104 



BIOLOGY AND TECHNIQUE 



Classification of the Most Important Pathogenic Bacteria 

 According to Gram's Stain. 



Gram-positive. 



(Retain the Gentian-violet.) 



Micrococcus pyogenes aureus 



Micrococcus pyogenes albils 



Streptococcus pyogenes 



Micrococcus tetragenus 



Pneumococcus 



Bacillus subtilis 



Bacillus anthracis 



Bacillus diphtherise 



Bacillus tetanus 



Bacillus tuberculosis and other 



acid-fast bacilli 

 Bacillus aerogenes capsulatus 

 Bacillus botulinus 



Gram-negative. 



{Take Counterstain.) 



Meningococcus 

 Gonococcus 



Micrococcus catarrhalis 

 Bacillus coli 

 Bacillus dysenterise 

 Bacillus typhosus 

 Bacillus paratyphosus 

 Bacillus fecalis alkaligenes 

 Bacillus enteritidis 

 Bacillus proteus (proteus) 

 Bacillus mallei 

 Bacillus pyocyaneus 

 Bacillus influenzae 

 Bacillus mucosus capsulatus 

 Bacillus pestis 

 Bacillus maligni oedematis 

 Spirillum cholerae 

 Bacillus Koch- Weeks 

 Bacillus Morax-Axenfeld 



Stains for Acid-Past Bacteria. — These methods of staining are chiefly 

 useful in the demonstration of tubercle bacilli. These bacteria because 

 of their waxy cell membranes are not easfly stained by any but the most 

 intensified dyes, but when once stained, retain the color in spite of ener- 

 getic decolorization with acid. For this reason they are known as acid- 

 fast bacilli. The first method devised for the staining of tubercle 

 and aUied bacilli was that of Ehrlich. 



Ehrlich Method.^ — ^This method is now rarely used. Cover-slip 

 preparations are prepared as usual and fixed by heat. 



Stain with anilin water gentian-violet, hot, three to five minutes, 

 or twenty-four hours at room temperature. 



' Ehrlich, Deut. med. Woch.. 1882. 



