Genetic Background of Antimicrobial Resistance in Multiantimicrobial-Resistant Escherichia coli Isolates from Feces of Healthy Broiler Chickens in Tunisia

Figure 1

Gene cassette arrangements included in the class 1 integrons detected in 20 class 1 integron-positive E. coli strains. IntI1: gene encoding integrase of class 1 integron; dfr1, dfrA5, dfrA12, and dfrA17: genes encoding trimethoprim resistance; aadA1 and aadA2 and aadA5: genes encoding streptomycin/spectinomycin resistance; qacE∆1: gene encoding quaternary ammonium; sul1 and sul3 (in inversion direction): genes encoding sulfonamide resistance; cmlA: gene encoding chloramphenicol resistance. orfF: open reading frame of unknown function; IS440: insertion section 440.