Congenital and opportunistic infections: Ureaplasma species and Mycoplasma hominis

Antibiotic susceptibility profiles of Mycoplasma hominis and ureaplasma urealyticum isolated during a population-based study concerning women infertility in northeast romania

The study was carried out on 1068 infertile women under initial evaluation. For Mycoplasma hominis, the highest resistance rates were registered for ciprofloxacin (72.22%), followed by macrolides and ofloxacin. For Ureaplasma urealyticum, the ciprofloxacin resistance was also high (51.72%), while the resistance rates to other tested antibiotics were significantly lower.

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.

Diversity of Mycoplasma hominis clinical isolates from Bordeaux, France, as assessed by multiple-locus variable-number tandem repeat analysis

Background

Mycoplasma hominis is an opportunistic human mycoplasma species that can cause various urogenital infections and, less frequently, extragenital infections. The objective of this work was to study the genetic diversity of this species using a molecular typing method based on multiple-locus variable-number tandem repeat (VNTR) analysis (MLVA).

Results

The genome content of M. hominis PG21 was analysed for tandem repeats (TRs), and five of the 130 TRs identified were selected for use in an MLVA assay. The method was based on GeneScan analysis of VNTR loci using multiplex PCR with fluorescent dyes and resolution by capillary electrophoresis. This approach was used on a collection of 210 urogenital and extragenital French clinical isolates collected between 1987 and 2009. Forty MLVA types were found. The discriminatory index of our MLVA scheme was 0.924. Using this new typing tool, persistent infection was suggested for six patients and new infection for one patient. Furthermore, mother-to-child transmission was confirmed in the two cases studied. Application of MLVA to a wide range of M. hominis isolates revealed high genotypic diversity and no obvious link between the MLVA type and the isolate year of collection, the patient’s age or sex, the anatomical origin of the isolates or resistance to antibiotics was found.

Conclusions

Our MLVA scheme highlights the high genetic heterogeneity of the M. hominis species. It seems too discriminatory to be used for large epidemiological studies but has proven its usefulness for molecular studies at the individual level.

Maternal azithromycin therapy for Ureaplasma intraamniotic infection delays preterm delivery and reduces fetal lung injury in a primate model

OBJECTIVE

We assessed the efficacy of a maternal multidose azithromycin (AZI) regimen, with and without antiinflammatory agents to delay preterm birth and to mitigate fetal lung injury associated with Ureaplasma parvum intraamniotic infection.

STUDY DESIGN

Long-term catheterized rhesus monkeys (n = 16) received intraamniotic inoculation of U parvum (10(7) colony-forming U/mL, serovar 1). After contraction onset, rhesus monkeys received no treatment (n = 6); AZI (12.5 mg/kg, every 12 h, intravenous for 10 days; n = 5); or AZI plus dexamethasone and indomethacin (n = 5). Outcomes included amniotic fluid proinflammatory mediators, U parvum cultures and polymerase chain reaction, AZI pharmacokinetics, and the extent of fetal lung inflammation.

RESULTS

Maternal AZI therapy eradicated U parvum intraamniotic infection from the amniotic fluid within 4 days. Placenta and fetal tissues were 90% culture negative at delivery. AZI therapy significantly delayed preterm delivery and prevented advanced fetal lung injury, although residual acute chorioamnionitis persisted.

CONCLUSION

Specific maternal antibiotic therapy can eradicate U parvum from the amniotic fluid and key fetal organs, with subsequent prolongation of pregnancy, which provides a therapeutic window of opportunity to effectively reduce the severity of fetal lung injury.

Incidence and antibiotic susceptibility of Mycoplasma hominis and Ureaplasma urealyticum isolated in Brescia, Italy, over 7 years

The prevalence and antimicrobial susceptibility of Ureaplasma urealyticum and Mycoplasma hominis collected during 2004-2011 were determined. A total of 9956 individuals was analyzed. Identification was performed by use of the mycoplasma IST-2 kit. Antimicrobial susceptibility against doxycycline, josamycin, ofloxacin, erythromycin, tetracycline, ciprofloxacin, azithromycin, clarithromycin, and pristinamycin was also tested by use of this commercial kit. Our results show a prevalence of 1856 positive patients for genital mycoplasmas (18.6 %). Among positive cultures, 89 and 1.1 % of isolates were Ureaplasma urealyticum and Mycoplasma hominis, respectively. For 9.8 % of isolates both urogenital mycoplasmas were grown. Doxycycline was the most active tetracycline for mycoplasma infections, and this is still the drug of first choice. Among macrolides, josamycin and clarithromycin are the most active agents against ureaplasmas; josamycin is also active against mycoplasmas and is an alternative to tetracyclines and erythromycin for mixed infections, especially for pregnant women and neonates. Fluoroquinolones had low efficacy against urogenital mycoplasmas. For Ureaplasma urealyticum, cross-resistance was found between erythromycin and macrolides (except josamycin) (40-80 %) and between erythromycin and ciprofloxacin (79 %). Antibiotic resistance over the test period did not vary significantly. Because of geographical differences among antibiotic resistance, local in-vitro susceptibility testing is recommended to avoid failure of therapy.

Host genetic background impacts disease outcome during intrauterine infection with Ureaplasma parvum

Ureaplasma parvum, an opportunistic pathogen of the human urogenital tract, has been implicated in contributing to chorioamnionitis, fetal morbidity, and fetal mortality. It has been proposed that the host genetic background is a critical factor in adverse pregnancy outcome as sequela to U. parvum intra-amniotic infection. To test this hypothesis we assessed the impact of intrauterine U. parvum infection in the prototypical TH1/M1 C57BL/6 and TH2/M2 BALB/c mouse strain. Sterile medium or U. parvum was inoculated into each uterine horn and animals were evaluated for intra-amniotic infection, fetal infection, chorioamnionitis and fetal pathology at 72 hours post-inoculation. Disease outcome was assessed by microbial culture, in situ detection of U. parvum in fetal and utero-placental tissues, grading of chorioamnionitis, and placental gene expression of IL-1α, IL-1β, IL-6, TNF-α, S100A8, and S100A9. Placental infection and colonization rates were equivalent in both strains. The in situ distribution of U. parvum in placental tissues was also similar. However, a significantly greater proportion of BALB/c fetuses were infected (P<0.02). C57BL/6 infected animals predominantly exhibited mild to moderate chorioamnionitis (P<0.0001), and a significant reduction in placental expression of IL-1α, IL-1β, IL-6, TNF-α, S100A8, and S100A9 compared to sham controls (P<0.02). Conversely, severe protracted chorioamnionitis with cellular necrosis was the predominant lesion phenotype in BALB/c mice, which also exhibited a significant increase in placental expression of IL-1α, IL-1β, IL-6, TNF-α, S100A8, and S100A9 (P<0.01). Fetal pathology in BALB/c was multi-organ and included brain, lung, heart, liver, and intestine, whereas fetal pathology in C57BL/6 was only detected in the liver and intestines. These results confirm that the host genetic background is a major determinant in ureaplasmal induced chorioamnionitis with fetal infection and fetal inflammatory response.

Comparative genome analysis of 19 Ureaplasma urealyticum and Ureaplasma parvum strains

Background

Ureaplasma urealyticum (UUR) and Ureaplasma parvum (UPA) are sexually transmitted bacteria among humans implicated in a variety of disease states including but not limited to: nongonococcal urethritis, infertility, adverse pregnancy outcomes, chorioamnionitis, and bronchopulmonary dysplasia in neonates. There are 10 distinct serotypes of UUR and 4 of UPA. Efforts to determine whether difference in pathogenic potential exists at the ureaplasma serovar level have been hampered by limitations of antibody-based typing methods, multiple cross-reactions and poor discriminating capacity in clinical samples containing two or more serovars.

Results

We determined the genome sequences of the American Type Culture Collection (ATCC) type strains of all UUR and UPA serovars as well as four clinical isolates of UUR for which we were not able to determine serovar designation. UPA serovars had 0.75−0.78 Mbp genomes and UUR serovars were 0.84−0.95 Mbp. The original classification of ureaplasma isolates into distinct serovars was largely based on differences in the major ureaplasma surface antigen called the multiple banded antigen (MBA) and reactions of human and animal sera to the organisms. Whole genome analysis of the 14 serovars and the 4 clinical isolates showed the mba gene was part of a large superfamily, which is a phase variable gene system, and that some serovars have identical sets of mba genes. Most of the differences among serovars are hypothetical genes, and in general the two species and 14 serovars are extremely similar at the genome level.

Conclusions

Comparative genome analysis suggests UUR is more capable of acquiring genes horizontally, which may contribute to its greater virulence for some conditions. The overwhelming evidence of extensive horizontal gene transfer among these organisms from our previous studies combined with our comparative analysis indicates that ureaplasmas exist as quasi-species rather than as stable serovars in their native environment. Therefore, differential pathogenicity and clinical outcome of a ureaplasmal infection is most likely not on the serovar level, but rather may be due to the presence or absence of potential pathogenicity factors in an individual ureaplasma clinical isolate and/or patient to patient differences in terms of autoimmunity and microbiome.

[Microbiological diagnosis of mycoplasma infections]

The microbiological diagnosis of mycoplasma and ureaplasma infections has always been limited due to the fastidious growth of these microorganisms, as well as the lack of commercially prepared growth media, absence of rapid diagnostic procedures, and the clinical perception that these organisms are less significant in the infectious diseases setting. During the last few years, this situation has substantially improved due to the commercial availability of culture media, the development of rapid serological techniques, and, in particular, to the introduction of nucleic acid amplification assays, commercially available or "in-house" preparations. Despite the lack of proper standardisation and validation of the molecular and serological techniques, methodological advances have led to an increased detection of these microorganisms and, consequently, a greater appreciation of their clinical relevance.

The role of the multiple banded antigen of Ureaplasma parvum in intra-amniotic infection: major virulence factor or decoy?

The multiple banded antigen (MBA) is a predicted virulence factor of Ureaplasma species. Antigenic variation of the MBA is a potential mechanism by which ureaplasmas avoid immune recognition and cause chronic infections of the upper genital tract of pregnant women. We tested whether the MBA is involved in the pathogenesis of intra-amniotic infection and chorioamnionitis by injecting virulent or avirulent-derived ureaplasma clones (expressing single MBA variants) into the amniotic fluid of pregnant sheep. At 55 days of gestation pregnant ewes (n = 20) received intra-amniotic injections of virulent-derived or avirulent-derived U. parvum serovar 6 strains (2×10⁴ CFU), or 10B medium (n = 5). Amniotic fluid was collected every two weeks post-infection and fetal tissues were collected at the time of surgical delivery of the fetus (140 days of gestation). Whilst chronic colonisation was established in the amniotic fluid of animals infected with avirulent-derived and virulent-derived ureaplasmas, the severity of chorioamnionitis and fetal inflammation was not different between these groups (p>0.05). MBA size variants (32–170 kDa) were generated in vivo in amniotic fluid samples from both the avirulent and virulent groups, whereas in vitro antibody selection experiments led to the emergence of MBA-negative escape variants in both strains. Anti-ureaplasma IgG antibodies were detected in the maternal serum of animals from the avirulent (40%) and virulent (55%) groups, and these antibodies correlated with increased IL-1β, IL-6 and IL-8 expression in chorioamnion tissue (p<0.05). We demonstrate that ureaplasmas are capable of MBA phase variation in vitro; however, ureaplasmas undergo MBA size variation in vivo, to potentially prevent eradication by the immune response. Size variation of the MBA did not correlate with the severity of chorioamnionitis. Nonetheless, the correlation between a maternal humoral response and the expression of chorioamnion cytokines is a novel finding. This host response may be important in the pathogenesis of inflammation-mediated adverse pregnancy outcomes.

A quantitative analysis of Ureaplasma urealyticum and Ureaplasma parvum compared with host immune response in preterm neonates at risk of developing bronchopulmonary dysplasia

Multiplex, real-time PCR for the identification of Ureaplasma urealyticum and Ureaplasma parvum was performed on nucleic acids extracted from sequential endotracheal aspirates obtained from preterm neonates born at <29 weeks of gestation and ventilated for more than 48 h admitted to two level 3 neonatal intensive care units. Specimens were obtained shortly after birth and sequentially up until extubation. One hundred fifty-two specimens (93.8%) contained material suitable for analysis. Ureaplasma spp. were identified in 5 of 13 neonates studied. In most cases, the DNA load of the detected Ureaplasma species was low and decreased over time. In addition, changes in detectable Ureaplasma species DNA did not relate to changes in the inflammatory marker C-reactive protein (CRP) or respiratory status. All but two blood samples obtained at times of suspected sepsis were culture positive for other microorganisms; the species cultured were typically coagulase-negative staphylococci and were associated with increased levels of CRP (>10 mg/liter). This study was limited by the small number of patients examined and does not have the power to support or contradict the hypothesis that postnatal lung infection with Ureaplasma parvum is causally related to bronchopulmonary dysplasia (BPD) or adverse respiratory outcomes after preterm birth. However, in this study, increases in CRP levels were not associated with patients in whom Ureaplasma parvum was detected, in contrast to the detection of other bacterial species.

Ureaplasma bacteremia in very low birth weight infants in Brazil

OBJECTIVE

To determine the prevalence of Ureaplasma urealyticum and Ureaplasma parvum bacteremia in very low birth weight (VLBW) infants and to evaluate the associated factors.

MATERIALS AND METHODS

Ninety-five VLBW newborns with gestational age ≤32 weeks were included in the study conducted between March 2009 and July 2010. DNA was extracted from the blood samples collected during the first 72 hours of life, and U. urealyticum and/or U. parvum were identified by polymerase chain reaction. The newborns were followed up until hospital discharge.

RESULTS

The prevalence of U. urealyticum and/or U. parvum bacteremia was 12.6% (12 cases): 5 (5.2%) for U. urealyticum, 5 (5.2%) for U. parvum, and 2 (2.1%) for both. Based on the univariate analysis, the presence of Ureaplasma was associated with clinical chorioamnionitis and spontaneous preterm labor. Preeclampsia and small for gestational age were associated with lower incidence of Ureaplasma. When spontaneous preterm labor was present, the prevalence of Ureaplasma bacteremia was 25%. Only spontaneous preterm labor was a statistically significant factor after step-by-step logistic regression analysis (P = 0.006), with 9-fold increase in chance of neonatal Ureaplasma bacteremia.

CONCLUSIONS

Ureaplasma bacteremia is common in VLBW infants, especially among those born after preterm labor.

Ureaplasma parvum infection alters filamin A dynamics in host cells

Background

Ureaplasmas are among the most common bacteria isolated from the human urogenital tract. Ureaplasmas can produce asymptomatic infections or disease characterized by an exaggerated inflammatory response. Most investigations have focused on elucidating the pathogenic potential of Ureaplasma species, but little attention has been paid to understanding the mechanisms by which these organisms are capable of establishing asymptomatic infection.

Methods

We employed differential proteome profiling of bladder tissues from rats experimentally infected with U. parvum in order to identify host cell processes perturbed by colonization with the microbe. Tissues were grouped into four categories: sham inoculated controls, animals that spontaneously cleared infection, asymptomatic urinary tract infection (UTI), and complicated UTI. One protein that was perturbed by infection (filamin A) was used to further elucidate the mechanism of U. parvum-induced disruption in human benign prostate cells (BPH-1). BPH-1 cells were evaluated by confocal microscopy, immunoblotting and ELISA.

Results

Bladder tissue from animals actively colonized with U. parvum displayed significant alterations in actin binding proteins (profilin 1, vinculin, α actinin, and filamin A) that regulate both actin polymerization and cell cytoskeletal function pertaining to focal adhesion formation and signal transduction (Fisher's exact test, P < 0.004; ANOVA, P < 0.02). This phenomenon was independent of clinical profile (asymptomatic vs. complicated UTI). We selected filamin A as a target for additional studies. In the BPH-1 model, we confirmed that U. parvum perturbed the regulation of filamin A. Specifically, infected BPH-1 cells exhibited a significant increase in filamin A phosphorylated at serine²¹⁵² (P ≤ 0.01), which correlated with impaired proteolysis of the protein and its normal intracellular distribution.

Conclusion

Filamin A dynamics were perturbed in both models of infection. Phosphorylation of filamin A occurs in response to various cell signaling cascades that regulate cell motility, differentiation, apoptosis and inflammation. Thus, this phenomenon may be a useful molecular marker for identifying the specific host cell pathways that are perturbed during U. parvum infection.

HISTOLOGICAL CHORIOAMNIONITIS: CURRENT CONCEPTS OF DIAGNOSIS, CLASSIFICATION AND CLINICAL SIGNIFICANCE

Interest in the clinical associations between maternal intrapartum fever and adverse neonatal outcome has been longstanding, with publications of a relationship between maternal fever and cerebral palsy dating from the 1950s. Further recognition of the associations between either clinically or histologically characterised chorioamnionitis, ascending infection and neonatal wellbeing followed, with numerous reports in the 1960s and 70s, particularly as the neonatal significance of group B streptococcal infections became apparent. Similarly, with the systematic introduction of diagnostic light microscopy into clinical medicine, chorioamnionitis (inflammation of the placental membranes) and funisitis (inflammation of the umbilical cord) were recognised as distinct histological entities, with increasing recognition that the aetiology was likely to be infective. There are numerous texts discussing in detail the pathogenesis and histological features of chorioamnionitis and funisitis. The aim of this review is to provide an overview of the salient associated issues for clinical practitioners and to highlight areas of ongoing uncertainty and recent developments in understanding.

Ureaplasma infections in pre-term infants: Recent information regarding the role of Ureaplasma species as neonatal pathogens

Although numerous clinical observational studies have been conducted over a period of over 30 years, the clinical significance of Ureaplasma infection is still under debate. The Ureaplasma speices. is a commensal in the female genital tract and considered to have of low virulence; however, Ureaplasma colonization has been associated with infertility, stillbirth, preterm delivery, histologic chorioamnionitis, and neonatal morbidities, including congenital pneumonia, meningitis, bronchopulmonary dysplasia, and perinatal death. Recently, Ureaplasma was subdivided into 2 separate species and 14 serovars. Ureaplasma parvum is known as biovar 1 and contains serovars 1, 3, 6, and 14, and Ureaplasma urealyticum (biovar 2) contains the remaining serovars (2, 4, 5, and 7-13). The existence of differences in pathogenicities of these 14 serovars and 2 biovars is controversial. Although macrolides are the only antimicrobial agents currently available for use in neonatal ureaplasmal infections, in the current clinical field, it is difficult to make decisions regarding which antibiotics should be used. Future investigations involving large, multicenter, randomized, controlled studies are needed before proper recommendations can be made for clinical practice.

T cell cytokines and the risk of blood stream infection in extremely low birth weight infants

Cytokines mediate the host immune response to infectious micro-organisms. The objective of this study was to determine whether immune regulatory interleukins (IL-4, IL-5, IL-6, and IL-10) and inflammatory cytokines (Interferon-γ [INF-γ], tumor necrosis factor-β [TNF-β], IL-2, and IL-17) are associated with an increased risk of developing blood stream bacterial/fungal infection (BSI) in extremely low birth weight (ELBW) infants. ELBW infants from 17 NICHD Neonatal Research Network centers without early onset sepsis were studied. Cytokines were measured from blood on days 1, 3, 7, 14, and 21 after birth. 996 ELBW infants contributed a minimum of 4080 unique measurements for each cytokine during the five sampling periods. Infants with BSI had lower levels of the inflammatory cytokines IL-17 (p=0.01), and higher levels of the regulatory cytokines, IL-6 (p=0.01) and IL-10 (p<0.001). Higher levels of regulatory cytokines relative to pro-inflammatory cytokines were associated with increased risk of BSI even after adjusting for confounding variables. In ELBW infants, the ratio of immune regulatory cytokines to inflammatory cytokines was associated with development of BSI. Altered maturation of regulatory and inflammatory cytokines may increase the risk of serious infection in this population.

Inflammation in fetal sheep from intra-amniotic injection of Ureaplasma parvum

Bronchopulmonary dysplasia is associated with chorioamnionitis and fetal lung inflammation. Ureaplasma species are the bacteria most frequently isolated from chorioamnionitis. Very chronic ureaplasma colonization of amniotic fluid causes low-grade lung inflammation and functional lung maturation in fetal sheep. Less is known about shorter exposures of the fetal lung. Therefore, we hypothesized that ureaplasmas would cause an acute inflammatory response that would alter lung development. Singleton ovine fetuses received intra-amniotic Ureaplasma parvum serovar 3 or control media at 110, 117, or 121 days and were delivered at 124 days gestational age (term = 150 days). Inflammation was assessed by 1) cell counts in bronchoalveolar lavage fluid (BALF), and 2) cytokine mRNA measurements, immunohistochemistry, and flow cytometry for inflammatory cells and elastin and α-smooth muscle actin (α-SMA) staining in lung tissue. Neutrophils were increased in BALF 3 days after exposure to ureaplasmas (P = 0.01). Myeloperoxidase-positive cells increased after 3 days (P = 0.03), and major histocompatibility complex (MHC) class II-positive cells increased after 14 days of ureaplasma exposure (P = 0.001). PU.1 (macrophage marker)- or CD3 (T lymphocyte marker)-positive cells were not induced by ureaplasmas. CD3-positive cells in the posterior mediastinal lymph node increased in ureaplasma-exposed animals at 3, 7, and 14 days (P = 0.002). Focal elastin depositions decreased in alveolar septa at 14 days (P = 0.002), whereas α-SMA increased in arteries and bronchioli. U. parvum induced a mild acute inflammatory response and changed elastin and α-SMA deposition in the lung, which may affect lung structure and subsequent development.

Mycoplasma, Ureaplasma, and adverse pregnancy outcomes: a fresh look

Recent work on the Molicutes that associate with genital tract tissues focuses on four species that may be of interest in potential maternal, fetal, and neonatal infection and in contributing to adverse pregnancy outcomes. Mycoplasma hominis and Ureaplasma urealyticum have historically been the subject of attention, but Mycoplasma genitalis which causes male urethritis in addition to colonizing the female genital tract and the division of Ureaplasma into two species, urealyticum and parvum, has also added new taxonomic clarity. The role of these genital tract inhabitants in infection during pregnancy and their ability to invade and infect placental and fetal tissue is discussed. In particular, the role of some of these organisms in prematurity may be mechanistically related to their ability to induce inflammatory cytokines, thereby triggering pathways leading to preterm labor. A review of this intensifying exploration of the mycoplasmas in relation to pregnancy yields several questions which will be important to examine in future research.

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.

Molecular microbiological characterization of preterm neonates at risk of bronchopulmonary dysplasia

The role of infection in bronchopulmonary dysplasia (BPD) is unknown. We present an observational study of 55 premature infants born weighing less than 1.3 kg within two level III neonatal intensive care units. Endotracheal aspirates (ETA) and nasogastric aspirates (NGA) were studied with denaturing gradient gel electrophoresis (DGGE) profiling to elucidate the total bacterial community, and species-specific PCR was used to detect the presence of Mycoplasma hominis, Ureaplasma urealyticum, and Ureaplasma parvum. DGGE identified bacterial species in 59% of NGA and ETA samples combined. A diverse range of species were identified including several implicated in preterm labor. Species-specific PCR identified M. hominis in 25% of NGA and 11% of ETA samples. Among the 48 infants surviving up to 36 wk-postconceptual age, ordinal logistic regression showed the odds ratio for BPD or death where Ureaplasma was present/absent as 4.80 (95% CI 1.15-20.13). After adjusting for number of days ventilated, this was reduced to 2.04 (0.41-10.25). These data demonstrate how the combined use of DGGE and species-specific PCR identifies a high exposure in utero and around the time of birth to bacteria that might be causally related to preterm delivery and subsequent lung injury.

Placental features of chorioamnionitis colonized with Ureaplasma species in preterm delivery

Ureaplasma spp. is detected in the urogenital tract, including the vagina, cervix, chorioamnion, and placenta. Their colonization is associated with histologic chorioamnionitis (CAM), often observed in placentas from preterm delivery. We isolated Ureaplasma spp. from 63 preterm placentas among 151 specimens, which were delivered at <32 wk of gestation. Of the 63 placentas, 52 (83%) revealed CAM in cultures positive for Ureaplasma spp., however, CAM was observed only in 30% (26/88) of cultures negative for Ureaplasma spp. (p < 0.01). Colonization by Ureaplasma spp. was an independent risk factor for CAM (OR, 11.27; 95% CI, 5.09-24.98). Characteristic neutrophil infiltration was observed in the amnion and subchorion (bistratified pattern) in cultures positive for Ureaplasma spp. FISH analysis of CAM placenta with male infant pregnancy indicated that bistratified infiltrated neutrophils showed the XX karyotype and umbilical vein infiltrated neutrophils showed XY karyotype. The distribution of sulfoglycolipid, the receptor of Ureaplasma spp., was mainly detected in the amnion. Ureaplasmal urease D protein and ureB gene were both detected in the amnion, indicating direct colonization by Ureaplasma spp.

Choriodecidual inflammation: a harbinger of the preterm labor syndrome

Causal, cellular, and inflammatory links between choriodecidual infection with group B streptococcus (GBS) and preterm labor were assessed in a nonhuman primate model. Rhesus monkeys received varying doses of a clinical isolate of GBS, type III or saline, via an indwelling catheter placed between the chorion/decidua and myometrium in the lower pole of the uterus. Choriodecidual inoculation of GBS was followed by a graded response in amniotic fluid (AF) leukocytes, proinflammatory cytokines, prostaglandin E(2) and F(2alpha), and uterine activity (P < .05). The magnitude of the inflammatory response in AF was related, in part, to the initial inoculum size and whether AF cultures remained negative or became positive for GBS. Microbial invasion of AF was associated with advanced inflammation and preterm labor. We provide experimental evidence that choriodeciduitis is a transitional stage of intrauterine infection, which may be self-limited, remain dormant, or progress to intraamniotic infection. These data, coupled with clinical observations, suggest that choriodecidual inflammation is an antecedent event in the pathogenesis of premature cervical ripening (functional cervical insufficiency), premature rupture of the fetal membranes, or preterm labor.