Fig. 2

Schematic representation of the various cassette arrays found in class 1 and class 2 integrons. The arrows display the open reading frames of the different genes. All aadA and aadB genes are presented as white arrows, dhfrA, aacA4, orfD, oxa2, catB, cmlA6, sat2 genes are presented as black, yellow, light grey, grey, blue and light blue arrows respectively. The grey light boxes indicate the 3′ and 5′ CSs of class1 or class 2 integrons