Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:6.3.4.6 (urease)
 7,490 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The fastidious growth requirements of mycoplasmas and ureaplasmas necessitated development of special growth media for them. The 1st mycoplasma was isolated from humans in 1937, and in 1954 a previously unknown mycoplasma was isolated from men with nonspecific urethritis. This organism, Ureaplasma urealyticum, is found most frequently in the genitourinary tract, followed by Mycoplasma hominus. M. fermentans and other mycoplasmas are isolated only rarely. Mycoplasmas and ureaplasmas have been implicated in pelvic inflammatory disease, puerperal infection, septic abortion, low birth weight, nongonococcal urethritis, and prostatisis, as well as spontaneous abortion and infertility, but there are no clinical symptoms pathognomonic of these infections. In spite of clinical suggestions of Mycoplasma or Ureaplasma infection, only a properly obtained specimen evaluatd with the use of selective cultures can lead to unequivocal diagnosis. The cultural characteristics and hence diagnostic procedures for Mycoplasma and Ureaplasma are quite different. Sterile calcium alginate swabs are used for obtaining urethral specimens, while sterile cotton swabs can be used for prostatic or vaginal secretions or semen. The swab should not touch antiseptic solutions, creams, or jellies, and the specimen must not dry out. Urine, if cultured, is best examined after centrifugattion at 600 g. Several different transport media are available. Optimally the specimen should be taken directly to the laboratory and subcultured on arrival. The metabolic activity of Mycoplasmas and Ureaplasmas is used in their detection. A phenol red indicator is added to the medium and the color change to or from yellow to pink indicates metabolic change. The growth medium is supplemented with glucose and phenol red for M. fermentans and arginine and phenol red for M. hominis. After color change is observed, the growth medium is subcultured on solid medium, which is obtained by adding .6-.8% Noble agar to the growth medium. Colonies develop best in an atmosphere of 95% N2 and 5% CO2 and reach approximately 200-300 mcm in diameter. They have a fried-egg appearance. Staining with Dienes stain, use of specific antisera, or incident light fluorescence microscopy are used for identification of the classic mycoplasmas. To isolate ureaplasmas, the specimen is transferred on arrival in the laboratory to urease color test broth U9C. During incubation the presence of Ureaplasma induces a rapid color change usually observable in 24-48 hours. A subculture should be done on fresh U9C broth media and on agar media once a color change is observed. Serologic tests for detection of antibodies to mycoplasmas and ureaplasmas are still in the developmental stage.
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PMID:Diagnosis of genital Mycoplasma and Ureaplasma infections. 402 Jul 82

Ureaplasma species are the most prevalent genital Mycoplasma isolated from the urogenital tract of both men and women. Ureaplasma has 14 known serotypes and is divided into two biovars- Ureaplasma parvum and Ureaplasma urealyticum. The organism has several genes coding for surface proteins, the most important being the gene encoding the Multiple Banded Antigen (MBA). The C-terminal domain of MBA is antigenic and elicits a host antibody response. Other virulence factors include phospholipases A and C, IgA protease and urease. Besides genital tract infections and infertility, Ureaplasma is also associated with adverse pregnancy outcomes and diseases in the newborn (chronic lung disease and retinopathy of prematurity). Infection produces cytokines in the amniotic fluid which initiates preterm labour. They have also been reported from renal stone and suppurative arthritis. Genital infections have also been reported with an increasing frequency in HIV-infected patients. Ureaplasma may be a candidate 'co factor' in the pathogenesis of AIDS. Culture and polymerase chain reaction (PCR) are the mainstay of diagnosis. Commercial assays are available with improved turnaround time. Micro broth dilution is routinely used to test antimicrobial susceptibility of isolates. The organisms are tested against azithromycin, josamycin, ofloxacin and doxycycline. Resistance to macrolides, tetracyclines and fluoroquinolones have been reported. The susceptibility pattern also varies among the biovars with biovar 2 maintaining higher sensitivity rates. Prompt diagnosis and initiation of appropriate antibiotic therapy is essential to prevent long term complications of Ureaplasma infections. After surveying PubMed literature using the terms 'Ureaplasma', 'Ureaplasma urealyticum' and 'Ureaplasma parvum', relevant literature were selected to provide a concise review on the recent developments.
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PMID:Ureaplasma: current perspectives. 2586 69