[The effect of cefepime on ceftazidime, cefotaxime and imipenem resistant strains of Acinetobacter, Xanthomonas, Pseudomonas, Flavobacterium, Sphingobacterium and on producers of extended spectrum beta-lactamases (ESBL) with resistance transfer].

BACKGROUND: The new cephalosporins with heterocyclic positively charged substituent at position C3 belong to the 4th generation cephalosporins. It is not evident, whereas these antibiotics are effective against cefotaxime-ceftazidime-resistant bacteria. We investigated the efficiency of the cefepime (Maxipime, BMS) against Acinetobacter sp., X. maltophilia, Pseudomonas sp., Flavobacterium sp., Sphingobacterium sp. and against strains with production of ESBL (Extended Spectrum beta-Lactamases) (Enterobacter sp., Citrobacter sp., Klebsiella sp.).

METHODS AND RESULTS: We determined the susceptibility of the 54 strains resistant to 50 mg/l and more of ceftazidime. The majority of the strains (35) are susceptible to cefepime and MIC is the range 1.65-3.15 mg/l of cefepime. 17 strains have MIC = 6.25 mg/l. Two strains (one strain P. aeruginosa a one strain K. pneumoniae) were resistant to cefepime and MIC = 12.5 mg/l. The activity of beta-lactamases was determined by quantitative macroiodometric method in one strain of P. cepacia and two strains of Sphingobacterium multivorum. They hydrolyse actively imipenem (they produce metallo-beta-lactamase) and ceftazidime (they are highly resistant to this antibiotic), but cefepime is more slowly hydrolysed than ceftazidime.

CONCLUSIONS: At the present time cefepime is effective against ceftazidime-resistant strains in so-called "problematic" species of bacteria. However, it is important to protect its efficiency in the future, this requires its rational use.