037), having current abnormal vaginal discharge (p = 0.010) and a borderline significance (p = 0.052), which were noted for previous pre-term delivery. However, none of these factors were sustained in the multivariate analysis. There was a statistically significant association between M. hominis and BV positivity (p < 0.001). Similarly, M. hominis and M. genitalium positivity was significant (p = 0.006).

Conclusion

This study showed that M. hominis does not share common risk factors with known genital tract pathogens in a population of pregnant women and therefore cannot be considered a genital tract pathogen.

Presence of Chlamydia trachomatis DNA in the amniotic fluid in women with preterm prelabor rupture of membranes

OBJECTIVE

The primary aim of this study was to assess the rate and load of amniotic fluid Chlamydia trachomatis DNA and their associations with intra-amniotic infection and intra-uterine inflammatory complications in women with preterm prelabor rupture of membranes (PPROM). The secondary aim was to assess the short-term morbidity of newborns from PPROM pregnancies complicated by amniotic fluid C. trachomatis DNA.

METHODS

A retrospective study of 788 women with singleton pregnancies complicated by PPROM between 24 + 0 and 36 + 6 weeks of gestation was performed. Transabdominal amniocenteses were performed at the time of admission. C. trachomatis DNA in the amniotic fluid was assessed by real-time polymerase chain reaction using a commercial AmpliSens® C. trachomatis/Ureaplasma/Mycoplasma hominis-FRT kit, and the level of Ct DNA was quantified.

RESULTS

Amniotic fluid C. trachomatis DNA complicated 2% (16/788) of the PPROM pregnancies and was present in very low loads (median 57 copies DNA/mL). In addition to amniotic fluid C. trachomatis DNA, other bacteria were detected in 62% (10/16) of the C. trachomatis DNA-complicated PPROM pregnancies. Amniotic fluid C. trachomatis DNA was associated with intra-amniotic infection, histologic chorioamnionitis (HCA), and funisitis in 31%, 47%, and 33%, respectively. The presence of C. trachomatis DNA accompanied by Ureaplasma species in the amniotic fluid was associated with a higher rate of HCA than the presence of amniotic fluid C. trachomatis DNA alone. The composite neonatal morbidity in newborns from PPROM pregnancies with amniotic fluid C. trachomatis DNA was 31%.

CONCLUSION

The presence of C. trachomatis DNA in the amniotic fluid is a relatively rare condition in PPROM. Amniotic fluid C. trachomatis DNA in PPROM is not related to intensive intra-amniotic and intr-auterine inflammatory responses or adverse short-term neonatal outcomes.

Maternal Vaginal Ureaplasma spp. Colonization in Early Pregnancy Is Associated with Adverse Short- and Long-Term Outcome of Very Preterm Infants

Vaginal colonization with Ureaplasma (U.) spp. has been shown to be associated with adverse pregnancy outcome; however, data on neonatal outcome are scarce. The aim of the study was to investigate whether maternal vaginal colonization with U. spp. in early pregnancy represents a risk factor for adverse short- or long-term outcome of preterm infants. Previously, 4330 pregnant women were enrolled in an observational multicenter study, analyzing the association between vaginal U. spp. colonization and spontaneous preterm birth. U. spp. colonization was diagnosed via PCR analysis from vaginal swabs. For this study, data on short-term outcome were collected from medical records and long-term outcome was examined via Bayley Scales of Infant Development at 24 months adjusted age. Two-hundred-and-thirty-eight children were born <33 weeks gestational age. After exclusion due to asphyxia, malformations, and lost-to-follow-up, data on short-term and long-term outcome were available from 222 and 92 infants, respectively. Results show a significant association between vaginal U. spp. colonization and severe intraventricular hemorrhage (10.4% vs. 2.6%, p = 0.03), retinopathy of prematurity (21.7% vs. 10.3%, p = 0.03), and adverse psychomotor outcome (24.3% vs. 1.8%, OR 13.154, 95%CI 1.6,110.2, p = 0.005). The data suggest an association between vaginal U. spp. colonization in early pregnancy and adverse short- and long-term outcome of very preterm infants.

Clinical chorioamnionitis at term X: microbiology, clinical signs, placental pathology, and neonatal bacteremia - implications for clinical care

OBJECTIVES

Clinical chorioamnionitis at term is considered the most common infection-related diagnosis in labor and delivery units worldwide. The syndrome affects 5-12% of all term pregnancies and is a leading cause of maternal morbidity and mortality as well as neonatal death and sepsis. The objectives of this study were to determine the (1) amniotic fluid microbiology using cultivation and molecular microbiologic techniques; (2) diagnostic accuracy of the clinical criteria used to identify patients with intra-amniotic infection; (3) relationship between acute inflammatory lesions of the placenta (maternal and fetal inflammatory responses) and amniotic fluid microbiology and inflammatory markers; and (4) frequency of neonatal bacteremia.

METHODS

This retrospective cross-sectional study included 43 women with the diagnosis of clinical chorioamnionitis at term. The presence of microorganisms in the amniotic cavity was determined through the analysis of amniotic fluid samples by cultivation for aerobes, anaerobes, and genital mycoplasmas. A broad-range polymerase chain reaction coupled with electrospray ionization mass spectrometry was also used to detect bacteria, select viruses, and fungi. Intra-amniotic inflammation was defined as an elevated amniotic fluid interleukin-6 (IL-6) concentration ≥2.6 ng/mL.

RESULTS

(1) Intra-amniotic infection (defined as the combination of microorganisms detected in amniotic fluid and an elevated IL-6 concentration) was present in 63% (27/43) of cases; (2) the most common microorganisms found in the amniotic fluid samples were Ureaplasma species, followed by Gardnerella vaginalis; (3) sterile intra-amniotic inflammation (elevated IL-6 in amniotic fluid but without detectable microorganisms) was present in 5% (2/43) of cases; (4) 26% of patients with the diagnosis of clinical chorioamnionitis had no evidence of intra-amniotic infection or intra-amniotic inflammation; (5) intra-amniotic infection was more common when the membranes were ruptured than when they were intact (78% [21/27] vs. 38% [6/16]; p=0.01); (6) the traditional criteria for the diagnosis of clinical chorioamnionitis had poor diagnostic performance in identifying proven intra-amniotic infection (overall accuracy, 40-58%); (7) neonatal bacteremia was diagnosed in 4.9% (2/41) of cases; and (8) a fetal inflammatory response defined as the presence of severe acute funisitis was observed in 33% (9/27) of cases.

CONCLUSIONS

Clinical chorioamnionitis at term, a syndrome that can result from intra-amniotic infection, was diagnosed in approximately 63% of cases and sterile intra-amniotic inflammation in 5% of cases. However, a substantial number of patients had no evidence of intra-amniotic infection or intra-amniotic inflammation. Evidence of the fetal inflammatory response syndrome was frequently present, but microorganisms were detected in only 4.9% of cases based on cultures of aerobic and anaerobic bacteria in neonatal blood.

Lack of resistance to macrolides in Mycoplasma genitalium detected in South African pregnant women

BACKGROUND

Azithromycin regimens have been considered first-line treatment for Mycoplasma genitalium (M. genitalium), a sexually transmitted infection (STI) associated with adverse pregnancy outcomes. However, recent years have seen rapid emergence of macrolide resistance in M. genitalium as a result of widespread administration of azithromycin. Currently, there are limited data on macrolide resistance in pregnant women from KwaZulu-Natal (KZN), South Africa. This study investigated the prevalence of M. genitalium and emerging patterns of macrolide resistance in pregnant women from KZN.

METHODS

This was a sub-study of a larger study which involved laboratory-based detection of STIs in pregnant women. In the main study, pregnant women provided urine samples for detection of STIs. For this study, deoxyribose nucleic acid (DNA) extracted from stored urine was used to determine emerging macrolide resistance by amplification of the 23S ribosomal ribonucleic acid (rRNA) gene of M. genitalium by polymerase chain reaction (PCR) and sequencing of amplicons to identify mutations associated with resistance. The Allplex™ MG & AziR assay was used as a confirmatory assay.

RESULTS

The prevalence of M. genitalium in pregnant women was 5.9% (13 out of 221). Sequencing of PCR amplicons did not reveal the presence of the A2059G and A2058G mutations associated with macrolide resistance. These findings were confirmed by the Allplex™ MG & AziR assay.

CONCLUSION

Despite the lack of resistance to macrolides in this study population, continued antimicrobial resistance surveillance for M. genitalium in pregnant women is important because azithromycin is now part of the South African national STI syndromic management guidelines for vaginal discharge syndrome.

Neonatal Mycoplasma and Ureaplasma Infections

Mycoplasma species (spp.) can be commensals or opportunistic pathogens of the urogenital tract, and they can be commonly isolated from amniotic fluid, placenta, and fetal/neonatal tissue or blood in mothers delivering prematurely or their preterm infants. Although the presence of Mycoplasma spp. has been associated with adverse maternal-fetal outcomes such as preterm birth and maternal chorioamnionitis, it is less clear whether vertical transmission to the neonate results in colonization or active infection/inflammation. Moreover, the presence of Mycoplasma spp. in neonatal blood, cerebrospinal fluid, or tissue has been variably associated with increased risk of neonatal comorbidities, especially bronchopulmonary dysplasia (BPD). Although the treatment of the mother or neonate with antibiotics is effective in eradicating ureaplasma, it is not clear that the treatment is effective in reducing the incidence of major morbidities of the preterm neonate (eg, BPD). In this article, we review the animal and clinical data for ureaplasma-related complications and treatment strategies. [Pediatr Ann. 2020;49(7):e305-e312.].

Evaluation of the prevalence of sexually transmitted bacterial pathogens in Northern Cyprus by nucleic acid amplification tests, and investigation of the relationship between these pathogens and cervicitis

Objective:

To evaluate the prevalence of pathogens, Chlamydia trachomatis, Neisseria gonorrhea and Trichomonas vaginalis, Mycoplasma hominis, Mycoplasma genitalium, Ureaplasma urealyticum, and Ureaplasma parvum in women via multiplex-polymerase chain reaction (PCR)-deoxyribonucleic acid (DNA).

Materials and Methods:

Cervical swabs of 273 women in reproductive age who underwent gynecologic examination in our outpatient clinic were evaluated using the multiplex-PCR-DNA method. The presence of cervicitis, contraceptive methods, marital status, and the number of partners were evaluated.

Results:

One hundred six (39%) of the 273 women had at least one bacterium, 25 women (9.8%) had two bacteria, and three women (1%) had three bacteria. U. urealyticum was the most frequently encountered bacterium (13.9%), followed by M. hominis (12.8%), U. parvum (12.4%), C. trachomatis (5.4%), M. genitalium (2.9%), N. gonorrhea (2.5%), and T. vaginalis (0.3%). Bacterial infection was detected more frequently in women aged <25 years, single, who had multiple partners, and clinically diagnosed with cervicitis. The cervicitis rate was 39% in our study. M. genitalium was significantly more frequent in women with cervicitis than in women without cervicitis (5.6 vs. 1.2%, p=0.005). C. trachomatis and N. gonorrhea, which are often associated with cervicitis, were comparable in women with and without cervicitis.

Conclusion:

Women with clinically diagnosed cervicitis or even with a normal-appearing cervix should be tested using multiplex-real-time PCR-nucleic-acidamplification tests on suspicion of such an infection. M. genitalium is an emerging bacterial agent for cervicitis along with C. trachomatis and N. gonorrhea.

Ureaplasma species and preterm birth: current perspectives

Preterm birth is the leading cause of neonatal morbidity and mortality worldwide, and the human Ureaplasma species are most frequently isolated from the amniotic fluid and placenta in these cases. Ureaplasma colonisation is associated with infertility, stillbirth, histologic chorioamnionitis, and neonatal morbidities, including congenital pneumonia, bronchopulmonary dysplasia, meningitis and perinatal death. The human Ureaplasma spp. are separated into Ureaplasma urealyticum and Ureaplasma parvum with 14 known serotypes. The small genome has several genes, which code for surface proteins; most significantly the Multiple Banded Antigen (MBA) where an antigenic C-terminal domain elicits a host antibody response. Other genes code for various virulence factors such as IgA protease and urease. Ureaplasma spp. infection is diagnosed by culture and polymerase chain reaction (PCR) and commercial assays are available to improve turnaround time. Microbroth dilution assays are routinely used to test antimicrobial susceptibility of clinical Ureaplasma spp. especially against doxycycline, azithromycin, ofloxacin and josamycin. Resistance to macrolides, fluoroquinolones and tetracyclines has been reported. A concise review of Ureaplasma spp. and their role in pregnancy outcomes, especially preterm birth, offers insight into the early diagnosis and appropriate antibiotic therapy to prevent long-term complications of Ureaplasma spp. infections.

Characteristics and influence of Mycoplasma/Ureaplasma cultures in amniotic fluid on perinatal outcomes

AIM

To investigate the effects of Mycoplasma/Ureaplasma cultured in amniotic fluid on perinatal characteristics in preterm delivery between 22 and 33 weeks of gestation.

METHODS

The study was conducted in a tertiary perinatal center and involved 38 pregnant women who had undergone amniocentesis to evaluate intrauterine infection due to preterm labor or premature rupture of membranes. The subjects were divided into three groups based on the culture results: negative (Negative Group, n = 24), positive for Mycoplasma/Ureaplasma (M/U Group, n = 6), and positive for other pathogens (Other Pathogens Group, n = 8). One-way analysis of variance was used to compare the three groups.

RESULTS

The incidence of histological chorioamnionitis and neonatal sepsis was significantly different among the three groups (the Negative Group and the Other Pathogens Group, P < 0.01; the M/U Group and the Other Pathogens Group, P = 0.03). In the M/U Group, no infants had sepsis, severe intraventricular hemorrhage, cystic periventricular leukomalacia, or poor neurological outcomes, but one infant developed bronchopulmonary dysplasia and needed home oxygen treatment. Although one died of gastrorrhexis, the remaining five patients had normal brain magnetic resonance imaging findings and developed normally.

CONCLUSION

The presence of Mycoplasma/Ureaplasma isolated from amniotic fluid did not cause neonatal sepsis or poor prognosis. In some infants, there was no histological chorioamnionitis in the placenta. These pathogens thus seem to be less invasive than any other microbes with respect to perinatal outcomes.

Predictive value of cervical cytokine, antimicrobial and microflora levels for pre-term birth in high-risk women

Spontaneous preterm birth (sPTB, delivery <37 weeks gestation), accounts for approximately 10% of births worldwide; the aetiology is multifactorial with intra-amniotic infection being one contributing factor. This study aimed to determine whether asymptomatic women with a history of sPTB or cervical surgery have altered levels of inflammatory/antimicrobial mediators and/or microflora within cervical fluid at 22-24 weeks gestation. External cervical fluid was collected from women with history of previous sPTB and/or cervical surgery at 22-24 weeks gestation (n = 135). Cytokine and antimicrobial peptides were measured on a multiplex platform or by ELISA. qPCR was performed for detection of 7 potentially pathogenic bacterial species. IL-8 and IL-1β levels were lower in women who delivered preterm compared to those who delivered at term (IL-8 P = 0.02; IL-1β P = 0.04). There were no differences in elafin or human beta defensin-1 protein levels between the two groups. Multiple bacterial species were detected in a higher proportion of women who delivered preterm than in those who delivered at term (P = 0.005). Cervical fluid IL-8 and IL-1β and microflora have the potential to be used as biomarkers to predict sPTB in high risk women.

First Trimester Vaginal Ureaplasma Biovar Colonization and Preterm Birth: Results of a Prospective Multicenter Study

BACKGROUND

While there is a proven association of upper genital tract Ureaplasma infection during pregnancy with adverse pregnancy outcome, the effect of vaginal Ureaplasma colonization on preterm delivery has been controversially debated.

OBJECTIVES

We hypothesized that women with isolation of vaginal U. parvum but not U. urealyticum are at increased risk for spontaneous preterm birth (SPB) compared to women with negative results.

METHODS

A vaginal swab taken between 12 and 14 weeks of gestation was analyzed for the presence of Ureaplasma biovars by PCR in 4,330 pregnant women.

RESULTS

Of the study cohort, 37% were positive for U. parvum, 5.9% for U. urealyticum, and 3.1% for both. The rates of SPB were 10.4% (OR 1.7, 95% CI 1.3, 2.2, p < 0.001) and 8.9% (OR 1.4, 95% CI 0.9, 2.3, p = 0.193) in the groups with isolation of U. parvum and U. urealyticum, respectively, compared to 6.4% in the group with negative PCR results. Multiple logistic regression and interaction analyses showed that vaginal colonization with U. parvum but not U. urealyticum was a statistically significant risk factor for SPB (adjusted OR 1.6, 95% CI 1.2, 2.1, p < 0.001), independent of other risk factors such as bacterial vaginosis and history of SPB.

CONCLUSION

Our study demonstrates a statistically significant and independent association between first-trimester vaginal colonization with U. parvum and subsequent SPB.

Combinations and loads of bacteria affect the cytokine production by fetal membranes: An in vitro study

PROBLEM

The polybacterial invasion and inflammation of the amniotic cavity is a common scenario in PTB, and then, we analyzed the cytokine production by human fetal membranes to better understand the host response to polybacterial infections.

METHOD OF STUDY

Fetal membranes were treated by heat-inactivated genital mycoplasmas and Gardnerella vaginalis at 10³ or 10⁶ colony/color-forming units/mL alone or in combination. Cytokines/receptors were measured in the medium by immunoassays.

RESULTS

Stimulation of genital mycoplasmas did not increase the proinflammatory cytokines, except Ureaplasma urealyticum that increased IL-8 levels. However, U. urealyticum and Mycoplasma hominis significantly increased IL-10 and IL-13 levels. G. vaginalis alone or in combination with genital mycoplasmas showed an increased proinflammatory and anti-inflammatory cytokines.

CONCLUSIONS

G. vaginalis sustain a proinflammatory response in the fetal membranes in vitro, while genital mycoplasmas induce a strong control of the inflammatory response. The ability of genital mycoplasmas to control the proinflammatory response may favor their survival in the upper genital tract.

Mycoplasma/Ureaplasma infection in pregnancy: to screen or not to screen

Mycoplasmata have been linked to pregnancy complications and neonatal risk. While formerly a limited number of species could be discovered by cultures, molecular biology nowadays discovers both lower quantities and more diverse species, making us realize that mycoplasmata are ubiquitous in the vaginal milieu and do not always pose a danger for pregnant women. As the meaning of mycoplasmata in pregnancy is not clear to many clinicians, we summarized the current knowledge about the meaning of different kinds of mycoplasmata in pregnancy and discuss the potential benefits and disadvantages of treatment. Currently, there is no general rule to screen and treat for mycoplasmata in pregnancy. New techniques seem to indicate that Ureaplasma parvum (Up), which now can be distinguished from U. urealyticum (Uu), may pose an increased risk for preterm birth and bronchopulmonary disease in the preterm neonate. Mycoplasma hominis (Mh) is related to early miscarriages and midtrimester abortions, especially in the presence of abnormal vaginal flora. Mycoplasma genitalium (Mg) is now recognized as a sexually transmitted infection (STI) that is involved in the causation of cervicitis, pelvic inflammatory disease (PID) in non-pregnant, and preterm birth and miscarriages in pregnant women, irrespective of the presence of concurrent other STIs, like Chlamydia or gonorrhoea. Proper studies to test for efficacy and improved pregnancy outcome are scarce and inconclusive. Azythromycin is the standard treatment now, although, for Mg, this may not be sufficient. The role of clarithromycin in clinical practice still has to be established. There is a stringent need for new studies based on molecular diagnostic techniques and randomized treatment protocols with promising and safe antimicrobials.

Intrauterine infection, immune system and premature birth

Preterm birth accounts for nearly one million deaths among children under five years of age, and although its etiopathogenesis is not fully elucidated, ascending intrauterine infection and fetal inflammatory response seem to be the main triggers. The intense inflammatory response mediated by IL-1β, TNF-α, PAF, IFN-γ and IL-6, PGE₂ and MMP-1 and MMP-9 causes fetal membrane damage and rupture, increased uterine contractions and biochemical and structural changes in the cervix. Furthermore, preterm neonates have deficient innate and adaptive immune responses characterized by reduced levels of IgG, opsonization and phagocytosis, as well as increased activation of Th1 cells in relation to Th2 cells. Therefore, this triad is favors the occurrence of neonatal complications, such as respiratory distress syndrome, necrotizing enterocolitis, retinopathy of prematurity and bronchopulmonary dysplasia. Due to serious maternal and child health complications of intrauterine infection, several studies have tried to identify biomarkers for the early diagnosis of this entity. This literature review aims to discuss the main scientific findings regarding the association between ascending intrauterine infection, immune system and preterm birth.

Preterm Premature Rupture of the Membranes and Genital Mycoplasmas

Objective: The purpose of this study was to evaluate the prevalence of cervical colonization by genital mycoplasmas in patients with preterm premature rupture of the membranes (PPROM). Method: We studied 225 women between 24 and 36 weeks of gestation with PPROM. Cervical swabs were obtained for genital mycoplasmas and standard vaginal smears of bacterial culture were performed at the time of patients’ admission. In the control group were 225 women with a normal pregnancy. Results: Ureaplasma urealyticum was detected in 68 % (152/225) and Mycoplasma hominis was detected in 28 % (63/225) of the patients with PPROM between 24 and 36 weeks of gestation and. In the control group Ureaplasma urealyticum was found in 17 % (38/225) and Mycoplasma hominis in 15 % (35/225) pregnant women. Conclusion: Our results provide evidence of an association between cervical colonization with genital mycoplasmas and preterm premature rupture of the membranes.

Association between maternal genital mycoplasma colonization and histologic chorioamnionitis in preterm births

OBJECTIVE

Genital mycoplasmas (GMs) can be associated with chorioamnionitis and preterm birth, but are viewed as commensal organisms with low virulence. We sought to determine if cervical GM colonization is associated with histologic chorioamnionitis independent of infection with other bacteria.

STUDY DESIGN

Retrospective study of patients who delivered preterm, had cervical cultures for GMs, and placental cultures for bacteria other than GM. GM positive patients were compared to GM negative patients. Histologic grading of placentas was compared between GM negative patients with negative placental cultures (Group 1), GM positive patients with negative placental cultures (Group 2), GM negative patients with positive placental cultures (Group 3) and GM positive patients with positive placental cultures (Group 4).

RESULTS

GM positive patients were less likely than GM negative patients to have placental cultures positive for other bacteria (39% versus 47%, P = 0.0071). Group 2 had higher rates of membrane inflammation compared to Group 1 (p = 0.0079), and no significant difference in rates of membrane inflammation compared to Groups 3 or 4 (p = 0.36, p = 0.18). GM positivity was independently associated with increased membrane inflammation and decreased inflammation in the chorionic plate.

CONCLUSIONS

GM colonization is associated decreased inflammation of the chorionic plate, and increased inflammation of the membranes.

The placental membrane microbiome is altered among subjects with spontaneous preterm birth with and without chorioamnionitis

BACKGROUND

Preterm birth (PTB) is a leading cause of neonatal morbidity and mortality and is not uncommonly associated with chorioamnionitis. We recently have demonstrated that the placenta harbors a unique microbiome with similar flora to the oral community. We also have shown an association of these placental microbiota with PTB, history of antenatal infection, and excess maternal weight gain. On the basis of these previous observations, we hypothesized that the placental membranes would retain a microbiome community that would vary in association with preterm birth and chorioamnionitis.

OBJECTIVE

In the current study, we aimed to examine the differences in the placental membrane microbiome in association with PTB in both the presence and absence of chorioamnionitis and/or funisitis using state-of-the-science whole-genome shotgun metagenomics.

STUDY DESIGN

This was a cross-sectional analysis with 6 nested spontaneous birth cohorts (n = 9-15 subjects/cohort): Term gestations without chorioamnionitis, term with chorioamnionitis, preterm without chorioamnionitis, preterm with mild chorioamnionitis, preterm with severe chorioamnionitis, and preterm with chorioamnionitis and funisitis. Histologic analysis was performed with Redline's criteria, and inflammatory cytokines were analyzed in the cord blood. DNA from placental membranes was extracted from sterile swabs collected at delivery, and whole-genome shotgun sequencing was performed on the Illumina HiSeq platform. Filtered microbial DNA sequences were annotated and analyzed with MG-RAST (ie, Metagenomic Rapid Annotations using Subsystems Technology) and R.

RESULTS

Subjects were assigned to cohorts on the basis of gestational age at delivery and independent scoring of histologic chorioamnionitis. We found that preterm subjects with severe chorioamnionitis and funisitis had increases in cord blood inflammatory cytokines. Of interest, although the placental membrane microbiome was altered in association with severity of histologic chorioamnionitis (permutational multivariate analysis of variance P = .005), there was no observable impact with either betamethasone or antibiotic treatment. In preterm subjects with chorioamnionitis, we found a high abundance of both urogenital and oral commensal bacteria. These alterations in the microbiome were accompanied by significant variation (P < .05) in microbial metabolic pathways important in the glucose-fed pentose phosphate pathway (term subjects), or glycerophopholipid metabolism, and the biosynthesis of the siderophore group nonribosomal peptides (preterm subjects).

CONCLUSION

Consistent with ours and others previous findings, women who experienced spontaneous PTB harbor placental microbiota that further differed by severity of chorioamnionitis. Integrative metagenomic analysis revealed significant variation in distinct bacterial metabolic pathways, which we speculate may contribute to risk of preterm birth with and without severe chorioamnionitis.

Gastric fluid versus amniotic fluid analysis for the identification of intra-amniotic infection due to Ureaplasma species

OBJECTIVE

Early neonatal sepsis is often due to intra-amniotic infection. The stomach of the neonate contains fluid swallowed before and during delivery. The presence of bacteria as well as neutrophils detected by culture or Gram stain of the gastric fluid during the first day of life is suggestive of exposure to bacteria or inflammation. We undertook this study to determine the relationship between gastric fluid analysis and amniotic fluid obtained by transabdominal amniocentesis in the detection of Ureaplasma species, the most frequent microorganisms responsible for intra-amniotic infection.

MATERIALS AND METHODS

The study population consisted of 100 singleton pregnant women who delivered preterm neonates (<35 weeks) within 7 days of amniocentesis. Gastric fluid of newborns was obtained by nasogastric intubation on the day of birth. Amniotic fluid and gastric fluid were cultured for genital Mycoplasmas, and polymerase chain reaction (PCR) for Ureaplasma species was performed. Intra-amniotic inflammation was defined as an elevated amniotic fluid matrix metalloproteinase-8 concentration (>23 ng/mL).

RESULTS

(1) Ureaplasma species were detected by culture or PCR in 18% (18/100) of amniotic fluid samples and in 5% (5/100) of gastric fluid samples; (2) among the amniotic fluid cases positive for Ureaplasma species, these microorganisms were identified in 27.8% (5/18) of gastric fluid samples; (3) none of the cases negative for Ureaplasma species in the amniotic fluid were found to be positive for these microorganisms in the gastric fluid; (4) patients with amniotic fluid positive for Ureaplasma species but with gastric fluid negative for these microorganisms had a significantly higher rate of intra-amniotic inflammation, acute histologic chorioamnionitis, and neonatal death than those with both amniotic fluid and gastric fluid negative for Ureaplasma species; and (5) no significant differences were observed in the rate of intra-amniotic inflammation, acute histologic chorioamnionitis, and neonatal death between patients with amniotic fluid positive for Ureaplasma species but with gastric fluid negative for these microorganisms and those with both amniotic fluid and gastric fluid positive for Ureaplasma species.

CONCLUSIONS

Gastric fluid analysis has 100% specificity in the identification of intra-amniotic infection with Ureaplasma species. However, the detection of Ureaplasma species by culture or PCR in the gastric fluid of neonates at birth did not identify these microorganisms in two-thirds of cases with microbial invasion of the amniotic cavity. Thus, amniotic fluid analysis is superior to that of gastric fluid in the identification of intra-amniotic infection.

Eukaryote-Made Thermostable DNA Polymerase Enables Rapid PCR-Based Detection of Mycoplasma, Ureaplasma and Other Bacteria in the Amniotic Fluid of Preterm Labor Cases

Background

Intra-amniotic infection has long been recognized as the leading cause of preterm delivery. Microbial culture is the gold standard for the detection of intra-amniotic infection, but several days are required, and many bacterial species in the amniotic fluid are difficult to cultivate.

Methods

We developed a novel nested-PCR-based assay for detecting Mycoplasma, Ureaplasma, other bacteria and fungi in amniotic fluid samples within three hours of sample collection. To detect prokaryotes, eukaryote-made thermostable DNA polymerase, which is free from bacterial DNA contamination, is used in combination with bacterial universal primers. In contrast, to detect eukaryotes, conventional bacterially-made thermostable DNA polymerase is used in combination with fungal universal primers. To assess the validity of the PCR assay, we compared the PCR and conventional culture results using 300 amniotic fluid samples.

Results

Based on the detection level (positive and negative), 93.3% (280/300) of Mycoplasma, 94.3% (283/300) of Ureaplasma, 89.3% (268/300) of other bacteria and 99.7% (299/300) of fungi matched the culture results. Meanwhile, concerning the detection of bacteria other than Mycoplasma and Ureaplasma, 228 samples were negative according to the PCR method, 98.2% (224/228) of which were also negative based on the culture method. Employing the devised primer sets, mixed amniotic fluid infections of Mycoplasma, Ureaplasma and/or other bacteria could be clearly distinguished. In addition, we also attempted to compare the relative abundance in 28 amniotic fluid samples with mixed infection, and judged dominance by comparing the Ct values of quantitative real-time PCR.

Conclusions

We developed a novel PCR assay for the rapid detection of Mycoplasma, Ureaplasma, other bacteria and fungi in amniotic fluid samples. This assay can also be applied to accurately diagnose the absence of bacteria in samples. We believe that this assay will positively contribute to the treatment of intra-amniotic infection and the prevention of preterm delivery.

Preterm premature rupture of the fetal membranes: association with sociodemographic factors and maternal genitourinary infections

OBJECTIVE

this study aimed to investigate the incidence of premature rupture of fetal membranes in preterm singleton pregnancies and its association with sociodemographic factors and maternal self-reported genitourinary infections.

METHODS

this was a population-based cross-sectional study, which included all mothers of newborns of singleton deliveries that occurred in 2010, with birth weight ≥ 500 grams, who resided in the city of Rio Grande. Women were interviewed in the two maternity hospitals. Cases were women who had lost amniotic fluid before hospitalization and whose gestational age was less than 37 weeks. Statistical analysis was performed by levels to control for confounding factors using Poisson regression.

RESULTS

of the 2,244 women eligible for the study, 3.1% had preterm premature rupture of fetal membranes, which was more frequent, after adjustment, in women of lower socioeconomic status, (prevalence ratio [PR]=1.94), with lower level of schooling (PR=2.43), age > 29 years (PR=2.49), and smokers (PR=2.04). It was also associated with threatened miscarriage (PR=1.68) and preterm labor, (PR=3.40). There was no association with maternal urinary tract infection or presence of genital discharge.

CONCLUSIONS

the outcome was more common in puerperal women with lower level of schooling, lower socioeconomic status, older, and smokers, as well as those with a history of threatened miscarriage and premature labor. These factors should be considered in the prevention, diagnosis, and therapy approach.

Bacteria and endotoxin in meconium-stained amniotic fluid at term: could intra-amniotic infection cause meconium passage?

BACKGROUND

Meconium-stained amniotic fluid (MSAF) is a common occurrence among women in spontaneous labor at term, and has been associated with adverse outcomes in both mother and neonate. MSAF is a risk factor for microbial invasion of the amniotic cavity (MIAC) and preterm birth among women with preterm labor and intact membranes. We now report the frequency of MIAC and the presence of bacterial endotoxin in the amniotic fluid of patients with MSAF at term.

MATERIALS AND METHODS

We conducted a cross-sectional study including women in presumed preterm labor because of uncertain dates who underwent amniocentesis, and were later determined to be at term (n = 108). Patients were allocated into two groups: (1) MSAF (n = 66) and (2) clear amniotic fluid (n = 42). The presence of bacteria was determined by microbiologic techniques, and endotoxin was detected using the Limulus amebocyte lysate (LAL) gel clot assay. Statistical analyses were performed to test for normality and bivariate comparisons.

RESULTS

Bacteria were more frequently present in patients with MSAF compared to those with clear amniotic fluid [19.6% (13/66) versus 4.7% (2/42); p < 0.05]. The microorganisms were Gram-negative rods (n = 7), Ureaplasma urealyticum (n = 4), Gram-positive rods (n = 2) and Mycoplasma hominis (n = 1). The LAL gel clot assay was positive in 46.9% (31/66) of patients with MSAF, and in 4.7% (2/42) of those with clear amniotic fluid (p < 0.001). After heat treatment, the frequency of a positive LAL gel clot assay remained higher in the MSAF group [18.1% (12/66) versus 2.3% (1/42), p < 0.05]. Median amniotic fluid IL-6 concentration (ng/mL) was higher [1.3 (0.7-1.9) versus 0.6 (0.3-1.2), p = 0.04], and median amniotic fluid glucose concentration (mg/dL) was lower [6 (0-8.9) versus 9 (7.4-12.6), p < 0.001] in the MSAF group, than in those with clear amniotic fluid.

CONCLUSION

MSAF at term was associated with an increased incidence of MIAC. The index of suspicion for an infection-related process in postpartum women and their neonates should be increased in the presence of MSAF.

Ureaplasma urealyticum, Mycoplasma hominis and adverse pregnancy outcomes

PURPOSE OF REVIEW

Mycoplasma hominis and Ureaplasma urealyticum may colonize the human genital tract and have been associated with adverse pregnancy outcomes. Chorioamnionitis, spontaneous preterm labour and preterm premature rupture of membranes are significant contributors to neonatal morbidity and mortality. However, as these bacteria can reside in the normal vaginal flora, there are controversies regarding their true role during pregnancy and thus the need to treat these organisms.

RECENT FINDINGS

We review here the recent data on the epidemiology of mycoplasmas and their clinical role during pregnancy. The association of these organisms with preterm labour has been suggested by many observational studies, but proof of causality remains limited. PCR is an excellent alternative to culture to detect the presence of these organisms, but culture allows antibiotic susceptibility testing. Whether antimicrobial treatment of mycoplasma-colonized pregnant patients can effectively reduce the incidence of adverse pregnancy outcomes warrants further investigations.

SUMMARY

The role of Mycoplasma spp. and U. urealyticum in adverse pregnancy outcomes is increasingly accepted. However, sole presence of these microorganisms in the vaginal flora might be insufficient to cause pathological issues, but their combination with other factors such as bacterial vaginosis or cervical incompetence may be additionally needed to induce preterm birth.

Ureaplasma urealyticum and Ureaplasma parvum in women of reproductive age

OBJECTIVES

To determine the incidence of Ureaplasma urealyticum and Ureaplasma parvum (UP) in symptomatic and asymptomatic women of reproductive age and to estimate antibiotic susceptibility of ureaplasma isolates.

MATERIALS AND METHODS

This study included 424 ureaplasma positive women of 1,370 tested women who visited gynecological practices during 2010. Cervicovaginal or urethral swab specimens from each patient were obtained for cultivation and molecular typing by RT-PCR.

RESULTS

Ureaplasma spp. was identified by cultivation in 424 (34.4 %) cases, of which 79.0 % were from women with symptoms and 21.0 % from women without symptoms. Among ureaplasma positive women, 121 (28.5 %) were pregnant. Genotyping was successful in 244 strains, and the majority of samples were identified as UP (92.6 %). Among genotyped isolates, there were 79.5 % from symptomatic and 20.5 % from asymptomatic women; 29.9 % from pregnant and 70.1 % from non-pregnant women. There was no difference in the incidence of ureaplasma type regarding symptoms. Antibiotic susceptibility of 424 ureaplasma isolates identified by cultivation showed that all strains were susceptible to doxycycline, josamycin, erythromycin, tetracycline, clarithromycin and pristinamycin, but there was lower susceptibility to quinolone antibiotics, i.e., 42.9 and 24.5 % isolates were susceptible to ofloxacin and ciprofloxacin, respectively.

CONCLUSION

This study shows that UP was the most frequent isolated ureaplasma species (92.6 %). Regarding antibiotic susceptibility, quinolones are not the best choice for the treatment of ureaplasma infections, while macrolides and tetracyclines are still effective.

Co-infection with vaginal Ureaplasma urealyticum and Mycoplasma hominis increases adverse pregnancy outcomes in patients with preterm labor or preterm premature rupture of membranes

OBJECTIVE

The purpose of this study was to determine the prevalence of Ureaplasma urealyticum (UU) and Mycoplasma hominis (MH) in patients with preterm labor or preterm premature rupture of membranes (PPROM) and to determine the effect of these organisms on pregnancy outcomes based on the density of colonization.

METHODS

The study group consisted of 184 women with preterm labor or PPROM. Vaginal cultures for UU and MH were performed for all patients at admission, and the placentas were histologically evaluated after delivery.

RESULTS

The prevalence of positive vaginal fluid cultures for genital mycoplasma was 62.5% (112/179). This group included 99 patients carrying only UU and 13 carrying both organisms. No patients were found to carry only MH. Compared to patients only positive for UU, patients with both organisms showed significantly decreased gestational age at birth and birth weight, and significant increases in the incidences of preterm birth, NICU admissions and histologic chorioamnionitis.

CONCLUSION

Vaginal MH tends to be detected with UU, and patients carrying both organisms simultaneously had more severe adverse pregnancy outcomes compared to patients in preterm labor or PPROM who were only positive for UU.

Current concepts of genetic variability of genital mycoplasmas and their role in the development of inflammatory diseases of the urogenital system

The authors disclose current concepts of the taxonomic and morphologic characteristics of genital mycoplasmas and their role in the development of inflammatory urogenital diseases and reproductive disorders. They also discuss such issues as genetic variability of genital mycoplasmas and possible interrelation with different variants of the clinical course of inflammatory processes in the urogenital tract.

Ureaplasma and BPD

Ureaplasma is an organism with low virulence and is a commensal of the lower genito-urinary tract in females. From here, it can gain entry in the amniotic fluid to cause inflammation in the amniotic compartment during pregnancy. Ureaplasma spp. are the most common organisms isolated from women with chorioamnionitis. Ureaplasma spp. are associated with increased risk for preterm labor and morbidity in the preterm neonate. However, there is some controversy regarding the importance of Ureaplasma in the pathogenesis of bronchopulmonary dysplasia (BPD). This article will review the microbiology of Ureaplasma, host innate immune responses, and the pathology of lung injury in animal models of Ureaplasma chorioamnionitis. We will review epidemiological studies of Ureaplasma and BPD in preterm infants and efficacy of antibiotics in preventing preterm labor and BPD.

Viral invasion of the amniotic cavity (VIAC) in the midtrimester of pregnancy

INTRODUCTION

The prevalence of viral infections in the amniotic fluid (AF) has not yet been ascertained. The aim of this study was to determine the prevalence of specific viral nucleic acids in the AF and its relationship to pregnancy outcome.

STUDY DESIGN

From a cohort of 847 consecutive women undergoing midtrimester amniocentesis, 729 cases were included in this study after exclusion of documented fetal anomalies, chromosomal abnormalities, unavailability of AF specimens and clinical outcomes. AF specimens were tested by quantitative real-time PCR for the presence of genome sequences of the following viruses: adenoviruses, herpes simplex virus (HSV), varicella zoster virus (VZV), human herpesvirus 6 (HHV6), human cytomegalovirus (HCMV), Epstein-Barr virus (EBV), parvovirus B19 and enteroviruses. Viral nucleic acid testing was also performed in maternal blood and cord blood in the population of women in whom AF was positive for viruses and in a control group of 29 women with AF negative for viral nucleic acids. The relationship between the presence of viruses and pregnancy and neonatal outcome was examined. The correlation between the presence of nucleic acids of viruses in the AF and the concentration of the cytokine interleukin-6 (IL-6) and the T cell chemokine CXCL-10 (or IP-10) in AF and maternal blood were analyzed.

RESULTS

Viral genome sequences were found in 16 of 729 (2.2%) AF samples. HHV6 was the most commonly detected virus (7 cases, 1.0%), followed by HCMV (6 cases, 0.8%), parvovirus B19 (2 cases, 0.3%) and EBV (1 case, 0.1%), while HSV, VZV, enteroviruses and adenoviruses were not found in this cohort. Corresponding viral DNA was also detected in maternal blood of six out of seven women with HHV6-positive AF and in the umbilical cord plasma, which was available in one case. In contrast, viral DNA was not detected in maternal blood of women with AF positive for parvovirus B19, HCMV, EBV or of women with AF negative for viruses. HHV6 genome copy number in AF and maternal blood was consistent with genomic integration of viral DNA and genetic infection in all women. There was no significant difference in the AF concentration of IL-6 and IP-10 between patients with and without VIAC. However, for HCMV, there was a significant relationship between viral copy number and IP-10 concentration in maternal blood and AF. The group of women with AF positive for viral DNA delivered at term healthy neonates without complications in 14 out of 16 cases. In one case of HHV6 infection in the AF, the patient developed gestational hypertension at term, and in another case of HHV6 infection in the AF, the patient delivered at 33 weeks after preterm premature rupture of membranes (PPROM).

CONCLUSION

Viral nucleic acids are detectable in 2.2% of AF samples obtained from asymptomatic women in the midtrimester. HHV6 was the most frequently detected virus in AF. Adenoviruses were not detected. Vertical transmission of HHV6 was demonstrated in one case.

Cord blood interleukin-6 and neonatal morbidities among preterm infants with PCR-positive Ureaplasma urealyticum

OBJECTIVES

To evaluate the clinical significance of Ureaplasma urealyticum recovery from umbilical cord blood, using Polymerase Chain Reaction (PCR), and its association with umbilical cord interleukin-6 (IL-6) levels and neonatal morbidity in preterm infants.

METHODS

Cord blood PCR for Ureaplasma urealyticum, and IL-6 were assessed in relation to neonatal outcomes of 30 preterm deliveries of less than 35 weeks' gestation.

RESULTS

Ureaplasma urealyticum was present in 43.3% of the examined cord blood samples. Positive neonatal Ureaplasma urealyticum was more common in association with premature rupture of membranes, chorioamnionitis, antenatal maternal use of antibiotics, and earlier gestation. Ureaplasma urealyticum was also associated with an early pro-inflammatory immune response (i.e. elevated IL-6 and positive C-reactive protein). Cutoff level of interleukin-6 of 240 pg% predicts the occurrence of respiratory distress syndrome (RDS), in neonates with positive PCR for Ureaplasma urealyticum.

CONCLUSIONS

Preterm patients with positive cord blood PCR for Ureaplasma urealyticum were more likely to have premature rupture of membrane, antenatal antibiotics, chorioamnionitis, earlier gestation, pro-inflammatory response, and RDS than those with a negative PCR. High IL-6 is more likely associated with RDS in Ureaplasma urealyticum positive neonates.

In utero exposure to Ureaplasma spp. is associated with increased rate of bronchopulmonary dysplasia and intraventricular hemorrhage in preterm infants

AIMS

We determined the association between short-term neonatal morbidities, such as bronchopulmonary dysplasia (BPD) and intraventricular hemorrhage (IVH), and Ureaplasma spp. in amniotic fluid, placental and amniotic membrane of preterm infants.

METHODS

This study enrolled 257 patients who were born by cesarean section at <34 weeks' gestation. Patients were divided into two groups according to detection of Ureaplasma spp. by culture-based and/or polymerase chain reaction (PCR) techniques.

RESULTS

Significant differences were observed between both groups for all IVH (P=0.032) and IVH grades III or IV (P=0.013), as wells as for BPD [odds ratio (OR) 5.46, 95% confidence interval (CI) 2.02-14.77], oxygen requirement at 28 days postnatal age (OR 1.93, 95% CI 1.00-3.70), and for death between 28 days and 36 postmenstrual weeks or BPD (OR 4.20, 95% CI 1.77-9.96). Ureaplasma spp. was a significant predictor (P<0.001) of BPD after correcting for birth weight (P=0.003) and positive pressure ventilation (P=0.001).

CONCLUSIONS

In our study population Ureaplasma spp. was associated with BPD and IVH in preterm infants even after adjustment for multiple risk factors.

Ventilation-mediated injury after preterm delivery of Ureaplasma parvum colonized fetal lambs

Ureaplasma species are the microorganisms most frequently isolated from women with preterm birth and are associated with an increased risk of bronchopulmonary dysplasia. Initiation of ventilation with high tidal volumes (VT) causes lung injury and inflammation. We investigated whether antenatal colonization with Ureaplasma parvum serovar 3 (UP) would alter the inflammatory response to mechanical ventilation of preterm lambs. Merino ewes were given intraamniotic injections of UP at 55-d gestation, and the lambs were surgically delivered at 128+/-1 d gestation and assigned to three groups: 1) gentle ventilation (GV), 2) high VT ventilation, or 3) unventilated control. Lambs delivered from noncolonized ewes were assigned to parallel groups. GV lambs received surfactant before ventilation with a VT of 7 mL/kg, positive end expiratory pressure (PEEP) 5 cm H2O. High VT lambs received no PEEP and escalating VT to 15 mL/kg by 15 min. At 15 min, surfactant was given, VT was reduced to 7 mL/kg, and PEEP was increased to 5 cm H2O. Monocytes in bronchoalveolar lavage were increased by UP, but colonization did not affect lung function. High VT ventilation increased Egr-1 signaling, proinflammatory cytokine expression, and injury scores compared with GV. Antenatal colonization with UP did not change lung function or modulate the lung injury and inflammation caused by high VT ventilation.

Ureaplasma species: role in diseases of prematurity

There is accumulating epidemiologic and experimental evidence that intrauterine or postnatal infection with Ureaplasma species is a significant risk factor for adverse pregnancy outcomes and complications of extreme preterm birth such as bronchopulmonary dysplasia and intraventricular hemorrhage. In a cohort of very low birth weight infants, Ureaplasma spp were detected by culture or polymerase chain reaction in respiratory secretions, blood, or cerebrospinal fluid of almost half of the subjects, suggesting that this organism is the most common pathogen affecting this population. This review summarizes the evidence supporting the hypothesis that Ureaplasma-mediated inflammation in different compartments (intrauterine, lung, blood, or brain) during a common developmental window of vulnerability contributes to preterm labor and lung and brain injury. Appropriate methods for detecting these fastidious organisms and potential strategies to prevent or ameliorate the effects of Ureaplasma infection are discussed.

Diagnosis and management of clinical chorioamnionitis

Chorioamnionitis is a common complication of pregnancy associated with significant maternal, perinatal, and long-term adverse outcomes. Adverse maternal outcomes include postpartum infections and sepsis whereas adverse infant outcomes include stillbirth, premature birth, neonatal sepsis, chronic lung disease, and brain injury leading to cerebral palsy and other neurodevelopmental disabilities. Research in the past 2 decades has expanded understanding of the mechanistic links between intra-amniotic infection and preterm delivery as well as morbidities of preterm and term infants. Recent and ongoing clinical research into better methods for diagnosing, treating, and preventing chorioamnionitis is likely to have a substantial impact on short and long-term outcomes in the neonate.

Pulmonary vascular and alveolar development in preterm lambs chronically colonized with Ureaplasma parvum

Ureaplasma species, the most commonly isolated microorganisms in women with chorioamnionitis, are associated with preterm delivery. Chorioamnionitis increases the risk and severity of bronchopulmonary dysplasia and persistent pulmonary hypertension in newborns. It is not known whether the timing of exposure to inflammation in utero is an important contributor to the pathogenesis of bronchopulmonary dysplasia. We hypothesized that chronic inflammation would alter the pulmonary air space and vascular development after 70 days of exposure to infection. Pregnant ewes were given intra-amniotic injection of Ureaplasma parvum serovars 3 or 6 at low (2 x 10(4) cfu) or high doses (2 x 10(7) cfu) or media (controls) at 55 days gestational age. Fetuses were delivered at 125 days (term = 150 days). U. parvum was grown from the lungs of all exposed fetuses, and neutrophils and monocytes were increased in the air spaces. Lung mRNA expression of IL-1beta and IL-8, but not IL-6, was modestly increased in U. parvum-exposed fetuses. U. parvum exposure increased surfactant and improved lung gas volumes. The changes in lung inflammation and maturation were independent of serovar or dose. Exposure to U. parvum did not change multiple indices of air space or vascular development. Parenchymal elastin and collagen content were similar between groups. Expression of several endothelial proteins and pulmonary resistance arteriolar media thickness were also not different between groups. We conclude that chronic exposure to U. parvum does not cause sustained effects on air space or vascular development in premature lambs.

The bacterial load of Ureaplasma parvum in amniotic fluid is correlated with an increased intrauterine inflammatory response

Ureaplasma spp. are the most frequently isolated microorganisms inside the amniotic cavity and have been associated with spontaneous abortion, chorioamnionitis, premature rupture of the membranes (PROM), and preterm labor (PL). We analyzed 118 samples from amniotic fluid of preterm infants before 34 weeks of gestation by quantitative polymerase chain reaction (qPCR). Bacterial load, Ureaplasma biovar discrimination (Ureaplasma urealyticum and Ureaplasma parvum), and the level of inflammation were correlated with short-term clinical outcome. U. parvum was the predominant biovar, and increased bacterial load was significantly linked to histologic chorioamnionitis, PROM + PL, early-onset sepsis, and bronchopulmonary dysplasia. Furthermore, there was a positive correlation between the amount of U. parvum and the magnitude of inflammatory response inside the amniotic cavity observed by elevated interleukin 8 levels. We postulate that the bacterial load of Ureaplasma spp. measured by qPCR should be determined in studies investigating the potential clinical impact of intrauterine Ureaplasma spp. on the outcome of preterm infants.

Prematurity prevention: the role of cerclage

PURPOSE OF REVIEW

To summarize the literature on the value of cervical cerclage for the prevention of preterm birth and present the recent advances in its clinical application.

RECENT FINDINGS

The diagnosis of cervical insufficiency is difficult as there are no objective diagnostic criteria. Although widely used, the value of cervical cerclage is still a matter of controversy. The current literature suggests that cerclage placement can prevent preterm delivery in women with a history of at least three second-trimester losses or at least three preterm births and in those with a history of prematurity who have a cervical length of less than 25 mm in the second trimester. It is also possible to improve the perinatal outcome in patients with cervical dilation in the mid-trimester. It is not indicated in multiple pregnancies, however. Further research is needed in methods of excluding inflammation in women with cervical changes on ultrasound prior to cerclage insertion. Transabdominal or laparoscopic cerclage seems to be a promising alternative in women with a history of transvaginal cerclage failure.

SUMMARY

Strict recommendations on the proper use of cerclage cannot be easily made. Data from randomized trials do not support what the current practice in many cases is.

Differing prevalence and diversity of bacterial species in fetal membranes from very preterm and term labor

BACKGROUND

Intrauterine infection may play a role in preterm delivery due to spontaneous preterm labor (PTL) and preterm prolonged rupture of membranes (PPROM). Because bacteria previously associated with preterm delivery are often difficult to culture, a molecular biology approach was used to identify bacterial DNA in placenta and fetal membranes.

METHODOLOGY/PRINCIPAL FINDINGS

We used broad-range 16S rDNA PCR and species-specific, real-time assays to amplify bacterial DNA from fetal membranes and placenta. 74 women were recruited to the following groups: PPROM <32 weeks (n = 26; 11 caesarean); PTL with intact membranes <32 weeks (n = 19; all vaginal birth); indicated preterm delivery <32 weeks (n = 8; all caesarean); term (n = 21; 11 caesarean). 50% (5/10) of term vaginal deliveries were positive for bacterial DNA. However, little spread was observed through tissues and species diversity was restricted. Minimal bacteria were detected in term elective section or indicated preterm deliveries. Bacterial prevalence was significantly increased in samples from PTL with intact membranes [89% (17/19) versus 50% (5/10) in term vaginal delivery p = 0.03] and PPROM (CS) [55% (6/11) versus 0% (0/11) in term elective CS, p = 0.01]. In addition, bacterial spread and diversity was greater in the preterm groups with 68% (13/19) PTL group having 3 or more positive samples and over 60% (12/19) showing two or more bacterial species (versus 20% (2/10) in term vaginal deliveries). Blood monocytes from women with PTL with intact membranes and PPROM who were 16S bacterial positive showed greater level of immune paresis (p = 0.03). A positive PCR result was associated with histological chorioamnionitis in preterm deliveries.

CONCLUSION/SIGNIFICANCE

Bacteria are found in both preterm and term fetal membranes. A greater spread and diversity of bacterial species were found in tissues of women who had very preterm births. It is unclear to what extent the greater bacterial prevalence observed in all vaginal delivery groups reflects bacterial contamination or colonization of membranes during labor. Bacteria positive preterm tissues are associated with histological chorioamnionitis and a pronounced maternal immune paresis.

Diversity in cytokine response to bacteria associated with preterm birth by fetal membranes

OBJECTIVE

This study compared cytokine and prostaglandin (PG) responses by fetal membranes stimulated with 4 different bacterial species associated with preterm birth (PTB).

STUDY DESIGN

Fetal membranes (n = 13 from normal term cesarean sections [not in labor]) in an organ explant system were stimulated with heat-killed Ureaplasma parvum, Gardanerella vaginalis, Escherichia coli, group B Streptococcus (GBS), or lipopolysaccharide (LPS). Cytokines (interleukin [IL]-1beta, IL-6, IL-8, IL-10, tumor necrosis factor [TNF]-alpha, and interferon-gamma) and PG (PGF(2alpha) and PGE(2)) concentrations were quantitated and compared.

RESULTS

LPS and E coli increased all cytokine and PG productions compared with controls. Cytokine profiles were similar after G vaginalis and GBS stimulation. G vaginalis increased PGE(2), whereas GBS increased PGF(2alpha). U parvum demonstrated the mildest response with only IL-10 and TNF-alpha concentrations being higher with no detectible effect on PGs.

CONCLUSION

Fetal membrane cytokine signatures of 4 different bacteria associated with PTB are distinct, suggesting that infection as a potential cause of PTB is not homogeneous in its presentation.

Prevalence and antibiotic susceptibility of Mycoplasma hominis and Ureaplasma urealyticum in pregnant women

BACKGROUND

Mycoplasma hominis and Ureaplasma urealyticum are important opportunistic pathogens implicated in urogenital infections and complicated pregnancy. We aimed to study the role of these pathogens in symptomatic and asymptomatic pregnant women and determine their clinical significance and antibiotic susceptibility.

METHODS

One hundred pregnant women were included in the study, 50 symptomatic patients and 50 asymptomatic controls. Duplicate endocervical samples were taken from each individual and analyzed using the Mycoplasma IST-2 kit and A7 agar medium. Antimicrobial susceptibility was tested against doxycycline, josamycin, ofloxacin, erythromycin, tetracycline, ciprofloxacin, azithromycin, clarithromycin, and pristinamycin using the Mycoplasma IST-2 kit.

RESULTS

Twelve symptomatic pregnant women had spontaneous abortions. Of these, eight (66.7%) cases had been colonized with M. hominis and/or U. urealyticum. Of the pregnant women infected with M. hominis and/or U. urealyticum, 40.7% delivered a low birth weight infant. M. hominis was successfully cultured in five women (5%) and U. urealyticum in 27 (27%). Among positive cultures, 15.6% and 84.4% of isolates were M. hominis and U. urealyticum, respectively. M. hominis and U. urealyticum were uniformly susceptible to doxycycline, tetracycline, and pristinamycin, which may be successfully used in the empirical therapy of infected individuals.

CONCLUSIONS

It can be concluded that genital colonization with M. hominis and U. urealyticum may predispose to spontaneous abortion and low birth weight.

Perinatal correlates of Ureaplasma urealyticum in placenta parenchyma of singleton pregnancies that end before 28 weeks of gestation

OBJECTIVES

The purpose of this work was to examine the relationship between Ureaplasma urealyticum in the placenta and perinatal outcomes in extreme preterm deliveries and to explore the influence of bacteria coinfection on perinatal outcomes in U urealyticum-positive placentas.

METHODS

Under sterile conditions, a piece of chorion from 866 singleton deliveries before 28 weeks' gestation was obtained and flash frozen. The tissue was later homogenized and cultured for Ureaplasma and bacteria. Placentas were also examined histologically. Maternal and neonatal data were obtained prospectively. Each infant had 3 sets of cranial ultrasound scans between days 1 to 4, 5 to 14, and between day 15 and 40th week postconceptional age. Cranial ultrasound findings were by consensus of 2 or 2 of 3 sonologists.

RESULTS

U urealyticum was recovered from 6% and bacteria from 47%; 47% of placentas had no bacteria detectable. Sixty-seven percent of Ureaplasma-positive placentas also harbored bacteria. Placentas that harbored U urealyticum only were more likely than sterile placentas to be associated with a higher prevalence of preterm labor and preterm premature rupture of membranes, as well as umbilical cord, fetal vessel, membrane, and parenchymal inflammation and to predict intraventricular hemorrhage and echolucent brain lesions. Placentas that harbored U urealyticum only were similar to placentas that harbored bacteria only. Recovery of U urealyticum and bacteria from same placenta did not enhance the differences between placentas with U urealyticum alone and sterile placentas. Recovery of U urealyticum only was not associated with a higher risk of death before day 7 of life.

CONCLUSIONS

The presence of U urealyticum in placental parenchyma before 28 weeks is associated with increased risk of preterm labor and delivery, higher risk of fetal and maternal inflammation, and increased risk of intraventricular hemorrhage and echolucent brain lesions but not of early neonatal death.