Introduction: In humans, anti-sperm antibodies are a common cause of infertility. 10% to 30% of infertile couples credit ASAs for their problem. The mechanisms through which ASA is produced in either sex remains elusive. The current manifestations of ASAs, which may be cross-reactive antibodies produced against microbial antigen, have been recently elucidated (bacteria, viruses, fungi, allergens). Common antigens between microorganisms and humans have long been suspected as contributing to autoimmune diseases. Material and Methods: Serum was taken from infected animals on day 45 for agglutination testing and FITC binding experiments to detect ASAs after intraperitoneal inoculum of different bacteria in test and PBS in control. The agglutination of the bacterial strains and spermatozoa was evaluated by combining them with the serum from infected mice and control serum. FITC-binding investigations included labelling serum with the FITC dye and then incubating it with bacteria and spermatozoa in order to determine whether the ASAs were formed or not. Results: In the agglutination test, it was observed that serum from mice infected with the bacterial strains elicits agglutination with both bacteria and spermatozoa, but no agglutination was detected in control serum. Whereas in FITC studies the PBS administrated mice’s FITC-tagged control serum exhibited no fluorescence with bacteria and spermatozoa. However, FITC-labeled test serum from mice infected with Proteus mirabilis, Serratia marcescens, and Escherichia coli fluoresced brilliantly green on bacterial surfaces and on complete spermatozoa. Conclusion: Present research indicates that bacteria and spermatozoa have an antigenic similarity that triggers a cross-reaction.