Vaginal infection withUreaplasma urealyticumaccounts for preterm delivery via induction of inflammatory responses

Does vaginal bacterial colonization contribute to preterm birth in women with asymptomatic shortened cervix?

PURPOSE

The aim of this study is to describe the typical microbial spectrum and the influence of distinct vaginal infections on preterm birth in pregnancies affected by cervical incompetence.

METHODS

327 patients were admitted because of asymptomatic shortening of the cervix in the second and third trimester of pregnancy. Clinical data such as age, cervical length, gestational age at admission and at delivery and vaginal microbiologic findings were collected and analyzed.

RESULTS

The spectrum of germs in the vagina revealed seven different distinct species; the most common bacteria were Ureaplasma spp. and E. coli. In 327 included patients, 217 revealed a bacterial colonization, 110 did not. Most common bacteria in women with preterm birth before 34 weeks were Ureaplasma spp., while E. coli was most common in women undergoing preterm birth after 34 weeks. Nevertheless, the rates of occurrence of these bacterial taxa were not significantly different between who underwent preterm birth to those who did not.

CONCLUSIONS

This study gives an overview over the vaginal bacterial colonization in pregnant women with cervical incompetence. The clinical relevance of vaginal bacterial colonization remains unclear.

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

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

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..

Retrospective Analysis of the Ureaplasma spp. Prevalence with Reference to Other Genital Tract Infections in Women of Reproductive Age

Ureaplasma spp. are frequently isolated from the genital tract of women of reproductive age. To date, it remains unclear whether they are commensal or pathogenic. In our study, we assessed the prevalence of Ureaplasma spp. in a group of 1,155 women of childbearing age. In addition, we assessed how often women with positive Ureaplasma spp. develop genital tract co-infections and how the vaginal pH changes. This study showed a relationship between colonization by Ureaplasma spp. and presenting symptoms. In fact, we showed that colonization of the genital tract by Ureaplasma spp. can affect the occurrence of co-infections such as Gardnerella vaginalis. We also observed a relationship between increased pH values and the presence of Ureaplasma spp.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

PROSPERO REGISTRATION NUMBER

CRD42016050962.

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.

Neonatal Mycoplasma and Ureaplasma Infections

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

The earlier the gestational age, the greater the intensity of the intra-amniotic inflammatory response in women with preterm premature rupture of membranes and amniotic fluid infection by Ureaplasma species

Objectives To determine the relationship between the intensity of the intra-amniotic inflammatory response and the gestational age at the time of diagnosis in cases with preterm premature rupture of membranes (PROM) and intra-amniotic infection caused by Ureaplasma spp. Methods A retrospective cohort study was conducted which included 71 women with preterm PROM and a positive amniotic fluid culture with Ureaplasma spp. Women with mixed intra-amniotic infections were excluded. The study population was classified into three groups according to gestational age: group 1, <26 weeks (extreme preterm PROM, n = 17); group 2, 26.0-33.9 weeks (moderate preterm PROM, n = 39); group 3, 34.0-36.9 weeks (late preterm PROM, n = 15). The intensity of the intra-amniotic and maternal inflammatory response was compared among the three groups. The intensity of the intra-amniotic inflammatory response was assessed by the concentration of amniotic fluid matrix metalloproteinase-8 (MMP-8) and white blood cell (WBC) count. The maternal inflammatory response was assessed by the concentration of C-reactive protein (CRP) and WBC count in maternal blood at the time of amniocentesis. Results (1) The median values of amniotic fluid MMP-8 concentration and WBC count were the highest in the extreme preterm PROM group and the lowest in the late preterm PROM group (P < 0.001 and P = 0.01, respectively); (2) the intensity of the maternal inflammatory response measured by maternal blood WBC count and CRP concentration was not significantly associated with gestational age at the time of diagnosis. Conclusion The earlier the gestational age at the time of PROM, the higher the intensity of the intra-amniotic inflammatory response in women with preterm PROM and intra-amniotic infection caused by Ureaplasma spp.

Current understanding and treatment of intra-amniotic infection with Ureaplasma spp

Considerable evidence has shown that intra-amniotic infection with Ureaplasma spp. increases the risk of chorioamnionitis and preterm labor. Ureaplasma spp. are among the smallest organisms, and their isolation is uncommon in routine clinical practice because of their size and high auxotrophy. Although Ureaplasma spp. have been reported as causative agents of preterm birth, they also have a high incidence in vaginal swabs collected from healthy reproductive-age women; this has led to questions on the virulence of Ureaplasma spp. and to them being considered as harmless commensal bacteria. Therefore, many efforts have been made to clarify the pathogenicity of Ureaplasma spp. at the molecular level. Ureaplasma spp. are surrounded by lipoproteins, including multiple-banded antigen. Both multiple-banded antigen and its derivative, that is, the synthetic lipopeptide, UPM-1, induce an inflammatory response in a preterm mice model, which was adequate to cause preterm birth or stillbirth. In this review, we present an overview of the virulence mechanisms of Ureaplasma spp. and treatment of ureaplasma infection during pregnancy to prevent possible serious sequelae in infants. In addition, relevant mechanisms underlying antibiotic resistance in Ureaplasma spp. are discussed. Ureaplasma spp. are naturally resistant against β-lactam antibiotics because of the lack of a cell wall. Azithromycin is one of the effective agents that can control intrauterine ureaplasma infection. In fact, macrolide- and fluoroquinolone-resistant isolates of Ureaplasma spp. have already been observed in perinatal practice in Japan.

Vaginal Ureaplasma parvum serovars and spontaneous preterm birth

BACKGROUND

Ureaplasma species (spp) are the bacteria most often isolated from the amniotic cavity of women with preterm labor or preterm premature rupture of membranes; thus, the link between intrauterine Ureaplasma spp infection and adverse pregnancy outcome clearly is established. However, because vaginal Ureaplasma spp colonization is very common in pregnant women, the reason that these microorganisms cause ascending infections in some cases but remain asymptomatic in most pregnancies is not clear. Previous studies suggested an association between vaginal colonization with Ureaplasma parvum as opposed to U urealyticum and preterm delivery. However, because of the high frequency of vaginal Ureaplasma spp colonization during pregnancy, additional risk factors are needed to select a group of women who might benefit from treatment.

OBJECTIVE

To further identify pregnant women who are at increased risk for preterm delivery, the aim of the present study was to investigate U parvum serovar-specific pathogenicity in a large clinical cohort.

STUDY DESIGN

We serotyped 1316 samples that were positive for U parvum using a high-resolution melt polymerase chain reaction assay, and results were correlated with pregnancy outcome.

RESULTS

Within U parvum positive samples, serovar 3 was the most common isolate (43.3%), followed by serovar 6 (31.4%) and serovar 1 (25.2%). There was a significantly increased risk for spontaneous preterm birth at very low (<32 weeks gestation; P<.005) and extremely low (<28 weeks gestation; P<.005) gestational age in the group with vaginal U parvum serovar 3 colonization compared with the control group of pregnant women who tested negative for vaginal Ureaplasma spp colonization. This association was found for neither serovar 1 nor serovar 6. The combination of vaginal U parvum serovar 3 colonization and diagnosis of bacterial vaginosis in early pregnancy or a history of preterm birth further increased the risk for adverse pregnancy outcome.

CONCLUSION

Colonization with U parvum serovar 3, but not serovar 1 or serovar 6, in early pregnancy is associated with preterm delivery at very and extremely low gestational age. The combination of U parvum serovar 3 colonization and a history of preterm birth or bacterial vaginosis further increases the risk for spontaneous preterm birth at low gestational age and may define a target group for therapeutic intervention studies.

Trichomonas vaginalis Induces NLRP3 Inflammasome Activation and Pyroptotic Cell Death in Human Macrophages

Trichomonas vaginalis is a sexually transmitted, eukaryotic parasite that causes trichomoniasis, the most common nonviral, sexually transmitted disease in the USA and worldwide. Little is known about the molecular mechanisms involved in the host immune response to this widespread parasite. Here we report that T. vaginalis induces NLRP3 inflammasome activation in human macrophages, leading to caspase-1 activation and the processing of pro-IL-1β to the mature and bioactive form of the cytokine. Using inhibitor-based approaches, we show that NLRP3 activation by T. vaginalis involves host cell detection of extracellular ATP via P2X7 receptors and potassium efflux. In addition, our data reveal that T. vaginalis inflammasome activation induces macrophage inflammatory cell death by pyroptosis, known to occur via caspase-1 cleavage of the gasdermin D protein, which assembles to form pores in the host cell membrane. We found that T. vaginalis-induced cytolysis of macrophages is attenuated in gasdermin D knockout cells. Lastly, in a murine challenge model, we detected IL-1β production in vaginal fluids in response to T. vaginalis infection in vivo. Together, our findings mechanistically dissect how T. vaginalis contributes to the production of the proinflammatory IL-1β cytokine and uncover pyroptosis as a mechanism by which the parasite can trigger host macrophage cell death.

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

PROBLEM

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

METHOD OF STUDY

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

RESULTS

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

CONCLUSIONS

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

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

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

Mollicutes in vaginal microbiology: Mycoplasma hominis, Ureaplasma urealyticum, Ureaplasma parvum and Mycoplasma genitalium

Mycoplasma hominis was isolated in 1937 from the human genital tract, followed 17 years later by Ureaplasma urealyticum and 27 years after that by Mycoplasma genitalium. The first two proved relatively easy to culture but the latter required a polymerase chain reaction assay for further studies. In sexually mature women, M. hominis may be found in the vagina/cervix of about 20-50%, ureaplasmas in 40-80% and M. genitalium in 0-5%. Some heterogeneity has been found among strains of all these species, sufficient to divide ureaplasmas into two species, namely U. urealyticum and Ureaplasma parvum. Studies in female mice show that sex hormones have a profound influence on colonization, multiplication and persistence of mycoplasmas/ureaplasmas in the genital tract and provoke the question, unanswered, of whether there is such an effect in the human tract. In women, there is no evidence that any of the mycoplasmal species stimulate an inflammatory vaginitis. M. hominis organisms increase hugely in number in the case of bacterial vaginosis (BV), and to a lesser extent so do ureaplasmas. Despite this, they have not been incriminated as a sole cause of BV. Evidence for the involvement of M. genitalium remains controversial. The strong association of BV with preterm birth raises the possibility that the genital mycoplasmas might play a part, but assurance that any do will be difficult to obtain. Detailed examination of the vaginal microbiome has not yet provided an answer.

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.

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

OBJECTIVE

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

STUDY DESIGN

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

RESULTS

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

CONCLUSIONS

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

The role of Mycoplasma and Ureaplasma in adverse pregnancy outcomes

Genital mycoplasmas are frequently found in the vaginal flora across socioeconomic and ethnic groups and have been demonstrated to be involved in adverse perinatal outcomes. Both Mycoplasma and Ureaplasma spp cause inflammation potentially leading to spontaneous preterm birth and PPROM as well as postdelivery infectious complications and neonatal infections. Herein we have provided an overview of the existing literature and supportive evidence for genital mycoplasma's role in perinatal complications. Future research will need to focus on clearly delineating the species, allowing for discrimination of their effects.

Apoptosis in HEp-2 cells infected with Ureaplasma diversum

BACKGROUND

Bacterial pathogens have many strategies for infecting and persisting in host cells. Adhesion, invasion and intracellular life are important features in the biology of mollicutes. The intracellular location of Ureaplasma diversum may trigger disturbances in the host cell. This includes activation or inhibition of pro and anti-apoptotic factors, which facilitate the development of host damage. The aim of the present study was to associate U. diversum infection in HEp-2 cells and apoptosis induction. Cells were infected for 72hs with four U. diversum clinical isolates and an ATCC strain. The U. diversum invasion was analyzed by Confocal Laser Scanning Microscopy and gentamicin invasion assay. The apoptosis was evaluated using pro-apoptotic and anti-apoptotic gene expression, and FITC Annexin V/Dead Cell Apoptosis Kit.

RESULTS

The number of internalized ureaplasma in HEp-2 cells increased significantly throughout the infection. The flow cytometry analysis with fluorochromes to detect membrane depolarization and gene expression for caspase 2, 3 and 9 increased in infected cells after 24 hours. However, after 72 hours a considerable decrease of apoptotic cells was observed.

CONCLUSIONS

The data suggests that apoptosis may be initially induced by some isolates in association with HEp-2 cells, but over time, there was no evidence of apoptosis in the presence of ureaplasma and HEp-2 cells. The initial increase and then decrease in apoptosis could be related to bacterial pathogen-associated molecular pattern (PAMPS). Moreover, the isolates of U. diversum presented differences in the studied parameters for apoptosis. It was also observed that the amount of microorganisms was not proportional to the induction of apoptosis in HEp-2 cells.

Effects of Ureaplasma parvum lipoprotein multiple-banded antigen on pregnancy outcome in mice

Ureaplasma spp. are members of the family Mycoplasmataceae and have been considered to be associated with chorioamnionitis and preterm delivery. However, it is unclear whether Ureaplasma spp. have virulence factors related to these manifestations. The purpose of the present study was to determine whether the immunogenic protein multiple-banded antigen (MBA) from Ureaplasma parvum is a virulence factor for preterm delivery. We partially purified MBA from a type strain and clinical isolates of U. parvum, and also synthesized a diacylated lipopeptide derived from U. parvum, UPM-1. Using luciferase assays, both MBA-rich fraction MRF and UPM-1 activated the NF-κB pathway via TLR2. UPM-1 upregulated IL-1β, IL-6, IL-12p35, TNF-α, MIP2, LIX, and iNOS in mouse peritoneal macrophage. MRF or UPM-1 was injected into uteri on day 15 of gestation on pregnant C3H/HeN mice. The intrauterine MRF injection group had a significantly higher incidence of intrauterine fetal death (IUFD; 38.5%) than the control group (14.0%). Interestingly, intrauterine injection of UPM-1 caused preterm deliveries at high concentration (80.0%). In contrast, a low concentration of UPM-1 induced a significantly higher rate of fetal deaths (55.2%) than the control group (14.0%). The placentas of the UPM-1 injection group showed neutrophil infiltration and increased iNOS protein expression. Our data indicate that MBA from the clinical isolate of U. parvum is a potential virulence factor for IUFD and preterm delivery in mice and that the N-terminal diacylated lipopeptide is essential for the initiation of inflammation.

Ureaplasma urealyticum, Mycoplasma hominis and adverse pregnancy outcomes

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Ureaplasma bacteremia in very low birth weight infants in Brazil

OBJECTIVE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Mycoplasma mycoides, from "mycoides Small Colony" to "capri". A microevolutionary perspective

BACKGROUND

The Mycoplasma mycoides cluster consists of five species or subspecies that are ruminant pathogens. One subspecies, Mycoplasma mycoides subspecies mycoides Small Colony (MmmSC), is the causative agent of contagious bovine pleuropneumonia. Its very close relative, Mycoplasma mycoides subsp. capri (Mmc), is a more ubiquitous pathogen in small ruminants causing mastitis, arthritis, keratitis, pneumonia and septicaemia and is also found as saprophyte in the ear canal. To understand the genetics underlying these phenotypic differences, we compared the MmmSC PG1 type strain genome, which was already available, with the genome of an Mmc field strain (95010) that was sequenced in this study. We also compared the 95010 genome with the recently published genome of another Mmc strain (GM12) to evaluate Mmc strain diversity.

RESULTS

The MmmSC PG1 genome is 1,212 kbp and that of Mmc 95010 is ca. 58 kbp shorter. Most of the sequences present in PG1 but not 95010 are highly repeated Insertion Sequences (three types of IS) and large duplicated DNA fragments. The 95010 genome contains five types of IS, present in fewer copies than in PG1, and two copies of an integrative conjugative element. These mobile genetic elements have played a key role in genome plasticity, leading to inversions of large DNA fragments. Comparison of the two genomes suggested a marked decay of the PG1 genome that seems to be correlated with a greater number of IS. The repertoire of gene families encoding surface proteins is smaller in PG1. Several genes involved in polysaccharide metabolism and protein degradation are also absent from, or degraded in, PG1.

CONCLUSIONS

The genome of MmmSC PG1 is larger than that of Mmc 95010, its very close relative, but has less coding capacity. This is the result of large genetic rearrangements due to mobile elements that have also led to marked gene decay. This is consistent with a non-adaptative genomic complexity theory, allowing duplications or pseudogenes to be maintained in the absence of adaptive selection that would lead to purifying selection and genome streamlining over longer evolutionary times. These findings also suggest that MmmSC only recently adapted to its bovine host.