ACTIVITY OF MCCJ25 AND ITS ANALOGOUS MCCJ25-T9P ON Salmonella newport INSIDE OF MACROPHAGE

LOPEZ FE,; ZENOFF AM, MA, FARIAS RN.; VINCENT PA, ,; SALOMON RA; DELGADO MA; FARIAS RN

BIOCELL 32 (Suppl.), 2008 pag 106

Congreso; SAIB 2008; 2008

SAIB

The microcin J25 (MccJ25) is an antibiotic of 21 amino acid residues, active against Escherichia coli, Salmonella and Yersinia strains. Convincing evidence shown that RNA polymerase (RNAP) and respiratory chain membrane are the targets for MccJ25 action. We study the ability of this antibiotic to internalize inside of macrophages reaching an intracellular concentration required to inhibit the S. newport cells replication. The monolayer of infected macrophages was treated with 1 and 5 µM MccJ25 and a recount of CFU/ml at different times was carried out. The viable recount with 1µM of MccJ25 was of 6.1; 5.55 and 4.95 units log10 and with 5 µM of MccJ25 it was of 5.71; 5.37 and 4.94 units log10; at 6, 18 and 24 hours post-infection, respectively. In both cases we observed a decrease of two log10 units, approximately, compared wiht the untreated macrophage as a control. The same difference in viable recount was obtained when the experiment was performed with 1 and 5 µM of the MccJ25 variant, MccJ25 T9P. Any effect of the MccJ25 on the Salmonella invasion ability was observed when the macrophages were pretreated with the antibiotic. No morphological or viability changes was observed when the macrophages were incubated with MccJ25 or MccJ25 T9P. Our results could be useful for potential therapeutic application of this antibiotic in the control of Salmonella human infection.