Journal of Bacteriology & Parasitology

Isualizing novel macrolide antibiotics bound to their ribosomal target

3^rd International Congress on Bacteriology and Infectious Diseases

August 04-06, 2015 Valencia, Spain

Stephen Douthwaite

Posters-Accepted Abstracts: J Bacteriol Parasitol

Abstract:

Respiratory tract infections in cattle are commonly associated with the bacterial pathogens Mannheimia haemolytica
and Pasteurella multocida, and are treated with several types of veterinary antibiotics including macrolides. Tildipirosin
(20,23-dipiperidinyl-mycaminosyl-tylonolide) is a semi-synthetic macrolide derived from the naturally occurring compound
tylosin. Compared to tylosin and tilmicosin (an earlier tylosin-derivative), tildipirosin is effective against macrolide-susceptible
isolates, and retains activity against some of the recently emerging resistant strains (1-3). Here, the molecular interactions of
the macrolides are mapped and visualized at their inhibitory target on the bacterial ribosome.
Tildipirosin, tilmicosin and tylosin all bind and inhibit the drug site within the large subunit of the bacterial ribosome.
There are, however, subtle differences in how they occupy the site. Interactions of the two piperidine components, which
are particular to tildipirosin (green), indicate how its mode of action is distinct from tylosin, tilmicosin (magenta) and the
15-membered macrolide tulathromycin (red) (4).
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