Susceptibilities of neonatal respiratory isolates of Ureaplasma urealyticum to antimicrobial agents

Potentially inappropriate prescribing in hospitalised children: a retrospective, cross-sectional study at a tertiary children's hospital in China

INTRODUCTION

For improving and optimising drug use in children, we previously developed a tool (including a series of criteria for identifying potentially inappropriate prescribing in children) by literature review and the two-round Delphi technique to prevent inappropriate medication prescriptions at the prescribing stage.

OBJECTIVE

To assess the prevalence of potentially inappropriate prescription (PIP) among hospitalised children and explore risk factors associated with PIP.

DESIGN

A retrospective cross-sectional study.

SETTING

A tertiary children's hospital in China.

PARTICIPANTS

Hospitalised children with complete medical records who received drug treatment and discharged from 1 January to 31 December 2021.

OUTCOME MEASURES

We evaluated the medication prescriptions by using a series of previously developed criteria for detecting the prevalence of PIP in hospitalised children and used logistic regression to explore the risk factors (including sex, age, number of drugs, number of comorbidities, days of hospitalisation and admission departments) for PIP in children.

RESULTS

A total of 87 555 medication prescriptions for 16 995 hospitalised children were analysed, and 19 722 PIPs were detected. The prevalence of PIP was 22.53%, and 36.92% of the children had at least one PIP during hospitalisation. The department with the highest prevalence of PIP was the surgical department (OR 9.413; 95% CI 5.521 to 16.046), followed by the paediatric intensive care unit (PICU; OR 8.206; 95% CI 6.643 to 10.137). 'Inhaled corticosteroids for children with respiratory infections but without chronic respiratory diseases' was the most frequent PIP. Logistic regression results showed that PIP was more likely to occur in male patients (OR 1.128, 95% CI 1.059 to 1.202) and younger patients (<2 years old; OR 1.974; 95% CI 1.739 to 2.241), and in those with more comorbidities (≥11 types; OR 4.181; 95% CI 3.671 to 4.761), concomitant drugs (≥11 types; OR 22.250; 95% CI 14.468 to 34.223) or longer hospital stay (≥30 days; OR 8.130; 95% CI 6.727 to 9.827).

CONCLUSIONS

Medications for long-term hospitalised young children with multiple comorbidities should be minimised and optimised, to avoid PIP, reduce adverse drug reactions and ensure children's medication safety. The surgery department and PICU had a high prevalence of PIP in the studied hospital and should be the focus of supervision and management in routine prescription review.

Pharmacotherapy in Bronchopulmonary Dysplasia: What Is the Evidence?

Bronchopulmonary Dysplasia (BPD) is a multifactorial disease affecting over 35% of extremely preterm infants born each year. Despite the advances made in understanding the pathogenesis of this disease over the last five decades, BPD remains one of the major causes of morbidity and mortality in this population, and the incidence of the disease increases with decreasing gestational age. As inflammation is one of the key drivers in the pathogenesis, it has been targeted by majority of pharmacological and non-pharmacological methods to prevent BPD. Most extremely premature infants receive a myriad of medications during their stay in the neonatal intensive care unit in an effort to prevent or manage BPD, with corticosteroids, caffeine, and diuretics being the most commonly used medications. However, there is no consensus regarding their use and benefits in this population. This review summarizes the available literature regarding these medications and aims to provide neonatologists and neonatal providers with evidence-based recommendations.

Antimicrobial activity of bitespiramycin, a new genetically engineered macrolide

The antimicrobial activity of bitespiramycin (BT) against Chlamydia trachomatis (Ct), Chlamydia pneumoniae (Cp), Ureaplasma urealyticum (Uu), and Mycoplasma pneumoniae (Mp), was compared with those of azithromycin (AZM) and acetylspiramycin (AT-SP) in vitro. Furthermore, the anti-Mp activities of BT and AZM were evaluated in a hamster model. The activities of BT in vitro were similar to those of AZM but were more effective than those of AT-SP. BT effectively inhibited Mp infection at a dose of 200mg/kg in a hamster model.

Role of Ureaplasma Respiratory Tract Colonization in Bronchopulmonary Dysplasia Pathogenesis: Current Concepts and Update

Respiratory tract colonization with the genital mycoplasma species Ureaplasma parvum and Ureaplasma urealyticum in preterm infants is a significant risk factor for bronchopulmonary dysplasia (BPD). Recent studies of the ureaplasmal genome, animal infection models, and human infants have provided a better understanding of specific virulence factors, pathogen-host interactions, and variability in genetic susceptibility that contribute to chronic infection, inflammation, and altered lung development. This review provides an update on the current evidence supporting a causal role of ureaplasma infection in BPD pathogenesis. The current status of antibiotic trials to prevent BPD in Ureaplasma-infected preterm infants is also reviewed.

Pharmacokinetics, microbial response, and pulmonary outcomes of multidose intravenous azithromycin in preterm infants at risk for Ureaplasma respiratory colonization

The study objectives were to refine the population pharmacokinetics (PK) model, determine microbial clearance, and assess short-term pulmonary outcomes of multiple-dose azithromycin treatment in preterm infants at risk for Ureaplasma respiratory colonization. Fifteen subjects (7 of whom were Ureaplasma positive) received intravenous azithromycin at 20 mg/kg of body weight every 24 h for 3 doses. Azithromycin concentrations were determined in plasma samples obtained up to 168 h post-first dose by using a validated liquid chromatography-tandem mass spectrometry method. Respiratory samples were obtained predose and at three time points post-last dose for Ureaplasma culture, PCR, antibiotic susceptibility testing, and cytokine concentration determinations. Pharmacokinetic data from these 15 subjects as well as 25 additional subjects (who received either a single 10-mg/kg dose [n = 12] or a single 20-mg/kg dose [n = 13]) were analyzed by using a nonlinear mixed-effect population modeling (NONMEM) approach. Pulmonary outcomes were assessed at 36 weeks post-menstrual age and 6 months adjusted age. A 2-compartment model with all PK parameters allometrically scaled on body weight best described the azithromycin pharmacokinetics in preterm neonates. The population pharmacokinetics parameter estimates for clearance, central volume of distribution, intercompartmental clearance, and peripheral volume of distribution were 0.15 liters/h · kg(0.75), 1.88 liters · kg, 1.79 liters/h · kg(0.75), and 13 liters · kg, respectively. The estimated area under the concentration-time curve over 24 h (AUC24)/MIC90 value was ∼ 4 h. All posttreatment cultures were negative, and there were no drug-related adverse events. One Ureaplasma-positive infant died at 4 months of age, but no survivors were hospitalized for respiratory etiologies during the first 6 months (adjusted age). Thus, a 3-day course of 20 mg/kg/day intravenous azithromycin shows preliminary efficacy in eradicating Ureaplasma spp. from the preterm respiratory tract.

Azithromycin to prevent bronchopulmonary dysplasia in ureaplasma-infected preterm infants: pharmacokinetics, safety, microbial response, and clinical outcomes with a 20-milligram-per-kilogram single intravenous dose

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.

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.

Appropriate antibiotic therapy improves Ureaplasma sepsis outcome in the neonatal mouse

BACKGROUND

Ureaplasma causes sepsis in human neonates. Although erythromycin has been the standard treatment, it is not always effective. No published reports have evaluated Ureaplasma sepsis in a neonatal model. We hypothesized that appropriate antibiotic treatment improves Ureaplasma sepsis in a neonatal mouse model.

METHODS

Two ATCC strains and two clinical strains of Ureaplasma were evaluated in vitro for antibiotic minimum inhibitory concentration (MIC). In addition, FVB albino mice pups infected with Ureaplasma were randomly assigned to saline, erythromycin, or azithromycin therapy and survival, quantitative blood culture, and growth were evaluated.

RESULTS

MICs ranged from 0.125 to 62.5 µg/ml and 0.25 to 1.0 µg/ml for erythromycin and azithromycin, respectively. The infecting strain and antibiotic selected for treatment appeared to affect survival and bacteremia, but only the infecting strain affected growth. Azithromycin improved survival and bacteremia against each strain, whereas erythromycin was effective against only one of four strains.

CONCLUSION

We have established a neonatal model of Ureaplasma sepsis and observed that treatment outcome is related to infecting strain and antibiotic treatment. We speculate that appropriate antibiotic selection and dosing are required for effective treatment of Ureaplasma sepsis in neonates, and this model could be used to further evaluate these relationships.

Use of azithromycin for the prevention of bronchopulmonary dysplasia in preterm infants: a randomized, double-blind, placebo controlled trial

OBJECTIVE

Since preventive therapies for bronchopulmonary dysplasia (BPD) are limited we treated preterm infants with azithromycin to decrease the incidence of BPD.

METHODS

Infants less than 1,250 g birth weight were randomized to azithromycin or placebo within 12 hr of beginning mechanical ventilation and within 72 hr of birth. The treatment group received azithromycin 10 mg/kg/day for 7 days followed by 5 mg/kg/day for a maximum of 6 weeks. Aspirates were collected during the study to assay for Ureaplasma. The primary endpoints were incidence of BPD or mortality. (Clinical Trials Identifier: NCT00319956.)

RESULTS

A total of 220 infants were enrolled (n=111 azithromycin, and 109 placebo). Mortality was 18% for the azithromycin group versus 22% for the placebo group (P = 0.45). Incidence of BPD was 76% for the azithromycin group versus 84% for the placebo group (P=0.2). The multiple logistic regression analysis demonstrated an odds ratio of 0.46 decrease in the chance of developing BPD or death for the azithromycin group, but was not statistically significant. The incidence of BPD in the Ureaplasma subgroup was 73% in the azithromycin group versus 94% in the placebo group (P=0.03). Analysis of patients in the Ureaplasma subgroup only, using the exact logistic model demonstrated a decrease in BPD or death in the azithromycin group with an estimated odds ratio of 0.026 (0.001-0.618, 95% confidence interval).

CONCLUSIONS

Routine use of azithromycin therapy for the prevention of BPD cannot be recommended. The early treatment of Ureaplasma colonized/infected patients might be beneficial, but a larger multi-centered trial is required to assess this more definitively.

Congenital and opportunistic infections: Ureaplasma species and Mycoplasma hominis

There is strong evidence from clinical and experimental animal studies that ureaplasmas can invade the amnionic sac and induce an inflammatory response resulting in chorioamnionitis, preterm labor and neonatal lung injury. The ability of Ureaplasma spp. and Mycoplasma hominis to cause pneumonia, bacteremia, and meningitis in newborns can no longer be questioned. The association of Ureaplasma spp. with bronchopulmonary dysplasia has been supported by the majority of observational studies, but proof of causality is still lacking. The availability of molecular diagnostic technologies has enabled the designation of the two Ureaplasma biovars as individual species, but additional work must be done to establish whether there is differential pathogenicity between the Ureaplasma spp. or among their respective serovars. Future investigations to prevent prematurity should be directed toward identification and localization of specific micro-organisms combined with targeted antibiotic trials to determine whether such interventions can improve long-term infant outcomes.

Antibiotic prophylaxis improves Ureaplasma-associated lung disease in suckling mice

Ureaplasma infection is associated with increased lung disease in high-risk neonates. Our goal was to determine the impact of antibiotic prophylaxis on Ureaplasma and oxygen-induced lung disease in newborn mice. In animal model development and prophylaxis experiments, pups were randomly assigned to either 0.8 or 0.21 inspired oxygen concentration [fraction of inspired oxygen (FiO2)] from 1 to 14 d of age and either Ureaplasma or 10 B media daily from 1 to 3 d. All pups were observed for growth and survival. Surviving pups had culture and PCR evaluated for blood, bronchoalveolar lavage, and lung, and lung weights, pathology, morphometry, histology, and immunohistochemistry were determined. In prophylaxis experiments, erythromycin, azithromycin, or normal saline was given for the first 3 d, and minimum inhibitory concentration and pharmacokinetics were determined. In model development, 0.8 FiO2 and Ureaplasma infection survival and growth were significantly decreased and lung edema and inflammation were significantly increased. In prophylaxis experiments, we observed significantly improved survival and growth with azithromycin versus normal saline controls, whereas erythromycin was not significantly different from controls, and decreased inflammatory response with azithromycin versus normal saline and erythromycin. In a neonatal mouse model of Ureaplasma and oxygen-induced lung disease, appropriate antibiotic prophylaxis improves survival and morbidity and decreases lung inflammation.

Does Ureaplasma spp. cause chronic lung disease of prematurity: ask the audience?

Ureaplasma has long been implicated in the pathogenesis of both preterm labour and neonatal morbidity, particularly chronic lung disease of prematurity (CLD), but despite numerous studies, reviews and meta-analyses, its exact role remains unclear. Many papers call for a definitive randomised control trial to determine if eradication of pulmonary Ureaplasma decreases the rates of CLD but few address in detail the obstacles to an adequately powered clinical trial. We review the evidence for Ureaplasma as a causative agent in CLD, asking why a randomised control trial has not been performed. We surveyed the opinions of senior neonatologists in the UK on whether they felt that there was sufficient evidence for Ureaplasma either causing or not causing CLD and whether a definitive trial was needed, as well as their views on the design of such a trial. Additionally, we ascertained current practice with respect to Ureaplasma detection in preterm neonates in the UK. There is clear support for an adequately powered randomised controlled clinical trial by senior neonatologists in the UK. There are no reasons why a definitive trial cannot be conducted especially as the appropriate samples, and methods to culture or identify the organism by PCR are already available.

Concurrent titration and determination of antibiotic resistance in ureaplasma species with identification of novel point mutations in genes associated with resistance

Antibiotic resistance determination of Ureaplasma spp. (Ureaplasma parvum and Ureaplasma urealyticum) usually requires predetermination of bacterial titer, followed by antibiotic interrogation using a set bacterial input. This 96-well method allows simultaneous quantification of bacteria in the presence and absence of antibiotics. A method for determining precise MICs and a method for screening against multiple antibiotics using breakpoint thresholds are detailed. Of the 61 Ureaplasma-positive clinical isolates screened, one (1.6%) was resistant to erythromycin (MIC, >64 mg/liter) and clarithromycin (MIC, 4 mg/liter), one to ciprofloxacin (1.6%), and one to tetracycline/doxycycline (1.6%). Five isolates were also consistently found to have an elevated MIC of 8 mg/liter for erythromycin, but this may not represent true antibiotic resistance, as no mutations were found in the 23S rRNA operons or ribosome-associated L4 and L22 proteins for these strains. However, two amino acids (R66Q67) were deleted from the L4 protein of the erythromycin-/clarithromycin-resistant strain. The tetM genetic element was detected in the tetracycline-resistant clinical isolate as well as in the positive control Vancouver strain serotype 9. The tetM gene was also found in a fully tetracycline-susceptible Ureaplasma clinical isolate, and no mutations were found in the coding region that would explain its failure to mediate tetracycline resistance. An amino acid substitution (D82N) was found in the ParC subunit of the ciprofloxacin-resistant isolate, adjacent to the S83L mutation reported by other investigators in many ciprofloxacin-resistant Ureaplasma isolates. It is now possible to detect antibiotic resistance in Ureaplasma within 48 h of positive culture without prior knowledge of bacterial load, identifying them for further molecular analysis.

Ureaplasma urealyticum meningitis in an adult patient

A 38-year-old patient developed meningitis after a complicated kidney transplantation and organ rejection. Ureaplasma urealyticum was identified as the etiological agent by molecular and microbiological analyses of the cerebrospinal fluid. The patient was successfully treated with doxycycline and chloramphenicol. This is the first report of Ureaplasma urealyticum meningitis in an adult.

Azithromycin in the extremely low birth weight infant for the prevention of bronchopulmonary dysplasia: a pilot study

BACKGROUND

Azithromycin reduces the severity of illness in patients with inflammatory lung disease such as cystic fibrosis and diffuse panbronchiolitis. Bronchopulmonary dysplasia (BPD) is a pulmonary disorder which causes significant morbidity and mortality in premature infants. BPD is pathologically characterized by inflammation, fibrosis and impaired alveolar development. The purpose of this study was to obtain pilot data on the effectiveness and safety of prophylactic azithromycin in reducing the incidence and severity of BPD in an extremely low birth weight (< or = 1000 grams) population.

METHODS

Infants < or = 1000 g birth weight admitted to the University of Kentucky Neonatal Intensive Care Unit (level III, regional referral center) from 9/1/02-6/30/03 were eligible for this pilot study. The pilot study was double-blinded, randomized, and placebo-controlled. Infants were randomized to treatment or placebo within 12 hours of beginning mechanical ventilation (IMV) and within 72 hours of birth. The treatment group received azithromycin 10 mg/kg/day for 7 days followed by 5 mg/kg/day for the duration of the study. Azithromycin or placebo was continued until the infant no longer required IMV or supplemental oxygen, to a maximum of 6 weeks. Primary endpoints were incidence of BPD as defined by oxygen requirement at 36 weeks gestation, post-natal steroid use, days of IMV, and mortality. Data was analyzed by intention to treat using Chi-square and ANOVA.

RESULTS

A total of 43 extremely premature infants were enrolled in this pilot study. Mean gestational age and birth weight were similar between groups. Mortality, incidence of BPD, days of IMV, and other morbidities were not significantly different between groups. Post-natal steroid use was significantly less in the treatment group [31% (6/19)] vs. placebo group [62% (10/16)] (p = 0.05). Duration of mechanical ventilation was significantly less in treatment survivors, with a median of 13 days (1-47 days) vs. 35 days (1-112 days)(p = 0.02).

CONCLUSION

Our study suggests that azithromycin prophylaxis in extremely low birth weight infants may effectively reduce post-natal steroid use for infants. Further studies are needed to assess the effects of azithromycin on the incidence of BPD and possible less common side effects, before any recommendations regarding routine clinical use can be made.

Ureaplasma infection and neonatal lung disease

Infection with the ureaplasmas may occur in utero or perinatally in prematurely born infants. For some infants, infection with these organisms triggers a vigorous pro-inflammatory response in the lungs and increases the risk of developing bronchopulmonary dysplasia (BPD). At present, there is insufficient evidence from clinical trials to determine whether antibiotic treatment of Ureaplasma has any influence on the development of BPD and its comorbidities. Future investigation in the context of well-designed, adequately powered controlled clinical trials should focus on determining whether treatment of ureaplasmal infection lessens lung inflammation, decreases rates of BPD, and improves long-term, neurodevelopmental outcome.

The significance of Ureaplasma urealyticum as a pathogenic agent in the paediatric population

PURPOSE OF REVIEW

Ureaplasma urealyticum is a frequent commensal in the lower genital tract of sexually active women. It may be transmitted perinatally from the colonized mother to her offspring, often resulting in prematurity and neonatal disease. The microorganism also sustains a causative role for infectious diseases in older children.

RECENT FINDINGS

U. urealyticum infection can be diagnosed by culture, polymerase chain reaction, and the detection of specific antibodies. Neonatal infection has been implicated in various pathological conditions including pneumonia, chronic lung disease, central nervous system disorders, sepsis, osteomyelitis and even death. Older children may present with wheezing, pneumonitis, pertussis-like syndrome and different forms of arthritis. Large well-designed trials have demonstrated that the regular administration of antibiotics to vaginally colonized women are not beneficial in terms of preventing preterm labour. Macrolide-containing antibiotic regimens are, however, recommended for preterm premature rupture of the membranes. Erythromycin treatment of ureaplasma respiratory colonized premature infants shows no reduction in the incidence of chronic lung disease. Treatment of central nervous system infections, sepsis and arthritides includes tetracyclines, fluoroquinolones and anti-inflammatory agents, respectively.

SUMMARY

This review covers recent evidence concerning the role of U. urealyticum as a pathogen during childhood. It also includes an evaluation of contemporary diagnostic techniques and optimal therapeutic approaches.

Ureaplasma urealyticum-harmless commensal or underestimated enemy of human reproduction? A review

This article reviews the role, diagnosis and treatment of Ureaplasma infections in human reproduction.

Failure of erythromycin to eliminate airway colonization with ureaplasma urealyticum in very low birth weight infants

BACKGROUND

Airway colonization of mechanically ventilated very low birth weight infants (birth weight < 1500 grams) by Ureaplasma urealyticum (Uu) is associated with an increased risk of bronchopulmonary dysplasia (BPD). While Uu is sensitive to erythromycin in vitro, the efficacy of intravenous (IV) erythromycin to eliminate Uu from the airways has not been studied.

METHODS

17 very low birth weight infants with Uu positive tracheal aspirate (TA) cultures were randomized to either 5 (8 infants) or 10 days (9 infants) of IV erythromycin lactobionate (40 mg/kg/day in 3 divided doses). Tracheal aspirate cultures for Uu were performed on days 0, 5, 10 and 15.

RESULTS

Intravenous erythromycin failed to eliminate airway colonization in a large proportion of infants regardless of whether they received 5 or 10 days of treatment. Ureaplasma urealyticum was isolated from 4/15 (27%) of TAs obtained at 5 days, 5/12 TAs (42%) obtained at 10 days and 6/11(55%) TAs obtained at 15 days (combined group data).

CONCLUSIONS

Erythromycin administered IV does not eliminate Uu from the airways in a large proportion of infants. Failure of erythromycin to eliminate Uu from the airways may contribute to the lack of efficacy of this drug in reducing the incidence of BPD in very low birth weight infants.

Perinatal infections and brain injury: current treatment options

Antimicrobial therapy can ameliorate infection and prevent long-term morbidity caused by several pathogens that infect the fetus and neonate. Ultimately, however, preventive strategies need to be developed and incorporated into routine preconceptional care. The future of prevention lies in immunizations, and if past and current successes with smallpox, polio, rubella, and measles vaccination programs are any indication, the future is bright for the developing fetus.

Ureaplasma urealyticum biovar determination in women attending a family planning clinic in Guiné-Bissau, using polymerase chain reaction of the multiple-banded antigen gene

Although Ureaplasma urealyticum is commonly found in the genital tract of asymptomatic women, it has been suggested that only certain subgroups of this microorganism are disease associated. Vaginal specimens were collected to determine the distribution of U. urealyticum biovars and to estimate their possible association with age, absence of lactobacilli, and tetracycline resistance. Of the 94 women studied, 40 (43%) carried U. urealyticum and were biotyped by polymerase chain reaction (PCR). Twenty-nine (73%) strains presented with parvo biovar, 10 (25%) with T960 biovar, and one (2.5%) with both biovars. Parvo biovar was predominant in all age groups and appears to be more frequent in women 20-25 years of age (41%), whereas T960 was common in women 30-35 years of age (22%). In this study, U. urealyticum was not associated with changes in vaginal flora, although the inverse apparently was true for Mycoplasma hominis. However, T960 biovar was more associated with the loss of lactobacilli than was parvo biovar. The number of T960 biovar strains that presented tetracycline (40%) or multiple (100%) resistance was higher than that of parvo biovar strains (27% and 69%, respectively).

Role of erythromycin for treatment of incipient chronic lung disease in preterm infants colonised with Ureaplasma urealyticum

Ureaplasma urealyticum is frequently isolated from tracheal aspirates of very low birthweight infants who go on to develop chronic lung disease. The use of erythromycin has been advocated in ventilated very low birthweight infants who are colonised with U. urealyticum, although the association between U. urealyticum and chronic lung disease remains controversial. There are only two randomised, controlled trials involving a total of 37 U. urealyticum-positive very low birthweight infants. Both trials failed to demonstrate a reduction in the incidence of chronic lung disease after 7 or 10 days of erythromycin. On the other hand, there are reports of rare but serious adverse effects of erythromycin in newborn infants including sudden cardiovascular compromise and hypertrophic pyloric stenosis. We conclude that, at present, there is insufficient evidence to support the use of erythromycin for the treatment of incipient chronic lung disease in very low birthweight infants colonised with U. urealyticum.

Occurrence and antimicrobial susceptibility of Ureaplasma parvum (Ureaplasma urealyticum biovar 1) and Ureaplasma urealyticum (Ureaplasma urealyticum biovar 2) from patients with adverse pregnancy outcomes and normal pregnant women

A recent phylogenetic analysis of Ureaplasma urealyticum resulted in the proposal to divide their 2 biovars into species. We used PCR to compare the distribution of species and the presence of the tet(M) and int-Tn resistance determinants in 63 strains of Ureaplasma spp. isolated from the amniotic fluid of patients with an adverse pregnancy outcome and in 22 strains obtained from the lower genital tract of healthy pregnant women. We also determined the antimicrobial susceptibility of the organisms to erythromycin and tetracycline. U. parvum was the most frequent Ureaplasma species detected in our study. Thus, 50/63 (79.4%) invasive isolates and 17/22 (77.3%) lower genital tract isolates corresponded to U. parvum, whereas 12/63 (19%) invasive isolates and 4/22 (18.2%) non-invasive strains corresponded to U. urealyticum. A mixture of species was found in 2 women. We found no significant differences in the antimicrobial susceptibility of isolates according to species or origin of isolation. Sixty-two strains of Ureaplasma spp. (74.7%) were susceptible to erythromycin, and 21 strains (25.3%) were intermediately susceptible. Sixty-eight isolates (81.9%) were susceptible to tetracycline, 2 strains (2.4%) were intermediate and 13 strains (15.7%) were resistant. DNA sequences related to the tet(M) determinant and the int-Tn gene were found in all tetracycline-resistant isolates.

[Colonization by Ureaplasma urealyticum and chronic lung disease in premature newborn infants under 32 weeks of gestation]

Colonization of the respiratory tract of premature newborn infants by genital mycoplasma is suspected to be associated with chronic lung disease.

METHODS AND PATIENTS

We prospectively determined the prevalence of genital mycoplasma colonization with nasopharyngeal or endotracheal culture in preterm neonates younger than 32 weeks gestation and its possible association with the development of chronic lung disease in a prospective study.

RESULTS

Fifty-nine infants were enrolled and 11 (19%) were colonized with Ureaplasma urealyticum. In the subgroup of 45 ventilated infants, seven of seven U. urealyticum-positive infants developed chronic pulmonary disease versus ten of 38 (26%) of U. urealyticum-negative infants (relative risk [RR] = 3.8; 95% confidence interval [CI] 2.2 to 6.5, P < 0.001). U. urealyticum-colonized infants had a lower median birth weight (760 vs 1,083 g, P = 0.04), a lower gestational age (26 vs 28 weeks, P = 0.03), and a higher incidence of symptomatic patent ductus arteriosus (P = 0.03). These potential confounding factors may partially explain the association between U. urealyticum and chronic pulmonary disease. However, this association remained statistically significant when the analysis was restricted to infants with birth weight of 1,000 g or less (RR = 2.3; 95% CI 1.3 to 4, P = 0.02) or to infants with a patent ductus arteriosus (RR = 2; 95% CI 1.3 to 3.1, P = 0.02).

CONCLUSION

Colonization with U. urealyticum in ventilated preterm neonates younger than 32 weeks gestation is a significant risk factor of developing chronic pulmonary disease.

Erythromycin

ERYTHROMYCIN, A MACROLIDE ANTIBIOTIC, HAS BEEN USED widely in pediatrics to treat a number of infections. Initially given as an alternative to penicillin because of that drug’s potential for allergic reactions, erythromycin was first introduced in 1952.1 Erythromycin is currently used in neonatal settings for treatment of infections caused by Chlamydia, Ureaplasma, and Mycoplasma.1,2 Prophylaxis for ophthalmia neonatorum and treatment of otitis media are often managed with erythromycin. Erythromycin is the only drug currently proven effective for both prophylaxis and treatment of Bordetella pertussis (not a common pathogen in neonatal intensive care units, however).