STUDIES ON THE BACTERIA ASSOCIATED WITH 

 EUROPEAN FOULBROOD 



By C. E. BuRNSiDE, Assistant Apiculturist, Bureau of Entomology, United 

 States Department of Agriculture 



The etiology of European foulbrood of bees is an unsettled problem, 

 several theories having been advanced regarding the cause of this dis- 

 ease. In 1885 Cheshire and Cheyne (2) described Bacillus alvei, which 

 they claimed was the cause of the brood disease now known as European 

 foulbrood. In 1907 Maassen (9) stated his belief that the etiology of the 

 mild form of foulbrood (European foulbrood) is not uniform but that 

 the disease is caused principally by Streptococcus apis and B. alvei. 

 White (11, 12, 13) was unsuccessful in attempts to produce typical 

 European foulbrood with cultures of B. alvei, S. apis, or Bacterium 

 eurydice and concluded that this disease is caused by a new species. 

 Bacillus pluton White, which failed to grow on artificial media. Bor- 

 chert {1 p. 12) and Lehmann and Newman {4 p. 236), of Germany, have 

 pointed out that uncertainty still exists concerning the etiology of 

 European foulbrood. Wharton (14) reported having cultured B. pluton 

 and producing infection in a colony of black bees by inoculation with 

 cultures derived from primary colonies. Lochhead (5) says that this 

 organism cultured by Wharton "appears to be closely related if not iden- 

 tical with Streptococcus apis described by Maassen." Wharton (14) 

 also says that "cultures of B. pluton have been observed to change to B. 

 alvei form resembling biologically the B. alvei isolated from infected 

 larvae.'' Lochhead (5, 6) reported the origin of a coccoid bacillus in 

 cultures of B. alvei. The coccoid was isolated and stabilized and is said 

 to have "all the appearance of what White calls Bacillus pluton.'' Both 

 Lochhead and Wharton question the secondary-organism theory of 

 White as regards European foulbrood. 



At the time White conducted his studies on European foulbrood it 

 was generally believed that bacterial species remain constant in mor- 

 phological and cultural characteristics. In recent years evidence has 

 been constantly increasing that bacteria are capable of morphological. 



