Type III Secretion System-Associated Toxins, Proteases, Serotypes, and Antibiotic Resistance of Pseudomonas aeruginosa Isolates Associated with Keratitis

• Published in: Current eye research Vol. 31; no. 4; pp. 297 - 306
• Main Authors: Zhu, Hua, Conibear, Tim C.R., Bandara, Rani, Aliwarga, Yulina, Stapleton, Fiona, Willcox, Mark D.P.
• Format: Journal Article
• Language: English
• Published: England Informa UK Ltd 01.04.2006; Taylor & Francis
• Subjects: ADP Ribose Transferases - genetics; Anti-Bacterial Agents - pharmacology; antibiotic resistance; Bacterial Proteins - genetics; Bacterial Toxins - genetics; Cytotoxicity Tests, Immunologic; Cytotoxins - genetics; Drug Resistance - genetics; Eye Infections, Bacterial - microbiology; Genes, Bacterial - genetics; Genotype; Humans; Keratitis - microbiology; Polymerase Chain Reaction; proteases; Pseudomonas aeruginosa; Pseudomonas aeruginosa - classification; Pseudomonas aeruginosa - drug effects; Pseudomonas aeruginosa - genetics; Pseudomonas aeruginosa - isolation & purification; Serine Endopeptidases - genetics; serotypes; type III secretion toxins
• ISSN: 0271-3683; 1460-2202
• DOI: 10.1080/02713680500536746

The association between possession of toxin gene-related type III secretory system, protease profiles, O serotypes, and antibiotic resistance patterns was characterized genetically and phenotypically in 46 keratitis isolates of Pseudomonas aeruginosa. There was no significant difference in exoU or exoS prevalence among the keratitis strains. Distinct protease profiles were seen in isolates harboring either exoU or exoS genes. One hundred percent (13/13) of serotype E (O:11) strains contained type III secretion system-associated cytotoxin gene exoU. Multidrug resistance was identified in 4% of Australian and 29% of Indian isolates. None of the Australian isolates was resistant to ciprofloxacin. In general, the rate of multidrug resistance in the exoU positive cytotoxic and serotype E (O:11) strains was significantly higher than in exoS positive invasive strains (p < 0.01). The results suggest that multidrug resistance may be more commonly associated with the corneal isolates of P. aeruginosa having type III secretion system-associated cytotoxin gene exoU and belonging to serotype E (O:11) group.