THE STUDY OF OBLIGATELY ANAEROBIC BACTERIA iii«-13 



dye which serves as an oxidation reduction potential indicator.) 

 Place plates in the incubator immediately after they are prepared 

 and examine as needed during the incubation period. When trans- 

 fers are to be made from the plate, break the seal by a slight turn 

 of the lid. 



Advantages: A useful, quick method of single plate culture. An extremely simple 

 method which is easy to learn and use. The only trick in the technic is to have 

 sufBcieut agar in the original dish that a perfect seal is formed when the special lid 

 is added. Recommended for routine use in hospital laboratories, and particularly 

 for mobile laboratories, where anaerobic cultures for pathogens may be encountered. 

 Disadvantages: Surface moisture may result in film formation in some instances; 

 this may be reduced by using a porcelain top ( see footnote 4) on the regular dish prior 

 to the Brewer anaerobic lid or drying the plates in incubator before streaking. Some 

 organisms apparently are inhibited by the reducing agents. This is not serious since 

 the reports indicate that all pathogenic types are easily cultured by this method. 

 The Brewer anaerobic lids are, at the present time, relatively expensive. 



There are other anaerobic systems which are satisfactory as, for 

 example, the Novy jar which depends upon evacuation and gas 

 replacement in a specially designed desiccator. These will not be 

 discussed, however, as they are less commonly used at the present 

 time, and it is believed that the methods discussed above will be 

 satisfactory in most instances. 



TECHNICS FOR STUDY OF ANAEROBIC BACTERIA^^ 



In the above section the various pieces of apparatus and methods 

 for their use with anaerobic bacteria have been considered. Formu- 

 lae for the particular media which are recommended may be found in 

 the 9th edition of Leaflet 11^^. The remainder of this Leaflet will 

 be devoted to a discussion of the details of certain technics which 

 should aid the worker who has not had previous experience w^ith 

 anaerobes. 



It may not be amiss to insert here a precautionary note concerning 

 the necessity of very careful inspection of the purity of cultures. 

 There are instances on record, in the older literature, where two 

 species grew symbiotically on plate culture with such constancy 

 that recorded observations were made of the colony type of mixture, 

 the investigator being unaware of the existence of more than one 

 type. In all studies concerning obligate anaerobes, a check on the 

 purity of the culture should be made with regard to aerobic contami- 



•'In this Leaflet reference will be made to the "pathogenic group" and the "butyric- 

 butyl group". The former term is used to designate such organisms as Clostridium 

 tetani, C. septicum, C. histolyticum, C. chauvoei, C. pcrfriiigens, C. parabotulinum, C. 

 botulinum and C. sporogenes. In the butyric-butyl group are included C. bntyricum, C. 

 beijerinckii, C. butylicum, C. pasteurianum, C. acetobutylicum, C. felsineum, C. roseum, 

 and C. thermosaccharolyticum. 



"To be published about February, 1944. 



