Moraxella catarrhalis'den edinilen yeni bir bakteriyofaj'a dair bulgular

Moraxella catarrhalis is one of the major causes of RTI and otitis media, whichwas known as a harmless inhabitant of upper respiratory tract until 1980s. Theknowledge on virulence factors, pathogenesis of this bacterium is scarce and thereason/(s) for recent pathogenic conversion of M. catarrhalis is/are not known.Several examples demonstrate that bacteriophages control bacterial virulence inalmost every step of pathogenesis. Number of bacteriophages are known to besolely responsible from bacterial virulence. We hypothesize that a bacteriophagemay be responsible for pathogenic conversion of M. catarrhalis, and we inves-tigated whether a bacteriophage is present in M. catarrhalis. In this study,evidence for a bacteriophage from M.catarrhalis is presented. Supernatants ofM.catarrhalis broth cultures were shown to cause bacterial cell lysis on soft agarcultures, indicating presence of bacteriophages released from them. Two particleshaving different morphologies and different size ranges (p<0. 05) were co-purifiedfrom these supernatants. One segment of dsDNA molecule and three segments ofssRNA molecules were extracted from these particles. The comparison betweenpathogenic and non-pathogenic strains of M.catarrhalis demonstrated markeddifferences in the quantity of these RNA and DNA molecules.Future studies arenecessary to determine the origins of RNA and DNA molecules.Keywords: Moraxella catarrhalis, bacteriophage, virulence.iii