co-occurrence of seminal bacteriospermia, sperm functional impairment, and anti-sperm antibody positivity in male infertility: a case-control study

Introduction:bacterial infections and anti-sperm antibodies (asa) are significant factors contributing to male infertility. this study examines the relationship between bacterial infection and asa presence in the seminal fluid of infertile males.materials and methods:a case-control study was conducted from november 2024 to august 2025 at dr. nyaz omer rostam clinic, sulaymaniyah, iraq. eighty married men aged 20–40 years with abnormal semen analysis were enrolled and divided into two groups: 40 with confirmed bacterial infections (case group) and 40 without (control group). semen analysis, bacterial culture, and mar test for asa were performed according to who 2021 guidelines.results:the case group (cg) (n=40) exhibited significantly lower sperm motility (30.10% ± 12.05 vs. 44.48% ± 4.60; p ≤ 0.001), viability (55.78% ± 8.04 vs. 63.95% ± 6.26; p ≤ 0.001), and normal morphology (3.05 ± 1.44 vs. 4.78 ± 0.768; p ≤ 0.001) compared to controls (n=40). semen volume was higher in the cg (3.85 ± 1.69 ml vs. 3.18 ± 1.29 ml; p = 0.05). no significant differences were observed in sperm concentration or total sperm count. bacterial cultures were positive in 40 (100%) of the cg, with enterococcus faecalis detected in 10 (25%) and staphylococcus haemolyticus in 8 (20%), while all controls (0%) were negative (p ≤ 0.001). mar test positivity (≥30%) was observed in all of the cg and in none of the controls (0%) (p ≤ 0.001).conclusion:the present study demonstrated that bacterial infections in the semen of infertile men are significantly associated with reduced sperm quality (especially motility, viability, and normal morphology.