122 



ESSENTIALS OF BACTERIOLOGY 



Antituberculous Serum. The attempts to produce an 

 effective serum have so far been unsuccessful. Marmorek, 

 by growing the bacillus on a special serum obtained by in- 

 jecting calves with the leukocytes of guinea-pigs, has secured 

 a toxin which he used to immunize horses, and the serum so 

 obtained has been tried with encouraging results, but its 

 value is still doubtful. Several other sera have been intro- 

 duced, but none of them has shown any lasting virtues. 



Lepra Bacillus (Hansen). Origin. In 1880 Armauer 

 Hansen declared, as the result of many years' investigation, 



that he found specific bacil- 

 lus in all leprous processes. 



Form. Small slender rods, 

 somewhat shorter than tu- 

 bercle bacilli, otherwise very 

 similar in appearance. 

 Neither in the form nor 

 staining reactions can B. 

 lepra be distinguished from 

 B. tuberculosis. 



In the interior of the cell 

 two or three oval spaces are 

 usually seen, not believed tc 

 be spores. 



They are immotile. 

 Growth. Bordoni-UfTred- 

 uzzi have obtained growths 



upon blood-serum to which peptone and glycerin had been 

 added, but the accuracy of this observation was doubted, 

 and not until Clegg, in 1909, and Duval, in 1910, in work in 

 the Philippine Islands devised special media was it possible 

 to obtain readily initial and subcultures. 



The method depends upon supplying the organism with 

 albumin partially metabolized. Clegg prepared this by 

 planting the lepra bacilli on media containing ameba and 

 bacteria; then, by short sterilization, destroying these, while 

 the resistant B. lepra lived on. Duval, by adding trypsin to 



Fig. 51. Pure culture of bacil- 

 lus of leprosy, showing the charac- 

 teristic morphology and arrange- 

 ment of the bacilli (Duval). 



