Summary of the strains used in this study.

aObtained with 5′-CS and 3′-CS primers [24]. bThe resistance trait was used for selection in the natural transformation assays. cTransformants obtained after exposure to these sources of DNA were only tested at the phenotypic level. dObtained by natural transformation of A. baylyi BD413 with purified DNA from A. baumannii 064. Integron acquisition was shown first by PCR, which explains the antimicrobial susceptibility profile of the tested antibiotics. The PFGE profile obtained with restriction digestion using the enzyme I-CeuI revealed unexpected bands that co-hybridized with the probe for intI1 gene in Southern blot. eObtained by natural transformation of A. baylyi BD413 with purified DNA from S. enterica serovar Thypimurium 490. Integron acquisition was shown first by PCR, which explains the antimicrobial susceptibility profile of the tested antibiotics. Initial sequencing of the integron flanking regions, by primer walking, showed that the acquired fragment was large; suggestive of the possible acquisition of a plasmid (excluded after sequencing). Rresistance; CN – gentamicin, CTX – cefotaxime, K – kanamycin, R – rifampicin, SC – spectinomycin, W – trimethoprim. n.d.- not determined.