摘要Aim: To report the detection in vitro of secretory inhibitor of platelet microbicidal protein (SIPMP) phenotypes of urethral isolates along with a comparison with isolates from patients with or without chronic bacterial prostatitis (CBP). Methods: Urethral isolates of Staphylococcus spp. (n = 64), diphtheroids (n = 28), micrococci (n = 15),streptococci (n = 21), Enterobacteriaceae (n = 9) and Enterococcusfaecalis (n = 19) from patients with or without CBP were tested. SIPMP production was tested by inhibition of platelet microbicidal protein (PMP) bioactivity against Bacillus subtilis and was expressed as percentage of inhibition of PMP bactericidal activity. Results: A significantly higher proportion of CBP-strains (57.78% vs. 16.67%) reduced PMP-induced killing of Bacillus subtilis than non-CBP strains did (P < 0.01), SIPMP levels of staphylococci and Enterococcusfaecalis from the CBP group were significantly higher than those of the control group. Conclusion: These results suggest that SIPMP production is associated with the CBP source. Data from the present study might have significant implications for the understanding of the pathogenesis of CBP.