512 PATHOGENIC MICROORGANISMS 



chancroidal lesions because of the apparent relative frequency of 

 such lesions among venereally infected soldiers in Europe. We are 

 informed by Walker that during the post-armistice periods of the 

 existence of American troops in France, the proportion of chancroids 

 to other venereal infections rose quite beyond the ordinary relative 

 proportion of this variety of infection, apparently for the reason 

 that prophylaxis as practiced had less effect upon chancroidal infec- 

 tion than it did upon the syphilitic and gonorrheal infections. Since 

 there had apparently developed in the minds of genito-urinary 

 specialists, a certain amount of skepticism regarding the role played 

 by the Ducrey bacillus at this time, the matter was reinvestigated 

 in our laboratory by Teague and Deibert. 11 They developed a 

 method for direct diagnostic cultivation of Ducrey bacilli from chan- 

 croidal lesions which has so much practical value that it will be well 

 to quote it in considerable detail. The method as described by them 

 is as follows: A rabbit is bled from the heart with a sterile 20 c.c. 

 syringe and the blood is distributed in amounts of 1 c.c. in small test 

 tubes, a little larger than the ordinary Wassermann tube. The blood 

 is allowed to clot at room temperature and is then heated for five 

 minutes at 55 C. It can thus be preserved in the ice-box or can be 

 used immediately. Equally good results can be obtained when the 

 tubes are kept in the ice-box for three to four days before use with- 

 out heating. 



Pieces of stiff iron wire, gauge 18, about 5y 2 inches long are bent 

 upon themselves at one end for about % inch. Ten or twelve of 

 these wires are placed in a 6-inch test tube and are heated in the 

 dry sterilizer. The patient removes the dressing and a bit of the pus 

 is picked up with the bent end of the wire, the latter having been 

 first rubbed gently over the base of the ulcer or under its undermined 

 edge. The pus is then transferred to a tube of clotted blood and 

 distributed in the serum by passing the wire around the clot. A 

 second tube is prepared in the same way. After twenty-four hours 

 incubation at 37 C. the serum around the clot is thoroughly stirred 

 with a platinum loop and a smear is made. Examination with the 

 oil-immersion lens shows characteristic chains of small Gram- 

 negative bacilli, sometimes in pure culture, sometimes in mixed cul- 

 ture. The organism is usually so characteristic that such an exam- 

 ination is sufficient basis for a positive diagnosis. Even when anti- 



11 league and Deibert, Jour, of Urology, 4, 1920, 543. 



