PCR amplification of four genes coding for aminoglycoside-modifying enzymes in bacteria of clinical isolates from Jordan University Hospital

Three species of Gram-negative G(-) bacteria were chosen for this study: Escherichia spp. (29 isolates), Pseudomonas spp. (16 isolates) and Enterobacter spp. (17 isolates), utilizing colony PCR to detect genes coding for aminoglycoside-modifying enzymes. The 62 isolates were purified and cultured on nutrient broth media supplemented with 50 mug kanamycin/ml. Only 17 out of the 62 isolates were resistant to kanamycin and were subjected to colony PCR protocol using 20 mul cell lysate and eight sets of primers with each isolate. Sizing of the amplified fragments was carried out in order to determine the specificity of PCR. The 17 isolates were shown to carry the rrs, aacC2, aacA-aphD and aphA3 genes.