TABLE 1.
Published studies examining the relationship between Ureaplasma spp. and NGUa
| Authors (yr) | Reference | Country of study | Patient group | Sample type | No. of participants | Method of identification | Differentiation of Ureaplasma spp. | Key findings relating to Ureaplasma spp. |
|---|---|---|---|---|---|---|---|---|
| Frolund et al. (2016) | 45 | Sweden | Male patients attending STD clinic | First-void urine | 187 men with acute NGU, 24 men with chronic NGU, and 73 men without NGU | Species-specific qPCR | Yes | The number of lifetime sexual partners was negatively associated with the U. urealyticum load. |
| Urine containing U. urealyticum with >1.3 × 103 genome equivalents/ml was associated with NGU. | ||||||||
| Cox et al. (2016) | 41 | UK | Male patients attending a GUM clinic | Urine | 75 men with NCNGU and 90 men without NCNGU | Species-specific real-time PCR | Yes | The prevalence of U. parvum was significantly higher in the NCNGU group. |
| There was no association between U. urealyticum and NCNGU. | ||||||||
| Khatib et al. (2015) | 19 | UK | Males attending an urban sexual health clinic | Urine | 83 men with urethritis | Multiplex PCR | Yes | Only four patients were positive for U. urealyticum. |
| Deguchi et al. (2015) | 48 | Japan | Retrospective study of men attending a urology clinic | First-void urine | 15 symptomatic men and 38 asymptomatic men | qPCR | Yes | A U. parvum load of >5 × 103 cells/ml was significantly associated with >12.5 leucocytes/μl of urine. |
| 83% of subjects had <5 × 103 cells/ml, suggesting a low bacterial load and a lack of signs of inflammation. | ||||||||
| Zhang et al. (2014) | 40 | Multiple countries | Meta-analysis | NA | 1,507 men with NGU and 1,223 men without NGU | NA | Yes | No significant difference in the undifferentiated Ureaplasma species-positive rate was found between the NGU and control groups. |
| When the species was differentiated, U. urealyticum was significantly associated with the NGU group, whereas U. parvum was significantly associated with the control group. | ||||||||
| Shimada et al. (2014) | 47 | Japan | Retrospective study of men attending a urology clinic | First-void urine | 25 symptomatic men and 26 asymptomatic men | Species-specific qPCR | Yes | The bacterial load of U. urealyticum was positively correlated with NGU and the number of leukocytes in urine. |
| Wetmore et al. (2011) | 17 | USA | Men attending an STD clinic | Urine | 329 men with NGU, control group 1 consisting of 191 males without NGU attending an STD clinic, and control group 2 consisting of 193 males without NGU attending an emergency room | Culture | Yes | U. urealyticum was associated with NGU. |
| The association was significantly stronger when analyzing men with <10 vaginal partners. | ||||||||
| The association was further strengthened when analyzing men with <5 vaginal partners. | ||||||||
| U. parvum was not associated with NGU. | ||||||||
| Couldwell et al. (2010) | 38 | Australia | Men attending a sexual health clinic | First-void urine | 237 men with NGU and 268 controls | PCR | Yes | U. urealyticum was significantly associated with NGU in the absence of another urethral pathogen. |
| Ondondo et al. (2010) | 21 | USA | Archived samples from heterosexual males attending an STD clinic | Urine | 119 men with NGU and 117 controls | PCR | Yes | U. urealyticum was strongly associated with NGU. |
| This association was the strongest in men <28 yr of age. | ||||||||
| U. parvum was not associated with NGU. | ||||||||
| Yu et al. (2008) | 18 | Hong Kong | Males attending a government STD clinic | Urine | 98 men with NGU and 235 controls | Real-time PCR targeting the urease gene | No | Neither Ureaplasma nor M. genitalium was associated with symptomatic NGU. |
| Bradshaw et al. (2006) | 39 | Australia | Men attending a sexual health clinic | First-stream urine | 329 men with NGU and 307 controls | PCR | Yes | Neither U. urealyticum nor U. parvum was associated with NGU. |
| Povlsen et al. (2002) | 36 | Sweden | Men attending a sexual health clinic | Urethral swab | 125 men with NGU and 205 without NGU | PCR | Yes | No difference was found between the NGU and non-NGU group if ureaplasmas were not differentiated to the species level. |
| When differentiated, significantly more U. urealyticum bacteria were associated with males with NGU than those without. | ||||||||
| Horner et al. (2001) | 16 | UK | Heterosexual men with NGU and a control group | First-pass urine | 114 men with NGU and 64 without NGU | Culture | No | Ureaplasmas were not associated with acute NGU. |
| Ureaplasmas were associated with NGU during follow-up. | ||||||||
| Ureaplasmas were associated with chronic NGU. |
a
qPCR, quantitative PCR; NCNGU, nonchlamydial nongonococcal urethritis; NA, not applicable.