سمية نجم عبد علي الخطيب

Resistance mechanism of aminoglycoside is the inactivation of enzyme action (aminoglycoside modifying enzymes (AMEs) for example. aminoglycoside phosphotransferase, acetyltransferase and nucleotidyltransferas) by the genes in plasmids or transposons. aacA-aph Dcoded by aac(6′)gene, it is the most commonly encountered AMEs in staphy.aureus. Other AMEs are aph(3”)-IIIa (phosphotransferases) diffusion method. All of the genes were investigated by polymerase chain reaction (PCR) methods. Fifty MRSA strains samples were determined by the polymerase chain reaction (PCR) methods, for the detection of genes (three types): aaacA-aphD, aaadD andaaph (3”) - IIIa. The obtained results were correlated genotyping with the susceptibility of the antibiotics (gentamicin, tobramicin, kanamicin, neomicin, amikacin and netilmicin). aacA-aphD,aaaadD and aph(3”) – IIIa genes (positive strains) were methicillin - resistant staphylococci. The aacA-aphDwas the most commonly detected.