Two novel class I integron arrays containing IMP-18 metallo-β- lactamase gene in Pseudomonas aeruginosa clinical isolates from Puerto Rico

During a β-lactam resistance surveillance study, 12 IMP-18-positive Pseudomonas aeruginosa isolates belonging to 9 different pulsed-field gel electrophoresis groups were identified. In nine isolates, a class I integron with a novel gene array was identified that contained bla _IMP-18 and bla _OXA-224, while in two isolates the class I integron contained bla _IMP-18 and bla _OXA-2 but in a new arrangement. Our findings show the dissemination of two novel class I integrons in P. aeruginosa from different regions of Puerto Rico.