78 STUDY AND IDENTIFICATION OF BACTERIA 



SPORE-BEARING ANAEROBES 



There are four very important pathogens in this group that of gas 

 gangrene; that of malignant oedema; that of botulism, and the organism 

 of tetanus. 



The B. enteritidis sporogenes is of importance in connection with indications of 

 faecal contamination of water. In connection with B. aero genes capsulatus, there is 

 some question as to whether the extensive oedema produced by it may not usually 



be from a terminal or cadaveric infec- 

 tion. At any rate necrotic material 

 seems necessary. 



It should be stated that our knowl- 

 edge of the differential cultural charac- 

 teristics of anaerobes is unsatisfactory. 

 The exact methods which are in use 

 for aerobes have not been applied to 

 anaerobic organisms. 



To Cultivate Anaerobes. Prob- 

 ably the apparatus giving the most 

 perfect anaerobic conditions is the 

 Novy jar, in which the air has been 

 replaced by hydrogen. The diffi- 

 culties attending the method are: 



i. Unless a special apparatus (Kipp's) 

 is at hand, there may be difficulty in pre- 

 FIG. 20. Novy jar. venting the sulphuric acid from frothing 



over when poured on the zinc. It should, 

 at first, be added in small quantities at a time well diluted (i to 6). 



2. Various wash-bottles are required: one containing silver nitrate solution for 

 traces of AsH 3 and one with lead acetate for H 2 S and another with pyrogallic acid 

 and caustic soda for any oxygen that may come over. 



3. Mixtures of hydrogen and air explode. Consequently, in determining whether 

 all air has been expelled and in its place an atmosphere of hydrogen exists, it is 

 necessary to see if the escaping gas burns with a blue flame. Unless this is collected 

 in a test-tube and examined, we may have an explosion. 



4. Except in a large laboratory, where the apparatus is set up and ready for use, 

 too much time would be required. 



5. Simpler methods appear to give as good results. 



In Tarozzi's method, pieces of fresh sterile organs are added to 

 bouillon. Pieces of kidney, liver, or spleen are best suited. After 

 adding the tissue the media may be heated to 8oC. for a few minutes 



