b. The influence of genes encoding beta-lactamase on treatment response - In BSI patients caused by cephalosporin susceptible strains, the clinical outcome was worse in group with CTX-M positive (shock 21.6% - 33.3% and mortality 18.9% - 26.7%) than group with CTX-M negative (shock 14.6% - 19.2% and mortality 10.4% - 15.4%), duration of fever after diagnosis, length of hospital stay was significant longer in group with CTX-M positive.