Extensive horizontal gene transfer in ureaplasmas from humans questions the utility of serotyping for diagnostic purposes

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.

Cervical HPV Infections, Sexually Transmitted Bacterial Pathogens and Cytology Findings-A Molecular Epidemiology Study

Prevalent cervical HPV infection and high-risk HPV persistence consequences have been extensively investigated in the literature; nevertheless, any causative interrelations of other sexually transmitted bacterial infections (STIs) with cervical HPV infection have not yet been fully elucidated. This study aimed to investigate the possible association of STIs with cervical cytology aberrations and HPV genotyping results in a representative sample of predominantly young Greek women. Liquid-based cytology and molecular detection for bacterial STIs and HPV as well as extended HPV genotyping were simultaneously assessed in cervical samples from 2256 individuals visiting several urban outpatient Gynecology Departments for well-woman visits or cervical screening throughout a 20-month period. All specimens were centrally processed with validated molecular assays. The mean age of the studied women was 37.0 ± 11.7 years; 722 women (33.30%) tested positive for STI (mean age 34.23 ± 10.87 years). A higher mean age (38.34 ± 11.83 years (p < 0.05)) was associated with negative STI testing. Chlamydia trachomatis was detected in 59 individuals (8.2%), Mycoplasma hominis in 156 (21.6%), Mycoplasma genitalium in 14 (1.9%), and Ureaplasma spp. in 555 (76.9%); infections with two bacterial pathogens were identified in 73 samples (10.1%). Cervical HPV was detected in 357 out of 1385 samples with a valid HPV typing result (25.8%). The mean age of HPV-positive women was 32.0 ± 8.4 years; individuals testing HPV-negative were slightly older (N = 1028): 34.4 ± 9.2 (p < 0.05). Among the 1371 individuals with valid results both for bacterial STIs and cervical HPV detection, women with an HPV-positive sample were more likely to harbor an STI (OR: 2.69, 95% CI 2.10-3.46, p < 0.05). Interestingly, bacterial STI positivity illustrated significant heterogeneity between NILM and LSIL cases, with 28.88% of NILM and 46.33% of LSIL cases harboring an STI, respectively (p < 0.05). In brief, in a population with a high prevalence for STIs, especially Ureaplasma spp., an association was documented between bacterial pathogen detection and cervical HPV infection, as well as abnormal cytology; these findings merit further investigation.

Development of a Rapid and High-Throughput Multiplex Real-Time PCR Assay for Mycoplasma hominis and Ureaplasma Species

Bacterial commensals of the human genitourinary tract, Mycoplasma hominis and Ureaplasma species (parvum and urealyticum) can be sexually transmitted, and may cause nongonococcal urethritis, pelvic inflammatory disease, and infertility. Mycoplasma hominis and Ureaplasma species may also cause severe invasive infections in immunocompromised patients. Current culture-based methods for Mycoplasma/Ureaplasma identification are costly and laborious, with a turnaround time between 1 and 2 weeks. We developed a high-throughput, real-time multiplex PCR assay for the rapid detection of M. hominis and Ureaplasma species in urine, genital swab, body fluid, and tissue. In total, 282 specimens were tested by PCR and compared with historic culture results; a molecular reference method was used to moderate discrepancies. Overall result agreement was 99% for M. hominis (97% positive percentage agreement and 100% negative percentage agreement) and 96% for Ureaplasma species (96% positive percentage agreement and 97% negative percentage agreement). Specimen stability was validated for up to 7 days at room temperature. This multiplex molecular assay was designed for implementation in a high-complexity clinical microbiology laboratory. With this method, >90 samples can be tested in one run, with a turnaround time of 4 to 5 hours from specimen extraction to reporting of results. This PCR test is also more labor effective and cheaper than the conventional culture-based test, thus improving laboratory efficiency and alleviating labor shortages.

Association between human papillomavirus infection and common sexually transmitted infections, and the clinical significance of different Mycoplasma subtypes

Introduction

Human papillomavirus (HPV) infection, especially persistent high-risk HPV, is associated with cervical cancer. Female reproductive tract microecological disorders and lower genital tract infections have been increasingly correlated with HPV infection and cervical lesions. Due to their common risk factors and transmission routes, coinfection with other sexually transmitted infections (STIs) has become a concern. Additionally, the clinical significance of Mycoplasma subtypes appear to vary. This study aimed to assess the correlations between common STIs and HPV infection, and to investigate the clinical significance of Mycoplasma subtypes.

Methods

We recruited 1,175 patients undergoing cervical cancer screening at the Peking University First Hospital gynecological clinic from March 2021 to February 2022 for vaginitis and cervicitis tests. They all received HPV genotyping and detection of STIs, and 749 of them underwent colposcopy and cervical biopsy.

Results

Aerobic vaginitis/desquamative inflammatory vaginitis and STIs (mainly single STIs) were found significantly more often in the HPV-positive group than in the HPV-negative group. Among patients with a single STI, rates of infection with herpes simplex virus type 2 or UP6 in the HPV-positive group were significantly higher than in the HPV-negative group (ORadj: 1.810, 95%CI: 1.211–2.705, P=0.004; ORadj: 11.032, 95%CI: 1.465–83.056, P=0.020, respectively).

Discussion

Through detailed Mycoplasma typing, a correlation was found between different Mycoplasma subtypes and HPV infection. These findings suggest that greater attention should be paid to detecting vaginal microecological disorders in those who are HPV-positive. Further, lower genital tract infections, including both vaginal infections and cervical STIs, are significantly more common among women who are HPV-positive and who thus require more thorough testing. Detailed typing and targeted treatment of Mycoplasma should become more routine in clinical practice.

Prevalence and Load of Cervical Ureaplasma Species With Respect to Intra-amniotic Complications in Women With Preterm Prelabor Rupture of Membranes Before 34 weeks

Objectives: To determine the prevalence and load of Ureaplasma spp. DNA in the cervical fluid of women with singleton pregnancies complicated by preterm prelabor rupture of membranes (PPROM) with respect to intra-amniotic infection, sterile intra-amniotic inflammation, and colonization of the amniotic fluid.

Methods: A total of 217 women with PPROM between gestational ages 24 + 0 and 33 + 6 weeks were included in this study. Paired amniotic and cervical fluid samples were collected at the time of admission via transabdominal amniocentesis and using a Dacron polyester swab, respectively. Microbial invasion of the amniotic cavity was diagnosed using a combination of culture and molecular biology methods. Intra-amniotic inflammation was determined based on the concentration of interleukin-6 in the amniotic fluid. Based on the presence or absence of these conditions, the women were stratified into the following subgroups: intra-amniotic infection (with both), sterile intra-amniotic inflammation (with inflammation only), colonization (with microorganisms only), and negative amniotic fluid (without either). The Ureaplasma spp. DNA load in the cervical fluid was assessed using PCR.

Results:Ureaplasma spp. DNA in the cervical fluid was found in 61% (133/217) of the women. Women with negative amniotic had similar prevalence of Ureaplasma spp. DNA in cervical fluid (55%) to those with sterile intra-amniotic inflammation (54%) but lower than those with intra-amniotic infection (73%) and colonization (86%; p < 0.0001). Women with negative amniotic fluid had a lower load of Ureaplasma spp. DNA in their cervical fluid (median: 4.7 × 10³ copies of DNA/ml) than those with intra-amniotic infection (median: 2.8 × 10⁵ copies DNA/ml), sterile intra-amniotic inflammation (median: 5.3 × 10⁴ copies DNA/ml), and colonization (median: 1.2 × 10⁵ copies DNA/mL; p < 0.0001).

Conclusion: In conclusion, in PPROM at <34 weeks, the presence of intra-amniotic infection, sterile intra-amniotic inflammation, or colonization of the amniotic fluid was associated with a higher prevalence and/or load of Ureaplasma spp. DNA in the cervical fluid than the absence of intra-amniotic complications.

Genome mosaicism in field strains of Mycoplasma bovis as footprints of in-host horizontal chromosomal transfer

Horizontal gene transfer was long thought to be marginal in Mollicutes, but the capacity of some of these wall-less bacteria to exchange large chromosomal regions has been recently documented. Mycoplasma chromosomal transfer (MCT) is an unconventional mechanism that relies on the presence of a functional integrative conjugative element (ICE) in at least one partner and involves the horizontal acquisition of small and large chromosomal fragments from any part of the donor genome, which results in progenies composed of an infinitive variety of mosaic genomes. The present study focuses on Mycoplasma bovis, an important pathogen of cattle responsible for major economic losses worldwide. By combining phylogenetic tree reconstructions and detailed comparative genome analyses of 36 isolates collected in Spain (2016-2018) we confirmed the mosaic nature of 16 field isolates and mapped chromosomal transfers exchanged between their hypothetical ancestors. This study provides evidence that MCT can take place in the field, most likely during co-infections by multiple strains. Because mobile genetic elements (MGEs) are classical contributors of genome plasticity, the presence of phages, insertion sequences (ISs) and ICEs was also investigated. Data revealed that these elements are widespread within the M. bovis species and evidenced classical horizontal transfer of phages and ICEs in addition to MCT. These events contribute to wide-genome diversity and reorganization within this species and may have a tremendous impact on diagnostic and disease control. IMPORTANCE Mycoplasma bovis is a major pathogen of cattle with significant detrimental economic and animal welfare on cattle rearing worldwide. Understanding the evolution and the adaptative potential of pathogenic mycoplasma species in the natural host is essential to combating them. In this study, we documented the occurrence of mycoplasma chromosomal transfer, an atypical mechanism of horizontal gene transfer, in field isolates of M. bovis that provide new insights into the evolution of this pathogenic species in their natural host. Despite these events are expected to occur at low frequency, their impact is accountable for genome-wide variety and reorganization within M. bovis species, which may compromise both diagnostic and disease control.

A requirement for flow to enable the development of Ureaplasma parvum biofilms in vitro

AIMS

To use a flow-based method to establish, quantify and visualize biofilms of Ureaplasma parvum.

METHODS AND RESULTS

Absorbance readings of a U. parvum HPA5 culture were taken at 550 nm every 3 h for 30 h in order to establish a growth curve, with viability determined by the number of colour changing units (CCUs). Biofilms were established using the DTU flow-cell with a flow rate of 0·01 ml min^-1 and compared to the static control. Titres of bacteria were determined by CCU and biofilm biomass was quantified by Syto9 staining and COMSTAT analysis. High-resolution images were obtained by scanning electron microscopy (SEM). Flow resulted in significantly more biofilm and higher cell titre (0·599 µm³ /µm²  ± 0·152 and 4 × 10⁸  CCU per ml, respectively) compared with static conditions (0·008 µm³ /µm²  ± 0·010 and no recoverable cells, respectively). SEM revealed pleomorphic cells, with signs of budding and possible membrane vesicle formation.

CONCLUSIONS

Flow is an essential requirement for the establishment of U. parvum biofilms.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first quantification of biofilm biomass formed by U. parvum. It is now possible to establish viable biofilms of U. parvum which will allow for future testing of antimicrobial agents and understanding of virulence-associated with adhesion.

Are Mycoplasma hominis, Ureaplasma urealyticum and Ureaplasma parvum associated with specific genital symptoms and clinical signs in non-pregnant women?

BACKGROUND

There is limited evidence supporting an association between Mycoplasma hominis, Ureaplasma urealyticum and Ureaplasma parvum and symptoms or disease in non-pregnant women. However, testing and reporting of these organisms frequently occurs, in-part due to their inclusion in multiplex-PCR assays for sexually transmitted infection (STI) detection. We investigated if M. hominis, U. urealyticum and U. parvum were associated with symptoms and/or signs in non-pregnant women attending a sexual health service.

METHODS

Eligible women attending Melbourne Sexual Health Centre completed a questionnaire regarding sexual practices and symptoms. Symptomatic women underwent examination. Women were assessed for bacterial vaginosis (BV) and vulvovaginal candidiasis (VVC), and tested for M. hominis, U. urealyticum and U. parvum, and four non-viral STIs using a commercial multiplex-PCR.

RESULTS

1,272 women were analysed. After adjusting for STIs and VVC, M. hominis was associated with abnormal vaginal discharge (aOR=2.70, 95%CI:1.92-3.79), vaginal malodour (aOR=4.27, 95%CI:3.08-5.91), vaginal pH>4.5 (aOR=4.27, 95%CI:3.22-5.66) and presence of clue cells (aOR=8.08, 95%CI:5.68-11.48). Ureaplasma spp. were not associated with symptoms/signs. BV was strongly associated with M. hominis (aOR=8.01, 95%CI:5.99-10.71), but was not associated with either Ureaplasma spp. In stratified analyses, M. hominis was associated with self-reported vaginal malodour and clinician-recorded vaginal discharge in women with BV, but not with symptoms/signs in women without BV.

CONCLUSION

Only M. hominis was associated with symptoms/signs, and these were manifestations of BV. Importantly, M. hominis was not associated with symptoms/signs in women without BV. These findings do not support routine testing for M. hominis, U. urealyticum and U. parvum in non-pregnant women.

Detection of Ureaplasma Biovars and Subtyping of Ureaplasma parvum among Women Referring to a University Hospital in Morocco

Objectives

The aim of this study was to determine the prevalence of Ureaplasma biovars and Ureaplasma parvum (U. parvum) serovars, their associated risk factors, and genital STI-related symptoms.

Methods

DNA obtained from cervical samples of 1053 women attending the department of Obstetrics and Gynecology and the laboratory of pathological anatomy of Hassan II university hospital of Fez, Morocco, was used to detect Ureaplasma biovars (U. urealyticum and U. parvum) and to subtype U. parvum by polymerase chain reaction (PCR).

Results

Of the 1053 women examined, 25.4% (268/1053) were Ureaplasma positives. The rates of U. urealyticum and U. parvum were 12.1% (128/1053) and 7% (74/1053), respectively, and the copresence of these biovars was noted in 6.3% (66/1053) cases. The U. parvum subtyping revealed a predominance of the serovar 3/14 (61.4%). The association of demographics variables with Ureaplasma biovars was studied and shows that the age (“<30” years) seems to be a risk factor of Ureaplasma spp. and U. urealyticum carriage (OR 1.729, 95% CI [1.113-2.687] and OR 1.848, 95% CI [1.026-3.330], respectively). There was no difference in the prevalence of Ureaplasma type regarding symptoms. However, a significant association was found between U. parvum serovar 1 and infertility (P = 0.011).

Conclusion

This first study conducted in Morocco provides an idea on Ureaplasma biovars and U. parvum serovars circulating in this region, their associated risk factors, and genital STI-related symptoms. Therefore, further studies are required to clarify and confirm the pathogenic role of these Ureaplasma species.

Ureaplasma species and preterm birth: current perspectives

Preterm birth is the leading cause of neonatal morbidity and mortality worldwide, and the human Ureaplasma species are most frequently isolated from the amniotic fluid and placenta in these cases. Ureaplasma colonisation is associated with infertility, stillbirth, histologic chorioamnionitis, and neonatal morbidities, including congenital pneumonia, bronchopulmonary dysplasia, meningitis and perinatal death. The human Ureaplasma spp. are separated into Ureaplasma urealyticum and Ureaplasma parvum with 14 known serotypes. The small genome has several genes, which code for surface proteins; most significantly the Multiple Banded Antigen (MBA) where an antigenic C-terminal domain elicits a host antibody response. Other genes code for various virulence factors such as IgA protease and urease. Ureaplasma spp. infection is diagnosed by culture and polymerase chain reaction (PCR) and commercial assays are available to improve turnaround time. Microbroth dilution assays are routinely used to test antimicrobial susceptibility of clinical Ureaplasma spp. especially against doxycycline, azithromycin, ofloxacin and josamycin. Resistance to macrolides, fluoroquinolones and tetracyclines has been reported. A concise review of Ureaplasma spp. and their role in pregnancy outcomes, especially preterm birth, offers insight into the early diagnosis and appropriate antibiotic therapy to prevent long-term complications of Ureaplasma spp. infections.

Comparative genomics of three clinical Ureaplasma species: analysis of their core genomes and multiple-banded antigen locus

Aim: To compare the genome sequences among clinical and American-Type Culture Collection Ureaplasma strains and to reveal the potential molecular mechanisms of multiple banded antigen (MBA) variation. Materials & methods: Two strains of Ureaplasma urealyticum 132 and 315 and one strain of Ureaplasma parvum 106 isolated from infertile males were sequenced using Illumina and Nanopore technologies. Comparative genomic analysis was performed of the three strains and two American-Type Culture Collection strains. Results & conclusion: The Ureaplasma species shared a core genome. Strains 132 and 315 shared a distant relationship with previously sequenced Ureaplasma spp. The MBA locus is more informative for studying MBA mutations than is the mba gene alone. The mechanisms of MBA variation are more flexible and complex than previously reported. The variation in MBA is not limited to the mba gene but occurs in other genes within the MBA locus.

Mycoplasma Chromosomal Transfer: A Distributive, Conjugative Process Creating an Infinite Variety of Mosaic Genomes

The capacity of Mycoplasmas to engage in horizontal gene transfers has recently been highlighted. Despite their small genome, some of these wall-less bacteria are able to exchange multiple, large portions of their chromosome via a conjugative mechanism that does not conform to canonical Hfr/oriT models. To understand the exact features underlying mycoplasma chromosomal transfer (MCT), extensive genomic analyses were performed at the nucleotide level, using individual mating progenies derived from our model organism, Mycoplasma agalactiae. Genome reconstruction showed that MCT resulted in the distributive transfer of multiple chromosomal DNA fragments and generated progenies composed of a variety of mosaic genomes, each being unique. Analyses of macro- and micro-events resulting from MCT revealed that the vast majority of the acquired fragments were unrelated and co-transferred independently from the selection marker, these resulted in up to 17% of the genome being exchanged. Housekeeping and accessory genes were equally affected by MCT, with up to 35 CDSs being gained or lost. This efficient HGT process also created a number of chimeric genes and genetic micro-variations that may impact gene regulation and/or expression. Our study unraveled the tremendous plasticity of M. agalactiae genome and point toward MCT as a major player in diversification and adaptation to changing environments, offering a significant advantage to this minimal pathogen.

Aetiology and prevalence of mixed-infections and mono-infections in non-gonococcal urethritis in men: a case-control study

OBJECTIVES

Chlamydia trachomatis (CT) and Mycoplasma genitalium (MG) cause the majority of non-gonococcal urethritis (NGU). The role of Ureaplasma urealyticum (UU) in NGU is unclear. Prior case-control studies that examined the association of UU and NGU may have been confounded by mixed infections and less stringent criteria for controls. The objective of this case-control study was to determine the prevalence and aetiology of mixed infections in men and assess if UU monoinfection is associated with NGU.

METHODS

We identified 155 men with NGU and 103 controls. Behavioural and clinical information was obtained and men were tested for Neisseria gonorrhoeae and CT, MG, UU and Trichomonas vaginalis (TV). Men who were five-pathogen negative were classified as idiopathic urethritis (IU).

RESULTS

Twelve per cent of NGU cases in which a pathogen was identified had mixed infections, mostly UU coinfections with MG or CT; 27% had IU. In monoinfected NGU cases, 34% had CT, 17% had MG, 11% had UU and 2% had TV. In controls, pathogens were rarely identified, except for UU, which was present in 20%. Comparing cases and controls, NGU was associated with CT and MG monoinfections and mixed infections. UU monoinfection was not associated with NGU and was almost twice as prevalent in controls. Men in both the case and control groups who were younger and who reported no prior NGU diagnosis were more likely to have UU (OR 0.97 per year of age, 95% CI 0.94 to 0.998 and OR 6.3, 95% CI 1.4 to 28.5, respectively).

CONCLUSIONS

Mixed infections are common in men with NGU and most of these are UU coinfections with other pathogens that are well-established causes of NGU. UU monoinfections are not associated with NGU and are common in younger men and men who have never previously had NGU. Almost half of NGU cases are idiopathic.

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.

Differential modulation of pulmonary caspases: Is this the key to Ureaplasma-driven chronic inflammation?

Although accepted agents in chorioamnionitis and preterm birth, the role of Ureaplasma species (spp.) in inflammation-driven morbidities of prematurity, including the development of bronchopulmonary dysplasia, remains controversial. To add to scarce in vitro data addressing the pro-inflammatory capacity of Ureaplasma spp., pulmonary epithelial-like A549 cells and human pulmonary microvascular endothelial cells (HPMEC) were incubated with Ureaplasma (U.) urealyticum, U. parvum, and Escherichia coli lipopolysaccharide (LPS). Ureaplasma isolates down-regulated caspase mRNA levels in A549 cells (caspase 8: p<0.001, 9: p<0.001, vs. broth), while increasing caspase protein expression, enzyme activity, and cell death in HPMEC (active caspase 3: p<0.05, caspase 8: p<0.05, active caspase 9: p<0.05, viability: p<0.05). LPS, contrarily, induced caspase mRNA expression in HPMEC (caspase 3: p<0.01, 4: p<0.001, 5: p<0.001, 8: p<0.001, vs. control), but not in A549 cells, and did not affect enzyme activity or protein levels in either cell line. LPS, but neither Ureaplasma isolate, enhanced mRNA expression of pro-inflammatory interleukin (IL)-6 in both A549 (p<0.05, vs. control) and HPMEC (p<0.001) as well as tumor necrosis factor-α (p<0.01), IL-1β (p<0.001), and IL-8 (p<0.05) in HPMEC. We are therefore the first to demonstrate a differential modulation of pulmonary caspases by Ureaplasma spp. in vitro. Ureaplasma-driven enhanced protein expression and activity of caspases in pulmonary endothelial cells result in cell death and may cause structural damage. Down-regulated caspase mRNA in pulmonary epithelial cells, contrarily, may indicate Ureaplasma-induced inhibition of apoptosis and prevent effective immune responses. Both may ultimately contribute to chronic Ureaplasma colonization and long-term pulmonary inflammation.

Ureaplasma diversum protein interaction networks: evidence of horizontal gene transfer and evolution of reduced genomes among Mollicutes

Ureaplasma diversum is a member of the Mollicutes class responsible for urogenital tract infection in cattle and small ruminants. Studies indicate that the process of horizontal gene transfer, the exchange of genetic material among different species, has a crucial role in mollicute evolution, affecting the group's characteristic genomic reduction process and simplification of metabolic pathways. Using bioinformatics tools and the STRING database of known and predicted protein interactions, we constructed the protein-protein interaction network of U. diversum and compared it with the networks of other members of the Mollicutes class. We also investigated horizontal gene transfer events in subnetworks of interest involved in purine and pyrimidine metabolism and urease function, chosen because of their intrinsic importance for host colonization and virulence. We identified horizontal gene transfer events among Mollicutes and from Ureaplasma to Staphylococcus aureus and Corynebacterium, bacterial groups that colonize the urogenital niche. The overall tendency of genome reduction and simplification in the Mollicutes is echoed in their protein interaction networks, which tend to be more generalized and less selective. Our data suggest that the process was permitted (or enabled) by an increase in host dependence and the available gene repertoire in the urogenital tract shared via horizontal gene transfer.

Perinatal Ureaplasma Exposure Is Associated With Increased Risk of Late Onset Sepsis and Imbalanced Inflammation in Preterm Infants and May Add to Lung Injury

Background: Controversy remains concerning the impact of Ureaplasma on preterm neonatal morbidity.

Methods: Prospective single-center study in very low birth weight infants <30 weeks' gestation. Cord blood and initial nasopharyngeal swabs were screened for Ureaplasma parvum and U. urealyticum using culture technique and polymerase chain reaction. Neonatal outcomes were followed until death or discharge. Multi-analyte immunoassay provided cord blood levels of inflammatory markers. Using multivariate regression analyses, perinatal Ureaplasma exposure was evaluated as risk factor for the development of bronchopulmonary dysplasia (BPD), other neonatal morbidities until discharge and systemic inflammation at admission.

Results: 40/103 (39%) infants were positive for Ureaplasma in one or both specimens, with U. parvum being the predominant species. While exposure to Ureaplasma alone was not associated with BPD, we found an increased risk of BPD in Ureaplasma-positive infants ventilated ≥5 days (OR 1.64; 95% CI 0.12–22.98; p = 0.009). Presence of Ureaplasma was associated with a 7-fold risk of late onset sepsis (LOS) (95% CI 1.80–27.39; p = 0.014). Moreover, Ureaplasma-positive infants had higher I/T ratios (b 0.39; 95% CI 0.08–0.71; p = 0.014), increased levels of interleukin (IL)-17 (b 0.16; 95% CI 0.02–0.30; p = 0.025) and matrix metalloproteinase 8 (b 0.77; 95% CI 0.10–1.44; p = 0.020), decreased levels of IL-10 (b −0.77; 95% CI −1.58 to −0.01; p = 0.043) and increased ratios of Tumor necrosis factor-α, IL-8, and IL-17 to anti-inflammatory IL-10 (p = 0.003, p = 0.012, p < 0.001).

Conclusions: Positive Ureaplasma screening was not associated with BPD. However, exposure contributed to BPD in infants ventilated ≥5 days and conferred an increased risk of LOS and imbalanced inflammatory cytokine responses.

Detection of Ureaplasma spp. serovars in genital tract of infertile males

BACKGROUND

The colonization of Ureaplasma species in genital tract is related with male infertility. However, it has been postulated based upon limited study that virulence is related to serotype specificity. The aim of this study was to determine the distribution of Ureaplasma serovars in genital tract of infertile males and analyze their role in male infertility.

METHODS

A total of 358 urethral swabs samples were obtained from infertile males. The culture of Ureaplasma species were performed using a commercially available Mycoplasma IST 2 kit. Serovars were determined by real-time polymerase chain reaction (real-time PCR).

RESULTS

A total of 92 (25.7%) infertile males were positive for Ureaplasma spp; among them, Ureaplasma parvum (UPA) was detected in 73 (79.3%) isolates, and Ureaplasma urealyticum (UUR) was detected in 19 (20.7%) isolates. Serovars 1, 6, or in combination accounted for 63.0% (46/73) of UPA isolates. Serovar 9 (alone and in combination of other serovars) was the most common serovar in UUR (47.4%, 9/19). Multiple serovars were detected in 21 (22.8%) isolates, and serovars 4, 5, 7, and 12 were not detected in any sample.

CONCLUSION

The distribution of 14 Ureaplasma serovars in genital tract of infertile males was identified for the first time by real-time PCR assay. UPA serovars 1 and 6, and UUR serovar 9 are the most common serovars colonization in urogenital tract of infertile males.

Mycoplasmas under experimental antimicrobial selection: The unpredicted contribution of horizontal chromosomal transfer

Horizontal Gene Transfer was long thought to be marginal in Mycoplasma a large group of wall-less bacteria often portrayed as minimal cells because of their reduced genomes (ca. 0.5 to 2.0 Mb) and their limited metabolic pathways. This view was recently challenged by the discovery of conjugative exchanges of large chromosomal fragments that equally affected all parts of the chromosome via an unconventional mechanism, so that the whole mycoplasma genome is potentially mobile. By combining next generation sequencing to classical mating and evolutionary experiments, the current study further explored the contribution and impact of this phenomenon on mycoplasma evolution and adaptation using the fluoroquinolone enrofloxacin (Enro), for selective pressure and the ruminant pathogen Mycoplasma agalactiae, as a model organism. For this purpose, we generated isogenic lineages that displayed different combination of spontaneous mutations in Enro target genes (gyrA, gyrB, parC and parE) in association to gradual level of resistance to Enro. We then tested whether these mutations can be acquired by a susceptible population via conjugative chromosomal transfer knowing that, in our model organism, the 4 target genes are scattered in three distinct and distant loci. Our data show that under antibiotic selective pressure, the time scale of the mutational pathway leading to high-level of Enro resistance can be readily compressed into a single conjugative step, in which several EnroR alleles were transferred from resistant to susceptible mycoplasma cells. In addition to acting as an accelerator for antimicrobial dissemination, mycoplasma chromosomal transfer reshuffled genomes beyond expectations and created a mosaic of resistant sub-populations with unpredicted and unrelated features. Our findings provide insights into the process that may drive evolution and adaptability of several pathogenic Mycoplasma spp. via an unconventional conjugative mechanism.

A novel mba-based Real time PCR approach for genotyping of Ureaplasma parvum validated in a cohort of Mongolian mothers and offspring

The role of Ureaplasma parvum in abnormal outcomes of human pregnancy has been discussed controversially in the past. Of the 14 known ureaplasma serovars, the Ureaplasma parvum serovars 1, 3, 6 and 14, have been found to derive from smaller genomes. Serovars 3 and 6 have been described more often to cause complications in pregnancy. To elucidate the serovar distribution in U. parvum positive specimens of 200 Mongolian mothers and their offspring, a new set of mba-targeting PCRs was developed enabling a fast and reliable serovar differentiation by melting peak analysis in a Real time PCR approach or by conventional agarose gel electrophoresis. 92% maternal and 55% neonatal samples were retrospectively genotyped and a dominance of serovars 3 and 6 was detected while serovar 14 was almost absent. Transmission from mothers to newborns was detected in 83% of U. parvum positive neonates exhibiting serovar patterns identical to their mothers. No statistically significant correlation between a distinct serovar and pregnancy outcome could be detected. However, neonatal colonization with serovar 1 declined with progressing pregnancy suggesting that a higher ureaplasma load shortened pregnancy and thereby had a potential negative effect on offspring health. Our novel mba-based Real time PCR approach, which can also be used in conventional PCR and gel electrophoretic analysis, provides the proof of principle that the four U. parvum serovars 1, 3, 6 and 14 can be differentially detected and quantified. A larger scale study outside the scope of this work should be conducted to clarify the impact of serovar 1 on pregnancy outcome.

Ureaplasma urealyticum and U. parvum in sexually active women attending public health clinics in Brazil

Ureaplasma urealyticum and U. parvum have been associated with genital infections. The purpose of this study was to detect the presence of ureaplasmas and other sexually transmitted infections in sexually active women from Brazil and relate these data to demographic and sexual health, and cytokines IL-6 and IL-1β. Samples of cervical swab of 302 women were examined at the Family Health Units in Vitória da Conquista. The frequency of detection by conventional PCR was 76·2% for Mollicutes. In qPCR, the frequency found was 16·6% for U. urealyticum and 60·6% U. parvum and the bacterial load of these microorganisms was not significantly associated with signs and symptoms of genital infection. The frequency found for Trichomonas vaginalis, Neisseria gonorrhoeae, Gardnerella vaginalis and Chlamydia trachomatis was 3·0%, 21·5%, 42·4% and 1·7%, respectively. Higher levels of IL-1β were associated with control women colonized by U. urealyticum and U. parvum. Increased levels of IL-6 were associated with women who exhibited U. parvum. Sexually active women, with more than one sexual partner in the last 3 months, living in a rural area were associated with increased odds of certain U. parvum serovar infection.

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.

Neonatal CNS infection and inflammation caused by Ureaplasma species: rare or relevant?

Colonization with Ureaplasma species has been associated with adverse pregnancy outcome, and perinatal transmission has been implicated in the development of bronchopulmonary dysplasia in preterm neonates. Little is known about Ureaplasma-mediated infection and inflammation of the CNS in neonates. Controversy remains concerning its incidence and implication in the pathogenesis of neonatal brain injury. In vivo and in vitro data are limited. Despite improving care options for extremely immature preterm infants, relevant complications remain. Systematic knowledge of ureaplasmal infection may be of great benefit. This review aims to summarize pathogenic mechanisms, clinical data and diagnostic pitfalls. Studies in preterm and term neonates are critically discussed with regard to their limitations. Clinical questions concerning therapy or prophylaxis are posed. We conclude that ureaplasmas may be true pathogens, especially in preterm neonates, and may cause CNS inflammation in a complex interplay of host susceptibility, serovar pathogenicity and gestational age-dependent CNS vulnerability.

Molecular biology of mycoplasmas: from the minimum cell concept to the artificial cell

ABSTRACT Mycoplasmas are a large group of bacteria, sorted into different genera in the Mollicutes class, whose main characteristic in common, besides the small genome, is the absence of cell wall. They are considered cellular and molecular biology study models. We present an updated review of the molecular biology of these model microorganisms and the development of replicative vectors for the transformation of mycoplasmas. Synthetic biology studies inspired by these pioneering works became possible and won the attention of the mainstream media. For the first time, an artificial genome was synthesized (a minimal genome produced from consensus sequences obtained from mycoplasmas). For the first time, a functional artificial cell has been constructed by introducing a genome completely synthesized within a cell envelope of a mycoplasma obtained by transformation techniques. Therefore, this article offers an updated insight to the state of the art of these peculiar organisms' molecular biology.

Found and Lost: The Fates of Horizontally Acquired Genes in Arthropod-Symbiotic Spiroplasma

Horizontal gene transfer (HGT) is an important mechanism that contributed to biological diversity, particularly in bacteria. Through acquisition of novel genes, the recipient cell may change its ecological preference and the process could promote speciation. In this study, we determined the complete genome sequence of two Spiroplasma species for comparative analyses and inferred the putative gene gains and losses. Although most Spiroplasma species are symbionts of terrestrial insects, Spiroplasma eriocheiris has evolved to be a lethal pathogen of freshwater crustaceans. We found that approximately 7% of the genes in this genome may have originated from HGT and these genes expanded the metabolic capacity of this organism. Through comparison with the closely related Spiroplasma atrichopogonis, as well as other more divergent lineages, our results indicated that these HGT events could be traced back to the most recent common ancestor of these two species. However, most of these horizontally acquired genes have been pseudogenized in S. atrichopogonis, suggesting that they did not contribute to the fitness of this lineage that maintained the association with terrestrial insects. Thus, accumulation of small deletions that disrupted these foreign genes was not countered by natural selection. On the other hand, the long-term survival of these horizontally acquired genes in the S. eriocheiris genome hinted that they might play a role in the ecological shift of this species. Finally, the implications of these findings and the conflicts among gene content, 16S rRNA gene sequencing, and serological typing, are discussed in light of defining bacterial species.

The Maternal Serological Response to Intrauterine Ureaplasma sp. Infection and Prediction of Risk of Pre-Term Birth

Pre-term birth (PTB) associated with intrauterine infection and inflammation (IUI) is the major cause of early PTB less than 32 weeks of gestation. Ureaplasma spp. are common commensals of the urogenital tract in pregnancy and are the most commonly identified microorganisms in amniotic fluid of pre-term pregnancies. While we have an understanding of the causal relationship between intra-amniotic infection, inflammation and PTB, we are still unable to explain why vaginal Ureaplasma sp. colonization is tolerated in some women but causes PTB in others. It is now known that placental tissues are frequently colonized by bacteria even in apparently healthy pregnancies delivered at term; usually this occurs in the absence of a significant local inflammatory response. It appears, therefore, that the site, nature, and magnitude of the immune response to infiltrating microorganisms are key in determining pregnancy outcome. Some evidence exists that the maternal serological response to Ureaplasma sp. colonization may be predictive of adverse pregnancy outcome, although issues such as the importance of virulence factors (serovars) and the timing, magnitude, and functional consequences of the immune response await clarification. This mini-review discusses the evidence linking the maternal immune response to risk of PTB and the potential applications of maternal serological analysis for predicting obstetric outcome.

Chromosomal transfers in mycoplasmas: when minimal genomes go mobile

Horizontal gene transfer (HGT) is a main driving force of bacterial evolution and innovation. This phenomenon was long thought to be marginal in mycoplasmas, a large group of self-replicating bacteria characterized by minute genomes as a result of successive gene losses during evolution. Recent comparative genomic analyses challenged this paradigm, but the occurrence of chromosomal exchanges had never been formally addressed in mycoplasmas. Here, we demonstrated the conjugal transfer of large chromosomal regions within and among ruminant mycoplasma species, with the incorporation of the incoming DNA occurring by homologous recombination into the recipient chromosome. By combining classical mating experiments with high-throughput next-generation sequencing, we documented the transfer of almost every position of the mycoplasma chromosome. Mycoplasma conjugation relies on the occurrence of an integrative conjugative element (ICE) in at least one parent cell. While ICE propagates horizontally from ICE-positive to ICE-negative cells, chromosomal transfers (CTs) occurred in the opposite direction, from ICE-negative to ICE-positive cells, independently of ICE movement. These findings challenged the classical mechanisms proposed for other bacteria in which conjugative CTs are driven by conjugative elements, bringing into the spotlight a new means for rapid mycoplasma innovation. Overall, they radically change our current views concerning the evolution of mycoplasmas, with particularly far-reaching implications given that over 50 species are human or animal pathogens.

Horizontal gene transfers (HGT) shape bacterial genomes and are key contributors to microbial diversity and innovation. One main mechanism involves conjugation, a process that allows the simultaneous transfer of significant amounts of DNA upon cell-to-cell contact. Recognizing and deciphering conjugal mechanisms are thus essential in understanding the impact of gene flux on bacterial evolution. We addressed this issue in mycoplasmas, the smallest and simplest self-replicating bacteria. In these organisms, HGT was long thought to be marginal. We showed here that nearly every position of the Mycoplasma agalactiae chromosome could be transferred via conjugation, using an unconventional mechanism. The transfer involved DNA blocks containing up to 80 genes that were incorporated into the host chromosome by homologous recombination. These findings radically change our views concerning mycoplasma evolution and adaptation with particularly far-reaching implications given that over 50 species are human or animal pathogens.

Ureaplasma parvum undergoes selection in utero resulting in genetically diverse isolates colonizing the chorioamnion of fetal sheep

Ureaplasmas are the microorganisms most frequently isolated from the amniotic fluid of pregnant women and can cause chronic intrauterine infections. These tiny bacteria are thought to undergo rapid evolution and exhibit a hypermutatable phenotype; however, little is known about how ureaplasmas respond to selective pressures in utero. Using an ovine model of chronic intraamniotic infection, we investigated if exposure of ureaplasmas to subinhibitory concentrations of erythromycin could induce phenotypic or genetic indicators of macrolide resistance. At 55 days gestation, 12 pregnant ewes received an intraamniotic injection of a nonclonal, clinical Ureaplasma parvum strain followed by (i) erythromycin treatment (intramuscularly, 30 mg/kg/day, n = 6) or (ii) saline (intramuscularly, n = 6) at 100 days gestation. Fetuses were then delivered surgically at 125 days gestation. Despite injecting the same inoculum into all the ewes, significant differences between amniotic fluid and chorioamnion ureaplasmas were detected following chronic intraamniotic infection. Numerous polymorphisms were observed in domain V of the 23S rRNA gene of ureaplasmas isolated from the chorioamnion (but not the amniotic fluid), resulting in a mosaiclike sequence. Chorioamnion isolates also harbored the macrolide resistance genes erm(B) and msr(D) and were associated with variable roxithromycin minimum inhibitory concentrations. Remarkably, this variability occurred independently of exposure of ureaplasmas to erythromycin, suggesting that low-level erythromycin exposure does not induce ureaplasmal macrolide resistance in utero. Rather, the significant differences observed between amniotic fluid and chorioamnion ureaplasmas suggest that different anatomical sites may select for ureaplasma subtypes within nonclonal, clinical strains. This may have implications for the treatment of intrauterine ureaplasma infections.

Suppression of antimicrobial peptide expression by ureaplasma species

Ureaplasma species commonly colonize the adult urogenital tract and are implicated in invasive diseases of adults and neonates. Factors that permit the organisms to cause chronic colonization or infection are poorly understood. We sought to investigate whether host innate immune responses, specifically, antimicrobial peptides (AMPs), are involved in determining the outcome of Ureaplasma infections. THP-1 cells, a human monocytoid tumor line, were cocultured with Ureaplasma parvum and U. urealyticum. Gene expression levels of a variety of host defense genes were quantified by real-time PCR. In vitro antimicrobial activities of synthetic AMPs against Ureaplasma spp. were determined using a flow cytometry-based assay. Chromosomal histone modifications in host defense gene promoters were tested by chromatin immunoprecipitation (ChIP). DNA methylation status in the AMP promoter regions was also investigated. After stimulation with U. parvum and U. urealyticum, the expression of cell defense genes, including the AMP genes (DEFB1, DEFA5, DEFA6, and CAMP), was significantly downregulated compared to that of TNFA and IL-8, which were upregulated. In vitro flow cytometry-based antimicrobial assay revealed that synthetic peptides LL-37, hBD-3, and hBD-1 had activity against Ureaplasma spp. Downregulation of the AMP genes was associated with chromatin modification alterations, including the significantly decreased histone H3K9 acetylation with U. parvum infection. No DNA methylation status changes were detected upon Ureaplasma infection. In conclusion, AMPs have in vitro activity against Ureaplasma spp., and suppression of AMP expression might be important for the organisms to avoid this aspect of the host innate immune response and to establish chronic infection and colonization.

Fetal immune response to chorioamnionitis

Chorioamnionitis is a frequent cause of preterm birth and is associated with an increased risk for injury responses in the lung, gastrointestinal tract, brain, and other fetal organs. Chorioamnionitis is a polymicrobial nontraditional infectious disease because the organisms causing chorioamnionitis are generally of low virulence and colonize the amniotic fluid often for extended periods, and the host (mother and the fetus) does not have typical infection-related symptoms such as fever. In this review, we discuss the effects of chorioamnionitis in experimental animal models that mimic the human disease. Our focus is on the immune changes in multiple fetal organs and the pathogenesis of chorioamnionitis-induced injury in different fetal compartments. As chorioamnionitis disproportionately affects preterm infants, we discuss the relevant developmental context for the immune system. We also provide a clinical context for the fetal responses.

High-resolution melt PCR analysis for genotyping of Ureaplasma parvum isolates directly from clinical samples

Ureaplasma sp. infection in neonates and adults underlies a variety of disease pathologies. Of the two human Ureaplasma spp., Ureaplasma parvum is clinically the most common. We have developed a high-resolution melt (HRM) PCR assay for the differentiation of the four serovars of U. parvum in a single step. Currently U. parvum strains are separated into four serovars by sequencing the promoter and coding region of the multiple-banded antigen (MBA) gene. We designed primers to conserved sequences within this region for PCR amplification and HRM analysis to generate reproducible and distinct melt profiles that distinguish clonal representatives of serovars 1, 3, 6, and 14. Furthermore, our HRM PCR assay could classify DNA extracted from 74 known (MBA-sequenced) test strains with 100% accuracy. Importantly, HRM PCR was also able to identify U. parvum serovars directly from 16 clinical swabs. HRM PCR performed with DNA consisting of mixtures of combined known serovars yielded profiles that were easily distinguished from those for single-serovar controls. These profiles mirrored clinical samples that contained mixed serovars. Unfortunately, melt curve analysis software is not yet robust enough to identify the composition of mixed serovar samples, only that more than one serovar is present. HRM PCR provides a single-step, rapid, cost-effective means to differentiate the four serovars of U. parvum that did not amplify any of the known 10 serovars of Ureaplasma urealyticum tested in parallel. Choice of reaction reagents was found to be crucial to allow sufficient sensitivity to differentiate U. parvum serovars directly from clinical swabs rather than requiring cell enrichment using microbial culture techniques.

Identification and subtyping of clinically relevant human and ruminant mycoplasmas by use of matrix-assisted laser desorption ionization-time of flight mass spectrometry

Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) recently emerged as a technology for the identification of bacteria. In this study, we aimed to evaluate its applicability to human and ruminant mycoplasmal identification, which can be demanding and time-consuming when using phenotypic or molecular methods. In addition, MALDI-TOF MS was tested as a subtyping tool for certain species. A total of 29 main spectra (MSP) from 10 human and 13 ruminant mycoplasma (sub)species were included in a mycoplasma MSP database to complete the Bruker MALDI Biotyper database. After broth culture and protein extraction, MALDI-TOF MS was applied for the identification of 119 human and 143 ruminant clinical isolates that were previously identified by antigenic or molecular methods and for subcultures of 73 ruminant clinical specimens that potentially contained several mycoplasma species. MALDI-TOF MS resulted in accurate (sub)species-level identification with a score of ≥1.700 for 96% (251/262) of the isolates. The phylogenetically closest (sub)species were unequivocally distinguished. Although mixtures of the strains were reliably detected up to a certain cellular ratio, only the predominant species was identified from the cultures of polymicrobial clinical specimens. For typing purposes, MALDI-TOF MS proved to cluster Mycoplasma bovis and Mycoplasma agalactiae isolates by their year of isolation and genome profiles, respectively, and Mycoplasma pneumoniae isolates by their adhesin P1 type. In conclusion, MALDI-TOF MS is a rapid, reliable, and cost-effective method for the routine identification of high-density growing mycoplasmal species and shows promising prospects for its capacity for strain typing.

Ureaplasma and BPD

Ureaplasma is an organism with low virulence and is a commensal of the lower genito-urinary tract in females. From here, it can gain entry in the amniotic fluid to cause inflammation in the amniotic compartment during pregnancy. Ureaplasma spp. are the most common organisms isolated from women with chorioamnionitis. Ureaplasma spp. are associated with increased risk for preterm labor and morbidity in the preterm neonate. However, there is some controversy regarding the importance of Ureaplasma in the pathogenesis of bronchopulmonary dysplasia (BPD). This article will review the microbiology of Ureaplasma, host innate immune responses, and the pathology of lung injury in animal models of Ureaplasma chorioamnionitis. We will review epidemiological studies of Ureaplasma and BPD in preterm infants and efficacy of antibiotics in preventing preterm labor and BPD.

Interaction of the putative tyrosine recombinases RipX (UU145), XerC (UU222), and CodV (UU529) of Ureaplasma parvum serovar 3 with specific DNA

Phase variation of two loci (‘mba locus’ and ‘UU172 phase-variable element’) in Ureaplasma parvum serovar 3 has been suggested as result of site-specific DNA inversion occurring at short inverted repeats. Three potential tyrosine recombinases (RipX, XerC, and CodV encoded by the genes UU145, UU222, and UU529) have been annotated in the genome of U. parvum serovar 3, which could be mediators in the proposed recombination event. We document that only orthologs of the gene xerC are present in all strains that show phase variation in the two loci. We demonstrate in vitro binding of recombinant maltose-binding protein fusions of XerC to the inverted repeats of the phase-variable loci, of RipX to a direct repeat that flanks a 20-kbp region, which has been proposed as putative pathogenicity island, and of CodV to a putative dif site. Co-transformation of the model organism Mycoplasma pneumoniae M129 with both the ‘mba locus’ and the recombinase gene xerC behind an active promoter region resulted in DNA inversion in the ‘mba locus’. Results suggest that XerC of U. parvum serovar 3 is a mediator in the proposed DNA inversion event of the two phase-variable loci.

Molecular methods for the detection of Mycoplasma and ureaplasma infections in humans: a paper from the 2011 William Beaumont Hospital Symposium on molecular pathology

Mycoplasma and Ureaplasma species are well-known human pathogens responsible for a broad array of inflammatory conditions involving the respiratory and urogenital tracts of neonates, children, and adults. Greater attention is being given to these organisms in diagnostic microbiology, largely as a result of improved methods for their laboratory detection, made possible by powerful molecular-based techniques that can be used for primary detection in clinical specimens. For slow-growing species, such as Mycoplasma pneumoniae and Mycoplasma genitalium, molecular-based detection is the only practical means for rapid microbiological diagnosis. Most molecular-based methods used for detection and characterization of conventional bacteria have been applied to these organisms. A complete genome sequence is available for one or more strains of all of the important human pathogens in the Mycoplasma and Ureaplasma genera. Information gained from genome analyses and improvements in efficiency of DNA sequencing are expected to significantly advance the field of molecular detection and genotyping during the next few years. This review provides a summary and critical review of methods suitable for detection and characterization of mycoplasmas and ureaplasmas of humans, with emphasis on molecular genotypic techniques.

Comparative genome analysis of 19 Ureaplasma urealyticum and Ureaplasma parvum strains

Background

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

Results

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

Conclusions

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

Chromosomal mutations responsible for fluoroquinolone resistance in Ureaplasma species in the United States

We sequenced the full lengths of the gyrA, gyrB, parC, and parE genes in 13 fluoroquinolone-resistant Ureaplasma isolates (levofloxacin MICs, 4 to 32 μg/ml) and 10 susceptible isolates (MICs ≤ 2 μg/ml). Mutations were detected in all resistant isolates but in none of the susceptible isolates. The most prevalent mutation was the S83L substitution in the ParC protein. No plasmid-mediated fluoroquinolone resistance genes were detected.

Genotypic characterization of ureaplasma serovars from clinical isolates by pulsed-field gel electrophoresis

Genetic relationships within ureaplasma serovars were investigated by pulsed-field gel electrophoresis (PFGE). One hundred thirteen Ureaplasma parvum isolates and 78 Ureaplasma urealyticum isolates were different from their ATCC serovar type strains and different within the same serovars. The organisms were geographically widespread. No unique patterns were associated with invasive disease.