In vitro activity of pristinamycin against respiratory tract germs

Two-phase action: Pristinamycin is composed of two active substances A and B. Pristinamycin A(SA) first binds to the ribosome subunit 50s. Pristinamyc in B (SB) then locks onto SA causing irreversible inhibition of bacterial p rotein production. Well-adapted activity spectrum: A member of the streptogramin family of ant ibiotics, pristinamycin is active against the main bacteria causing respira tory tract infections (pneumococci; S. aureus, H. influenzae) as well as ag ainst mycoplasma and anaerobic pathogens. Anti-pneomococci activity: Minimal inhibitory concentrations measured over the last 5 years have confirmed that the antibacterial activity of pristina mycin against pneumococci remains unchanged even for-strains which develop resistance to other antibiotics, particularly to penicellin or erythromycin . Other bacteria: The activity of pristinamycin against H. influenzae is a co nstant finding (unimodal distribution of MIG). The persistent of pristinamy cin activity against S. aureus strains, excepting a few, SA-resistant strai ns and SA+SB-resistant strains, is remarkable. MIC studies have also demons trated the constant susceptibility of Moraxella catarrhalis, non-groupable streptococci, anaerobic bacteria, and Legionello pneumophila.