This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Liu, P. V. Articles by Hsieh, H.-C. Search for Related Content PubMed PubMed Citation Articles by Liu, P. V. Articles by Hsieh, H.-C.

 Previous Article  |  Next Article 

J Bacteriol. 1969 August; 99(2): 406-413
Copyright © 1969 American Society for Microbiology. All Rights Reserved.

Inhibition of Protease Production of Various Bacteria by Ammonium Salts: Its Effect on Toxin Production and Virulence

Department of Microbiology, University of Louisville School of Medicine, Louisville, Kentucky 40202

ABSTRACT

Production of protease by many bacteria was found to be inhibited by ammonium salts, and the enzyme production was more sensitive to the salts than was growth of the organisms. Inhibition of protease production by some pathogenic bacteria may result in the recognition of an exotoxin which otherwise would have been digested by the protease. In the case of Pseudomonas aeruginosa, qualitatively different toxicities could be demonstrated in the culture fluids, depending on the presence or absence of protease in such a fluid. The toxicity of the culture in the presence of a high titer of protease may be due primarily to the protease, whereas the toxicity exhibited in the absence of protease could be due to proteinacious exotoxin. Producers of high titers of protease tended to be less virulent in vivo than producers of low titers of the enzyme, which exert their toxicities by a separate exotoxin.

This article has been cited by other articles:

• Swift, S., Lynch, M. J., Fish, L., Kirke, D. F., Tomas, J. M., Stewart, G. S. A. B., Williams, P. (1999). Quorum Sensing-Dependent Regulation and Blockade of Exoprotease Production in Aeromonas hydrophila. Infect. Immun. 67: 5192-5199 [Abstract] [Full Text]  
• Secades, P., Guijarro, J. A. (1999). Purification and Characterization of an Extracellular Protease from the Fish Pathogen Yersinia ruckeri and Effect of Culture Conditions on Production. Appl. Environ. Microbiol. 65: 3969-3975 [Abstract] [Full Text]