Comparative Susceptibilities of Anaerobic Bacteria to Metronidazole, Ornidazole, and SC-28538

Self Cite

Several new beta-lactam antimicrobial agents have been introduced in the last few years. In this investigation, the in vitro activities of several recently introduced cephalosporins (cefoperazone, cefotaxime, ceftazidime, and ceftizoxime), moxalactam, and N-formimidoyl thienamycin were compared with those of cefoxitin, clindamycin, and metronidazole against 203 strains of anaerobic bacteria. At achievable serum levels, all of the antimicrobial agents were active against essentially 100% of the strains of anaerobic gram-positive cocci, Clostridium perfringens, Leptotrichia buccalis, and species of Selenomonas, Veillonella, and Eubacterium. Clindamycin, metronidazole, and N-formimidoyl thienamycin were the most active agents against the Bacteroides fragilis group, inhibiting all strains at concentrations which can be achieved in serum. Of the remaining agents tested against the B. fragilis group, cefoxitin (which required 64 ,tg/ml to inhibit 90% of the strains) was the most active, followed by cefoperazone (128 ,ug/ml), cefotaxime (128 ,tg/ml), moxalactam (128 ,ug/ml), ceftizoxime (256 ,ug/mi), and ceftazidime (>256 pg/ml). Important differences in cephalosporin susceptibility among species of the B. fragilis group were observed. Metronidazole and N-formimidoyl thienamycin were the most active drugs against species of clostridia other than C. perfringens; the other antibiotics displayed poor activity, although this is partly due to inclusion of a relatively large number of strains of Clostridium difficile which were very resistant to several of the cephalosporins. Only metronidazole was active against all species of Fusobacterium. Clindamycin and N-formimidoyl thienamycin displayed excellent activity against gram-positive, non-spore-forming bacilli, requiring c8 ytg/ml to inhibit 100% of the strains. Ceftazidime, cefoperazone, and moxalactam were bactericidal for 25 strains of B. fragilis at concentrations equal or close to those required for inhibition. On the basis of its activity in vitro, N-formimidoyl thienamycin appears to be the most promising of the new beta-lactam antibiotics for the treatment of infections involving anaerobic bacteria.Several new beta-lactam antibiotics have been introduced in the last few years. Several recently introduced cephalosporins, including ceftizoxime, cefoperazone, cefotaxime, and ceftazidime, are distinguished from earlier cephalosporins by increased resistance to beta-lactamase degradation and extended antibacterial spectrum. N-formimidoyl thienamycin, a stable derivative of thienamycin, and moxalactam are beta-lactam antibiotics with potent and broad-spectrum activities.The purpose of the present study was to examine the in vitro activity of these new compounds against various strains of anaerobic bacteria. Using an agar dilution technique, the act Present address:

Section: Resultssupporting

confidence: 91%

Comparative In Vitro Activity of New Beta-Lactam Antibiotics Against Anaerobic Bacteria

Rolfe

Finegold

1981

Self Cite

“…The poor activity of metronidazole against gram-positive, nonsporeforming bacilli agrees with published reports (9,22 …”

Section: (13)supporting

confidence: 92%

Comparative in vitro activity of ceftriaxone against anaerobic bacteria

Rolfe¹,

Finegold²

1982

The in vitro activity of ceftriaxone was compared with those of other recently introduced beta-lactam antimicrobial agents (cefoperazone, cefotaxime, and moxalactam) and with those of cefoxitin, clindamycin, and metronidazole against 227 strains of anaerobic bacteria. The data obtained in this investigation suggest that ceftriaxone, like a majority of the new beta-lactam antimicrobial agents, may be of limited value in the treatment of serious infections involving anaerobic bacteria.

“…to metronidazole (3,12,14) , cefoxitin (3,4,19), and clindamycin (4,5,8) has been shown. Metronidazole is generally ineffective on the other nonsporulated, gram-positive rods, contrasting with the good activity of cefoxitin and clindamycin; even some Propionibacterium spp.…”

mentioning

confidence: 99%

Susceptibility of anaerobic bacteria from several French hospitals to three major antibiotics

Dubreuil¹,

Devos²,

Neut³

et al. 1984

The in vitro activity of cefoxitin was compared with those of metronidazole and clindamycin against 322 strains of anaerobic bacteria collected from several hospitals during 1982 and tested by an agar dilution method. Metronidazole and cefoxitin inhibited at least 89%o of strains tested, whereas clindamycin was less active.Continued updating of the susceptibility of recent clinical isolates and follow-up in changes of antibiotic patterns are periodically necessary in every country. When the same methodology is retained, an increase in resistance levels or local differences can be demonstrated (28,29). Considering the lack of such studies in France, our purpose was to determine the antibiotic susceptibility of anaerobic bacteria, using the first data available by the reference method of Sutter et al. (25)