Protective effect of amdinocillin against emergence of resistance to ceftazidime in Enterobacter cloacae.
نویسندگان
چکیده
Enterobacter cloacae infections have been shown clinically to respond less reliably to monotherapy with broad-spectrum cephalosporins than was initially expected. Selection of populations producing high levels of beta-lactamase has been shown to be the most frequent reason for treatment failure, and the use of these agents with another active antibiotic is recommended. In this study, E. cloacae strains from clinical specimens susceptible to ceftazidime and amdinocillin by broth dilution and disk tests were examined. In the presence of ceftazidime at 10 micrograms/ml, in vitro selection of resistant organisms was demonstrated for 3 of 11 strains. Selection was prevented when amdinocillin was added in combination. A more rapid killing was also demonstrated with this combination. At inocula of 10(8) CFU/ml, ceftazidime-resistant populations were isolated from 6 of 11 strains in vitro, and the emergence of this resistance was prevented by amdinocillin. The enhanced killing effect noted for amdinocillin with ceftazidime may have resulted in part from complementary activity of the antibiotics on penicillin-binding proteins. The ceftazidime-amdinocillin combination offers an interesting prospect for the therapy of infections caused by E. cloacae strains which are initially susceptible to both antibiotics.
منابع مشابه
Role of ceftazidime dose regimen on the selection of resistant Enterobacter cloacae in the intestinal flora of rats treated for an experimental pulmonary infection.
OBJECTIVES The effect of ceftazidime dosing increments and frequency of dosing on the selection of ceftazidime-resistant Enterobacter cloacae in the intestine was studied in rats, during treatment of a pulmonary infection caused by Klebsiella pneumoniae. METHODS Rats with pulmonary infection (n = 10 per group) received therapy with doses of ceftazidime at 3.1 to 400 mg/kg per day at a frequen...
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عنوان ژورنال:
- Antimicrobial agents and chemotherapy
دوره 32 11 شماره
صفحات -
تاریخ انتشار 1988