Characterization of ureaplasmas isolated from preterm infants with and without bronchopulmonary dysplasia.
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A PCR assay was used to analyze endotracheal aspirates from preterm infants for Ureaplasma parvum versus U. urealyticum. U. parvum was detected more often than U. urealyticum. There was no significant difference or trend in the prevalence of either species between infants with or without bronchopulmonary dysplasia when isolated alone. (+info)
Mycoplasmas and ureaplasmas as neonatal pathogens.
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The genital mycoplasmas represent a complex and unique group of microorganisms that have been associated with a wide array of infectious diseases in adults and infants. The lack of conclusive knowledge regarding the pathogenic potential of Mycoplasma and Ureaplasma spp. in many conditions is due to a general unfamiliarity of physicians and microbiology laboratories with their fastidious growth requirements, leading to difficulty in their detection; their high prevalence in healthy persons; the poor design of research studies attempting to base association with disease on the mere presence of the organisms in the lower urogenital tract; the failure to consider multifactorial aspects of diseases; and considering these genital mycoplasmas only as a last resort. The situation is now changing because of a greater appreciation of the genital mycoplasmas as perinatal pathogens and improvements in laboratory detection, particularly with regard to the development of powerful molecular nucleic acid amplification tests. This review summarizes the epidemiology of genital mycoplasmas as causes of neonatal infections and premature birth; evidence linking ureaplasmas with bronchopulmonary dysplasia; recent changes in the taxonomy of the genus Ureaplasma; the neonatal host response to mycoplasma and ureaplasma infections; advances in laboratory detection, including molecular methods; and therapeutic considerations for treatment of systemic diseases. (+info)
Severe endometritis caused by genital mycoplasmas after Caesarean section.
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Infrequently, post-Caesarean endometritis can progress to severe conditions. A case of post-Caesarean endometritis caused by Mycoplasma hominis and Ureaplasma urealyticum is reported in a young patient. In therapy-resistant endometritis unusual causative organisms should be considered and special microbiological investigations are recommended. (+info)
Structure of the substrate complex of thymidine kinase from Ureaplasma urealyticum and investigations of possible drug targets for the enzyme.
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Thymidine kinases have been found in most organisms, from viruses and bacteria to mammals. Ureaplasma urealyticum (parvum), which belongs to the class of cell-wall-lacking Mollicutes, has no de novo synthesis of DNA precursors and therefore has to rely on the salvage pathway. Thus, thymidine kinase (Uu-TK) is the key enzyme in dTTP synthesis. Recently the 3D structure of Uu-TK was determined in a feedback inhibitor complex, demonstrating that a lasso-like loop binds the thymidine moiety of the feedback inhibitor by hydrogen bonding to main-chain atoms. Here the structure with the substrate deoxythymidine is presented. The substrate binds similarly to the deoxythymidine part of the feedback inhibitor, and the lasso-like loop binds the base and deoxyribose moieties as in the complex determined previously. The catalytic base, Glu97, has a different position in the substrate complex from that in the complex with the feedback inhibitor, having moved in closer to the 5'-OH of the substrate to form a hydrogen bond. The phosphorylation of and inhibition by several nucleoside analogues were investigated and are discussed in the light of the substrate binding pocket, in comparison with human TK1. Kinetic differences between Uu-TK and human TK1 were observed that may be explained by structural differences. The tight interaction with the substrate allows minor substitutions at the 3 and 5 positions of the base, only fluorine substitutions at the 2'-Ara position, but larger substitutions at the 3' position of the deoxyribose. (+info)
Serotype diversity and antigen variation among invasive isolates of Ureaplasma urealyticum from neonates.
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Ureaplasma urealyticum has previously been isolated from the cultured cerebrospinal fluid of 13 of 418 newborn infants; additional bloodstream isolates were obtained from the same population. Ten of the 13 cerebrospinal fluid and 3 bloodstream isolates were available for serotyping in the present study. By the use of serotype-specific reagents, including monoclonal antibodies, 70% of the cerebrospinal fluid isolates were identifiable as serotype 1, 3, 6, 8, or 10; i.e., they represented 5 of the 14 established serotypes or both presently defined genomic clusters. One of the bloodstream isolates was identified as serotype 3. Our data support the hypothesis that the property of invasiveness for unreaplasmas is likely not limited to one or a few particular serotypes among the 14 established serovars. Additionally, our study has shown that even in isolates of the same serotype, there can be size variation in the antigens expressed. Therefore, it would appear that many serotypes are invasive and that perhaps antigen variability and host factors may be more important determinants for ureaplasma infections than different serotypes per se. (+info)
A sonographic short cervix as the only clinical manifestation of intra-amniotic infection.
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OBJECTIVE: A sonographically short cervix is a powerful predictor of spontaneous preterm delivery. However, the etiology and optimal management of a patient with a short cervix in the mid-trimester of pregnancy remain uncertain. Microbial invasion of the amniotic cavity (MIAC) and intra-amniotic inflammation are frequently present in patients with spontaneous preterm labor or acute cervical insufficiency. This study was conducted to determine the rate of MIAC and intra-amniotic inflammation in patients with a cervical length < 25 mm in the mid-trimester. STUDY DESIGN: A retrospective cohort study was conducted of patients referred to our high risk clinic because of a sonographic short cervix or a history of a previous preterm birth. Amniocenteses were performed for the evaluation of MIAC and for karyotype analysis in patients with a short cervix. Fluid was cultured for aerobic and anaerobic bacteria, as well as genital mycoplasmas. Patients with MIAC were treated with antibiotics selected by their physician. RESULTS: Of 152 patients with a short cervix at 14-24 weeks, 57 had amniotic fluid analysis. The prevalence of MIAC was 9% (5/57). Among these patients, the rate of preterm delivery (< 32 weeks) was 40% (2/5). Microorganisms isolated from amniotic fluid included Ureaplasma urealyticum (n=4) and Fusobacterium nucleatum (n=1). Patients with a positive culture for Ureaplasma urealyticum received intravenous Azithromycin. Three patients with Ureaplasma urealyticum had a sterile amniotic fluid culture after treatment, and subsequently delivered at term. The patient with Fusobacterium nucleatum developed clinical chorioamnionitis and was induced. CONCLUSION: (1) Sub-clinical MIAC was detected in 9% of patients with a sonographically short cervix (< 25 mm); and (2) maternal parenteral treatment with antibiotics can eradicate MIAC caused by Ureaplasma urealyticum. This was associated with delivery at term in the three patients whose successful treatment was documented by microbiologic studies. (+info)
Evaluation of the diagnostic efficacy of PCR for Ureaplasma urealyticum infection in Indian adults with symptoms of genital discharge.
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Ureaplasma urealyticum genital infection may lead to severe clinical implications if left undiagnosed and untreated. The present study was conducted to evaluate the diagnostic efficiency of a polymerase chain reaction (PCR) assay and to determine the prevalence of U. urealyticum in Indian adults with symptoms of genital discharge. Cervical swabs, vaginal swabs and male urethral swabs from 100 patients attending an sexually transmitted disease clinic at a tertiary care hospital in Delhi were screened prospectively for infection with U. urealyticum. The prevalence of U. urealyticum was found to be 32% by culture and 45% by PCR. U. urealyticum was recovered from 8 (47%) and 37 (45%) symptomatic men and women, respectively. The agreement between PCR and culture was 93.75%. PCR improved the test sensitivity by 13% compared to culture. The results confirm the need to use a sensitive and reliable molecular method to prevent the underdiagnosis of ureaplasma infection and to facilitate better clinical management of this infection in India. (+info)
Do Ureaplasma urealyticum infections in the genital tract affect semen quality?
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To investigate the relationship between Ureaplasma urealyticum (UU) infection and semen quality. METHODS: From 2001 to 2003, 346 eligible patients aged 20-45 years were invited from two hospitals in Shanghai, China, to participate in an investigation which included questionnaires about general and reproductive health, an external genital tract examination, UU culture and semen analysis. Multiple linear regression models were used to examine whether UU had a significant effect on semen quality after adjustment for confounding factors. RESULTS: Findings suggested that UU infection was associated with higher semen viscosity and lower semen pH value. Sperm concentration was lower in UU positive subjects than that in UU negative subjects (54.04 X 10(6)/mL vs.70.58 X 10(6)/mL). However, UU did not significantly affect other semen quality indexes. CONCLUSION: UU infection of the male genital tract could negatively influence semen quality. (+info)