PSEUDO-DIPHTHERIA BACILLUS 295 



throat indicate the importance of throat treatment which there has 

 been a tendency to ignore, on account of the increased use of antitoxin. 

 But antitoxin has little direct effect upon the bacilli in the throat, 

 which should, therefore, be treated by painting with perchloride of 

 mercury (1-500), or washed with chlorine water or permanganate of 

 potash (1-300). The methods to adopt in order to clean the throat 

 of the diphtheria bacillus are three, namely, (a) complete isolation of 

 the patient, coupled with open-air treatment; (6) application of 

 antiseptics to throat; and (c) antitoxin. 



The Pseudo-diphtheria Bacillus.* — In this group should not 

 be included non-virulent forms of the diphtheria bacillus, but allied 

 forms.j- Loflfler and Hofmann described a bacillus having similar 

 morphological characters as the true B. diphtherice, except that it had 

 no virulence. It is frequently found in healthy throats, and is 

 believed by some to be a common inhabitant of the mouths of the 

 poorer classes, especially children. The chief differences between the 

 real and the pseudo-bacillus are — 



1. The pseudo-bacillus is thicker in the middle than at the poles, 

 and not so variable as the B. diphtherice. Polar staining is generally 

 less marked. It appears as an oval bacillus of variable length, gener- 

 ally having one narrow unstained septum. In broth cultures it often 

 more closely resembles B. diphtherice, but under all other conditions 

 is shorter. It forms no toxins (Cobbett). 



2. Hofmann's bacillus forms no acid in glucose culture media. 



3. It does not give Neisser's reaction (see pp. 476 and 481) when 

 grown for twenty-four hours on Loffler's ox serum. 



4. The colonies produced by Hofmann's bacillus on blood serum 

 usually become after a few days larger, more opaque, and whiter 

 than those of the diphtheria bacillus. They also grow a little more 

 rapidly than the true bacillus. 



5. No pathogenic change is produced in guinea-pigs inoculated 

 with this bacillus (1 e.c. of a twenty-four hours' broth culture), and 

 it appears to be innocuous to man. In forming an opinion, all the 

 facts, including the clinical, if possible, must be taken into considera- 

 tion. But on the whole, recent evidence appears to support the view 

 that Hofmann's , bacillus possesses little, if any, pathological signifi- 

 cance in man. It does not agglutinate like B. diphtherice. 



Attempts, followed by some degree of success, have been made to 

 convert a virulent diphtheria bacillus into Hofmann's bacillus, and 

 Hofmann's bacillus into a virulent form (Eoux and Yersin,| 



* For a fuller statement, see Trans. Jenner Inst. (First Series), pp. 7-32. 



f For a discussion of the three forms (a) the true virulent bacillus, (6) the true 

 non-virulent bacillus, and (c) the pseudo-bacillus, see Report of Metropolitan Asylums 

 Board, 1901 (Gordon Pugh). 



I Ann. de VInst. Past., 1890, vol. iv. 



