Ureaplasma species, Molecular Detection, PCR
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Ureaplasma urealyticum and U parvum have been associated with a number of clinically significant infections, although their clinical significance may not always be clear as they are part of the normal genital flora. U urealyticum and U parvum have been associated with urethritis and epididymitis. They may cause upper urinary tract infection and they have been associated with infected renal stones. U urealyticum and U parvum may be isolated from amniotic fluid of women with preterm labor, premature rupture of membranes, spontaneous term labor, or chorioamnionitis. They may also cause neonatal infections, including meningoencephalitis and pneumonia. In addition, U urealyticum and U parvum have been reported to cause unusual infections, such as prosthetic joint infection and infections in transplant recipients.
Recently, U urealyticum and U parvum have been found to cause hyperammonemia in lung transplant recipients.(1) In lung transplant recipients with hyperammonemia, the ideal diagnostic specimen is a lower respiratory specimen (eg, bronchoalveolar lavage fluid), although Ureaplasma urealyticum and Ureaplasma parvum may also be detected in blood. Treatment directed against these organisms has resulted in resolution of hyperammonemia.
Culture of Ureaplasma species is laborious, requiring a high degree of technical skill and taking several days. PCR detection is sensitive, specific, and provides same-day results. In addition, PCR allows the differentiation of U urealyticum and U parvum, which is not easily accomplished with culture. PCR assay has replaced conventional culture for U urealyticum and U parvum at Mayo Medical Laboratories due to its speed and equivalent performance to culture.
Rapid, sensitive, and specific identification of Ureaplasma urealyticum and U parvum from genitourinary, reproductive, bone and joint, and lower respiratory sources
A positive PCR result for the presence of a specific sequence found within the Ureaplasma urealyticum and U parvum ureC gene indicates the presence of U urealyticum or U parvum DNA in the specimen.
A negative PCR result indicates the absence of detectable U urealyticum and U parvum DNA in the specimen, but does not rule-out infection as false-negative results may occur due to inhibition of PCR, sequence variability underlying the primers and probes, or the presence of U urealyticum or U parvum in quantities less than the limit of detection of the assay.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Interfering substances may affect the accuracy of this assay; results should always be interpreted in conjunction with clinical and epidemiological findings.
Since Ureaplasma species may be part of the normal flora, results should be interpreted accordingly.
This test is not intended for medicolegal use.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
Clinical References Provides recommendations for further in-depth reading of a clinical nature
1. Bharat A, Cunningham SA, Scott Budinger GR, Kreisel D, et al: Disseminated Ureaplasma infection as a cause of fatal hyperammonemia in humans. Sci Transl Med 2015;7(284):284re3
2. Stellrecht KA, Woron AM, Mishrik NG, Venezia RA: Comparison of multiplex PCR assay with culture detection of genital mycoplasmas. J Clin Microbiol 2004;42:1528-1533
3. Farrell JJ, Larson JA, Akeson JW, Lowery KS, et al: Ureaplasma parvum prosthetic joint infection detected by PCR. J Clin Microbiology 2014;52:2248-2250
4. Waites KB, Taylor-Robinson D: Mycoplasma and Ureaplasma. In Manual of Clinical Microbiology. 11th edition. Edited by JH Jorgensen. ASM Press, Washington, DC, 2015, pp 1088-1105
5. Kenny GE: Genital mycoplasmas: Mycoplasma genitalium, Mycoplasma hominis, and Ureaplasma species. In Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. Edited by GL Mandell, et al. Churchill Livingstone, New York, 2008