722 Glanders. 



negative in horses which gave positive or doubtful reactions to mallein, but the 

 blood serum of which did not distinctly agglutinate glanders bacilli. Subsequent 

 experiments showed that sera which agglutinated the typhoid bacillus, the Bacillus 

 suipestifer, or the colibacillus, would not affect the bacillus of glanders. 



In the experiments of Schiitz & Meissner the agglutination titer of the sera 

 of 1,911 horses which were free from glanders was 1:100-400 in 1,602 horses 

 (83.8%), 1:500-800 in 299 horses (15.7%) and 1:1000 in 10 horses (0.5%); on 

 the other hand, among 298 glanderous horses the titer was 1:400 in 6 (2.0%), 

 1:500-800 in 103 horses and 1:1000 in only 189 horses" (63.4%). If we regard titers 

 of 1:400 as decisively negative and 1:1000 or more as decisively positive evidence 

 of infection, the errors in diagnosis in these cases were only 0.7,7%. However, in 

 18.2% of all cases and in 34.6% of the infected horses that gave agglutination titers 

 of 1:500-800 the diagnosis had to be held in abeyance. 



Sehniirer places a similar value on the results of the agglutination test, 

 although according to his opinion the average amount of normal agglutinins fluc- 

 tuates between 400 and 600. However this investigator, whose observations extend 

 over 300 cases, recommends this method strongly for practical use, as do also 

 Benome, Wladimiroff, Fedorowsky, Langer, Moore, Taylor & Giltner, Berns & 

 Way, etc., while Foulerton, Preusse, Stanciu and Eiemer express themselves less 

 favorably. The last named author observed agglutination powers of 1:500, 1:700 

 and 1:1000 in glanderous horses, while the titers in six healthy horses were 1:800 

 (in four cases), 1:2000 and 1:4000, respectively. In pleuro-pneumonia (Miessner) 

 as well as in distemper (Sustmann) the serum seems sometimes to possess greater 

 agglutinating power, it has also in the course of a long period of observation been 

 found to be more uniform, while other diseases do not influence the agglutination 

 titer (Langer). 



After an experimental infection, the agglutinating power may rise to 1 : 2000 

 or more in 2 days (Bonome, Hutyra; according to Sustmann in 3 days; according 

 to Schiitz & Miessner in 6 days) remaining at this point about 4 weeks, whereupon 

 it gradually returns to the normal. 



Subcutaneous malleinization raises the agglutination titer in healthy as Well 

 as in infected horses. Pekschisehewsky saw the titer double in the course of a mal- 

 lein reaction, and according to Pfeiler it sometimes reaches 4,000 in these cases, 

 while Meissner as well as Fedorowsky, Kleine and Bonome observed only a mod- 

 erate but long continued increase of titer. Schiitz & Miessner failed to observe 

 any change in three horses. ,^rpad observed the titer increase in two days from 300 

 to 1,600 in healthy horses, but it dropped again to 800 in 7 days, while according 

 to Miessner the increase does not begin until the 5th or 7th day, reaching its max- 

 imum in 14 days and not beginning to gradually return to the normal until after 

 4-6 days. According to Sustmann the elevation continued for more than 3 months. 



Practical observations of Nevermann include statistics on 3,466 horses which 

 were tested in the course of two years in several hundred Prussian stables or studs. 

 According to these statistics the temporary diagnosis based upon the agglutination 

 test was confirmed by post-mortem examination in 79.2% of the negative results 

 (titer 300-400) and in 79.5% of the positive results (titer 1,000 or more, with 

 fluctuations). Of 18.2% of the horses destroyed on the ground of suspicion (giving 

 titers of 500-800) lesions of the disease were present in 46.6%. In more than 

 one-half of the stables the test for gome of the animals had to be repeated from 

 3 to 6 times. 



Technic of the Agglutination Method. The test fluid is prepared with 

 a suspension of agar or potato culture of 2 to 5 days' growth prepared from a 

 suitable strain of glanders bacilli and diluted with physiological salt solution. 

 After killing the bacilli by heating at 60° C. the test fluid is standardized 

 by adding the necessary amount of normal salt solution. For each 2.0 

 cc. of this fluid in test tubes the serum to be tested is added in success- 

 ively decreasing amounts (from 1:300 to 1:4000) whereupon the tubes are 

 incubated for 36 hours. By keeping the fluid in the thermostat for one-half hour 

 and suDsequently centrifuging for 5 to 15 minutes (the time being determined by 

 the_ number of revolutions), the result may be obtained within one to two hours, 

 positive reactions are indicated by the accumulation of agglutinated bacilli on the 

 bottom of the tubes in the form of a circular fllm with serrated border, while the 

 supernatant fluid has become perfectly clear. On the other hand a negative reaction. 

 is indicated by the cloudiness of the fluid, while the precipitated but not aggluti- 

 nated bacilli have accumulated on the bottom of the test tube in the form of a flat 

 disc with a smooth outline. 



King & Houghton have worked out a method by means of which the test can 

 easily be made in actual practice. Carefully measured amounts of properly prepared 

 test fluid are placed in graduated test tubes whereupon square pieces of filter paper 



