2. The value of genes encoding beta-lactamase to identify phenotypic beta-lactam resistance of bacteria and influence of genes encoding beta-lactamase on treatment response 24 a. CTX-M and NDM-1 were good candidates to predict Cephalosporin and Carbapenem resistance - The sensitivity of CTX-M on prediction of cephalosporin resistance to E coli and K pneumoniae was 84.9% - 90.2% and 77.8% - 89.5%, respectively.