Detection of Pseudomonas aeruginosa isolates carrying the blaOXA-142 extended-spectrum β-lactamase gene in Taiwan

Background/Purpose The emergence of extended-spectrum β-lactamase (ESBL) OXA-142 gene (blaOXA-142) in Pseudomonas aeruginosa has been reported in Bulgaria and other European countries, but rarely in Asia. Methods From January 2009 to December 2012, 90 P. aeruginosa isolates with reduced susceptibility or resistance to ceftazidime (minimum inhibitory concentration ≥ 8 mg/L) were screened for ESBL and other broad-spectrum β-lactamase genes by polymerase chain reaction and sequencing. Clonal relationship of the isolates was determined by pulsed-field gel electrophoresis. Results Three isolates were positive for ESBL production, exhibited resistance to ceftazidime, and carried the blaOXA-142 gene. The blaOXA-142 gene was integrated into class 1 integron. Using Southern blot analysis, blaOXA-142-containing integron was found to be located on a plasmid in all three isolates. Eleven strains of P. aeruginosa carrying blaOXA-17 gene were found. The oprD mutation was found in all the 21 ESBL strains of P. aeruginosa. Conclusions This study confirmed the presence of blaOXA-142-positive P. aeruginosa isolates in Taiwan.