

CHAPTER XVI. 

 BACILLUS PYOCYANEUS. 



Introduction. 



Section I. Experimental inoculation, p. 276. 



Section II. Morphology, p. 277. 



1. Microscopical appearance and staining reactions, p. 277. 2. Cultural charac- 

 teristics, p. 278. 

 Section III. Biological properties, p. 279. 



1. Pigments, p. 279. 2. Toxins, p. 280. 3. Vaccination and serum therapy, p. 280. 

 4. Agglutination, p. 281. 5. Antagonism, p. 281. 

 Section IV. Detection and isolation of the organism, p. 281. 



THE cause of blue suppuration was discovered by Gessard. 



Blue pus is rarely seen nowadays though it was very common before the 

 introduction of antiseptics. The bacillus pyocyaneus is always associated 

 in these conditions with the ordinary micro-organisms of suppuration ; its 

 presence in a wound is simply a complication and that not of a serious 

 nature. 



The bacillus pyocyaneus may invade the tissues of the body when the 

 resistance of the latter has been broken down by some pre-existing patho- 

 logical condition. It has, for instance, often been found in the internal 

 organs in cases of enteric fever ; Calmette found it in the blood of persons 

 suffering from chronic dysentery [and Williams and Lartigan in association 

 with diarrhoea]. [Of twenty- three cases of pyocyaneus infection occurring 

 in British Guiana and recorded by Minett and Duncan six were cases of 

 acute filariasis and six others showed intestinal ulceration.] On the other 

 hand it may be the primary cause of disease : e.g. of enteritis (Legros), appen- 

 dicitis (Coyne and Hobbs), otitis, pseudo-membranous sore throat (Calvo 

 Ignacig), etc. : some twenty cases of a generalized infection with the bacillus 

 pyocyaneus have moreover been recorded. 



[Dogs are liable to infection with the bacillus pyocyaneus and in these animals 

 the symptoms may clinically resemble rabies ; and moreover the inoculation of 

 brain tissue from the affected animals into normal rabbits and guinea-pigs produces 

 symptoms similar to those seen in the original animal.] 



The organism is sometimes found in the soil, in dust and in water. Besson has 

 recorded its almost constant presence in the waters of the regency of Tunis where 

 blue suppuration is very common and where serious infections are often com- 

 plicated by the bacillus pyocyaneus. 



SECTION I. EXPERIMENTAL INOCULATION. 



The bacillus pyocyaneus is pathogenic to rabbits, guinea-pigs, rats and 

 mice. 





