







SERUM THERAPY AGGLUTINATION 335 



on five successive occasions without producing any appreciable reaction. 

 The tuberculin test was negative and the serum of this animal inoculated 

 prophylactically into a calf (82 c.c. sub-cutaneously in a fortnight) protected 

 the latter against a sub-cutaneous inoculation of bacilli of the bovine type 

 while two controls similarly inoculated with the test culture became infected. 

 The passively immunized calf when killed 6 months afterwards showed no 

 tuberculous lesion. As a curative agent this serum is without effect. 



(viii) Vallee treats horses by inoculating them first with progressively 

 increasing doses of bacilli of equine origin then with bacilli of human origin. 

 The serum of such animals exhibits no agglutinating properties but contains 

 immune bodies (sensibilisatrices) and has distinct therapeutic properties in 

 the treatment of bovine tuberculosis. 



(ix) The serum of bovine animals, guinea-pigs and pigs vaccinated by 

 Friedmann with the chelonian bacillus has proved itself in the case of the 

 guinea-pig to possess undoubted prophylactic properties. While control 

 guinea-pigs died of generalized tuberculosis, the treated guinea-pigs killed 

 at the same time only showed insignificant lesions. 



5. Agglutination. 



1. The serum diagnosis of tuberculosis with ordinary cultures, consisting 

 as they do of bacilli massed together to form films or scales, is quite impossible. 

 Arloing and Courmont have described a method of obtaining homogeneous 

 cultures which are quite suitable for the demonstration of the phenomena 

 of agglutination. 



Arloing's homogeneous cultures are obtained from luxuriant, greasy-looking, 

 growths on glycerin- potato. After being sub-cultivated a few times on glycerin- 

 potato the tubercle bacillus is sown in cylindrical flasks with a flat base half filled 

 with a 1 per cent, peptone beef broth containing 6 per cent, glycerin. The cultures 

 are incubated at 38-39 C. and shaken daily. It is necessary to sub-cultivate 

 several times in order to get a copious growth. 



The cultures should be used when about 10 days old : later they are thick and 

 too rich in bacilli and are only partially agglutinated by the specific serum. 



Cultures sown in this way are ^distinctly cloudy after a few days, and when shaken 

 have a watered silk appearance ; the cloudiness subsequently increases and becomes 

 uniform, and after 2 or 3 weeks the growth is more or less milky. A drop of the 

 culture examined unstained shows small, isolated rods occasionally slightly motile. 

 The bacilli stain by Ziehl's method (except in rare cases recorded by Arloing and by 

 Ferran). On inoculation into animals they behave like tubercle bacilli of a very 

 low degree of virulence. 



Ten-day-old cultures suitable for agglutination can be kept for about a fortnight 

 in the ice-chest or by adding a little formalin (3-4 per cent.) to them ; the aggmtina- 

 bility diminishes after a few weeks. 



To obtain and to keep an agglutinable culture more easily Arloing and Courmont 

 now advise the use of old cultures which must be diluted as required. The culture 

 is left in the incubator for 30 or 40 days and can be used at once or kept in the ice- 

 chest for about 1 month. When required for use the culture is diluted with sterile 

 normal saline solution until it gives a milky, slightly opaque fluid like a solution of 

 glycogen (about 1 in 50). 



When a culture is used for purposes of serum diagnosis a control should always 

 be done with a standard serum of which the agglutinating property is known before- 

 hand (the serum of an experimentally infected animal, or a tuberculous pleural 

 exudate, for example). 



Homogeneous cultures are agglutinated by the serum of animals which 

 have been inoculated with tuberculin or living bacilli and by the serum of 

 most tuberculous human subjects (66-90 per cent.) when the serum is diluted 

 from 1 in 5 to 1 in 50. The degree of agglutinating power in serums from 

 the same animal species appears generally speaking to bear no relation to 



