RESUMEN
<p><b>Objective</b>To explore Mycoplasma genitalium (MG) infection in the urogenital tract of infertile men and its influence on semen quality.</p><p><b>METHODS</b>Semen samples were collected from 352 infertile males in the Center of Reproductive Medicine of Nanjing General Hospital from March to July 2015. MG infection was detected by real-time fluorescence simultaneous amplification and testing and semen analyses were conducted according to the WHO Laboratory Manual for the Examination and Processing of Human Semen (5th Ed) on the semen pH value, semen volume, total sperm count, sperm concentration, total sperm motility, percentages of progressively motile sperm (PMS) and immotile sperm (IMS), and sperm DNA fragmentation index (DFI). The data obtained were subjected to statistical analysis by t-test and non-parametric test (Wilcoxon test).</p><p><b>RESULTS</b>MG infection was found in 3.4% (12/352) of the infertile patients. Compared with the MG-positive cases, the MG-negative ones showed a significantly higher semen volume (［2.85 ± 0.14］ vs ［3.84 ± 0.12］ ml, P = 0.008) and percentage of PMS (［15.86±1.72］ vs ［60.95 ± 5.63］ %, P = 0.032) but a lower DFI (［30.73 ±2.24］ vs ［20.71 ± 1.55］%, P = 0.014). However, no statistically significant differences were observed between the two groups in the semen pH value (7.38 ±0.02 vs 7.39 ± 0.01, P = 0.774), sperm concentration (［52.96 ± 15.78］ vs ［60.05 ± 4.29］×10⁶/ml, P = 0.683), sperm count (［154.15 ± 46.37］ vs ［221.56 ± 15.43］×106, P = 0.236), total sperm motility (［29.04 ± 3.11］ vs ［33.52 ± 1.51］ %, P = 0.626), or percentage of IMS (［23.57 ± 0.99］ vs ［62.34 ± 1.69］ %, P = 0.691).</p><p><b>CONCLUSIONS</b>Urogenital MG infection is common in infertile males and potentially affects the semen quality, especially sperm vitality of the patient.</p>