@article{mbs:/content/journal/micro/10.1099/13500872-42-3-345, author = "COLE, M. and SUTHERLAND, R.", title = "The Role of Penicillin Acylase in the Resistance of Gram-Negative Bacteria to Penicillins", journal= "Microbiology", year = "1966", volume = "42", number = "3", pages = "345-356", doi = "https://doi.org/10.1099/13500872-42-3-345", url = "https://www.microbiologyresearch.org/content/journal/micro/10.1099/13500872-42-3-345", publisher = "Microbiology Society", issn = "1465-2080", type = "Journal Article", abstract = "SUMMARY: The resistance of 148 clinical isolates of Gram-negative bacteria to ampicillin and benzylpenicillin was determined in serial-dilution sensitivity tests, together with the extent of inactivation of the penicillins, and the production of 6-aminopenicillanic acid (6-APA). Many of the cultures were resistant to the penicillins and inactivated the compounds, but only one culture, a strain of Escherichia coli, showed penicillin acylase activity, as indicated by the production of 6-APA. However, the cultural conditions prevailing in serial-dilution tests, namely, stationary culture at 37°, although favourable for the functioning of penicillin acylases, were shown to be highly unfavourable for production of the enzyme by coliform bacteria.", }