RT Journal
A1 JORDAN EO
T1 THe production of indol by certain strains of the pfeiffer bacillus
JF Journal of the American Medical Association
JO Journal of the American Medical Association
YR 1919
FD May 24
VO 72
IS 21
SP 1542
OP 1543
DO 10.1001/jama.1919.02610210038012
UL http://dx.doi.org/10.1001/jama.1919.02610210038012
AB So few positive cultural characters have been recorded for the Pfeiffer bacillus that each additional biologic quality is of some interest. I have not found any statement that a previous test for indol production has been made. Zipfel,1 who seems to have carried out the most comprehensive series of observations by modern methods on the production of indol by bacteria, lists only four groups as indol-formers (B. coli group, B. dysenteriae Vars. Flexner and Y, the cholera vibrios and the cholera-like vibrios excepting V. Finkler-Prior and V. Deneke) and sixteen groups as not forming indol. Pfeiffer's bacillus was apparently not among those tested.The majority of strains of the Pfeiffer bacillus that I have been able to obtain form indol promptly. The paradimethylamidobenzaldehyde method is used. A satisfactory medium is standard meat infusion broth to which 5 per cent. of sheep blood is added while the broth is hot