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P V LIU

Publications and source records attributed to P V LIU.

17 recordsLinked to original sources
PubMed1964

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.

Alanine↗
PubMed1963

COMPLEMENTATION OF LECITHINASE ACTIVITIES BY CLOSELY RELATED PSEUDOMONADS: ITS TAXONOMIC IMPLICATION.

Bates, Janice L. (University of Louisville School of Medicine, Louisville, Ky.) and Pinghui V. Liu. Complementation of lecithinase activities by closely related pseudomonads: its taxonomic implication. J. Bacteriol. 86:585-592. 1963.-A lecithinase activity was demonstrated by a mixture of cell-free extracts from two strains of closely related pseudomonads, neither of which was able to show this activity when grown alone. One component, from B-2265 (Pseudomonas aureofaciens var. nonliquefaciens), was heatlabile, nondialyzable, and antigenic. The other component, from 22/3 (P. fluorescens), was relatively heat-stable, nondialyzable, and nonantigenic. Antisera produced with the component of B-2265 alone neutralized the activity of the complete enzyme made up with both components, as well as that of similar enzymes of related species, such as P. aureofaciens, P. chlororaphis, and P. fluorescens. The taxonomic implication of these findings is discussed. The suggestion is made that determination of the serological specificity of an enzyme or its antigenic subunits is a more reliable criterion for establishing relationships of bacterial strains than methods depending on the overall similarity of biochemical activities.

Metabolism↗
PubMed1962

Fermentation reactions of Pseudomonas caviae and its serological relationship to aeromonads.

Liu, Pinghui V. (University of Louisville School of Medicine, Louisville, Ky.). Fermentation reactions of Pseudomonas caviae and its serological relationship to aeromonads. J. Bacteriol. 83:750-753. 1962.-Pseudomonas caviae was found to ferment carbohydrates instead of oxidizing them. This characteristic would seem to eliminate this organism from the genus Pseudomonas and place it in the genus Aeromonas. It was identified as A. liquefaciens, by its species-specific extracellular antigens and by neutralization of its enzyme.

Aeromonas↗