SCE-129, Antipseudomonal Cephalosporin: In Vitro and In Vivo Antibacterial Activities

Abstract

SCE-129 [3-(4-carbamoyl-1-pyridiniomethyl)-7,8-(D-a-sulfophenylacetamido)-ceph-3-em-4-carboxylate monosodium salt], a new semisynthetic cephalosporin, shows potent in vitro antibacterial activities against Pseudomonas aeruginosa and some gram-positive bacteria, whereas it shows lower activity against many gram-negative rods. Against clinical isolates of P. aeruginosa this cephalosporin exhibited higher activity than did carbenicillin, and against the strains of Staphylococcus aureus, SCE-129 had similar activity to carbenicillin. Variations in pH, addition of horse serum, and type of growth medium had no significant effects on the activity of the cephalosporin; however, the inoculum size had some effect on the activity. SCE-129 is an effective bactericidal agent against P. aeruginosa and S. aureus. The protective effects of SCE-129 in mice infected with P. aeruginosa and S. aureus were more potent than those of carbenicillin. The protective effects of SCE-129 on Pseudomonas infection in mice varied according to the dosage schedule and the challenge dose. In a multiple dose schedule, a smaller amount of SCE-129 was necessary than that in a single dose schedule. The effects of SCE-129 after subcutaneous or intraperitoneal administration were more potent than were those by intravenous administration. No protective effect was observed by oral administration.

In vitro antibacterial activity and susceptibility of cefsulodin, an antipseudomonal cephalosporin, to beta-lactamases

“…Neither cefsulodin nor carbenicillin was a substrate for the Sabath and Abrahams ,8-lactamase (9) tected and it was mostly more susceptible to these enzymes than was cefuroxime. DISCUSSION Our findings that cefsulodin was active against P. aeruginosa and P. maltophilia and to some extent against P. paucimobilis, P. pseudoalcaligenes and P. stutzeri, but not against other species of Pseudomonas or the other gram-negative bacteria that we tested, do not conflict with previous work (11,12). We agree with Tsuchiya et al (12) that there was mostly little inoculum effect on the MICs of cefsulodin and carbenicillin and that, with a small inoculum, MBCs of cefsulodin were usually the same as or twice the MIC.…”

HR 756, a New Cephalosporin Active Against Gram-Positive and Gram-Negative Aerobic and Anaerobic Bacteria

“…The activity of HR 756 against P. aeruginosa was comparable to that of carbenicillin, mezlocillin, and ticarcillin (3, 4) but was not as active as piperacillin or azlocillin against P. aeruginosa (3,4), nor was it as active as SCE-129, a unique cephalosporin active against P. aeruginosa and S. aureus (16). Unfortunately, the HR 756 MICs were high, >50 ,ug/ml, against most P. aeruginosa which had piperacillin MICs above 200 ,Lg/ml.…”

Cefsulodin: antibacterial activity and tentative interpretive zone standards for the disk susceptibility test

“…Cefsulodin (formerly SCE-129) is a cephalosporin which has in vitro activity against Pseudomonas aeruginosa, Staphylococcus aureus, and most other gram-positive cocci (4,(7)(8)(9). However, it has very little activity against the enterococci and members of the Enterobacteriaceae (7)(8)(9).…”

“…However, it has very little activity against the enterococci and members of the Enterobacteriaceae (7)(8)(9). Such a limited-spectrum antimicrobial agent may be advantageous when treating bacterial infections of known etiology.…”