Abstract
OBJECTIVES: The present study aimed to investigate the effects of Ureaplasma urealyticum (U. urealyticum, UU) infection on sperm DNA, semen parameters and sperm quality in male patients for interpreting the proposed mechanisms of male infertility. METHODS: The morphology of sperm was observed under the standard bright-field microscope at 1000× magnification after the hematoxylin-eosin (HE) staining. All the experiments of semen biochemical parameters of seminal plasma zinc, fructose, citric acid, neutral α-glucosidase, elastase, and sperm acrosin activity were performed on the SK6000 Fully Automated Biochemical Analyzer. The values of DNA fragmentation index (DFI) and high DNA stainability (HDS) in semen were tested by using the sperm chromatin structure assay (SCSA). RESULTS: The seminal plasma elastase level increased (p = 0.0006) and sperm morphology abnormality increased in UU-positive group (p < 0.0001). There was no significant difference in each of other semen parameters including semen volume, leukocyte concentration, seminal plasma zinc, fructose, citric acid, neutral α-glucosidase, and sperm acrosin activity (p > 0.05 for each). The values of DFI in the UU-positive group were higher than those in the UU-negative group (p < 0.01), but there was no significant difference in HDS between UU-positive group and UU-negative group (p > 0.05). CONCLUSIONS: UU infection in male genital tract can not only significantly increase the seminal plasma elastase levels and sperm morphological abnormalities, but also markedly elevate sperm DNA fragmentation levels and decrease sperm DNA integrity. It may represent an important pathway contributing to male infertility.