[Efficacy of cefixime and cefepime vs. other cephalosporins in experimental plague of albino mice due to variants FI+ and FI- of the plague microbe].

Efficacy of cefixime and cefepime vs. ceftriaxone, cefotaxime, ceftazidime and cefoperazone was studied in vitro and in the treatment of experimental plague of albino mice due to natural, antigen complete strains of the plague microbe and the pathogen variants deprived of the ability to produce the capsule antigen fraction I (FI- phenotype). The MICs of cefixime and cefepime for 20 FI+ and 20 FI- strains of the plague microbe were 0.02-0.08 mg/l, that corresponded to the MICs of ceftriaxone, cefotaxime and ceftazidime. The MICs of cefoperazone were somewhat higher (0.1-0.2 mg/l). The ED50 values of cefixime and cefepime for prevention and treatment of experimental plague in mice statistically did not significantly differ from the ED50 values of ceftriaxone, cefotaxime, ceftazidime and cefoperazone. The efficacy indices (EIs) of cefixime and cefepime were > 10(4) independent of the infective strain phenotype (FI+ or FI-) and did not differ from those of ceftriaxone and ceftazidime. The efficacy of cefotaxime and cefoperazone was somewhat lower (EIs 1.7 x 10(3)-8.9 x 10(3)). Both the antibacterials were shown to provide high protective and therapeutic efficacy (80-100% of the survivors) independent of the phenotype (FI+ or FI-) of the pathogen infective strain. The results allowed to consider the antibiotics prospective in prevention and treatment of plague.