CHAPTEE XLVI. 



THE BACTERIOLOGY AND THE BACTERIOLOGIC EXAMINATION OF 

 MILK (CONTINUED) PATHOGENIC BACTERIA IN MILK THE 

 TUBERCLE BACILLUS METHODS FOR DETERMINING ITS 

 PRESENCE IN MILK HUMAN AND OTHER CATTLE 

 DISEASES TRANSMISSIBLE THROUGH MILK- 

 NUMBER AND SIGNIFICANCE OF 

 LEUKOCYTES IN MILK. 



PATHOGENIC BACTERIA IN MILK. 



THE organisms, such as the lactic-acid bacteria, the butyric-acid 

 bacteria, the alcohol formers, and the higher moulds, which have 

 already been discussed, are saprophytes and not disease producers. 

 Pathogenic bacteria, however, also occur in milk. They may be 

 derived directly from the cow, from those handling the milk, or 

 they may be accidentally introduced with water or otherwise. 



Tubercle Bacillus. Of the microorganisms pathogenic to man 

 which may occur in milk, tubercle bacilli are the most important. 

 It is possible to keep disease-producing bacteria, such as the typhoid, 

 diphtheria, and other bacilli out of milk by having the proper persons 

 collect it properly in sterile vessels; but tubercle bacilli which come 

 from the cow cannot, under certain conditions, be kept out of the milk. 

 This is undoubtedly the case in tuberculosis of the udder itself and in 

 advanced general tuberculosis. Examinations of market milk for the 

 presence of tubercle bacilli have been made in many cities and the 

 positive findings vary greatly. Anderson, in 223 specimens of milk 

 examined in Washington, D. C., found 15 (6.27 per cent.) with live, 

 virulent, tubercle bacilli; Hess, in New York, in 106 samples found 17 

 (16 to 17 per cent.); Delepine, in Manchester, in 125 samples found 

 22 (17.6 per cent.); Eber, in Leipzig, in 210 samples found 22 

 (10.5 per cent.); Klein, in London, in 100 samples found 7; and Petri, 

 in Berlin, in 86 samples found 33 (38.4 per cent.). Very low figures are 

 reported from Italy where in a number of cities no tubercle bacilli 

 were found in any of the samples examined; also from Wiirtemberg, 

 where Herbert examined 101 samples without any positive findings. 

 The highest findings have been reported by Kanthack and Sladen, who 

 found 9 samples out of 16 infected in England, and by Obermiiller, 

 in Berlin, who took 14 samples from one -place and found them all 

 infected. Schroeder states that most tubercle bacilli get into milk 

 from fecal contamination. He reports that he has been able to show 

 in a number of experiments their presence in the feces of cows which 

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