Author:
Auckenthaler R,Wilson W R,Wright A J,Washington J A,Durack D T,Geraci J E
Abstract
The minimal bactericidal concentrations of N-formimidoyl thienamycin (N-f-thienamycin) against 21 strains of enterococci isolated from patients with infective endocarditis were determined by macro- and microdilution methods. By a macrodilution technique with the minimal bactericidal concentration defined as greater than or equal to 99.9% killing of an initial inoculum, all 21 strains of enterococci were found to have minimal bactericidal concentration/minimal inhibitory concentration ratios of greater than or equal to 32. The mean minimal inhibitory concentration was 1.5 micrograms/ml (range, 0.5 to 4 micrograms/ml), and the minimal bactericidal concentration was greater than or equal to 128 micrograms/ml. The disparity between the results of our study and those published elsewhere, which reported that N-f-thienamycin is bactericidal in vitro against enterococci, may represent the relative insensitivity of the microdilution method in determining greater than or equal to 99.9% killing. The lack of in vitro bactericidal activity of N-f-thienamycin against enterococci was confirmed in vivo in the rabbit model of experimental endocarditis. N-f-Thienamycin was no more effective than penicillin alone in the treatment of experimental enterococcal endocarditis and was less effective than the combination of penicillin and gentamicin. The results indicate that N-f-thienamycin should not be used alone in the treatment of enterococcal endocarditis.
Publisher
American Society for Microbiology
Subject
Infectious Diseases,Pharmacology (medical),Pharmacology
Reference14 articles.
1. In vitro methods for determining minimal lethal concentrations of antimicrobial agents;Barry A. L.;Am. J. Clin. Pathol.,1979
2. Dixon W. J.; and F. J. Maa Jr. 1969. Introduction to statistical analysis 3rd ed. p. 167-181. McGraw Hill New York.
3. Susceptibility of enterococci and Listeria monocytogenes to N-formimidoyl thienamycin alone and in combination with an aminoglycoside;Eliopoulos G. M.;Antimicrob. Agents Chemother.,1981
4. Experimental endocarditis. I. Staphylococcal endocarditis in rabbits resulting from placement of a polyethylene catheter in the right side of the heart;Garrison P. K.;Yale J. Biol. Med.,1970
5. N-Formimidoyl thienamycin (MK0787): in vitro antibacterial activity and susceptibility to beta-lactamases compared with that of cefotaxime, moxalactam and other beta-lactam antibiotics;Hando D.;J. Antimicrob. Chemother.,1981
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