Features of antibiotic resistance in the Pseudomonas aeruginosa strains with a class I integron carrying new array of gene cassettes

Objective To analyze the characteristics of antibiotic resistance in the P. aeruginosa strains with a class Ⅰ integron carrying new array of gene cassettes.Methods PCR-RFLP method was used to detect and type the integron. Long-PCR was used to amplify the variable region of the integron. DNA sequencing analysis was finally applied to confirm the antibiotic resistance gene. Metallo-beta-lactamase gene and oprD2 gene were amplified by PCR.Results P. aeruginosa PA27 has a class Ⅰ integron which has a 3.0 kb length variable region,containing gene cassettes resistant to aminoglycosides,chloramphenicol and β-lactam antibiotics. A new array of gene cassettes in the integron:aac(6')-Ⅱ-cmlA8-OXA-10 was confirmed by comparing with GenBank database by BLAST. EU708817 is the GenBank accession number. Meanwhile PA27 was positive for oprD2 gene,negative for IMP-1,VIM-2 and IMP-2 MBL by PCR.Conclusions A class Ⅰ integron carrying new array of gene cassettes was identified in our region for the first time. This structure carries multi-antibiotic resistance genes should be paid close attention in the clinic.