Detection of new arr-4 and arr-5 gene cassettes in clinical Pseudomonas aeruginosa and Klebsiella pneumoniae strains from Brazil.

New arr alleles emerged in class 1 integrons from a clinical Pseudomonas aeruginosa strain (arr-4) and four Klebsiella pneumoniae strains (arr-5) in Brazil/American continent. arr-4 was preceded by aacA7-catB3, whereas arr-5 was the unique cassette. The putative proteins shared 75% (Arr-5) and 78% (Arr-4) identities with Arr-2.