The Regeneration of Acid-Fastness by Animal Passage.

Abstract

By following up the regeneration of tubercle bacilli reported in a study of the granules of this organism, 1 several strains of non-acid-fast or partially acid-fast organisms have been studied. One organism or series of organisms obtained from the organs of a patient dying of a generalized miliary tuberculosis will be reported with special emphasis on the ability of the organism to regain acid-fastness on animal passage.

The peculiar aspect of the case was that in the numerous miliary tubercules there were very few acid-fast organisms found. After a search for many hours none were found in the spleen. Instead, however, the miliary tubercles and giant cells contained coccoid bodies (non-acid-fast) arranged singly and in pairs. These possessed a refractile nature not found in ordinary cocci. These cocci, although quite numerous, did not produce colonies on agar media, and sodium hydroxide treatment apparently destroyed their ability to produce infection in guinea pigs.

Pieces of the spleen were placed in celloidin capsules and embedded in the body cavities of guinea pigs. In 3 weeks numerous acid-fast bacilli were found in the capsules. One animal (T93) on which the capsule had broken, had a generalized tuberculosis. The spleen of this animal was inoculated into another animal (T38) that died in 12 days of a septioemia-like condition. The spleen was enlarged many times and red. The lungs were pneumonic, the liver was fatty and acutely inflamed Numerous coccoid and bacillary organisms were observed as well as organisms that seemed to have a slight acid-fastness. The spleen was macerated, diluted and filtered and a single bacillus colony grown from a picked organism. This organism, a pleomorphic type, that possessed no constant morphology nor cultural characteristics, was inoculated into 2 guinea pigs.