Staphylococcal secretory inhibitor of platelet microbicidal protein is associated with prostatitis source

Department of Human Microbiology, Institute of Cellular and Intracellular Symbiosis, Russian Academy of Sciences, Orenburg, Russia Correspondence Iuri B. Ivanov mil-for{at}rambler.ru Received 1 June 2006 Accepted 16 August 2006 This study reports the detection of an extracellular staphylococcal product, designated secretory inhibitor of platelet microbicidal protein (SIPMP), that causes local inhibition of the bactericidal action of platelet microbicidal protein (PMP) in the fluid phase. Urethral isolates of Staphylococcus aureus ( n =24) and coagulase-negative staphylococci (CNS) ( n =47) from patients with or without chronic bacterial prostatitis (CBP) were tested. SIPMP production was tested by inhibition of PMP bioactivity against Bacillus subtilis and was expressed as percentage inhibition of PMP bactericidal activity. The PMP susceptibility of staphylococcal strains was determined by exposing bacterial cells to serial dilutions of PMP. Staphylococci from patients without CBP produced SIPMP at levels of 10.3±1.2 and 13.25±1.72 % for S. aureus and CNS, respectively. Strains isolated from men with CBP inhibited PMP-induced killing of B. subtilis by 23.38±4.2 % ( P