Evidence for a novel bacteriophage from moraxella catarrhalis
Author(s)
Advisor
Ahmed, KamruddinDate
2005Publisher
Bilkent University
Language
English
Type
ThesisItem Usage Stats
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Abstract
Moraxella catarrhalis is one of the major causes of RTI and otitis media, which
was known as a harmless inhabitant of upper respiratory tract until 1980s. The
knowledge on virulence factors, pathogenesis of this bacterium is scarce and the
reason/(s) for recent pathogenic conversion of M. catarrhalis is/are not known.
Several examples demonstrate that bacteriophages control bacterial virulence in
almost every step of pathogenesis. Number of bacteriophages are known to be
solely responsible from bacterial virulence. We hypothesize that a bacteriophage
may be responsible for pathogenic conversion of M. catarrhalis, and we investigated
whether a bacteriophage is present in M. catarrhalis. In this study,
evidence for a bacteriophage from M.catarrhalis is presented. Supernatants of
M.catarrhalis broth cultures were shown to cause bacterial cell lysis on soft agar
cultures, indicating presence of bacteriophages released from them. Two particles
having different morphologies and different size ranges (p<0. 05) were co-purified
from these supernatants. One segment of dsDNA molecule and three segments of
ssRNA molecules were extracted from these particles. The comparison between
pathogenic and non-pathogenic strains of M.catarrhalis demonstrated marked
differences in the quantity of these RNA and DNA molecules.Future studies are
necessary to determine the origins of RNA and DNA molecules.