Activity of cefepime against ceftazidime- and cefotaxime-resistant gram-negative bacteria and its relationship to beta-lactamase levels.
AUTOR(ES)
Fung-Tomc, J
RESUMO
One hundred clinical isolates resistant to ceftazidime and/or cefotaxime were examined for susceptibility to cefepime. The most frequently encountered ceftazidime-cefotaxime-resistant strains belonged to the genera Enterobacter, Pseudomonas, and Citrobacter. Among these strains, 92% were resistant to cefoperazone, 91% were resistant to cefotaxime, 84% were resistant to ceftazidime, and 6% were resistant to cefepime. Of the members of the family Enterobacteriaceae, 57% were resistant to ceftriaxone. The six strains resistant to cefepime were all Pseudomonas aeruginosa and were resistant to both cefotaxime and ceftazidime. Cefepime-resistant P. aeruginosa strains had exceptionally high levels of beta-lactamase activity, higher than the levels found in strains resistant to ceftazidime but susceptible to cefepime. The beta-lactamases from the cefepime-resistant strains were type I (Richmond-Sykes), were constitutively produced, and did not have increased affinity or hydrolytic activity for cefepime. Thus, cefepime was active against most gram-negative bacteria which have developed resistance to the broad-spectrum cephalosporins, and resistance to cefepime in P. aeruginosa appears to be associated with higher beta-lactamase levels than in cefepime-susceptible strains.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=172467Documentos Relacionados
- Bactericidal activity of ciprofloxacin against amikacin- and cefotaxime-resistant gram-negative bacilli and methicillin-resistant staphylococci.
- Antibacterial activity of Ro 17-2301 and other antimicrobial agents against cefotaxime-resistant aerobic gram-negative bacilli.
- Types of beta-lactamase determined by plasmids in gram-negative bacteria.
- In vitro activity against aerobic and anaerobic gram-positive and gram-negative bacteria and beta-lactamase stability of RS-533, a novel carbapenem.
- Comparative in vitro activity of N-formimidoyl thienamycin against gram-positive and gram-negative aerobic and anaerobic species and its beta-lactamase stability.