172 PATHOGENIC BACTERIA 



dyes. They grow well, best at body temperature, but 

 also as low as 12 C. or 54 F., or as high as 41 C. or 

 106 F. They are killed at 56 C. or 133 F. in ten 

 minutes. They resist drying quite well. Freezing is 

 rather rapidly fatal to them. They grow best in the 

 presence of oxygen, but may live without it. All the 

 artificial cultivations of this group are characterized 

 by luxurianqe, with a tendency to a slimy, smeary, or 

 tenacious consistency, hence the name "mucosus." 

 None of the group can soften gelatin or make indol. 

 They all produce some degree of acidity in milk, but 

 not all can curdle it. 



The various members behave very differently in 

 regard to sugars and upon these reactions they are 

 classified. The poison produced by the bacteria of 

 this group is probably all endotoxic. They irritate 

 the part also mechanically by their presence. These 

 bacilli are widely distributed in animal life, but less 

 so otherwise in nature. They are transmitted directly 

 from man to man, by particles of saliva or sputum or 

 in fecal discharges, or in pus, which should be disin- 

 fected as given for the colon bacillus. Besides the 

 special conditions to be mentioned later, members of 

 this group have been known to cause pyelitis, gastro- 

 enteritis, peritonitis, pleuritis, and septicemia. 



The most important member of the group is the 

 Bacterium pneumonia of Friedlander, a common cause 

 of pneumonia, next in importance for the acute lobar 

 pneumonia to the pneumococcus. The pneumonia 

 is characterized by its sticky nature. It is usually 

 short in duration and grave in prognosis. The bacilli 

 may enter the circulation and give rise to localized 



