510 PFEIFFER'S BACILLUS 



According to Rosenthal, Pfeiffer's bacillus exerts a reciprocal ancillary action on 

 the pneumococcus : thus after sub-cultivating a pure culture of the latter on blood- 

 agar a few times the organism dies out, but if it be mixed with Pfeiffer's bacillus the 

 pneumococcus may be sub-cultivated almost indefinitely on blood-agar. 



SECTION IV. THE DETECTION AND ISOLATION OF PFEIFFER'S 



BACILLUS. 



In cases of influenza Pfeiffer's bacillus occurs in the sputum and nasal 

 mucus, and more rarely in the blood ; for the purpose of demonstrating 

 the bacillus it is best to examine the sputum. Pfeiffer lays stress on the 

 somewhat characteristic appearance of the sputum thick, purulent, greenish- 

 yellow and generally inspissated in small compact masses : the bacillus lies 

 between and within the pus cells. Microscopical examination should always 

 be supplemented by cultivation. In sowing the sputum certain precautions 

 are necessary. 



Select a very solid portion of the sputum, and after washing it several 

 times in sterile distilled water (Kitasato's method : p. 192) remove a fragment 

 from the centre without introducing contaminations and sow it on the surface 

 of blood-agar plates. 



THE H^IMOGLOBINOPHILIC BACILLI. 



1. The pseudo-influenza bacillus of Pfeiffer, distinguished from Pfeiffer's influenza 

 bacillus by its rather larger size and by its property of forming filaments in culture, 

 is now admitted by Pfeiffer and others to be identical with the latter organism as 

 was suggested many years ago by Besson. 



Grassberger's micro-organisms A and B and the haemophilic cocco-bacillus of 

 Rosenthal must also be regarded as identical with Pfeiffer's bacillus. 



The bacillus found by Jochmann, Krause and Moltrecht in the sputum and in 

 the broncho-pneumonic patches of cases of whooping cough, and known as the 

 B. pertussis Eppendorf, should in the absence of further knowledge and if the 

 description given by these observers be accepted also be considered as identical 

 with Pfeiffer's bacillus. 



Elmassian's bacillus has all the morphological characteristics of Pfeiffer's bacillus, 

 but is highly pathogenic to guinea-pigs in which animals it produces a rapidly fatal 

 septicaemia. Probably this organism is one of a group of haemophilic micro-organisms 

 closely related to Pfeiffer's bacillus. Friedberger's B. hcemoglobinophilus canis 

 and the bacillus isolated by Wolff from the bronchial mucus of a rat which had 

 died as the result of the inoculation of cholera toxin are members of the same group. 



2. The bacillus of acute contagious conjunctivitis. 



Acute contagious conjunctivitis is caused by a bacillus described by Weeks and 

 Morax : the organism is very similar to Pfeiffer's bacillus. 



Jundell thinks that the conjunctivitis due to Weeks' bacillus is possibly a localized 

 influenza in the eye, and that the causal organisms in the two diseases are merely 

 variants of one and the same species. 



Experimental inoculation. Weeks' bacillus is not pathogenic for animals when 

 inoculated on the conjunctiva. In man, however, a trace of a culture smeared on 

 the conjunctiva gives rise to an acute conjunctivitis. 



Morphology. The bacillus occurs as small very slender and very short rods, 

 non-motile, arranged either singly or in chains of two or three bacilli, either free 

 or within the leucocytes. In cultures, the bacillus often assumes an elongated form. 

 It stains with the ordinary aniline dyes and is gram-negative. 



Cultural characteristics. The organism is aerobic and fails to grow or grows 

 very feebly on the ordinary media, but on media containing blood or serum gives 

 rise to a good growth. Growth only takes place at 37 C. The cultural charac- 

 teristics are in every way similar to those of Pfeiffer's bacillus. 



