title: Comparison of serum bactericidal activity among three antimicrobial combinations.
abstract: Three antimicrobial combinations, ticarcillin plus cephalothin (T+C), ticarcillin plus gentamicin (T+G), and cephalothin plus gentamicin (C+G), were administered to 105 febrile granulocytopenic cancer patients at the Baltimore Cancer Research Center as part of a multi-institutional prospective randomized antibiotic trial. The sera from 32 of these patients (T+C-10 patients, T+G-10 patients, and C+G-12 patients) obtained 1 h post-antibiotic administration were examined for bactericidal activity against 11 strains each of the most common pathogens infecting the granulocytopenic host: Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, and Staphylococcus aureus. Each of the three antibiotic regimens produced a high degree of bactericidal activity in these sera against S. aureus and E. coli. P. aeruginosa was equally, although poorly, killed by sera containing ticarcillin (T+G, T+C), whereas C+G produced no measurable serocidal activity (P < 0.05). Sera with C+G killed K. pneumoniae more effectively than T+G; T+C produced the least killing effect of the three regimens against this organism (P < 0.05). The bactericidal activity of the serum from these 32 patients supplements the overall clinical results of the multi-institutional antibiotic trial and suggests that T+G is a useful initial regimen for empiric therapy of febrile episodes in granulocytopenic cancer patients.
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001424:Bacterial Infections / Q000097:blood / Q000188:drug therapy; D001770:Blood Bactericidal Activity / Q000187:drug effects*; D002512:Cephalothin / Q000097:blood / Q000494:pharmacology; D004359:Drug Therapy, Combination; D005839:Gentamicins / Q000097:blood / Q000494:pharmacology; D006801:Humans; D008826:Microbial Sensitivity Tests; D013982:Ticarcillin / Q000097:blood / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D005839:Gentamicins; D013982:Ticarcillin; D002512:Cephalothin