title: Comparison of virulence factors in Pseudomonas aeruginosa strains isolated from contact lens- and non-contact lens-related keratitis.
abstract: Pseudomonas aeruginosa is one of the common pathogens associated with corneal infection, particularly in contact lens-related keratitis events. The pathogenesis of P. aeruginosa in keratitis is attributed to the production of virulence factors under certain environmental conditions. The aim of this study was to determine differences in the virulence factors of P. aeruginosa isolated from contact lens- and non-contact lens-related keratitis. Associations were assessed between type III secretion toxin-encoding genes, protease profiles, biofilm formation, serotypes and antibiotic-resistance patterns among 27 non-contact lens- and 28 contact lens-related P. aeruginosa keratitis isolates from Australia. Strains with a exoS+/exoU- genotype and a type I protease profile predominated in the non-contact lens-related keratitis isolates, whereas the exoS-/exoU+ and a type II protease profile was associated with contact lens-related isolates (P<0.05). A strong biofilm formation phenotype was found to be associated with the possession of the exoU gene, and serotypes E, I and C. The exoS gene was strongly associated with serotypes G, A and B, while exoU was associated with serotypes E and C. Six out of fifty-five (11 %) clinical isolates were non-susceptible (intermediate-resistant or resistant) to ofloxacin and moxifloxacin. All resistant isolates were from non-contact lens-related keratitis. The results suggest that P. aeruginosa isolates from different infection origins may have different characteristics. A better understanding of these differences may lead to further development of evidence-based clinical guidelines for the management of keratitis.
authors.affiliation: Vision Co-operative Research Centre, Sydney, Australia.|School of Optometry and Vision Science, University of New South Wales, Sydney, Australia.
authors.forename: Man H
authors.initials: MH
authors.lastname: Choy
authors.affiliation: Institute for Eye Research, Rupert Myers Building, Gate 14 Barker Street, University of New South Wales, Sydney, Australia.|Vision Co-operative Research Centre, Sydney, Australia.|School of Optometry and Vision Science, University of New South Wales, Sydney, Australia.
authors.forename: Fiona
authors.initials: F
authors.lastname: Stapleton
authors.affiliation: Institute for Eye Research, Rupert Myers Building, Gate 14 Barker Street, University of New South Wales, Sydney, Australia.|Vision Co-operative Research Centre, Sydney, Australia.|School of Optometry and Vision Science, University of New South Wales, Sydney, Australia.
authors.forename: Mark D P
authors.initials: MDP
authors.lastname: Willcox
authors.affiliation: Institute for Eye Research, Rupert Myers Building, Gate 14 Barker Street, University of New South Wales, Sydney, Australia.|Vision Co-operative Research Centre, Sydney, Australia.|School of Optometry and Vision Science, University of New South Wales, Sydney, Australia.
authors.forename: Hua
authors.initials: H
authors.lastname: Zhu
mesh_terms: D036002:ADP Ribose Transferases; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001315:Australia; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D018441:Biofilms / Q000254:growth & development; D003261:Contact Lenses / Q000009:adverse effects*; D024881:Drug Resistance, Bacterial; D005838:Genotype; D006801:Humans; D007634:Keratitis / Q000382:microbiology*; D008826:Microbial Sensitivity Tests; D010641:Phenotype; D011552:Pseudomonas Infections / Q000382:microbiology*; D011550:Pseudomonas aeruginosa / Q000145:classification* / Q000187:drug effects / Q000302:isolation & purification / Q000472:pathogenicity*; D012703:Serotyping; D037521:Virulence Factors
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D037521:Virulence Factors; C111749:pseudomonas exoprotein A protein, Pseudomonas aeruginosa; D036002:ADP Ribose Transferases; C444820:exoenzyme S