Premium
A PRELIMINARY BACTERIOLOGICAL SCREENING TEST FOR QUATERNARY AMMONIUM COMPOUNDS AND FORMULATIONS
Author(s) -
COUSINS CHRISTINA M.
Publication year - 1951
Publication title -
proceedings of the society for applied bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 0370-1778
DOI - 10.1111/j.1365-2672.1951.tb04632.x
Subject(s) - ammonium , serial dilution , suspension (topology) , chromatography , bacteria , microbiology and biotechnology , colony forming unit , chemistry , food science , biology , mathematics , organic chemistry , medicine , alternative medicine , pathology , homotopy , pure mathematics , genetics
SUMMARY: The test is based on a colony count method to determine the survival of a given test organism, Bacterium coli , in the presence of sterile homogenized whole milk added with the bacterial suspension to the quaternary ammonium compound dilutions, for an exposure time of two min. Attention is drawn to the special cleaning of the glassware used. The preparation and use of the Q.A.C. inhibitor, lecithin in ‘Lissapol N’, is described, with details of the testing procedure. Inconsistencies in survivor counts occurring when Q.A.C. solutions were tested against saline suspensions of Bact. coli were reduced by carrying out the test in the presence of whole milk solids. Examples quoted show how this test indicated a difference in bactericidal efficiency between (a) two different Q.A.C. solutions, and (b) the same Q.A.C. included in two powder formulations of differing pH value.