g 2 STUDY AND IDENTIFICATION OF BACTERIA 



Colonies smaller and less opaque than those of B. coli. 



Examples: B. pestis, B. suisepticus, B. cholerae gallinarum (chicken 



cholera). 



B. pseudo tuberculosis rodentium (very similar to plague). 



B. pestis is absolutely nonmotile, does not liquefy gelatin, does not 



produce indol, produces slight acid in glucose but not in lactose bouillon, 

 b. Dysentery group. Colonies similar to those of B. coli. 



Divided into two classes according as mannite is acted on: 



Those not giving acid nonacid group (Shiga-Kruse). 



Those giving acid acid group ( Fl ex ner- Strong). 

 2. Gas generated in glucose bouillon not in lactose. 



a. Friedlander group. Give very viscid, porcelain-like colonies. 



Tendency to capsule formation in favorable media. 



Examples: B. pneumonise, B. capsulatus mucosus, B rhinoscleromatis. 

 B. Motile bacilli. 



1. Do not liquefy gelatin. 



a. Do not produce gas in either glucose or lactose bouillon. 



Typhoid, or Eberth group. No indol. No coagulation of milk. No 

 reduction of neutral red. 



b. Gas generated in glucose, not in lactose media. Milk not coagulated. 

 Neutral red reduced. 



Gartner group. This includes: 



Pathogenic types for man; as B. enteritidis, B. icteroides, B. paratyphoid 

 B, B. psittacosis. Nonpathogenic for man; as B. cholerae suum (hog 

 cholera) . 



2. Liquefy gelatin. 



a. Proteus group. Colonies at first round later amoeboid, spreading. 

 Produce gas in glucose, not in lactose. Produces foul odor. 

 B. zopfii type of Proteus group does not liquefy gelatin; colonies at first 

 round, later amoeboid, spreading. Foul odor in cultures. Gelatin stab 

 shows lateral branching. 



NOTE. The Friedlander and the lactis aerogenes group, differing culturally 

 chiefly in carbohydrate fermentation activities, organisms considered as belonging 

 to the Friedlander group rather than to the lactis aerogenes group may show acid 

 in litmus milk. Where an organism having the characteristics of B. coli, but 

 fermenting saccharose, is found, it is termed B. coli communior. A non-gas 

 producing colon type organism has been designated B. coli anaerogenes. Cer- 

 tain organisrns which turn litmus milk lilac and which liquefy gelatin, but do not 

 produce gas in sugar media, belong to the "Booker" group. Other organisms 

 which acidify and coagulate litmus milk but do not liquefy gelatin or produce gas 

 in glucose or lactose media have been placed in the "Bienstock" group. The 

 proteus or Hauser group is composed of organisms showing various functions; 

 Proteus vulgaris liquefying gelatin rapidly, P. mirabilis slowly and P. zenkeri 

 not at all. 



GRAM NEGATIVE BACILLI REQUIRING SPECIAL MEDIA. 



Bacillus influenzae (Pfeiffer, 1892). This organism is the type of 

 the so-called haemophilic bacteria organisms whose growth is restricted 



