Molecular heterogeneity of bla(VIM-2)-containing integrons from Pseudomonas aeruginosa plasmids encoding the VIM-2 metallo-beta-lactamase

A bla(VIM-2) metallo-beta -lactamase determinant, identical to that previou sly identified in Pseudomonas aeruginosa COL-1 isolate from a French hospit al, was detected on a 28-kb plasmid carried by a nosocomial isolate of P. a eruginosa from Verona, Italy. In this plasmid the bla(VIM-2) determinant wa s inserted into a class 1 integron of original structure, named In72, that contains a partially deleted int11 integrase gene and two gene cassettes. T he first cassette carries an aacA4 aminoglycoside acetyl transferase determ inant. The second cassette carries a bla(VIM-2): determinant followed by a partially deleted attC site. The structure of In72 was notably different fr om that of In56, the bla(VIM-2)- containing integron found in the COL-1 iso late, revealing the existence of molecular heterogeneity among bla(VIM-2)-c ontaining integrons in clinical isolates of P. aeruginosa from Europe. (C) 2001 Federation of European Microbiological Societies. Published by Elsevie r Science B.V. All rights reserved.