Сomparative immune resistance of Enterococci and Staphylococci isolated in chronic bacterial prostatitis

The aim of the study was to conduct a comparative analysis of immunoresistance factors in enterococci and staphylococci strains isolated in chronic bacterial prostatitis (CBP). In vitro studies were conducted on 24 clinical strains of Gram-positive cocci of different species: Enterococcus faecalis (n = 6), Staphylococcus aureus (n = 6), coagulase-negative staphylococci (CoNS): S. haemolyticus (n = 6), S. epidermidis (n = 6), isolated from prostatic secretion in men with CBP. Antilysozyme activity (ALA) of bacteria and their ability to form biofilms (BFA) were determined photometrically; sIgA protease activity of bacteria and their anticytokine activity (ACA) in relation to pro- and anti-inflammatory cytokines (IL-6, IL-8, IL-17A, TNFα and IL-4) were determined by the enzyme immunoassay. The obtained data were processed by the methods of variation statistics and the Spearman correlation criterion. Upon the comparative analysis of immunoresistance factors in enterococci and staphylococci isolated in CBP, no significant differences in the expression levels of ALA, BPO, and ACA in relation to IL-8 and TNFα were revealed between the isolates of bacteria of the studied species, but their interspecies variability in sIgA protease expression and ACA against IL-4, IL-6, and IL-17A were noted. The results of correlation analysis have shown a close positive relationship between the expression of ACA IL-8 and ACA IL-6 in CoNS and S. aureus isolates, as well as between sIgA protease activity and ACA IL-6 in CoNS and E. faecalis strains. Inverse correlations were found between ACA to IL-8 and ACA to IL-17A, ACA IL-8 and BFA. Moreover, BFA and ACA to TNFα were detected in E. faecalis. These results allowed us to characterize a number of immunoresistance factors associated with inactivation/suppression of antimicrobial defense mechanisms in clinical strains of E. faecalis, S. aureus and CoNS of different species isolated from patients with CBP, which may contribute to the survival and long-term persistence of pathogens in the prostate gland. Further studies in this area can provide new practically useful data, including information related to the prediction of persistence for distinct bacterial strains.