Sperm culture and bacterial susceptibility to antibiotics in a large andrological population: prevalence and impact on seminal parameters

Background The aim of this study was to evaluate (i) the prevalence of subjects with a positive sperm culture (SC) for bacteria in subjects with or without genitourinary tract inflammation (GTI); (ii) the actual distribution of the species analysed, according to Gram stain; (iii) the impact on sperm parameters; and (iv) the actual bacterial susceptibility to antibiotics.Methods A total of 930 subjects (18-55) years, were retrospectively studied. All the patients underwent SC and in the case of positive tests (CFU> 10(6)), a microbiological susceptibility analysis. The subjects studied were subdivided into group A (n =452), with subjective signs of GTI; group B (n=478), male partners of infertile couples; and group C, 30 healthy normospermic subjects. In group B and in the control group, a semen analysis was performed.Results Overall, the prevalence of positive SC was 21.5% (200/930). The prevalence of positive SC in group A (113/200; 56.5%) was significantly higher vs. group B (87/200; 43.5%; p =0.01) and control group (1/30; 3.3%; p =0.0001). In subjects with GTI, the prevalence of asthenozoospermic (96/285; 33.7%) and oligo-asthenozoospermic (98/285; 34.4%) was significantly higher vs. normospermic, oligo-astheno-teratozoospermic, oligozoospermic and azoospermic subjects (22/285 (7.7%), 48/285 (16.8%), 15/285 (5.3%) and 6/285 (2.1%), respectively; p= 0.001). Finally, Enterococcus faecalis (Grampositive) and Escherichia coli (Gram-negative) showed the highest prevalence of antibiotic resistance.Conclusions The prevalence of positive SC is higher in GTI subjects; however, the SC could also be positive in subjects without GTI. Commonly used antibiotics have an increasing risk of being useless for the treatment of bacterial infections. Finally, the diagnosis of GTIs is important also for male fertility.