Phenotypic differences between coryneform bacteria isolated from seminal fluid of healthy men and men with chronic prostatitis syndrome

Abstract

We compared the potential phenotypic properties of coryneform bacteria associated with chronic prostatitis syndrome (CPS), such as secretory inhibitor of lysozyme (SIL) and secretory inhibitor of platelet microbicidal protein (SIPMP). A total of 110 clinical isolates of coryneform bacteria isolated from the seminal fluid of healthy men and men with CPS were tested. SIPMP production was tested by inhibiting platelet microbicidal protein (PMP) bioactivity against Bacillus subtilis, and was expressed as percentage of inhibition of PMP bactericidal activity. SIL production was tested by inhibiting lysozyme activity against Micrococcus lysodeikticus and was expressed in microgram per millilitre of inactivated lysozyme. A significantly higher proportion of CPS strains (58.7% vs. 19.2 %) was SIPMP-positive compared with non-CPS strains (P < 0.01). Of the CPS strains tested, 77.8% were SIL-positive compared with 34% of the non-CPS isolates (P < 0.05). These results suggest that the diagnosis of CPS should not rely solely on classical parameters, for example, the identification and counting of microorganisms, but the functional significance of these parameters must be estimated, possibly by the concentration of different bacterial substrains, detection of opportunistic microorganisms with pathogenic properties, such as pronounced resistance to the cationic antimicrobial peptides, and/or the ability to inhibit the antimicrobial host defence factors.