Abstract
When gram-negative β-lactamase-producing bacteria were incubated at 37 C in broth containing 100 to 250 μg or more of 7-cyanacetamidocephalosporanic acid (CAA) per ml, a red or orange color developed, irrespective of whether or not growth had occurred. This color development was paralleled by breakdown of CAA by Escherichia coli R+TEM, although there was a concurrent lethal effect on the cells. No red color developed with gram-positive or gram-negative strains that did not produce β-lactamase. Several methicillin-susceptible β-lactamase-producing strains of Staphylococcus aureus produced a faint red color, as did one of four penicillin acylase-producing E. coli strains. No color resulted when two methicillin-resistant, β-lactamase-nonproducing S. aureus strains were tested. Two methicillin-resistant, β-lactamase-producing S. aureus strains produced a bright red color at 37 C, but a much fainter one at 30 C.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Annear D. I. The effect of temperature on resistance of Staphylococcus aureus to methicillin and some other antibioics. Med J Aust. 1968 Mar 16;1(11):444–446. [PubMed] [Google Scholar]
- Dyke K. G. Penicillinase production and intrinsic resistance to penicillins in methicillin-resistant cultures of Staphylococcus aureus. J Med Microbiol. 1969 Aug;2(3):261–278. doi: 10.1099/00222615-2-3-261. [DOI] [PubMed] [Google Scholar]
- Knüsel F., Konopka E. A., Gelzer J., Rosselet A. Antimicrobial studies in vitro with CIBA 36278-Ba, a new cephalosporin derivative. Antimicrob Agents Chemother (Bethesda) 1970;10:140–149. [PubMed] [Google Scholar]
- SABATH L. D., ABRAHAM E. P. SYNERGISTIC ACTION OF PENICILLINS AND CEPHALOSPORINS AGAINST PSEUDOMONAS PYOCYANEA. Nature. 1964 Dec 12;204:1066–1069. doi: 10.1038/2041066a0. [DOI] [PubMed] [Google Scholar]