Study of seminal infection among an infertile male population in Qom, Iran, and its effect on sperm quality

Background and Objectives: There are very few analysis tools to examine seminal fluid specimens, so bacterial infections on male infertility has always been the subject of discussion. These infectious processes lead to deterioration of spermatogenesis, impairment of sperm function, and/or obstruction of the seminal tract. In this study, we aimed at determining the role of bacterial infection on semen parameters including motility, count and normal morphology in infertile male patients. Materials and Methods: In this cohort study, 150 infertile males having abnormal semen parameters (study group) and 150 healthy fertile males (control group) were included. A total of 300 semen samples were collected after 3 to 5 days of sexual abstinence. Volume, pH, concentration, normal morphology, and motility were evaluated. Samples were seeded using a calibrated loop on agar and EMB plates, which were incubated overnight. The microorganisms were identified by Gram staining technique, catalase and coagulase tests. Results: The prevalence of seminal infection among infertile males in Qom was 21%. Among these infected samples 61.9%, 14.28%, 14.28% and 9.25% were contaminated with Staphylococcus aureus, coagulase negative staphylococci, Streptococcus and Escherichia coli, respectively. All the identified bacteria except Streptococcus caused a significant decrease in sperm concentration. Sperm motility was significantly lower in E. coli contaminated samples than in the control group, and the presence of E. coli and S. aureus led to a decline in normal morphology of the sperms. Conclusion: Sperm bacterial contamination is quite frequent and could contribute to the deterioration of the sperm quality of infertile males.