Factors That Influence Toxigenicity of Pseudomonas Aeruginosa

Liu, Pinghui V. (University of Louisville, Louisville, Ky.). Factors that influence toxigenicity of Pseudomonas aeruginosa. J. Bacteriol. 88:1421-1427. 1964.-Hemolysin, lecithinase, and protease of Pseudomonas aeruginosa were produced with cellophane-covered plates and completely synthetic agar of simple composition containing alpha-alanine, aspartic acid, glutamic acid, glucose, and salts. The most critical factor in the production of these extracellular toxins appeared to be the concentration of phosphate, which had to be in the range of 0.003% for the lecithinase, 0.005 to 0.01% for the hemolysin, and 0.01 to 0.2% for the protease. alpha-Alanine and glutamic acid favored the production of the hemolysin and lecithinase, and aspartic acid supported the production of protease. The role of glucose in the production of these extracellular toxins appeared to be more important than just an energy source. It is likely that products of anaerobic metabolism of glucose are needed in the production of these toxins. In the absence of glucose, the production of protease was enhanced by lactic acid, pyruvic acid, or alpha-ketoglutaric acid. Possible implications of these findings in the pathogenesis of P. aeruginosa are discussed.