Studies on the Mode of Action of Chlortetracycline in the Preservation of Beef

The possibility cannot be eliminated that these varia- tions may result from differences in coliform flora for which the IMViC system of classification is not ade- quate.Using the BALB procedure as a single test, 1182 positive reactions or 26.7 per cent would have been considered as + + --type although only 731 strains or 16.5 per cent were actually + + --by IMViC classification.The BALB test alone could be used in survey work where an approximate value would be sufficient.However, by using both a positive indole and positive BALB test as a survey procedure, the elapsed time would not be increased and, by elimination of 385 false reactions, the positives would be reduced to 797 strains or 18.0 per cent of the 4423 strains tested.