In Vitro Activity of Cefazolin against Recent Clinical Bacterial Isolates

• Published in: The Journal of infectious diseases Vol. 128; no. Supplement-2; pp. S320 - S326
• Main Authors: Sabath, L. D., Wilcox, Clare, Garner, Carol, Finland, Maxwell
• Format: Journal Article
• Language: English
• Published: United States The University of Chicago Press 01.10.1973; University of Chicago Press
• Subjects: Agar - pharmacology; Ampicillin - pharmacology; Antibacterials; Antibiotics; Bacteria; Bacteria - drug effects; Carbenicillin - pharmacology; Cephalosporins; Cephalosporins - pharmacology; Cephalothin - pharmacology; Enterobacter; Escherichia coli - drug effects; Gram positive cocci; Inoculum; Klebsiella; Klebsiella - drug effects; Methicillin - pharmacology; Microbial Sensitivity Tests; Nafcillin - pharmacology; Neisseria gonorrhoeae - drug effects; Oxacillin - pharmacology; Penicillin; Penicillin G - pharmacology; Proteus; Pseudomonas - drug effects; Staphylococcus - drug effects; Staphylococcus aureus; Sulfides - pharmacology; Tetrazoles - pharmacology; Thiadiazoles - pharmacology
• ISSN: 0022-1899; 1537-6613
• DOI: 10.1093/infdis/128.Supplement_2.S320

The in vitro antibacterial activity of cefazolin was determined, by an agar-dilution technique, against 546 recent isolates of bacteria recovered from patients at Boston City Hospital. The activity of cefazolin was comparable to that. of cephalothin against most gram-positive cocci, but the former was more active against most strains of Escherichia coli and Klebsiella and against some isolates of Enterobacter. Neither of these two cephalosporins had significant activity against Serratia or Pseudomonas. The median MICs of undiluted cultures of some gramnegative bacilli tested in agar were 32–85 times higher than those of the same cultures diluted 1: 1,000 before inoculation. The results of these tests of susceptibility were influenced by the composition of the medium, sometimes by a factor of 16; none of the four media gave consistently higher or lower values with strains of all species tested.