52 CONTROL SERIES No. 63 



exposure. No agglutinins were detected in birds 195 and 227. Bird 209 revealed 

 a weak titer. No significant lesions were observed on necropsy. S. pullorum 

 was isolated from one bird, No. 188. 



Lot C consisted of 3 birds which received 3 consecutive daily doses. Bird 

 205 manifested a local imflammatory reaction aroimd the eye exposed to the 

 inoculum. Recovery was complete 4 weeks after the first exposure. All birds 

 in this lot possessed agglutinins 7 days after the first exposure. Table 21 shows 

 their weekly sera titers. Cardiac lesions commonly found in pullorum disease 

 were present in birds 200 and 205. S. pullorum was isolated from bird 200. 



Lot D consisted of 3 birds which received 1 dose of the suspension. Clinical 

 manifestations which consisted of a general systemic reaction and inflammatory 

 changes in both eyes were observed in bird 189. It was not definitely proved that 

 the reaction in both eyes was caused by pullorum infection. Bird 211 showed a 

 local reaction in the eye used for inoculation. Table 21 shows that agglutinins 

 were present 7 days after the first exposure and persisted during the course of 

 the experiment. Cardiac lesions were present in all birds. In bird 189, the par- 

 enchyma of the liver was friable with ecchymotic hemorrhages present on the 

 surface. A nephritis and enteritis were also observed. S. pullorum was isolated 

 from birds 189 and 234. 



In birds 194, 200, 224, and 234, S. pullorum was isolated from the pericardial 

 fluid only. In bird 189, the organism was isolated from the heart and spleen and 

 in bird 188 from the spleen only. 



Group III consisted of 15 pullorum disease-free Rhode Island Red birds, 

 approximately 3 months old which were divided into two lots. All birds were 

 retained in individual cages. Two avenues of ex-posure were employed, namely, 

 instillation of the infective agent into an incision in the skin of the plantar sur- 

 face of the foot and inoculation into the cloaca. The former avenue was selected 

 because occasionally birds show an enlargement of the foot, with a scab attached 

 to the plantar surface. S. pullorum has been isolated from a case of this type. 

 Whether 5. pullorum infection is the primary or secondary cause in such cases 

 cannot be stated. However, it appears plausible for the organism to enter the 

 body if the continuity of the skin is broken resulting in either localized or general- 

 ized foci of infection. 



The infective agent was a saline suspension prepared from a 24-hour agar 

 slant culture with a turdibity with a range between 1.5 and 1.75 on the McFarland 

 nephelometer scale. Quantitative determinations revealed that the different 

 suspensions varied from 550 to 710 million organisms per cubic centimeter. The 

 strain used was the same as employed for Group II. The size of the dose was 

 approximately 0.03 cc. The birds were tested with the macroscopic agglutina- 

 tion test at weekly intervals. Dilutions of 1 :10 and higher, suflficient to determine 

 their titers, were used. All birds were killed and necropsied approximately 10 

 weeks after the first exposure with one exception. This bird died 3 weeks after 

 the first exposure. Culture material was taken from the pericardial fluid, liver, 

 and spleen in all cases. Other tissues which appeared infected were also cultured. 

 Strains resembling 5. pullorum were examined in the same manner as those 

 isolated in Group II. 



Lot A consisted of 5 cockerels which were exposed to infection by placing 

 the inoculum in an incision in the skin of the plantar surface of the foot. Two 

 incisions, extending through the cutis, were made with a sharp pointed Icnife. 

 The incisions were approximately 0.5 cm. in length and bisected each other at 

 right angles. The date of the first exposure was August 31. The inoculum was 

 not completely absorbed in some cases because the dose (0.03 cc.) appeared to 

 be too large. Furthermore, the incision was disturbed at the time the second, 

 third, and fourth doses were administered which caused a shght hemorrhage, 



