SELECTIVE DESTRUCTION BY PSEUDOMONAS AERUGINOSA OF COMMON ANTIGEN OF ENTEROBACTERIACEAE

Whang , H. Y. (Children's Hospital, Buffalo, N.Y.), and E. Neter . Selective destruction by Pseudomonas aeruginosa of common antigen of Enterobacteriaceae. J. Bacteriol. 88: 1244–1248. 1964.—Supernatant fluids and filtrates from several strains of Pseudomonas aeruginosa , when incubated with common antigen from various enteric bacteria, will produce selective destruction of this antigen, leaving intact the simultaneously present O antigen. This effect is evidenced from hemagglutination, hemolysis, antibody absorption, hemagglutination inhibition, and immunization experiments. The Pseudomonas factor is heat-labile, being destroyed by heating at 100 C for 10 min. The action of this factor on the antigen is time-dependent and temperature-dependent, requiring incubation for 18 to 72 hr and progressing more rapidly at 50 or 56 C than at 37 C. The specificity of the reaction is indicated by the fact that supernatant fluids from cultures of Staphylococcus aureus and Bacillus subtilis , as well as several enzymes, such as pancreatic protease, trypsin, and lipase, have no effect on the common antigen. Utilization of the Pseudomonas factor, conceivably an enzyme, may aid in the eventual elucidation of the chemical nature of the common antigen of enteric bacteria.

GENE-ENZYME RELATIONS IN HISTIDINE BIOSYNTHESIS IN YEAST

Each of the histidine mutants of Saccharomyces cerevisiae has been correlated with a particular step in histidine biosynthesis. The relations of the genes controlling histidine biosynthesis in yeast appear to be identical with those found in Neurospora and clearly distinct from those found in Salmonella.