Bovine Tuberculosis and Its Control

Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: The Cause Of Tuberculosis In Cattle . In 1882, Robert Koch1 discovered the cause of tuberculosis to be a microorganism which he called the bacillus of tuberculosis. It is a slender rod-shaped organism. It is not motile and it does not produce spores. The more recent classifications of bacteria place this...
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Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: The Cause Of Tuberculosis In Cattle . In 1882, Robert Koch1 discovered the cause of tuberculosis to be a microorganism which he called the bacillus of tuberculosis. It is a slender rod-shaped organism. It is not motile and it does not produce spores. The more recent classifications of bacteria place this organism in the genus Bacterium because of its non motility. In the earlier classifications it was placed in the genus Bacillus. It is therefore referred to in the literature on the subject sometimes as a bacterium and sometimes as a bacillus. . Bacterium tuberculosis appears as a slender rod 1.5 to 4.0 microns in length and from 0.2 to 0.5 microns in width. The organisms may be straight or slightly curved. As a rule, the curve is more pronounced in the human variety. The diameter is quite uniform throughout its length. In the human variety, especially as found in tuberculous sputum, they are quite frequently beaded and stain somewhat irregularly. The unstained areas are regarded as vacuoles. The bovine variety is slightly shorter than the one from man. It is usually from 1.5 to 3 microns in length and from 0.3 to 0.8 microns in thickness when found in the tissues, milk or excreta. They do not so frequently present irregularly stained areas. A number of observers have found branched forms of tubercle bacteria2. The tubercle bacterium does not stain readily with theordinary aniline dyes used for staining bacteria. Once stained, however, the dye is retained, even after the application of alcohol and acids. It is for this reason that they are spoken of as acid proof bacteria. The chemical analyses of tubercle bacteria show that surrounding the organism or existing in its outer layers or cell wall there are fatty acids. This has given rise to the term acid fast as it is su...