Examination of Ureaplasma urealyticum and Mycoplasma hominis in 4082 Chinese patients

The objective of this study was to analyze the infection rate and drug resistance of Ureaplasma urealyticum (UU) and Mycoplasma hominis (MH) in the genitourinary tract of Chinese patients. From December 2018 to June 2019, vaginal secretion or urinary secretion of outpatients in our hospital were selected for culture and drug sensitivity analysis of Ureaplasma urealyticum and Mycoplasma hominis. In 4082 Chinese samples, 1567 Mycoplasma were detected, a detection rate of 38.39%, among which 1366 cases were UU single positive, accounting for 33.47%, 15 cases were MH single positive, accounting for 0.36%, 186 cases were UU and MH mixed positive, accounting for 4.56%. The most affected age groups were 21-30 years and 31-40 years, accounting for 19.09 and 15.05%, respectively. The results of drug sensitivity showed that doxycycline, minocycline, josamycin, clarithromycin, and roxithromycin were more sensitive to mycoplasma infection. The distribution of Ureaplasma urealyticum and Mycoplasma hominis in the human genitourinary system and their sensitivity to antibiotics is different for sex and age groups.

Ureaplasma urealyticum infection presenting as pyelonephritis and perinephric abscess in an immunocompromised patient.

We report a case of an immunosuppressed 67-year-old woman who presented with fever of unknown origin. Further investigation revealed multiple left renal and perinephric abscesses. These were managed with percutaneous drainage and broad-spectrum antibiotics; however, no clinical improvement resulted. No organism was identifiable on standard microscopy and culture of all drain, blood and urine samples taken. Left nephrectomy with right urinary diversion was performed for sepsis management and to protect the patient's right kidney. Eventually, Ureaplasma species' RNA was detected in the patient's drain fluid using PCR and 16S ribosomal RNA gene sequencing. The patient was treated successfully with targeted antibiotic therapy and underwent extensive rehabilitation following this. Histopathology of the nephrectomy specimen suggested xanthogranulomatous pyelonephritis.

Susceptibilidad antimicrobiana en muestras urogenitales de ureaplasma urealyticum, el principal agente en infección intramaniótica / Antimicrobial susceptibility in urogenital samples of ureaplasma urealyticum, the main agent in intramaniotic infection

RESUMEN OBJETIVO: Ureaplasma urealyticum es el agente más frecuentemente aislado en infección intraamniótica. Los macrólidos son los antimicrobianos de primera elección en embarazadas. Se ha descrito el aumento de resistencia, pudiendo limitar las opciones terapéuticas durante la gestación. El propósito del estudio es evaluar susceptibilidad antimicrobiana de Ureaplasma urealyticum aislado en mujeres en edad fértil, que se atienden en Clínica Alemana Temuco, Araucanía, Chile. METODO: Se estudian todas las muestras de orina y flujo vaginal para cultivo de U. urealyticum, de pacientes entre 18 y 40 años, recibidas en el Laboratorio de Microbiología Clínica Alemana Temuco, en período Abril 2013 a Enero 2015. Se procesan las muestras con kit Mycoplasma IST 2 de Biomerieux. En las que resultan positivas, se estudia susceptibilidad a macrólidos, tetraciclinas y quinolonas. RESULTADOS: 426 muestras de orina y flujo vaginal (390 pacientes). 197 pacientes resultaron positivas para U. urealyticum. (50,5%). La susceptibilidad fue 88,4% (174 pctes) a Eritromicina, 87,9% (173 pctes) a Claritromicina y 91,9% (181 pctes) a Azitromicina (NS). 15 de 197 pacientes (7,6%) fueron resistentes a los 3 macrólidos. La susceptibilidad a Quinolonas fue 55,3% a Ciprofloxacino, y 94% a Ofloxacino. El 100% resultó susceptible a Tetraciclinas. CONCLUSIONES: Cerca del 10% de U. urealyticum aislados en nuestra serie son resistentes a macrólidos, contribuyendo a la no erradicación de la infección en tratamientos empíricos. Dentro de ellos, azitromicina aparece con la mayor efectividad. El aumento de resistencia limitará opciones terapéuticas, con gran impacto perinatal en futuro. La vigilancia de susceptibilidad en cada hospital es fundamental para elección terapéutica.

ABSTRACT INTRODUCTION: Ureaplasma urealyticum is the most frequently isolated microorganism in intra-amniotic infection. The macrolides are the first choice antimicrobials for treat this infection in pregnancy. The increasing resistance has been described worldwide, seriously limiting therapeutic options in pregnancy. The aim of the study is to evaluate antimicrobial susceptibility of U. urealyticum aislated in fertile-age women in Clínica Alemana Temuco, Araucania region, Chile. METHOD: Urine and vaginal samples were analyzed for U. urealyticum, from every 18 to 40 years old patients, received at Microbiology Laboratory of Clínica Alemana Temuco, between April 2013 to January 2015. The samples are processed with Mycoplasma IST 2 kit of Biomerieux. If they became positives, susceptibility to macrolides, tetracyclines and quinolones was studied. RESULTS: 426 urine and vaginal samples were collected (390 patients). 197 patients were positive for U. urealyticum (50.5%). The susceptibility was 88.4% (174 pts) to Erythromicyn, 87.9% (173 pts) to Clarithromycin and 91.9% (181 pts) to Azithromycin (NS). Resistance to all macrolides was observed in 15 out of 197 patients (7.6%). The susceptibility to Quinolones was 55.3% to Ciprofloxacin, and 94% to Ofloxacin. The 100% was susceptible to Tetracyclines. DISCUSSION: Near to 10% of isolated Ureaplasma spp in our serie were resistant to some macrolide, being a factor for failing to eradicate the infection in empirical treatment. Azithromycin was the most effective. The increasing resistance will limit therapeutic options, with great perinatal impact in the future. Susceptibility surveillance in each hospital is very important for therapeutic options.

Effect of Tripterygium Wilfordii Polyglycoside on Experimental Prostatitis Caused by Ureaplasma Urealyticum in Rats.

BACKGROUND Prostatitis is a common and refractory urological disease with complicated etiology. Ureaplasma urealyticum (UU) has a close relationship with human urinary tract infection that can induce nonbacterial prostatitis. Tripterygium wilfordii polyglycoside (TWP) is a non-steroidal immune inhibitor that causes significant immune suppression and anti-inflammatory effects. Its role in prostatitis caused by UU has not yet been established. The aim of this study was to investigate the effect of TWP on UU-infected prostatitis in a rat model. MATERIAL AND METHODS UU-infected prostatitis SD model rats were randomly divided into 2 groups: the prostatitis group (model group) and the TWP treatment group (treatment group). At 7 days after treatment, prostate weight, leucocyte count, lecithin corpuscles, UU infection rate, and UU microbe count were compared between the 2 groups. Serum inflammatory cytokines TNF-α was determined by ELISA, and ICAM-1 and NF-κB expression were detected. RESULTS UU infection rate was 80% after modeling. The rat prostate weight and leucocyte count in the model group increased significantly, while lecithin corpuscles decreased. Compared with controls, inflammatory factor TNF-α, ICAM-1, and NF-κB expression were obviously higher (P<0.05). TWP markedly reduced prostate weight and leucocyte count, increased lecithin corpuscles, and decreased UU microbe count and TNF-α, ICAM-1, and NF-κB expression (P<0.05). CONCLUSIONS TWP can inhibit expression of inflammatory factors and may be useful in treating UU-infected prostatitis through reducing UU infection rate.

Vaginal infections among pregnant women at Omdurman Maternity Hospital in Khartoum, Sudan.

INTRODUCTION: Microbial infections of the vagina in pregnant women are health problems that lead to serious medical complications and consequences. This study aimed to investigate and determine antimicrobial susceptibilities of the causative agents of vaginal infections in pregnant women. METHODOLOGY: A cross-sectional study of pregnant women (n = 200) was conducted between August and December 2008 at Omdurman Maternity Hospital, Khartoum, Sudan. Vaginal and cervical swabs were obtained from each subject and processed for isolation and identification of pathogenic microorganisms using standard methods of wet mount preparation, direct Gram smear, Nugent scoring system, direct immunofluorescence, and cultural techniques. Antimicrobial susceptibility testing of bacterial isolates was performed using standard procedures. Statistical analysis was done using SPSS program version 12.0.1. A p value < 0.05 was considered statistically significant. RESULTS: Of the 200 pregnant women enrolled, BV was detected in 49.8%, followed by Chlamydia trachomatis (31.3%) and Candida albicans (16.6%), with low frequencies of Neisseria gonorrhoeae (1.8%) and Trichomonas vaginalis (0.5%). Higher infection rates were recorded among subjects in the third trimester (71.6%) than in the second trimester of gestation (28.4%). No significant association (p = 0.7) between history of abortions and C. trachomatis infections was found. Gentamicin was the most active agent against Gram-positive and Gram-negative bacteria. Clarythromycin was the most active against Mycoplasma species. CONCLUSIONS: Pregnant women with vaginal complaints revealed various positive microbiology results. Such cases may require specific medication. Routine culture of vaginal and cervical samples should be performed on all pregnant women during prenatal visits.

Role of biofilm formation in Ureaplasma antibiotic susceptibility and development of bronchopulmonary dysplasia in preterm neonates.

BACKGROUND: Ureaplasma respiratory tract colonization is a risk factor for bronchopulmonary dysplasia (BPD) in preterm infants, but whether Ureaplasma isolates from colonized infants can form biofilms is unknown. We hypothesized that Ureaplasma isolates vary in capacity to form biofilms that contribute to their antibiotic resistance and ability to evade host immune responses. Study objectives were to (1) determine the ability of Ureaplasma isolates from preterm neonates to form biofilms in vitro; (2) compare the susceptibility of the sessile and planktonic organisms to azithromycin (AZI) and erythromycin; and (3) determine the relationship of biofilm-forming capacity in Ureaplasma isolates and the risk for BPD. METHODS: Forty-three clinical isolates from preterm neonates and 5 American Tissue Culture Collection strains were characterized for their capacity to form biofilms in vitro, and antibiotic susceptibility was performed on each isolate prebiofilm and postbiofilm formation. RESULTS: Forty-one (95%) clinical and 4 of 5 (80%) American Tissue Culture Collection isolates formed biofilms. All isolates were more susceptible to AZI (minimum inhibitory concentration, MIC50 2 µg/mL) than erythromycin (MIC50 4 µg/mL), and biofilm formation did not significantly affect antibiotic susceptibility for the 2 tested antibiotics. The MIC50 and minimum biofilm inhibitory concentrations (MBIC50) for Ureaplasma urealyticum clinical isolates for AZI were higher than for MIC50 and MBIC50 for Ureaplasma parvum isolates. There were no differences in MIC or MBICs among isolates from BPD infants and non-BPD infants. CONCLUSIONS: Capacity to form biofilms is common among Ureaplasma spp. isolates, but biofilm formation did not impact MICs for AZI or erythromycin.

Cytokine production by peripheral blood mononuclear cells of women with a history of preterm birth.

Preterm birth is associated with elevated production of pro-inflammatory cytokines such as TNFalpha at the maternal-fetal interface. Previous studies have suggested that women with a history of preterm birth produce aberrantly strong inflammatory responses to bacterial lipopolysaccharide (LPS). However many intrauterine infections in women are associated with pathogens including Ureaplasma urealyticum, Mycoplasma hominis and Streptococcus agalactiae (group B streptococcus) that contain pro-inflammatory factors other than LPS. We evaluated whether peripheral blood leukocytes from women with a history of preterm birth produce elevated amounts of TNFalpha upon stimulation with pathogens associated with preterm birth and if pre-treatment with aspirin, an anti-inflammatory medication, decreases the ex vivo production of this cytokine. Heat-killed bacteria elicited increased TNFalpha production from leukocytes in a dose-dependent manner, but no differences in TNFalpha production between leukocytes from women with preterm birth and control women with term birth were detected. In women who consumed aspirin each day for one week, TNFalpha production was increased in leukocytes from control women stimulated with Escherichia coli and U. urealyticum, but was reduced or unchanged in leukocytes from women with preterm birth. Similar trends were observed for a subset of samples stimulated with U. urealyticum and assayed for IL-6, IL-10, IL-1beta and TNFalpha by bead array. We conclude that leukocytes from women with a history of preterm birth do not have elevated pro-inflammatory responses to pathogens, and that reproductive history is associated with different effects of aspirin on pro-inflammatory cytokine production.

Prevention and therapy of bronchopulmonary dysplasia - evidence and clinical practice.

The knowledge on the pathogenetic mechanisms of bronchopulmonary dysplasia (BPD) has increased considerably over recent years. However, the incidence of the disease has not substantially been changed by our therapeutic approaches. This review summarizes the existing evidence for a number of respiratory and medical strategies to prevent or ameliorate the disease and gives recommendations for clinical practice. Oxygen plays an important pathogenetic and therapeutic role for BPD. Targeting infants at lower oxygen saturation levels than traditionally used seems to confer major advantages. There is no sufficient evidence for a routine use of respiratory strategies like permissive hypercapnia or inhaled nitric oxide to prevent BPD. Diuretics can ameliorate lung function transiently. High intramuscular doses of vitamin A can reduce the risk of BPD. Early or prophylactic surfactant might also be advantageous. Postnatal corticosteroids are effective but, due to their severe side effects, should be restricted to the severest cases. Alpha1-proteinase inhibitor and superoxide dismutase have no proven benefits for BPD. The role of erythromycin has not been completely elucidated yet. Innovative strategies like Clara Cell 10 kD protein still have to be assessed in future trials.

The demographic and behavioural profile of women with cervicitis infected with Chlamydia trachomatis, Mycoplasma hominis and Ureaplasma urealyticum and the comparison of two medical regimens.

OBJECTIVE: The aim of this study was to compare the therapeutic effect of single dose oral azithromycin with twice-daily, 7-day doxycycline in women with chlamydial, mycoplasmic or ureaplasmic cervicitis and to demonstrate the demographic and behavioral profile of infected women. MATERIALS AND METHODS: Five hundred and thirty-three women with various gynecologic complaints were recruited for this study. All women were screened for Chlamydia trachomatis (CT), Ureaplasma urealyticum (UU) and Mycoplasma hominis (MH) by enzyme immune assay tests. Patients positive for Neisseria gonorrhoeae were excluded. Women treated for these infections were tested after completing medical therapy. Educational levels of infected women were similar in each group. The prevalence of CT, UU and MH was 3.4% (18/533), 11.8% (63/533) and 0.9% (5/533), respectively. In 452 patients, no treatment was administered. The remaining patients were either treated with azithromycin (n=41) or doxycycline (n=40). The eradication rate for the infectious agents was 87.3% and 93.5% in the group of azithromycin and doxycycline, respectively (P>0.05). There was no statistically significant difference in efficacy between single dose azithromycin and a 7-day course of doxycycline with respect to the treatment of culture-positive cases. Recurrences were observed in five cases in azithromycin group (12.5%) and in three cases in doxycycline group (7.5%). CONCLUSIONS: The treatment of uncomplicated chlamydial, mycoplasmic and ureaplasmic cervicitis with a single dose of azithromycin administered under supervision in the clinic is as effective as a 7-day course of doxycycline. This regimen may overcome the problem of compliance with the standard twice-daily, 7-day regimen of doxycycline.

Effect of fluoropyrimidines on the growth of Ureaplasma urealyticum.

In the present study, we investigated the effect of fluoropyrimidines on the growth of Ureaplasma urealyticum. Addition of fluoropyrimidines strongly inhibited bacterial growth. Growth inhibition by these analogues could be reversed by addition of either thymidine or deoxyuridine, suggesting inhibition of thymidylate biosynthesis as the mechanism in operation.

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

BACKGROUND: Airway colonization of mechanically ventilated very low birth weight infants (birth weight < 1500 grams) by Ureaplasma urealyticum (Uu) is associated with an increased risk of bronchopulmonary dysplasia (BPD). While Uu is sensitive to erythromycin in vitro, the efficacy of intravenous (IV) erythromycin to eliminate Uu from the airways has not been studied. METHODS: 17 very low birth weight infants with Uu positive tracheal aspirate (TA) cultures were randomized to either 5 (8 infants) or 10 days (9 infants) of IV erythromycin lactobionate (40 mg/kg/day in 3 divided doses). Tracheal aspirate cultures for Uu were performed on days 0, 5, 10 and 15. RESULTS: Intravenous erythromycin failed to eliminate airway colonization in a large proportion of infants regardless of whether they received 5 or 10 days of treatment. Ureaplasma urealyticum was isolated from 4/15 (27%) of TAs obtained at 5 days, 5/12 TAs (42%) obtained at 10 days and 6/11(55%) TAs obtained at 15 days (combined group data). CONCLUSIONS: Erythromycin administered IV does not eliminate Uu from the airways in a large proportion of infants. Failure of erythromycin to eliminate Uu from the airways may contribute to the lack of efficacy of this drug in reducing the incidence of BPD in very low birth weight infants.

Pneumonitis associated with Ureaplasma urealyticum in children with cancer.

We describe 3 pediatric patients with cancer who had clinical and radiographic evidence of pneumonitis and for whom cultures of bronchoalveolar lavage fluid specimens yielded Ureaplasma urealyticum. Two of the patients died; for the surviving patient, clinical improvement coincided temporally with administration of erythromycin. Immunocompromised patients with pneumonitis of unclear etiology should have respiratory secretions cultured for mycoplasmas and should receive empiric therapy that includes a macrolide antibiotic.

The four categories of prostatitis: a practical approach to treatment.

To diagnose prostatitis correctly and select appropriate therapy, one should use the Meares-Stamey technique for culturing urine and prostatic secretions and apply the classification system for prostatitis devised by the National Institutes of Health. The continuing search for an effective therapy for the most common type, chronic abacterial prostatitis, has led to adoption of treatments from other specialties and reevaluation of standard treatments.

Association of chronic urinary symptoms in women and Ureaplasma urealyticum.

UNLABELLED: OBJECTIVES. To determine the incidence of Ureaplasma urealyticum in women experiencing chronic urinary symptoms and to determine whether antibiotic therapy targeting these organisms is effective. METHODS: Forty-eight consecutive women referred to our academic medical center for chronic voiding symptoms and possible interstitial cystitis underwent urologic evaluation, including culture screening for U. urealyticum and Mycoplasma hominis. Patients with positive cultures were treated with a 1-g dose of azithromycin; persistent infection was treated with 7 days of doxycycline, ofloxacin, or erythromycin. Patients reported symptom severity (0, mild; 3, severe) and voiding frequency before and 6 months after treatment. RESULTS: Positive cultures were obtained in 23 (48%) of 48 patients; 22 had U. urealyticum and 1 had M. hominis. All had negative cultures after treatment. The mean symptom severity score improved with treatment (2.2 to 0.7, P <0.001), and the mean urinary frequency decreased (9.2 daily to 6.8 daily, P <0.001). Two of the 23 patients experienced no improvement; one had detrusor instability and the other had medically related urinary frequency. Of the 25 patients with negative cultures, interstitial cystitis was established in only 9 (19% of the total sample). CONCLUSIONS: Although often overlooked or improperly treated, U. urealyticum and M. hominis infections may account for a large proportion of unexplained chronic voiding symptoms. Culture and treatment should be considered before pursuing more costly and invasive tests.

Chlamydia trachomatis y ureaplasma urealyticum / Chlamydia trachomatis and ureaplasma urealyticum

La etiología de la uretitis no gonocóccica trasciende las infecciones por chlamydia trachomatis y ureaplasma urealyticum. otros agentes etiológicos comunes son responsables de aproximadamente 20 por ciento de los casos y en un tercio no se precisa una etiología. Por esta situación se requiere de una nueva terminología para caracterizar mejor esta entidad. Test de amplificación genómica aplicados a la secreción uretral u orina son nuevas herramientas para un diagnóstico precoz de chlamydia trachomatis. El diagnóstico precoz es muy importante para evitar complicaciones y secuelas, especialmente infertilidad en mujeres, mediante un tratamiento oportuno y adecuado. Azitromicina, 1g oral, en dosis única es un avance significativo en el tratamiento de la uretritis causada por clamidias

Mycoplasma in urine and blood following catheterisation of patients undergoing vascular surgery.

OBJECTIVES: The purpose of this investigation was to determine if mycoplasmas enter the bloodstream after urinary tract catheterisation in patients undergoing vascular surgery in order to evaluate the efficiency of the routine prophylactic antibiotic treatment. DESIGN: Prospective study. MATERIALS AND METHODS: A total of 100 patients (63 men and 37 women) undergoing elective vascular surgery had urine and blood cultures performed for mycoplasmas. Blood cultures were taken preoperatively after urinary tract catheterisation and the urine was collected during catheterisation. The median age of the patients was 67 years (range 42-87). RESULTS: A total of 12 (12%), 5 men and 7 women, had a positive urine culture for mycoplasmas (One patient had Mycoplasma hominis and 11 had Ureaplasma urealyticum isolated). Their median age was 60 years (range 42-76). No blood cultures were positive for Mycoplasma. CONCLUSIONS: Mycoplasmas do not enter the blood-stream after catheterization in sufficient amounts and sufficiently often to be detected by blood-cultures in this small patient sample. The number of vascular patients harbouring mycoplasmas in the urine was low and we found no indication for changes in the prophylactic antibiotic treatment based on these findings.

Growth inhibition of Ureaplasma urealyticum by the proton pump inhibitor lansoprazole: direct attribution to inhibition by lansoprazole of urease activity and urea-induced ATP synthesis in U. urealyticum.

The proton pump inhibitors (PPIs) omeprazole and lansoprazole and the acid-activated analog of lansoprazole AG-2000, which potently inhibit the urease of Helicobacter pylori (K. Nagata, H. Satoh, T. Iwahi, T. Shimoyama, and T. Tamura, Antimicrob. Agents Chemother. 37:769-774, 1993), also inhibited the urease activities of cell-free extracts as well as intact cells of Ureaplasma urealyticum. The 50% inhibitory concentrations were between 1 and 25 microM. These compounds also inhibited the ATP synthesis induced by urea in ureaplasma cells. The 50% inhibitory concentrations for ATP synthesis were close to those for urease activity, but they were lower than those of urease inhibitors, such as acetohydroxamic acid, hydroxyurea, and thiourea. In addition, one of the metabolites of lansoprazole found in human urine, M-VI, also inhibited ureaplasmal urease activity and the ATP synthesis induced by urea at almost the same concentrations as those of lansoprazole. The inhibition of PPIs against ureaplasma urease was very similar to those against H. pylori urease, suggesting that the inhibitory mechanism against these ureases was due to the blockage of the SH residues on the cysteine of the enzyme. Omeprazole, lansoprazole, AG-2000, and M-VI inhibited the growth of U. urealyticum. Since ureaplasma urease is thought to be involved in the pathogenicity of this organism in the urogenital tract, PPIs and their analogs may be useful as chemotherapeutic agents against diseases caused by U. urealyticum.

Therapeutic considerations for Ureaplasma urealyticum infections in neonates.

Appreciation of Ureaplasma urealyticum as a human pathogen and documentation of antibiotic resistance have heightened interest in susceptibility testing and treatment alternatives. Treatment of neonates poses special problems because of potential drug toxicity, clinical unfamiliarity with the various conditions that may be due to or associated with ureaplasmal infection, and frequent isolation of the organism from mucosal surfaces in the absence of overt illness. Case reports have undeniably demonstrated the ability of U. urealyticum to cause neonatal bacteremia, pneumonia, and meningitis, although the frequency with which such clinically significant infections occur among the greater population of colonized neonates is unknown. The association of U. urealyticum with development of chronic lung disease of prematurity further intensifies the need for knowledge concerning effective antimicrobial treatment. Despite controversy stemming from nonstandardized susceptibility testing, erythromycin is the drug of choice for treating neonatal ureaplasmal infections not involving the central nervous system. The use of erythromycin is supported by its activity in vitro, limited data from clinical experience, and preliminary pharmacokinetic and safety studies.

Hydrolysis of urea by Ureaplasma urealyticum generates a transmembrane potential with resultant ATP synthesis.

When urea is added to Ureaplasma urealyticum, it is hydrolysed internally by a cytosolic urease. Under our measuring conditions, and at an external pH of 6.0, urea hydrolysis caused an ammonia chemical potential equivalent to almost 80 mV and, simultaneously, an increase in proton electrochemical potential (delta p) of about 24 mV with resultant de novo ATP synthesis. Inhibition of the urease with the potent inhibitor flurofamide abolished both the chemical potential and the increase of delta p such that ATP synthesis was reduced to approximately 5% of normally obtained levels. Uncouplers of electrochemical gradients had little or no effect on these systems. The electrochemical parameters and ATP synthesis were measured similarly at three other external pH values. Any change in delta p was primarily via membrane potential (delta psi), and the level of de novo ATP synthesis was related to the increase in delta p generated upon addition of urea and more closely to the ammonia chemical potential. Although the organisms lack an effective mechanism for internal pH homeostasis, they maintained a constant delta pH. The data reported are consistent with, and give evidence for, the direct involvement of a chemiosmotic mechanism in the generation of around 95% of the ATP by this organism. Furthermore, the data suggest that the ATP-generating system is coupled to urea hydrolysis by the cytosolic urease via an ammonia chemical potential.

[Ureaplasma urealyticum in newborn and premature infants. Its association with bronchopulmonary dysplasia]. / Ureaplasma urealyticum bei Neu- und Frühgeborenen. Assoziation mit der bronchopulmonalen Dysplasie.

Tests for the possible presence of Ureaplasma urealyticum (U. u.), a type of Mycoplasma transmitted perinatally, were performed on 53 consecutive mature newborns and a group of 108 predominantly premature infants. Standard microbiological tests were performed on smears from throat, nose and ear, as well as from vagina or anus. U. u. was isolated from 15 of the 53 mature newborns (28%): none of the children was ill. In the premature group the microorganism was isolated from 13 of the 108 infants (12%). Isolation was the more frequent the smaller the birth weight and the shorter the gestational period. The carrier rate was 50% (6 of 12) in those with birth weights under 1,500 g and a gestational period of less than 29 weeks. In all 6 newborns under 1,500 g who carried U. u. bronchopulmonary dysplasia developed, but in only 2 of the 9 in whom U. u. was not isolated. Administration of erythromycin (20-45 mg/kg.d intravenously) improved the clinical course of 3 of the 5 affected with bronchopulmonary dysplasia. The results demonstrate that U. u. is of significance in perinatal medicine and should be considered especially in the treatment of premature infants requiring artificial ventilation.