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Objective: To study the association between Ureaplasma colonization and bronchopulmonary dysplasia (BPD) with different definitions in very low birth weight (VLBW) infants., Methods: A retrospective cohort study was performed with VLBW infants admitted from January 2019 to October 2021. Neonates with a positive respiratory tract Ureaplasma culture were included in the study group. Control group infants, matched for gestational age (±1 week), birth weight (±100 g), and birth year, had a negative respiratory tract Ureaplasma culture during the same period. The primary outcomes included the incidence and severity of BPD, defined by various criteria., Results: The study included 302 neonates (151 in the study group and 151 in the control group). After adjusting for confounders, Ureaplasma colonization was not associated with BPD as defined by the National Institutes of Health (NIH) in 2001 (adjusted odds ratio [aOR]: 0.820, 95% confidence interval [CI]: 0.362-1.860, p = .635). However, it was associated with BPD as defined by the NIH in 2018 (aOR: 2.490, 95% CI: 1.128-5.497, p = .024) and the Neonatal Research Network (NRN) in 2019 (aOR: 2.352, 95% CI: 1.077-5.134, p = .032). Additionally, VLBW infants with Ureaplasma colonization had a higher risk of moderate-severe BPD according to the NIH 2001 (aOR: 2.352, 95% CI: 1.077-5.134, p = .032), NIH 2018 (aOR: 6.339, 95% CI: 1.686-23.836, p = .006), and NRN 2019 definitions (aOR: 3.542, 95% CI: 1.267-9.904, p = .016)., Conclusions: Ureaplasma colonization is not associated with BPD by the NIH 2001 definition, but is associated with an increased incidence by the NIH 2018 or NRN 2019 definitions., (© 2024 Wiley Periodicals LLC.)

Background: Ureaplasma species are considered commensals of the adult urogenital tract. Yet, in pregnancy, Ureaplasma parvum and Ureaplasma urealyticum have been associated with chorioamnionitis and preterm birth. In preterm infants, Ureaplasma respiratory tract colonization has been correlated with the development of bronchopulmonary dysplasia and has been implicated in the pathogenesis of other complications of prematurity. Controversies on the impact of Ureaplasma exposure on neonatal morbidity, however, remain, and recommendations for screening practices and therapeutic management in preterm infants are missing., Summary: In this review, we outline clinical and experimental evidence of Ureaplasma-driven fetal and neonatal morbidity, critically examining inconsistencies across some of the existing studies. We explore underlying mechanisms of Ureaplasma-associated neonatal morbidity and discuss gaps in the current understanding including the interplay between Ureaplasma and the maternal urogenital tract and the preterm airway microbiome. Ultimately, we highlight the importance of adequate diagnostics and review the potential efficacy of anti-infective therapies., Key Messages: There is strong evidence that perinatal Ureaplasma exposure is causally related to the development of bronchopulmonary dysplasia, and there are conclusive data of the role of Ureaplasma in the pathogenesis of neonatal central nervous system infection. Observational and experimental findings indicate immunomodulatory capacities that might promote an increased risk of secondary infections. The burden of Ureaplasma exposure is inversely related to gestational age - leaving the tiniest babies at highest risk. A better knowledge of contributing pathogen and host factors and modulating conditions remains paramount to define screening and treatment recommendations allowing early intervention in preterm infants at risk., (© 2024 S. Karger AG, Basel.)

Background: Both histologic chorioamnionitis (HCAM) and Ureaplasma infection are considered important contributors to perinatal lung injury. We tested the hypothesis that coexistence of maternal HCAM and perinatal Ureaplasma exposure increases the risk of prolonged mechanical ventilation in extremely low-birthweight (ELBW) infants., Methods: A retrospective cohort study was carried out of all ELBW infants born between January 2008 and December 2013 at a single academic center. Placental pathology and gastric fluid Ureaplasma data were available for all infants. Culture and polymerase chain reaction were used to detect Ureaplasma in gastric fluid. Prolonged mechanical ventilation was defined as mechanical ventilation that began within 28 days after birth and continued., Results: Of 111 ELBW infants enrolled, 84 survived beyond 36 weeks of postmenstrual age (PMA) and were included in the analysis. Eighteen infants (21.4%) had both HCAM and Ureaplasma exposure. Seven infants (8.3%) required mechanical ventilation beyond 36 weeks of PMA. Coexistence of HCAM and Ureaplasma in gastric fluid was significantly associated with prolonged mechanical ventilation after adjustment for gestational age, sex, mode of delivery, and use of macrolide antibiotics (OR, 8.7; 95%CI: 1.1-67.2)., Conclusions: Coexistence of maternal HCAM and perinatal Ureaplasma exposure significantly increases the risk of prolonged mechanical ventilation in ELBW infants., (© 2016 Japan Pediatric Society.)

Ureaplasma respiratory tract colonization is associated with bronchopulmonary dysplasia (BPD) in preterm infants. Previously, we demonstrated that a single intravenous (i.v.) dose of azithromycin (10 mg/kg of body weight) is safe but inadequate to eradicate Ureaplasma spp. in preterm infants. We performed a nonrandomized, single-arm open-label study of the pharmacokinetics (PK) and safety of intravenous 20-mg/kg single-dose azithromycin in 13 mechanically ventilated neonates with a gestational age between 24 weeks 0 days and 28 weeks 6 days. Pharmacokinetic data from 25 neonates (12 dosed with 10 mg/kg i.v. and 13 dosed with 20 mg/kg i.v.) were analyzed using a population modeling approach. Using a two-compartment model with allometric scaling of parameters on body weight (WT), the population PK parameter estimates were as follows: clearance, 0.21 liter/h × WT(kg)(0.75) [WT(kg)(0.75) indicates that clearance was allometrically scaled on body weight (in kilograms) with a fixed exponent of 0.75]; intercompartmental clearance, 2.1 liters/h × WT(kg)(0.75); central volume of distribution (V), 1.97 liters × WT (kg); and peripheral V, 17.9 liters × WT (kg). There was no evidence of departure from dose proportionality in azithromycin exposure over the tested dose range. The calculated area under the concentration-time curve over 24 h in the steady state divided by the MIC90 (AUC24/MIC90) for the single dose of azithromycin (20 mg/kg) was 7.5 h. Simulations suggest that 20 mg/kg for 3 days will maintain azithromycin concentrations of >MIC50 of 1 μg/ml for this group of Ureaplasma isolates for ≥ 96 h after the first dose. Azithromycin was well tolerated with no drug-related adverse events. One of seven (14%) Ureaplasma-positive subjects and three of six (50%) Ureaplasma-negative subjects developed physiologic BPD. Ureaplasma was eradicated in all treated Ureaplasma-positive subjects. Simulations suggest that a multiple-dose regimen may be efficacious for microbial clearance, but the effect on BPD remains to be determined.

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., (Copyright © 2013 Elsevier Inc. All rights reserved.)

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.

Chorioamnionitis is associated with increased lung and brain injury in premature infants. Ureaplasma is the microorganisms most frequently associated with preterm birth. Whether Ureaplasma-induced antenatal inflammation worsens lung and brain injury is unknown. We developed a mouse model combining antenatal Ureaplasma infection and postnatal oxygen exposure. Intraamniotic Ureaplasma Parvum (UP) increased proinflammatory cytokines in placenta and fetal lungs. Antenatal exposure to UP or broth caused mild postnatal inflammation and worsened oxygen-induced lung injury. Antenatal UP exposure induced central microgliosis and disrupted brain development as detected by decreased number of calbindin-positive and calretinin-positive neurons in the neocortex. Postnatal oxygen decreased calretinin-positive neurons in the neocortex but combined with antenatal UP exposure did not worsen brain injury. Antenatal inflammation exacerbates the deleterious effects of oxygen on lung development, but the broth effects prohibit concluding that UP by itself is a compounding risk factor for bronchopulmonary dysplasia. In contrast, antenatal UP-induced inflammation alone is sufficient to disturb brain development. This model may be helpful in exploring the pathophysiology of perinatal lung and brain injury to develop new protective strategies.

Objective: Gastric fluid microbes were examined in preterm infants at birth to assess their influence on the postnatal outcome., Study Design: Prospective cohort study., Setting: Level III neonatal intensive care unit., Patients: A total of 103 premature neonates with a gestational age of less than 32 weeks., Main Outcome Measure: Gastric fluid microbes were identified by analysis of bacterial 16S ribosomal RNA gene. Additionally, the urease gene of Ureaplasma species was detected by polymerase chain reaction of gastric fluid obtained at birth and/or tracheal aspirate from ventilated preterm infants. The association between detection of microbes and bronchopulmonary dysplasia was investigated through assessment from clinical features and by a lung injury marker (KL-6)., Results: Forty-two of 103 gastric fluid specimens were positive for microbes. Ureaplasma species were detected in 23 of the 42 (55%) gastric fluid specimens. All infants with Ureaplasma species in tracheal aspirate fluid also had positive gastric fluid specimens. Compared to infants negative for gastric fluid microbes, infants positive for microbes had higher rates of maternal chorioamnionitis (18% vs 78%), premature rupture of membranes (11% vs 55%), severe bronchopulmonary dysplasia (1.6% vs 14%) and showed higher plasma KL-6 levels during the initial 4 weeks of life., Conclusion: Detection of gastric fluid microbes was correlated well with antenatal infection and severe bronchopulmonary dysplasia. Detection of Ureaplasma species in gastric fluid was associated with subsequent respiratory colonisation. These results suggest that antenatal exposure of the immature fetus to microbes may cause lung injury and promote the onset of bronchopulmonary dysplasia.

Background: Controversy exists over whether or not Ureaplasma colonization or infection of the respiratory tract contributes to the development of bronchopulmonary dysplasia (BPD). Because BPD is a major cause of morbidity and mortality in preterm infants and a potential therapeutic intervention with antimicrobials is possible, we sought to evaluate and critique the current medical literature and to document the reported association between Ureaplasma and BPD., Methods: We analyzed all peer-reviewed articles and previous reviews including cross-references that reported Ureaplasma respiratory tract colonization or infection and development of BPD in neonates published from January 1966 to December 2004. Inclusion criteria included a cohort limited to all neonatal intensive care unit admissions or all colonized infants, articles that did not define a numerator and a denominator for BPD and Ureaplasma or that included patients from other reports were excluded from the analysis. We evaluated BPD at 28 postnatal days (BPD28) or 36 weeks post-menstrual age (BPD36)., Results: Twenty-three studies with an aggregate of 2216 infants reported BPD28, and 8 studies with 751 infants reported BPD36. Although there was significant association between Ureaplasma colonization and both BPD28 and BPD36, there was substantial heterogeneity (Q test statistic, P < 0.01). We therefore focused on describing the study characteristics associated with an increased relative proportion of BPD. The greatest contribution to effect was from the studies enrolling fewer than 100 infants., Conclusion: Ureaplasma colonization is associated with higher reported rates of BPD, but the greatest reported effect is seen in small studies; reporting bias may be partially responsible for this effect.

A PCR assay was used to analyze endotracheal aspirates from preterm infants for Ureaplasma parvum versus U. urealyticum. U. parvum was detected more often than U. urealyticum. There was no significant difference or trend in the prevalence of either species between infants with or without bronchopulmonary dysplasia when isolated alone.

Maternal infections are known to play a major role in perinatal morbidity and mortality. Ureaplasma urealyticum and Mycoplasma hominis are sexually transmissible microorganisms associated with a number of pathologic conditions in the pregnant woman including chorioamnionitis and postpartum fever. They are rapidly gaining recognition as significant causes of perinatal infection, especially in infants born prematurely. This review summarizes current knowledge regarding the epidemiology, pathology, disease spectrum, and clinical manifestations of mycoplasmal and ureaplasmal perinatal infections and presents guidelines for proper diagnosis and treatment.