Ocular Microbiology and Immunology Group
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2013 OMIG Abstract 12

Ocular Isolates of Pseudomonas aeruginosa Produce the Exopolysaccharide Psl
Amanda Naimie¹, Antonio DiGiandomenico², Robert M.Q. Shanks⁴, Michael E. Zegans^1,3
1Dept. of Microbiology and Immunology, ³Dept. of Surgery (Ophthalmology), Geisel School of Medicine at Dartmouth, Hanover, NH, ²MedImmune LLC, Infectious Diseases/Vaccines, Gaithersburg, MD,
⁴Dept. of Ophthalmology, Campbell Laboratory, University of Pittsburgh School of Medicine, Pittsburgh, PA

Purpose:  Pseudomonas aeruginosa is capable of producing 3 known exopolysaccharides (EPS) - Psl, Pel and alginate. Not all strains produce all three types of EPS, and the production of certain EPS (e.g. alginate in Cystic Fibrosis) has been associated with specific disease states. EPS has been implicated in biofilm formation and virulence; however until recently it has been technically difficult to determine EPS production in clinical isolates. We present our characterization of clinical eye isolates of P. aeruginosa for Psl production using a recently described monoclonal antibody.

Methods: A Pseudomonas whole cell ELISA was used to characterize Psl production of unique clinical eye isolates and laboratory strains. Planktonic bacterial cultures of 44 clinical isolates, PA14 (Psl non-producer), 2 psl promoter mutants and PA01 (Psl producer) were tested with WapR-001: anti-Psl mAb (MedImmune).

Results: Psl was reliably detected in the Psl positive control strain PAO1. Psl was not detected in the negative control strain PA14 or 2 psl promoter mutants, validating the methodology. 43 of the 44 clinical isolates tested produced Psl comparable to that of PAO1 wild-type levels.

Conclusions:  Large scale characterization of Psl production has not previously been reported for Pseudomonas aeruginosa clinical eye isolates. We found that the majority of clinical eye isolates examined produced Psl similar to PAO1 wild-type levels. Given these preliminary data, further study of Psl both as a potential therapeutic target and for its role in the biology of ocular infection is warranted.

Disclosure: E - A DiGiandomenico is a MedImmune employee.

2013 Agenda and Abstracts | < Previous | Next >