DIPHTHERIA 187 



with the hands. This last precaution is most important, 

 and must be rigidly adhered to in all cases. 



DIPHTHERIA. 



Discovery and morphology of the organism — Growth on media— Bac- 

 teriological diagnosis — Method of staining — Varieties of organisms — 

 Pseudo-diphtheria bacilli — Other organisms accompanying diphtheria 

 — Distribution and occurrence — Transmission by means of milk, 

 dust, water, etc. — Pathogenesis — Antitoxin treatment — Method of 

 injection of antitoxin sertim — Besults and advantages of the treat- 

 ment — Need for proper dosage and standardisation of serum — 

 Practical disinfection. 



The bacillus causing diphtheria was first described by 

 Klebs in the year 1875, but was not universally regarded 

 as the true cause of the disease till Loffler succeeded in 

 obtaining pure cultures in the year 1884. The Klebs- 

 Loffler bacillus is a short rod devoid of motility, sometimes 

 apparently pear-shaped at the ends when stained. When 

 grown from the throat in the early stage of the disease, the 

 organism is usually seen as a short rod, about 3 fi long 

 and 1 ytt thick; but after subculturing through several 

 generations, it grows out into rods twice this length 

 and thickness ; the protoplasm then often takes the stain 

 unevenly. 



When specimens are examined from a case in which the 

 patient suffered from true diphtheria and is now con- 

 valescent, it is generally found that the bacilli are present 

 as long and short rods together. The bacillus does not 

 form spores, but is not killed by drying ; dust containing 

 the bacillus will retain its virulence for months under 

 certain conditions. The organism is aerobic, and its 

 thermal death-point is 58° C. 



Growth on Media. — The bacillus grows readily on gelatine, 



