Bacteriological Methods in Food and Drug Laboratories; With an Introduction to Micro-Analytical Methods (Paperback)

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1915 edition. Excerpt: ...contain more than 150,000,000 bacteria per cc. and most of which bacteria should be of the lactic acid group. Pathogenic bacteria which may be present in milk may also be present in the cream. Tubercle bacilli, diphtheria bacilli and typhoid bacilli are the most likely to occur. In the case of doubtful cream, the colon bacillus test should not be omitted and in the case of suspected contamination with pathogenic organisms, the cream, as well as the milk from the same source, should be examined, resorting to the usual animal inoculation tests. The tests for the presence of tubercle bacilli in milk, cream, meats, etc., comprises the microscopic examination of stained (ZiehlNeelsen method of staining) sediments or concentrates as may be required, and animal inoculations. For the animal inoculation test, ba' 2n_IpuTunf guinea-pigs are used. Centrifugalize (in a Stained with carbol, . x, -, t, . fuchsin and methy powerful machine) about 250 cc. of the milk ieneblue.--(Piufield.) in order to throw down the tubercle bacilli (with the other inclusions), and from this make the desired cover-slip preparations and inoculate (in the region of the left knee-joint of hind leg) the remainder of the sediment into three healthy guinea-pigs. Place the inoculated guinea-pigs in individual cages and keep them under observation for from 2 to 4 weeks. The reasons why several pigs should be inoculated are as follows. Some of the pigs may be killed by bacteria other than the tubercle bacilli and it is always desirable to duplicate the tests. At the end of the second week, one of the guinea-pigs should be dissected and the glands of the sublumbar region as well as the glands of the superficial tissues and of the popliteal region examined. If tubercular...