Antepartum cultures for Ureaplasma urealyticum are not useful in predicting pregnancy outcome. The Vaginal Infections and Prematurity Study Group

Next-generation sequencing-based detection of Ureaplasma in the gastric fluid of neonates with respiratory distress and chorioamnionitis

BACKGROUND

Respiratory distress is common in neonates admitted to neonatal intensive care units. Additionally, infectious diseases such as intrauterine infections or vertical transmission are important underlying causes of respiratory failure. However, pathogens often cannot be identified in neonates, and there are many cases in which antibacterial drugs are empirically administered. Next-generation sequencing (NGS) is advantageous in that it can detect trace amounts of bacteria that cannot be detected by culturing or bacteria that are difficult to cultivate. However, there are few reports on the diagnosis of infectious diseases using NGS in the neonatal field, especially those targeting respiratory distress.

OBJECTIVE

The purpose of our study was to investigate the microorganisms associated with neonatal respiratory distress and to determine whether less invasive collection specimens such as plasma and gastric fluid are useful.

METHODS

Neonates were prospectively recruited between January and August 2020 from Nagoya University Hospital. The inclusion criteria were as follows: 1) admission to the neonatal intensive care unit; 2) respiratory distress presentation within 48 h of birth; and 3) suspected infection, collection of blood culture, and administration of antibiotics. Plasma samples and blood cultures were simultaneously collected. Gastric fluid samples were also collected if the patient was not started on enteral nutrition. Information on the patients and their mothers were collected from the medical records. DNA was extracted from 140 µL of plasma and gastric fluid samples. DNA sequencing libraries were prepared, and their quality was analyzed. DNA libraries were sequenced using high-throughput NGS. The NGS data of plasma and gastric fluid samples were analyzed using the metagenomic pipeline PATHDET, which calculated the number of reads assigned to microorganisms and their relative abundance. Putative pathogens were listed.

RESULTS

Overall, 30 plasma samples and 25 gastric fluid samples from 30 neonates were analyzed. Microorganism-derived reads of gastric fluid samples were significantly higher than those of plasma samples. Transient tachypnea of the newborn was the most common cause of respiratory distress with 13 cases (43%), followed by respiratory distress syndrome with 7 cases (23%). There were 8 cases (29%) of chorioamnionitis and 7 cases (25%) of funisitis pathologically diagnosed. All blood cultures were negative, and only two gastric fluid cultures were positive for group B Streptococcus (Patient 15) and Candida albicans (Patient 24). Putative pathogens that met the positive criteria for PATHET were detected in four gastric fluid samples, one of which was group B Streptococcus from Patient 15. In the gastric fluid sample of Patient 24, Candida albicans were detected by NGS but did not meet the positive criteria for PATHDET. Cluster analysis of the plasma samples divided them into two study groups, and the indicator genera of each cluster (Phormidium or Toxoplasma) are shown in Figure 1. Clinical findings did not show any significant differences between the two groups. Cluster analysis of the gastric fluid samples divided them into three study groups, and the indicator genera of each cluster (Ureaplasma, Nostoc, and Streptococcus) are shown in Figure 2. The incidence rate of chorioamnionitis was significantly higher in Ureaplasma group than in the other two groups.

CONCLUSION

Gastric fluid may be useful for assessing neonatal patients with respiratory distress. To the best of our knowledge, this was the first study to reveal that the presence of Ureaplasma in the gastric fluid of neonates with respiratory distress was associated with chorioamnionitis. The early diagnosis of intra-amniotic infections using gastric fluid and its treatment may change the treatment strategy for neonatal respiratory distress. Screening for Ureaplasma in neonates with respiratory distress may reduce the need for empirical antibiotic administration. Further research is required to confirm these findings.

Effect of adjunctive prophylactic macrolides used at the caesarean section on endometritis and surgical site wound infection: A meta-analysis

A meta-analysis investigation was executed to measure the outcome of adjunctive prophylactic macrolides (APM) used at caesarean section (CS) on endometritis and surgical site wound infection (SSWI). A comprehensive literature inspection till February 2023 was applied and 1023 interrelated investigations were reviewed. The 10 chosen investigations enclosed 22 676 females with CS were in the chosen investigations' starting point, 14 034 of them were utilising APM, and 8642 were utilising control. Odds ratio (OR) in addition to 95% confidence intervals (CIs) were used to compute the value of the effect of APM used at CS on endometritis and SSWI by the dichotomous approaches and a fixed or random model. Adjunctive prophylactic macrolides had significantly lower SSWI (OR, 0.43; 95% CI, 0.34-0.55, P < .001), and endometritis (OR, 0.34; 95% CI, 0.20-0.60, P = .005) compared with those with control in females with CS. Adjunctive prophylactic macrolides had significantly lower SSWI, and endometritis compared with those with control in females with CS. However, care must be exercised when dealing with its values because of the low number of nominated investigations for the meta-analysis.

Maternal Baseline Risk Factors for Abnormal Vaginal Colonisation among High-Risk Pregnant Women and the Association with Adverse Pregnancy Outcomes: A Retrospective Cohort Study

Abnormal vaginal colonisation can lead to adverse pregnancy outcomes such as preterm birth through intra-amniotic inflammation. Despite the concern, little is known about its risk factors and impact in pregnant women at high-risk for spontaneous preterm birth. Thus, we conducted this single-centre retrospective cohort study including 1381 consecutive women who were admitted to the high-risk pregnancy unit. The results of vaginal culture at admission were categorised according to the colonising organism: bacteria (Gram-negative or -positive) and genital mycoplasmas. Maternal baseline socioeconomic, and clinical characteristics, as well as pregnancy, delivery, and neonatal outcomes were compared according to the category. Maternal risk factors for Gram-negative colonisation included advanced maternal age, increased pre-pregnancy BMI, a greater number of past spontaneous abortions, earlier gestational age at admission, and IVF. Gram-positive colonisation was likewise associated with earlier gestational age at admission. Genital mycoplasmal colonisation was associated with a greater number of past induced abortions, a lower level of education completed, and a lower rate of multifetal pregnancy and IVF. The neonates from mothers with Gram-negative colonisation had a greater risk of NICU admission, proven early onset neonatal sepsis, and mortality. However, not Gram-positive bacteria or genital mycoplasma was directly associated with adverse pregnancy outcomes.

Maternal Origins of Neonatal Infections: What Do Obstetrician-Gynecologist Should/Could Do?

Neonatal infections are responsible for 20% of neonatal deaths yearly. In this review, we focused on the origins of the commoner neonatal infections, and we define the role of obstetricians. Regarding group B Streptococcus, a key measure for the prevention of neonatal infection is the vaginal-rectal culture screening at term pregnancy. Intravenous penicillin is the first-line prophylaxis at the start of labor, with intravenous ampicillin as an alternative. First-generation cephalosporins or clindamycin are recommended in case of penicillin allergy. Concerning urinary tract infections (UTIs), guidelines recommend complete urinalysis and urine culture in the first trimester of pregnancy for the screening of asymptomatic bacteriuria. For lower UTIs, guidelines recommend nitrofurantoin as first-choice antibiotic. Amoxicillin or cefalexin are second-line antibiotics. For upper UTIs, guidelines recommend cephalexin per os as first line. Candida spp. colonization affects 20% of pregnant women; however, congenital fetal candidosis and Candida amnionitis are rare. First-line treatment in case of symptomatic vaginitis during pregnancy or asymptomatic colonization during the third trimester is vaginal clotrimazole. Fluconazole is not approved in pregnancy, especially during the first trimester. Genital mycoplasmas colonization during pregnancy is usually asymptomatic and associated with bacterial vaginosis. Colonization is related to neonatal respiratory distress syndrome (RDS), bronchopulmonary dysplasia (BPD), pneumonia, chorioamnionitis, and sepsis. Macrolides are the first-line treatment along with lactobacillus supplementation. In cases of preterm premature rupture of membranes or preterm labor, ceftriaxone, clarithromycin, and metronidazole are required to prevent intra-amniotic infection. Intra-amniotic infection affects 1 to 5% of deliveries at term and one-third of preterm ones and is associated with perinatal death, early-onset neonatal sepsis, RDS, BPD, pneumonia, meningitis, and prematurity-related diseases. Guidelines recommend a combination of ampicillin and gentamicin, and in case of caesarean section, an additional dose of clindamycin or metronidazole is required. In conclusion, obstetricians should be aware that the treatment of maternal infection during pregnancy can prevent potentially lethal infections in the newborn. KEY POINTS: · Part of neonatal infections starts from maternal infections that must be treated during pregnancy.. · Streptococcus group B and asymptomatic bacteriuria should be investigated in pregnancy and treated.. · Mycoplasma and ureaplasma vaginal colonization during pregnancy is related to negative neonatal outcomes..

Association between maternal cervicovaginal swab positivity for Ureaplasma spp. or other microorganisms and neonatal respiratory outcome and mortality

OBJECTIVE

We investigated the association between maternal cervicovaginal cultures, its antibiotic treatment, and neonatal outcome.

STUDY DESIGN

This retrospective cohort study enrolled 480 neonates born prior to 32 weeks' gestation. They were divided into groups according to maternal cervicovaginal culture results. Multivariate logistic regression analysis was used to predict neonatal outcome based on maternal culture results, adjusted for perinatal risk factors and neonatal morbidities.

RESULT

Maternal cervicovaginal Ureaplasma colonization was independently associated with bronchopulmonary dysplasia at 36 weeks (BPD) (OR 8.34; 95% CI 1.21-57.45). In neonates with and without maternal cervicovaginal Ureaplasma colonization BPD occurred in 12.3% and 3.8%, respectively. Maternal colonization with other microorganisms was associated with a higher neonatal mortality (p = 0.002), lower gestational age (p = 0.026), and birth weight (p = 0.036).

CONCLUSIONS

This study underscores the role of the maternal cervicovaginal microbiome as a predictor of neonatal outcome. Cervicovaginal Ureaplasma colonization seems not to be an innocent bystander in the multifactorial etiology of BPD.

A specific bacterial DNA signature in the vagina of Australian women in midpregnancy predicts high risk of spontaneous preterm birth (the Predict1000 study)

BACKGROUND

Intrauterine infection accounts for a quarter of the cases of spontaneous preterm birth; however, at present, it is not possible to efficiently identify pregnant women at risk to deliver preventative treatments.

OBJECTIVE

This study aimed to establish a vaginal microbial DNA test for Australian women in midpregnancy that will identify those at increased risk of spontaneous preterm birth.

STUDY DESIGN

A total of 1000 women with singleton pregnancies were recruited in Perth, Australia. Midvaginal swabs were collected between 12 and 23 weeks' gestation. DNA was extracted for the detection of 23 risk-related microbial DNA targets by quantitative polymerase chain reaction. Obstetrical history, pregnancy outcome, and demographics were recorded.

RESULTS

After excluding 64 women owing to losses to follow-up and insufficient sample for microbial analyses, the final cohort consisted of 936 women of predominantly white race (74.3%). The overall preterm birth rate was 12.6% (118 births); the spontaneous preterm birth rate at <37 weeks' gestation was 6.2% (2.9% at ≤34 weeks' gestation), whereas the preterm premature rupture of the membranes rate was 4.2%. No single individual microbial target predicted increased spontaneous preterm birth risk. Conversely, women who subsequently delivered at term had higher amounts of Lactobacillus crispatus, Lactobacillus gasseri, or Lactobacillus jensenii DNA in their vaginal swabs (13.8% spontaneous preterm birth vs 31.2% term; P=.005). In the remaining women, a specific microbial DNA signature was identified that was strongly predictive of spontaneous preterm birth risk, consisting of DNA from Gardnerella vaginalis (clade 4), Lactobacillus iners, and Ureaplasma parvum (serovars 3 and 6). Risk prediction was improved if Fusobacterium nucleatum detection was included in the test algorithm. The final algorithm, which we called the Gardnerella Lactobacillus Ureaplasma (GLU) test, was able to detect women at risk of spontaneous preterm birth at <37 and ≤34 weeks' gestation, with sensitivities of 37.9% and 44.4%, respectively, and likelihood ratios (plus or minus) of 2.22 per 0.75 and 2.52 per 0.67, respectively. Preterm premature rupture of the membranes was more than twice as common in GLU-positive women. Adjusting for maternal demographics, ethnicity, and clinical history did not improve prediction. Only a history of spontaneous preterm birth was more effective at predicting spontaneous preterm birth than a GLU-positive result (odds ratio, 3.6).

CONCLUSION

We have identified a vaginal bacterial DNA signature that identifies women with a singleton pregnancy who are at increased risk of spontaneous preterm birth and may benefit from targeted antimicrobial therapy.

Are prophylactic adjunctive macrolides efficacious against caesarean section surgical site infection: A systematic review and meta-analysis

Surgical site infection (SSI) post- caesarean section (CS) remains high, prophylactic adjunctive macrolides may reduce this. This systematic review and meta-analysis evaluated whether adjunctive prophylactic macrolides administered at CS reduce the risk of endometritis and wound infection. MEDLINE, EMBASE, CINHAL and the Cochrane library were searched from inception to July-2018. Observational and randomised studies investigating women undergoing a CS receiving standard prophylactic antibiotics, adjunctive prophylactic macrolides and assessed any SSI outcome was included. Data was double-extracted. Studies were included in a meta-analysis if the same study design and SSI outcome was used. Risk ratios were calculated and heterogeneity was assessed using the I² test. Five studies were included in the systematic review and four in the meta-analysis. Two RCT's (n = 2610) found that macrolides significantly reduce the risk of wound infection RR [0.34; 95 %, 0.22 0.53] P = 0.00001 and endometritis RR [0.66; 95 %, 0.52, 0.85] P = 0.001 with no evidence of heterogeneity (I² = 0 %). Two cohort studies (n = 13,809) found that azithromycin significantly reduces the risk of endometritis RR [0.16; 95 %, 0.04-0.62] P = 0.008, however significant heterogeneity was seen. Macrolides significantly reduce the risk of endometritis and wound infection post-CS. An effectiveness evaluation of post-cord clamping administration is needed to eliminate fetal antibiotic exposure and the long term infant implications this may have.

Different degrees of maternal Ureaplasma colonization and its correlation with bronchopulmonary dysplasia in <32 weeks' preterm infants

BACKGROUND

Ureaplasma spp. is a known risk factor for bronchopulmonary dysplasia (BPD). However, little is known about the effect of different degrees of maternal Ureaplasma colonization and their adverse outcomes. Hence, the aim of this study was to determine the effects of different degrees of maternal Ureaplasma colonization on BPD.

METHODS

A retrospective cohort study of preterm infants delivered at <32 weeks' gestational age (GA) was performed. The infants were divided according to maternal Ureaplasma status as follows: high-colonization (≥104 CCU/ml, UUH), low-colonization (<104 CCU/ml, UUL), and noncolonization (controls). Subgroup analysis according to neonatal respiratory Ureaplasma (n-UU) was also performed to evaluate vertical transmission.

RESULTS

In total, 245 infants were included in this study (UUH = 105, UUL = 47, controls = 93). The rates of preterm labor and histological chorioamnionitis were significantly different. The rate of BPD was significantly high in UUH (P = 0.044). The transmission rate of n-UU colonization was 36% in UUH and 32% in UUL (P = 0.609). The rate of BPD was 78% in n-UU (+) of UUH but 43% in n-UU (-) of UUL (P = 0.027).

CONCLUSIONS

High-degree colonization of maternal Ureaplasma was associated with preterm labor, histological chorioamnionitis, and neonatal BPD. The incidence of BPD was significantly higher in Ureaplasma-colonized infants born to women with high-degree colonization.

Ureaplasma isolates stimulate pro-inflammatory CC chemokines and matrix metalloproteinase-9 in neonatal and adult monocytes

Being generally regarded as commensal bacteria, the pro-inflammatory capacity of Ureaplasma species has long been debated. Recently, we confirmed Ureaplasma–driven pro-inflammatory cytokine responses and a disturbance of cytokine equilibrium in primary human monocytes in vitro. The present study addressed the expression of CC chemokines and matrix metalloproteinase-9 (MMP-9) in purified term neonatal and adult monocytes stimulated with serovar 8 of Ureaplasma urealyticum (Uu) and serovar 3 of U. parvum (Up). Using qRT-PCR and multi-analyte immunoassay, we assessed mRNA and protein expression of the monocyte chemotactic proteins 1 and 3 (MCP-1/3), the macrophage inflammatory proteins 1α and 1β (MIP-1α/β) as well as MMP-9. For the most part, both isolates stimulated mRNA expression of all given chemokines and MMP-9 in cord blood and adult monocytes (p<0.05 and p<0.01). These results were paralleled by Uu and Up-induced secretion of MCP-1 protein in both cells (neonatal: p<0.01, adult: p<0.05 and p<0.01). Release of MCP-3, MIP-1α, MIP-1β and MMP-9 was enhanced upon exposure to Up (neonatal: p<0.05, p<0.01 and p<0.001, respectively; adult: p<0.05). Co-stimulation of LPS-primed monocytes with Up increased LPS-induced MCP-1 release in neonatal cells (p<0.05) and aggravated LPS-induced MMP-9 mRNA in both cell subsets (neonatal: p<0.05, adult: p<0.01). Our results document considerable expression of pro-inflammatory CC chemokines and MMP-9 in human monocytes in response to Ureaplasma isolates in vitro, adding to our previous data. Findings from co-stimulated cells indicate that Ureaplasma may modulate monocyte immune responses to a second stimulus.

Associations between sexual habits, menstrual hygiene practices, demographics and the vaginal microbiome as revealed by Bayesian network analysis

The vaginal microbiome plays an influential role in several disease states in reproductive age women, including bacterial vaginosis (BV). While demographic characteristics are associated with differences in vaginal microbiome community structure, little is known about the influence of sexual and hygiene habits. Furthermore, associations between the vaginal microbiome and risk symptoms of bacterial vaginosis have not been fully elucidated. Using Bayesian network (BN) analysis of 16S rRNA gene sequence results, demographic and extensive questionnaire data, we describe both novel and previously documented associations between habits of women and their vaginal microbiome. The BN analysis approach shows promise in uncovering complex associations between disparate data types. Our findings based on this approach support published associations between specific microbiome members (e.g., Eggerthella, Gardnerella, Dialister, Sneathia and Ruminococcaceae), the Nugent score (a BV diagnostic) and vaginal pH (a risk symptom of BV). Additionally, we found that several microbiome members were directly connected to other risk symptoms of BV (such as vaginal discharge, odor, itch, irritation, and yeast infection) including L. jensenii, Corynebacteria, and Proteobacteria. No direct connections were found between the Nugent Score and risk symptoms of BV other than pH, indicating that the Nugent Score may not be the most useful criteria for assessment of clinical BV. We also found that demographics (i.e., age, ethnicity, previous pregnancy) were associated with the presence/absence of specific vaginal microbes. The resulting BN revealed several as-yet undocumented associations between birth control usage, menstrual hygiene practices and specific microbiome members. Many of these complex relationships were not identified using common analytical methods, i.e., ordination and PERMANOVA. While these associations require confirmatory follow-up study, our findings strongly suggest that future studies of the vaginal microbiome and vaginal pathologies should include detailed surveys of participants' sanitary, sexual and birth control habits, as these can act as confounders in the relationship between the microbiome and disease. Although the BN approach is powerful in revealing complex associations within multidimensional datasets, the need in some cases to discretize the data for use in BN analysis can result in loss of information. Future research is required to alleviate such limitations in constructing BN networks. Large sample sizes are also required in order to allow for the incorporation of a large number of variables (nodes) into the BN, particularly when studying associations between metadata and the microbiome. We believe that this approach is of great value, complementing other methods, to further our understanding of complex associations characteristic of microbiome research.

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.

The Human Ureaplasma Species as Causative Agents of Chorioamnionitis

The human Ureaplasma species are the most frequently isolated microorganisms from the amniotic fluid and placentae of women who deliver preterm and are also associated with spontaneous abortions or miscarriages, neonatal respiratory diseases, and chorioamnionitis. Despite the fact that these microorganisms have been habitually found within placentae of pregnancies with chorioamnionitis, the role of Ureaplasma species as a causative agent has not been satisfactorily explained. There is also controversy surrounding their role in disease, particularly as not all women infected with Ureaplasma spp. develop chorioamnionitis. In this review, we provide evidence that Ureaplasma spp. are associated with diseases of pregnancy and discuss recent findings which demonstrate that Ureaplasma spp. are associated with chorioamnionitis, regardless of gestational age at the time of delivery. Here, we also discuss the proposed major virulence factors of Ureaplasma spp., with a focus on the multiple-banded antigen (MBA), which may facilitate modulation/alteration of the host immune response and potentially explain why only subpopulations of infected women experience adverse pregnancy outcomes. The information presented within this review confirms that Ureaplasma spp. are not simply "innocent bystanders" in disease and highlights that these microorganisms are an often underestimated pathogen of pregnancy.

Ureaplasma parvum genotype, combined vaginal colonisation with Candida albicans, and spontaneous preterm birth in an Australian cohort of pregnant women

BACKGROUND

Detection of Ureaplasma, Mycoplasma and Candida spp. in the vagina during pregnancy has previously been associated with preterm birth (PTB). However, the prevalence of these microorganisms and the associated obstetric risks (likely to be population-specific) have not been determined in Australian women; furthermore, in the case of Ureaplasma spp., very few studies have attempted characterisation at the species level and none have examined genotype/serovar status to further refine risk assessment.

METHODS

In order to address these issues we sampled the vaginal fluid of 191 pregnant Australian women at three time points in pregnancy. Culture methods were used for detection of Ureaplasma spp. and Candida spp., and real-time PCR was used for speciation of U. parvum and U. urealyticum, non-albicans Candida spp., Mycoplasma hominis and Mycoplasma genitalium. High-resolution melt PCR was used to genotype U. parvum. Data on various lifestyle factors (including sex during pregnancy and smoking), antimicrobial use and pregnancy outcome were collected on all participants. Chi-square tests were used to assess the association of vaginal microorganisms with PTB.

RESULTS

Detection of Ureaplasma spp. was higher among spontaneous PTB cases, specifically in the presence of U. parvum [77 % preterm (95 % confidence interval (CI) 50-100 %) vs. 36 % term (CI: 29-43 %), p = 0.004], but not U. urealyticum. The association with PTB strengthened when U. parvum genotype SV6 was detected (54 % preterm (CI: 22-85 %) vs. 15 % term (CI: 10-20 %), p = 0.002); this genotype was also present in 80 % (4/5) of cases of PTB <34 weeks gestation. When present with Candida albicans in the same sample, the association with PTB remained strong for both U. parvum [46 % preterm (CI: 15-78 %) vs. 13 % term (CI: 8-18 %), p = 0.005] and U. parvum genotype SV6 [39 % preterm (CI: 8-69 %) vs. 7 % term (CI: 3-11 %), p = 0.003]. With the exception of Candida glabrata, vaginal colonisation status for all organisms was stable throughout pregnancy. Smoking significantly increased the likelihood of detection of all target organisms.

CONCLUSIONS

These data suggest that the presence of different species and serovars of Ureaplasma spp. in the vagina confers an increased risk of spontaneous PTB, findings which may be useful in risk assessment for identifying women who would benefit from antimicrobial treatment.

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.

Maternal influences on fetal microbial colonization and immune development

While critical for normal development, the exact timing of establishment of the intestinal microbiome is unknown. For example, although preterm labor and birth have been associated with bacterial colonization of the amniotic cavity and fetal membranes for many years, the prevailing dogma of a sterile intrauterine environment during normal term pregnancies has been challenged more recently. While found to be a key contributor of evolution in the animal kingdom, maternal transmission of commensal bacteria may also constitute a critical process during healthy pregnancies in humans with yet unclear developmental importance. Metagenomic sequencing has elucidated a rich placental microbiome in normal term pregnancies likely providing important metabolic and immune contributions to the growing fetus. Conversely, an altered microbial composition during pregnancy may produce aberrant metabolites impairing fetal brain development and life-long neurological outcomes. Here we review the current understanding of microbial colonization at the feto-maternal interface and explain how normal gut colonization drives a balanced neonatal mucosal immune system, while dysbiosis contributes to aberrant immune function early in life and beyond. We discuss how maternal genetics, diet, medications, and probiotics inform the fetal microbiome in preparation for perinatal and postnatal bacterial colonization.

Epidemiologic factors and urogenital infections associated with preterm birth in a midwestern U.S. population

OBJECTIVE

To correlate epidemiologic factors with urogenital infections associated with preterm birth.

METHODS

Pregnant women were sequentially included from four Wisconsin cohorts: large urban, midsize urban, small city, and rural city. Demographic, clinical, and current pregnancy data were collected. Cervical and urine specimens were analyzed by microscopy, culture, and polymerase chain reaction for potential pathogens.

RESULTS

Six hundred seventy-six women were evaluated. Fifty-four (8.0%) had preterm birth: 12.1% (19/157) large urban, 8.8% (15/170) midsize urban, 9.4% (16/171) small city, and 2.3% (4/178) rural city. Associated host factors and infections varied significantly among sites. Urogenital infection rates, especially Mycoplasma hominis and Ureaplasma parvum, were highest at the large urban site. Large urban site, minority ethnicity, multiple infections, and certain historical factors were associated with preterm birth by univariable analysis. By multivariable analysis, preterm birth was associated with prior preterm birth (adjusted odds ratio [aOR] 2.76, 95% confidence interval [CI] 1.27-6.02) and urinary tract infection (aOR 2.62, 95% CI 1.32-519), and negatively associated with provider-assessed good health (aOR 0.42, 95% CI 0.23-0.76) and group B streptococcal infection treatment (surrogate for health care use) (aOR 0.38, 95% CI 0.15-.99). Risk and protective factors were similar for women with birth at less than 35 weeks, and additionally associated with M hominis (aOR 3.6, 95% CI 1.4-9.7).

CONCLUSION

These measured differences among sites are consistent with observations that link epidemiologic factors, both environmental and genetic, with minimally pathogenic vaginal bacteria, inducing preterm birth, especially at less than 35 weeks of gestation.

Treatment of genital mycoplasma in colonized pregnant women in late pregnancy is associated with a lower rate of premature labour and neonatal complications

Mycoplasma hominis and Ureaplasma spp. may colonize the human genital tract and have been associated with adverse pregnancy outcomes such as preterm labour and preterm premature rupture of membranes. However, as these bacteria can reside in the normal vaginal flora, there are controversies regarding their true role during pregnancy and so the need to treat these organisms. We therefore conducted a retrospective analysis to evaluate the treatment of genital mycoplasma in 5377 pregnant patients showing symptoms of potential obstetric complications at 25-37 weeks of gestation. Women presenting with symptoms were routinely screened by culture for the presence of these bacteria and treated with clindamycin when positive. Compared with uninfected untreated patients, women treated for genital mycoplasma demonstrated lower rates of premature labour. Indeed preterm birth rates were, respectively, 40.9% and 37.7% in women colonized with Ureaplasma spp. and M. hominis, compared with 44.1% in uncolonized women (Ureaplasma spp., p 0.024; M. hominis, p 0.001). Moreover, a reduction of neonatal complications rates was observed, with 10.9% of newborns developing respiratory diseases in case of Ureaplasma spp. colonization and 5.9% in the presence of M. hominis, compared with 12.8% in the absence of those bacteria (Ureaplasma spp., p 0.050; M. hominis, p <0.001). Microbiological screening of Ureaplasma spp. and/or M. hominis and pre-emptive antibiotic therapy of symptomatic pregnant women in late pregnancy might represent a beneficial strategy to reduce premature labour and neonatal complications.

Ureaplasma urealyticum airway colonization and pulmonary outcome in neonates

Ureaplasma urealyticum genital tract colonization of pregnant women has been associated with an adverse pregnancy outcome, while its consequent perinatal transmission has been implicated in the development of respiratory disease of the neonate. Clinical manifestations or contributions of ureaplasmal airway colonization in newborns mainly include pneumonia, precocious dysplastic changes and chronic lung disease; although systemic disease has also been documented. This review aims to summarize current diagnostic techniques, pathogenetic mechanisms and pathological data in an attempt to establish an optimal therapeutic approach regarding neonatal U. urealyticum respiratory infection. Related morbidity and mortality, along with the high economic impact of neonatal respiratory disease worldwide, renders this topic particularly interesting and promotes further research in this field.

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.

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.

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.

The prevalence of vaginal microorganisms in pregnant women with preterm labor and preterm birth

Background

To investigate the risk factors for vaginal infections and antimicrobial susceptibilities of vaginal microorganisms among women who experienced preterm birth (PTB), we compared the prevalence of vaginal microorganisms between women who experienced preterm labor (PTL) without preterm delivery and spontaneous PTB.

Methods

Vaginal swab specimens from 126 pregnant women who experienced PTL were tested for group B streptococcus (GBS), Mycoplasma hominis, Mycoplasma genitalium, Ureaplasma urealyticum, Chlamydia trachomatis, Trichomonas vaginalis, Neisseria gonorrhoeae, Treponema pallidum, herpes simplex virus (HSV) I and II, and bacterial vaginosis. A control group of 91 pregnant women was tested for GBS. Antimicrobial susceptibility tests were performed for GBS, M. hominis, and U. urealyticum.

Results

The overall detection rates for each microorganism were: U. urealyticum, 62.7%; M. hominis, 12.7%; GBS, 7.9%; C. trachomatis, 2.4%; and HSV type II, 0.8%. The colonization rate of GBS in control group was 17.6%. The prevalence of GBS, M. hominis, and U. urealyticum in PTL without preterm delivery and spontaneous PTB were 3.8% and 8.7% (relative risk [RR], 2.26), 3.8% and 17.3% (RR, 4.52), and 53.8% and 60.9% (RR, 1.13), respectively, showing no significant difference between the 2 groups. The detection rate of M. hominis by PCR was higher than that by culture method (11.1% vs. 4.0%, P=0.010). The detection rates of U. urealyticum by PCR and culture method were 16.7% and 57.1%, respectively.

Conclusions

There was no significant difference in the prevalence of GBS, M. hominis, and U. urealyticum between the spontaneous PTB and PTL without preterm delivery groups.

Intraamniotic infection with genital mycoplasmas exhibits a more intense inflammatory response than intraamniotic infection with other microorganisms in patients with preterm premature rupture of membranes

OBJECTIVE

The objective of the study was to compare the intensity of inflammatory responses between intraamniotic infection with genital mycoplasmas and intraamniotic infection with other microorganisms.

STUDY DESIGN

We examined the intensity of intraamniotic and maternal inflammatory responses in 99 patients with preterm premature rupture of membranes and a positive amniotic fluid (AF) culture. AF was obtained by transabdominal amniocentesis or at the time of cesarean delivery. Patients were divided according to the recovered microorganisms: (1) genital mycoplasmas (n = 62); (2) other microorganisms (n = 31); or (3) mixed infection (n = 6).

RESULTS

The median AF white blood cell (WBC) count, maternal blood WBC count, and plasma C-reactive protein concentrations were significantly higher in patients with intraamniotic infection with genital mycoplasmas than in those with intraamniotic infection with other microorganisms (P < .05 for each).

CONCLUSION

Intraamniotic and maternal inflammatory responses are more intense in intraamniotic infection with genital mycoplasmas than in intraamniotic infection with other microorganisms in patients with preterm premature rupture of membranes.

Vaginal and oral microbes, host genotype and preterm birth

Preterm birth (PTB) is a leading cause of infant mortality and morbidity in the US and across the globe. Infection and associated inflammation are important initiators for PTB pathways; an estimated 40% of PTBs are attributed to amniochorionic-decidual or systemic inflammation. Historically, intrauterine infections have been implicated in PTB; recent evidence suggests that infections remote from the fetal site may also be causative. There is strong epidemiological evidence that bacterial vaginosis and periodontitis--two syndromes characterized by perturbations in the normal vaginal and oral bacterial microflora, respectively--are linked to infection-associated PTB. Oral and vaginal environments are similar in their bacterial microbiology; identical bacterial species have been independently isolated in periodontitis and bacterial vaginosis. Periodontitis and bacterial vaginosis also share many behavioral and sociodemographic risk factors suggesting a possible common pathophysiology. Genetic polymorphisms in host inflammatory responses to infection are shared between bacterial vaginosis, periodontitis and PTB, suggesting common mechanisms through which host genotype modify the effect of abnormal bacterial colonization on preterm birth. We review the state of knowledge regarding the risk of PTB attributable to perturbations in bacterial flora in oral and vaginal sites and the role of host genetics in modifying the risk of infection-related PTB. We posit that bacterial species that are common in perturbed vaginal and oral sites are associated with PTB through their interaction with the host immune system.

Mollicute infections in neonates

Mollicutes can cause a wide spectrum of disease, especially in neonates. To better define their disease spectrum in the United States, we reviewed the results of >14,000 mollicute isolates, including 1346 from neonates. When mollicute infection is suspected, clinicians should alert laboratories, which will optimize methods of detection.

Prevention of preterm birth

For an infant without lethal congenital malformations there is no risk greater than to be born too early. In addition, preterm birth with its many consequences may compromise the life of the whole family. Thus, prevention of preterm birth is one of the greatest challenges in obstetrics. However, this has proven to be difficult. This difficulty is in part due to the fact that, although we know a large number of clinical factors which are know a large number of clinical factors which are associated with preterm birth, the final mechanisms triggering the onset of preterm contractions or premature rupture of the fetal membranes (PROM) have remained largely unclear. We review the prevention of preterm birth in the light of the newest data; an interested reader is also referred to other recent overviews on the same topic.

Correlations of selected vaginal cytokine levels with pregnancy-related traits in women with bacterial vaginosis and mycoplasmas

The aim of this study was to examine correlations between vaginal inflammatory cytokines (IL-1alpha, IL-1beta, IL-6 and IL-8) and pregnancy-related traits (gestational age, birth-weight, BMI, weight gain during pregnancy and vaginal pH). Differences in correlation coefficients were examined among bacterial vaginosis (BV) status and the presence or absence of mycoplasmas. A total of 105 women between the 22nd and 34th week of pregnancy were enrolled in this study. There was a strong negative correlation between IL-1alpha and weight gain during pregnancy (r=-0.877, p<0.001) and a strong positive correlation between IL-6 and BMI (r=0.670, p=0.024) in women with normal vaginal flora and mycoplasmas. These correlations were not present in women who had normal flora and no mycoplasmas. In women with BV and no mycoplasmas, there were significant correlations of gestational age with IL-6 (r=0.727, p=0.027) and IL-8 (r=0.689, p=0.040); however, these correlations were not significant in women with mycoplasmas. Our findings support the conclusion that correlations between inflammatory cytokines and pregnancy-related traits are dependent on context, suggesting that expression is labile. In particular, BMI and gestational age correlation differs depending on BV status and the presence or absence of BV-related mycoplasmas such as Mycoplasma hominis and Ureaplasma urealyticum.

The Alabama Preterm Birth Study: umbilical cord blood Ureaplasma urealyticum and Mycoplasma hominis cultures in very preterm newborn infants

OBJECTIVE

This study was undertaken to evaluate the frequency of umbilical cord blood infections with Ureaplasma urealyticum and Mycoplasma hominis in preterm 23- to 32-week births and to determine their association with various obstetric conditions, markers of placental inflammation, and newborn outcomes.

STUDY DESIGN

351 mother/infant dyads with deliveries between 23 and 32 weeks' gestational age who had cord blood cultures for U. urealyticum and M. hominis had their medical records abstracted, other placental cultures performed, cord interleukin-6 levels determined, placentas evaluated histologically, and infant outcomes determined.

RESULTS

U. urealyticum and/or M. hominis were present in 23% of cord blood cultures. Positive cultures were more common in infants of nonwhite women (27.9% vs 16.8%; P = .016), in women less than 20 years of age, in those undergoing a spontaneous compared to an indicated preterm delivery (34.7% vs 3.2%; P = .0001), and in those delivering at earlier gestational ages. Intrauterine infection and inflammation were more common among infants with a positive U. urealyticum and M. hominis culture as evidenced by placental cultures for these and other bacteria, elevated cord blood interleukin-6 levels, and placental histology. Infants with positive cord blood U. urealyticum and M. hominis cultures were more likely to have neonatal systemic inflammatory response syndrome (41.3% vs 25.7%; P = .007; adjusted odds ratio, 1.86; 1.08-3.21) and probably bronchopulmonary dysplasia (26.8% vs 10.1%; P = .0001; adjusted odds ratio 1.99; 0.91-4.37), but were not significantly different for other neonatal outcomes, including respiratory distress syndrome, intraventricular hemorrhage, or death.

CONCLUSION

U. urealyticum and M. hominis cord blood infections are far more common in spontaneous vs indicated preterm deliveries and are strongly associated with markers of acute placental inflammation. Positive cultures are associated with neonatal systemic inflammatory response syndrome and probably bronchopulmonary dysplasia.

A randomized trial of the duration of therapy with metronidazole plus or minus azithromycin for treatment of symptomatic bacterial vaginosis

BACKGROUND

Bacterial vaginosis (BV) is the most common cause of vaginitis worldwide. Currently recommended treatments have poor efficacy and are associated with high rates of BV recurrence. We examined whether a longer duration of treatment with metronidazole or combination therapy with metronidazole and azithromycin would enhance the cure rates for BV. In addition, we examined factors other than drug therapy associated with cure.

METHODS

Women with symptomatic BV (defined by a modified Amsel criteria) were enrolled in a 4-arm study that compared metronidazole for 7 days versus 14 days, plus or minus azithromycin on days 1 and 3. Data regarding interim behaviors were also obtained, as were vaginal specimens for Gram staining.

RESULTS

At the first follow-up visit (7 days after the completion of therapy), there was a significant difference in cure rates among patients who received 7 days of metronidazole therapy, compared with those who received 14 days of therapy, combined across azithromycin therapy (P=.0003). There was no effect associated with azithromycin therapy. There were no differences in cure rates between any of the treatment groups at 21 days after completion of therapy. Abstinence or protected sex, refraining from douching, and a lower baseline Nugent score for the vaginal Gram stain were all significantly associated with cure.

CONCLUSIONS

Cure rates for BV were significantly improved by 14 days of metronidazole treatment (compared with 7 days of treatment), but the effects were not sustained, suggesting that relapse or reinfection occurred. Combination therapy with the addition of azithromycin had no benefit. Lower baseline Nugent scores--presumably reflecting less complex vaginal flora--were significantly associated with cure, as was refraining from unprotected sex and from douching.

Assessing the relationship between preterm delivery and various microorganisms recovered from the lower genital tract

OBJECTIVE

To determine if the likelihood of preterm delivery is more dependent on the specific organisms present in the vagina than on the presence of bacterial vaginosis.

METHODS

We evaluated the vaginal fluid of a prospective cohort of women at 23-32 weeks of gestation with signs and symptoms of preterm labor and intact membranes. Forward stepwise logistic regression models were used to evaluate the relationship between preterm delivery and the presence of anaerobic bacteria, Gardnerella, ureaplasmas and mycoplasmas, and sialidase.

RESULTS

The cohort included 137 women, and complete delivery information was available for 134 of them. The rate of preterm delivery was 28% (37 of 134). Mycoplasma genitalium independently was associated with spontaneous preterm delivery (OR 3.48; 95% CI 1.41, 8.57). After controlling for this factor, none of the other variables were significantly prognostic for spontaneous preterm delivery (residual overall p = 0.19).

CONCLUSION

The presence of Mycoplasma genitalium in the vagina of pregnant women is an independent risk factor for spontaneous preterm delivery.

Value of Endocervical Ureaplasma Species Colonization as a Marker of Preterm Delivery

AIMS

To study the predictive value for preterm delivery of colonization of the cervix and vagina by ureaplasmas and other potentially pathogenic microorganisms.

METHODS

Prospective analysis of a study group of 200 pregnant women with preterm labor and intact membranes, and a control group of 50 pregnant women. The subjects in both groups were between 24 and 34 weeks of gestation. Ureaplasma spp. and Mycoplasma hominis endocervical cultures were performed for both groups.

RESULTS

In the study group, 70 of the women delivered preterm, and all women in the control group carried their pregnancies to full term. Cervical cultures for Ureaplasma spp. were positive in 119 women, and were isolated more frequently in the study group (51.5%) than in the control group (32%), and more frequently in subjects in the study group who delivered preterm (65%) than in those who had a full-term delivery (45%), differences that were statistically significant.

CONCLUSION

Detection of Ureaplasma spp. in the endocervix has a statistically significant relationship to preterm labor (p = 0.03) and preterm delivery (p = 0.02) in pregnant women with preterm labor and intact membranes.

Mycoplasmas and ureaplasmas as neonatal pathogens

The genital mycoplasmas represent a complex and unique group of microorganisms that have been associated with a wide array of infectious diseases in adults and infants. The lack of conclusive knowledge regarding the pathogenic potential of Mycoplasma and Ureaplasma spp. in many conditions is due to a general unfamiliarity of physicians and microbiology laboratories with their fastidious growth requirements, leading to difficulty in their detection; their high prevalence in healthy persons; the poor design of research studies attempting to base association with disease on the mere presence of the organisms in the lower urogenital tract; the failure to consider multifactorial aspects of diseases; and considering these genital mycoplasmas only as a last resort. The situation is now changing because of a greater appreciation of the genital mycoplasmas as perinatal pathogens and improvements in laboratory detection, particularly with regard to the development of powerful molecular nucleic acid amplification tests. This review summarizes the epidemiology of genital mycoplasmas as causes of neonatal infections and premature birth; evidence linking ureaplasmas with bronchopulmonary dysplasia; recent changes in the taxonomy of the genus Ureaplasma; the neonatal host response to mycoplasma and ureaplasma infections; advances in laboratory detection, including molecular methods; and therapeutic considerations for treatment of systemic diseases.

Infection and Preterm Birth

As many as 50% of spontaneous preterm births are infection-associated. Intrauterine infection leads to a maternal and fetal inflammatory cascade, which produces uterine contractions and may also result in long-term adverse outcomes, such as cerebral palsy. This article addresses the prevalence, microbiology, and management of intrauterine infection in the setting of preterm labor with intact membranes. It also outlines antepartum treatment of infections for the purpose of preventing preterm birth.

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.

Experimental genital mycoplasmosis causes increased levels of mRNA for IL-6 and TNF-alpha in the placenta

PROBLEM

Previous studies with animal models have shown that injection of lipopolysaccharide (LPS) results in fetal loss and increases production of proinflammatory cytokines at the maternal-fetal interface. Most intrauterine infections, however, are associated with Ureaplasma urealyticum, a microorganism that lacks a cell wall and therefore does not contain LPS. Previous work in our laboratory with an animal model for genital infection with a similar organism, Mycoplasma pulmonis, revealed that widespread infection in maternal and fetal tissues can be experimentally induced with minimal manipulation of the animal. For this project, we tested the hypothesis that administration of the organism by a hematogenous route at gestational day (gd) 14 would result in increased tumor necrosis factor (TNF)-alpha and interleukin (IL)-6 production by the placenta.

STUDY DESIGN

Timed-pregnant, Sprague-Dawley rats were anesthetized on gd 14 and 10(7) CFU of M. pulmonis strain X1048 or an equivalent volume of sterile medium was injected into the heart. Rats were necropsied on gd 18 or 21, and ex vivo production of TNF-alpha and IL-6 was evaluated from six randomly selected placentas from each litter. The remaining placentas were harvested and either snap-frozen or placed in formalin. Frozen placentas were processed for real-time reverse transcriptase-polymerase chain reaction (RT-PCR) analysis of TNF-alpha and IL-6 mRNA. Formalin-fixed placentas were sectioned and stained with hematoxylin and eosin for lesion analysis.

RESULTS

Concentrations of TNF-alpha but not IL-6 were significantly higher in conditioned medium from placentas harvested from infected dams at gd 21. Levels of mRNA for IL-6 and TNF-alpha, however, were increased by M. pulmonis at gd 18 and 21. Analysis of gd 21 placentas by light microscopy revealed that significant histological chorioamnionitis was present in infected animals with accumulations of neutrophils in the capsular decidua.

CONCLUSION

These data indicate that experimental infection with M. pulmonis causes histological chorioamnionitis, elevated mRNA levels of TNF-alpha and IL-6 in placental tissues, and the secretion of TNF-alpha by the placenta during late gestation.

Cervical Ureaplasma urealyticum colonization might be associated with increased incidence of preterm delivery in pregnant women without prophlogistic microorganisms on routine examination

AIM

We examined whether the detection of Ureaplasma urealyticum DNA in the cervix is associated with preterm labor and delivery.

METHODS

Eighty-two women (23 preterm labor cases and 59 controls) with no evidence of prophlogistic microorganisms on routine microbiologic examination were enrolled for this study. U. urealyticum colonization was examined using polymerase chain reaction of cervical swabs.

RESULTS

The positivity rate of U. urealyticum DNA in preterm labor cases was significantly higher than that in the controls (87.0%vs 45.8%, P=0.0007). Women in the U. urealyticum-positive group more frequently delivered preterm compared with those in the negative group (36.2%vs 11.4%, P=0.0111). In five cases that delivered preterm with histologically confirmed chorioamnionitis, U. urealyticum DNA was detected in the placenta.

CONCLUSIONS

Cervical U. urealyticum colonization might be associated with preterm labor and delivery.

Maternal genital colonization with Ureaplasma urealyticum promotes preterm delivery: association of the respiratory colonization of premature infants with chronic lung disease and increased mortality

BACKGROUND

Infection of the chorioamnion with Ureaplasma urealyticum has been associated with low birth weight. Respiratory tract colonization in preterm infants has been associated with the development of chronic lung disease (CLD). The purpose of the present study was to determine the frequency of colonization of the mother's vagina and the preterm infant's respiratory tract and to associate U. urealyticum with premature birth and with development of CLD in the newborn.

METHODS

The present prospective study involved 126 mothers with preterm delivery and 125 mothers with full-term delivery, as well as their offspring. Vaginal secretion specimens were obtained from each mother before delivery. Rhinopharyngeal secretion or tracheal lavage specimens were collected after the birth of each premature and full-term infant and then periodically during hospitalization.

RESULTS

Vaginal Ureaplasma colonization occurred among 36.5% of mothers with preterm delivery and among 38% of mothers with full-term delivery. The rate of vertical transmission was 33% and 17% for mothers with preterm delivery and mothers with full-term delivery, respectively. The transmission rate for infants, according to birth weight, was as follows: 60%, for infants with a birth weight of <1000 g; 50%, for infants with a birth weight of 1000-1500 g; and 15.3%, for infants with a birth weight of > or =1500 g (P=.001). The median gestational age of preterm infants born to colonized mothers was 28.5 weeks, and that of preterm infants born to noncolonized mothers was 32 weeks (P<.0001). The median birth weight of colonized preterm infants was 1135 g, and that of noncolonized infants was 1670 g (P<.0001). Twenty-four percent of preterm infants and 10% of full-term infants were colonized with U. urealyticum. Of colonized preterm infants, 27% developed CLD, compared with 9% of noncolonized infants (P=.03). Mortality was significantly higher among colonized preterm infants (P=.003).

CONCLUSIONS

The rate of vertical transmission is highest among preterm infants with a birth weight of <1500 g. Vaginal colonization with Ureaplasma organisms is associated with premature delivery. Colonization of the respiratory tract of infants is associated with the development of CLD and with increased mortality.

Use of microbial cultures and antibiotics in the prevention of infection-associated preterm birth

OBJECTIVE

The purpose of this study was to summarize recent evidence regarding infection-associated preterm birth and to make appropriate recommendations. Antepartum treatment of lower genital tract infection or bacterial colonization has been found to reduce the incidence of preterm birth in the case of asymptomatic bacteriuria and bacterial vaginosis in selected patients but has been proved to be ineffective for vaginal colonization with organisms such as Ureaplasma urealyticum and group B streptococcus.

STUDY DESIGN

This is a clinical opinion based on a review of recent data related to 1) the association between lower genital tract infection and preterm birth and 2) antibiotic trials to prevent preterm birth.

RESULTS

Antepartum treatment of lower genital tract infection or bacterial colonization has been found to reduce the incidence of preterm birth in the case of asymptomatic bacteriuria and bacterial vaginosis in selected patients, but has been proven to be ineffective for vaginal colonization with organisms such as Ureaplasma urealyticum and group B streptococcus. Large well-designed trials have shown that the routine administration of antibiotics to women with preterm labor and intact membranes is not beneficial; however, antibiotic regimens including macrolides are recommended for preterm premature rupture of the membranes.

CONCLUSION

Large well-designed trials have shown that the routine administration of antibiotics to women with preterm labor and intact membranes is not beneficial; however, antibiotic regimens that include macrolides are recommended for preterm premature rupture of the membranes.

The relationship between infections and adverse pregnancy outcomes: an overview

Preterm birth with its subsequent morbidity and mortality is the leading perinatal problem in the United States. Infants born before the thirty-seventh week of gestation account for approximately 6% to 9% of all births, but 70% of all perinatal deaths and half of all long-term neurologic morbidity. Current approaches focus on symptomatic treatment. Despite widespread use of drugs to arrest preterm labor (tocolytics), there has been no decrease in low birth weight or preterm infants in the last 20 years. It is likely that therapy directed at preventing or treating underlying causes would be more successful. Evidence from many sources links preterm birth to symptomatic infections, for example, of the urinary or respiratory tracts. In the last decade, great interest has been generated to support the hypothesis that subclinical infection is an important cause of preterm labor. Evidence to support this may be categorized as follows: histological chorioamnionitis is increased in preterm births; clinical infection is increased after preterm birth; there is significant association of some lower genital tract organisms and infections with preterm birth or preterm premature rupture of the membranes; there are positive cultures of amniotic fluid or membranes from some patients with preterm labor and preterm birth; there are markers of infections in preterm birth; bacteria or their products induce preterm birth in animal models; and some antibiotic trials have shown a lower rate of preterm birth or have deferred preterm birth. In the last 5 years, additional exciting information has suggested that not only is subclinical infection responsible for preterm birth but also many serious neonatal sequelae including periventricular leukomalacia, cerebral palsy, respiratory distress, and even bronchopulmonary dysplasia and necrotizing enterocolitis. In sum, a large body of clinical and laboratory information suggests that subclinical infection is a major cause of preterm birth, especially those occurring before 30 weeks. This concept holds promise that new approaches can be developed to prevent prematurity.