Susceptibility of Clinical Isolates of Enterobacteriaceae to BL-S640, a New Oral Cephalosporin

The in vitro antibacterial activity of nine cephalosporins (cephalothin, cephaloridine, cephalexin, cefazolin, cefamandole, cefuroxime, cefatrizine, cefoxitin, and cefazaflur) was determined against 344 strains ofEnterobacteriaceae and 99 nonfermentative gram-negative bacilli. Cefamandole, cefazaflur, and cefuroxime were the most active cephalosporins against the Enterobacteriaceae (with the exception of Serratia marcescens). However, cefoxitin was the only cephalosporin that inhibited all 30 S. marcescens strains in a concentration of 16 ,g/ml and was by far the most active compound against selected cephalothin-resistant strains ofEscherichia coli, Klebsiella, and Proteus mirabilis. Acinetobacter spp. were inhibited best by cefuroxime, but none of the cephalosporins had appreciable activity against the Pseudomonas spp.

mentioning

confidence: 99%

Comparison of the Antibacterial Activity of Nine Cephalosporins Against Enterobacteriaceae and Nonfermentative Gram-Negative Bacilli

Verbist¹

1976

“…coli and Klebsiella were inhibited by low concentrations (<8 ,ug/ml) of BL-S640: 81% of E. coli and 70% of K. pneumoniae tested. As predicted, based on previous studies by other workers (5,8,10,11), Serratia and Pseudomonas species were uniformly resistant to >128 ,g of each of the cephalosporins per ml.…”

Section: Resultsmentioning

confidence: 76%

In Vitro Evaluation of the New Oral Cephalosporin Cefatrizine: Comparison with Other Cephalosporins

Blackwell

Freimer²,

Tuke³

1976

Cefatrizine (BL-S640), a semisynthetic, orally administered cephalosporin, was found to have an in vitro spectrum of activity comparable to those of four other cephalosporins tested. It is as effective as cephalexin, the other orally administered cephalosporin evaluated, against most species, and it appears to be more effective than cephalexin against many Enterobacter, Haemophilus , and Proteus strains isolated in our hospital. It is not inactivated by the plasmid-determined β-lactamases of 14 strains of ampicillin-resistant Salmonella typhimurium or the ampicillin resistance determinant of an H. influenza strain from the Center for Disease Control. No synergy was observed between cefatrizine and gentamicin, kanamycin, carbenicillin, or polymyxin when tested against selected strains.

“…A similar situation was found with an Acinetobacter isolate. DISCUSSION Earlier publications (1,2,6,8,9) have suggested that cefatrizine is an agent that would extend the spectrum of oral and parenteral cephalosporins, but these studies compared its activity with that of older agents and not with that of cefamandole, cefuroxime, and cefoxitin, which have an expanded spectrum of activity (3)(4)(5). Although cefatrizine has excellent stability com- …”

Section: Resultsmentioning

confidence: 99%

Cefatrizine Activity Compared with That of Other Cephalosporins

Neu

1979

Cefatrizine, a new orally administered cephalosporin, was tested against 400 clinical isolates. Cefatrizine had excellent activity against gram-positive cocci, inhibiting all except enterococci at minimal inhibitory concentrations below 1 μg/ml. Cefatrizine inhibited the majority of Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis , and Salmonella at concentrations below 12.5 μg/ml. Although cefatrizine was not hydrolyzed by many β-lactamases, it did not inhibit a number of strains of Enterobacter, Serratia , or indole-positive Proteus . Cefatrizine was more active than cephalothin or cephalexin against E. coli, Klebsiella, Enterobacter, Citrobacter, Salmonella , and Shigella . Its overall activity was less than that of cefoxitin against strains resistant to cephalothin, but its activity against cephalothin-susceptible strains was equivalent to that of cefamandole.