The Action on Nitrates and Nitrites of Dysentery Organisms killed by various processes and of Filtrates from Fluid Cultures

Abstract

The organisms examined have been killed, (a) by temperatures which should not have destroyed the reducing enzyme, (b) by sodium fluoride and four other antiseptics, derivatives of phenol, and (c) by acetone. In each case there has been total destruction of the reducing power, any apparent production of nitrite from nitrate being too slight to justify the assumption that it is due to anything more than experimental error. Filtrates of fluid cultures have also failed to reduce. The results may be summed up as follows:(1) The reduction of nitrite by certain dysentery bacilli is not due to a soluble extra-cellular enzyme.(2) Dysentery bacilli and B. coli killed by a minimal degree of heat have little if any effect in reducing nitrites.(3) Organisms killed by antiseptics or by acetone do not reduce nitrates and nitrites.(4) Even where all the organisms are not dead, reduction may be prevented by antiseptics.(5) The high antiseptic value of tetrachlor-o-biphenol, tetrabrom-o-kresol, p-chlor-m-kresol and hexabrom-dioxy-diphenyl-carbinol has been established for the organisms of the dysentery group.