442 Pathogenesis o£ Undulant Fever 



clusters neatly arranged in discs or spheres are intracellular colonies of Brucella which de- 

 veloped in the living epithelium of the proximal convoluted tubules and the capsule (pi. 3, 

 figs. 11 and 12). Surrounding these abnormal tubules, massive infiltrations of the stroma by 

 monocytes, lymphocytes, plasma cells, and an occasional polyblast give the lesion a pattern 

 which distinguishes it from the common renal abscesses induced by pyogenic cocci. Moreover, 

 the arrangement of the epithelioid cells indicates a focal giowth incited and maintained 

 by the activity of the bacteria (pi. 3, fig. 13). As a whole, the lesions resemble those described 

 by Fabyan for the kidneys of guinea pigs infected with Br. abortus. The infiltration extends 

 along and between the collecting system and compresses other tubules. On the outer zones 

 of these areas the capillaries are greatly dilated and filled with red cells. 



Throughout the tubular system one encounters single or small clusters of bacteria as free 

 masses or embedded in albuminous material and desquamated cells ^vithin the lumen. In the 

 medullary zone an occasional collecting tubule with completely necrotic epithelial cells 

 encloses a solid plug of gram-negative bacilli (pi. 3, fig. 14). The reactive inflammatory process 

 surroimding these tubules consists predominantly of monocytes or histiocytes and a few 

 polyblasts, and extends rootlike between the uriniferous structures deep into the pyramids. 

 These cells are imbedded in a mesh of slightly thickened reticular fibers. Some of the cells 

 harbor phagocytized fragments of nuclear material in the broad cytoplasm. The epithelium 

 of the convoluted tubules not involved contains small fat droplets, and occasional single cells 

 or groups of cells are acidophilic and necrotic. 



Bacteriological Examination of Body Fluids and Tissues Recovered at Autopsy 



The specimens were cultured by impressing freshly cut surfaces of the organs over several 

 blood- or liver-agar-plates or by streaking 0.1 cc. of the fluid-triturated organs (1 gm. in 10 cc. 

 of broth) over the media. 



Heart Blood: Pneumococcus Type 2 and Type IV (?); E. coli and Staphylococcus aureus. 



Right Lung: Metastatic abscesses: Brucella suis (about 80 per cent), pneumococci, Staphylo- 

 coccus aureus, very few E. coli. 



Consolidated area: Pneumococci, hemolytic cocci and few E. coli. 



Mediastinal Lymph Node: Pneumococci, E. coli and staphylococci, about 4 Brucella colonies. 



Liver: 18-25 colonies of Brucella suis, a few E. coli (2 types not identified). 



Bile: 0.1 cc. of dilution 1:10 yields approximately 300 Brucella colonies or approximately 

 30,000 bacilli per cc. of bile and 400 E. coli. 



Portal Lymph Nodes: Second dilution plate: 14 colonies of Br. suis, 9 E. coli and a few 

 colonies of staphylococcus. 



Spleen: Second dilution plate: 100 colonies of Br. suis, 40 hemolytic coccal colonies; third 

 dilution plate: 20 colonies of Br. suis, few coccal colonies. 



One gm. of splenic tissue was emulsified in 10 cc. of broth; 0.1 cc. of the organ suspension 

 yielded 36 colonies of Brucella suis or j,6oo organisms per gm. of splenic pulp. 



Left Kidney: Innumerable colonies of Br. suis. 



Right Kidney: Innumerable colonies of Br. suis and 4-5 of E. coli. 



Ileum: (hemorrhagic segment); principally E. coli but a few Br. suis. 



The Brucella strain isolated from the blood culture taken on November 26 and at least 

 10 other strains grown from organs and selected at random, grew freely aerobically, formed 

 abundant H2S, developed readily in the presence of thionin and moderately heavily in basic 

 fuchsin (1:50,000), and were identified with the laboratory strain Br. suis No. 80 (Meyer 

 and ZobelP). It was specifically agglutinated by an absorbed abortus serum and it infected 

 guinea pigs with typical granulomas which presented central aggregates of polymorpho- 

 nuclear leucocytes. 



