bla VIM-2 -Harboring Integrons Isolated in India, Russia, and the United States Arise from an Ancestral Class 1 Integron Predating the Formation of the 3′ Conserved Sequence

The metallo-beta-lactamase gene bla(VIM-2) was identified in a strain of Pseudomonas aeruginosa isolated in India. The integron encoding bla(VIM-2) was virtually identical to those recently found in the United States and Russia. These unusual structures are likely to have arisen from an ancestral integron predating the formation of the 3' conserved sequence.