[Characteristics and clinical value of extended-spectrum beta-lactamases].

The literature data and the findings of the authors' studies on the role of extended-spectrum bata-lactamases (ESBL) in providing the clinical effect in the treatment of infections due to ESBL-producing organisms were analyzed. The analysis allowed to consider the NCCLS recommendations not sufficiently valid. According to these recommendations the ESBL-producing organisms (among E. coli and Klebsiella spp.) should be regarded as resistant to penicillins, cephalosporins and aztreonam. Susceptibility of 62 Enterobacteriaceae strains that were isolated in 4 therapeutic centres of Tomsk, Nazran and Moscow and proved to be ESBL-producing organisms was tested and it was shown that the 3rd and 4th generation cephalosporins could not be referred to a homogenous group. The same was confirmed by the prospective and retrospective investigations of a multiprofile hospital on the clinical and bacteriological efficacies of the 3rd generation cephalosporins and cefepime in the treatment of hospital-acquired infections due to Enterobacteriaceae strains producing ESBL.