Melissococcus plutonius that causes European foulbrood in honeybee larvae has been isolated from diseased larvae globally. In Japan, this bacterium has been isolated from European honeybee (Apis mellifera) as well as from Japanese honeybee (Apis cerana japonica). However, relationship between M. plutonius isolates from different countries and different honeybee species have not been well studied. Therefore, in this study, we analyzed 85 Japanese M. plutonius isolates by multilocus sequence typing (MLST), combined the data with those deposited in M. plutonius MLST database, and investigated the relationship between M. plutonius isolates from different countries and different honeybee species. A total of 352 M. plutonius isolates from 15 countries were resolved into 27 sequence types (STs). The 27 STs were classified into 3 clonal complexes (CCs). Japanese isolates belong to ST3 (24 isolates) of CC3, ST12 (52 isolates), ST25 (1 isolate), and ST27 (4 isolates) of CC12, and ST4 (1 isolate) and ST26 (3 isolates) of CC13. The two most common STs in Japan (ST3 and ST12) were found in isolates from both European and Japanese honeybees. Moreover, these two STs were identified not only in Japan but also in other countries. These results suggest that some M. plutonius strains are spreading across borders and between different honeybee species.
(Bacterial and Parasitic Diseases Research Division)
References:
Takamatsu D. et al. (2014) Vet. Microbiol. 171:221-226
