EFFECT OF QUORUM QUENCHING WITH AZITHROMYCIN ON PSEUDOMONAS AERUGINOSA ASSOCIATED OTITIS EXTERNA/MEDIA IN DOGS

摘要

Many bacteria can express their virulence via quorum sensing (QS); in Pseudomonas aeruginosa (PA) the QS signal molecules are N-acyl-homoserine lactones (PA-AHLs). The use of QS blockers or quorum quenching (QQ) to attenuate bacterial growth and virulence is a new strategy for treatment of resistant bacterial pathogens. Azithromycin (AZ) expresses in-vitro and in-vivo QQ effect, and is used clinically to reduce PA virulence. Hypotheses were tested that topical treatment with AZ will: 1) Attenuate theformation of most common PA-AHLs: N-butyryl-L-homoserine lactone (BHL), N-decanoyl-L- homoserine lactone (HHL) and N-(3-oxo-dodecanoyl)-L-homoserine-lactone (OdDHL); 2) Enhance PA clearance from the ear canal; 3) Have a positive effect on ear canal sample cytology; and 4) Reduce the severity of clinical signs related to PA associated otitis externa/media (PAOEM) in dogs.