Abstract
We investigated the relationship between beta-lactamases of Bacteroides fragilis organisms and their resistance to cephalosporins. Timed killing curves were used to study the in vitro activity of three cephalosporins, cephalothin, cefazolin, and cefamandole, and a semisynthetic cephamycin, cefoxitin. Measurements of residual antibiotic concentrations in culture supernatants were made, and they were compared with the beta-lactamase activity of the microorganism. A cephalosporin-susceptible strain was rapidly killed by cephalothin, cefazolin, cefamandole, and cefoxitin. Four cephalosporin-resistant strains were not killed by cephalothin, cefazolin, or cefamandole but were killed by cefoxitin. An inoculum effect was noted with cefazolin and not with cefoxitin. The resistant strains of Bacteroides inactivated the three cephalosporins, but there was no inactivation of cefoxitin. A constitutive beta-lactamase was detected in all the isolates of the B. fragilis group that were resistant to the cephalosporins. There was no distinction of the species based on isoelectric focusing of the enzyme. These data suggest that inactivation by beta-lactamase may be the mechanism for resistance of B. fragilis to the cephalosporins and would explai...Continue Reading
References
May 1, 1976·Antimicrobial Agents and Chemotherapy·B OlssonT Wadström
Mar 1, 1978·Antimicrobial Agents and Chemotherapy·M L Britz, R G Wilkinson
Jul 1, 1978·The Journal of Antimicrobial Chemotherapy·T Leung, J D Williams
Mar 1, 1977·The Journal of Infectious Diseases·T J LouieJ G Bartlett
Apr 1, 1978·The Journal of Infectious Diseases·J P O'KeefeS L Gorbach
Sep 1, 1978·Antimicrobial Agents and Chemotherapy·F P TallyS L Gorbach
May 1, 1976·Journal of General Microbiology·M Matthew, A M Harris
Apr 1, 1977·Antimicrobial Agents and Chemotherapy·G Darland, J Birnbaum
Jul 1, 1976·Antimicrobial Agents and Chemotherapy·A E Weinrich, V E Del bene
Oct 1, 1976·Antimicrobial Agents and Chemotherapy·V L Sutter, S M Finegold
Mar 1, 1975·The Journal of Infectious Diseases·C RegameyM M Kirby
Apr 1, 1972·Antimicrobial Agents and Chemotherapy·C H O'CallaghanA H Shingler
May 1, 1973·Journal of Medical Microbiology·J D Anderson, R B Sykes
Feb 1, 1972·Antimicrobial Agents and Chemotherapy·W J MartinJ A Washington
Oct 1, 1968·Journal of Bacteriology·G PinkusA I Braude
Citations
Jun 1, 1994·European Journal of Clinical Microbiology & Infectious Diseases : Official Publication of the European Society of Clinical Microbiology·P MastrantonioA Sebastianelli
Jun 1, 1987·Diagnostic Microbiology and Infectious Disease·V M BieluchF P Tally
Jul 1, 1989·Diagnostic Microbiology and Infectious Disease·S M Finegold
May 1, 1992·Diagnostic Microbiology and Infectious Disease·C W StrattonK E Aldridge
Mar 1, 1996·The Journal of Emergency Medicine·E S Pollack, C V Pollack
Oct 1, 1980·Antimicrobial Agents and Chemotherapy·F P TallyS L Gorbach
Dec 1, 1980·Antimicrobial Agents and Chemotherapy·A P PanwalkerP E Porembski
Jan 1, 1981·Antimicrobial Agents and Chemotherapy·T J MarrieE A Kerr
Feb 1, 1981·Antimicrobial Agents and Chemotherapy·J E BrownC D Collins
May 1, 1981·Antimicrobial Agents and Chemotherapy·R M TimewellC E Nord
Jul 1, 1981·Antimicrobial Agents and Chemotherapy·E J GoldsteinV L Sutter
Sep 1, 1981·Antimicrobial Agents and Chemotherapy·A Eley, D Greenwood
Nov 1, 1981·Antimicrobial Agents and Chemotherapy·R D Rolfe, S M Finegold
Dec 1, 1983·Antimicrobial Agents and Chemotherapy·G J CuchuralJ W Mayhew
Jan 1, 1984·Antimicrobial Agents and Chemotherapy·T KesadoK Ueno
May 1, 1984·Antimicrobial Agents and Chemotherapy·F LamotheJ M Lacroix
May 1, 1985·Antimicrobial Agents and Chemotherapy·V E Del BeneL J Burkey
Jun 1, 1985·Antimicrobial Agents and Chemotherapy·K TunérC E Nord
May 1, 1986·Antimicrobial Agents and Chemotherapy·G J CuchuralM H Malamy
Mar 1, 1988·Antimicrobial Agents and Chemotherapy·W J Brown
Nov 1, 1990·Antimicrobial Agents and Chemotherapy·P C AppelbaumL Gutmann
Jan 1, 1992·Antimicrobial Agents and Chemotherapy·K LeeY Chong
Nov 1, 1988·The Veterinary Clinics of North America. Small Animal Practice·S W Dow
Aug 3, 1989·The New England Journal of Medicine·B Styrt, S L Gorbach
Apr 1, 1983·Antimicrobial Agents and Chemotherapy·F P TallyC L Pierson
Mar 1, 1986·Journal of Clinical Microbiology·J H JorgensenA W Howell
Jul 1, 1983·Antimicrobial Agents and Chemotherapy·P K Yu, J A Washington