Biological properties and antibiotic susceptibility of Bacillus larvae originated from American foulbrood of honeybee in Japan.

The biological properties and susceptibility to antimicrobial agents of Bacillus larvae were examined. Twenty-nine strains, 28 isolates from each outbreak of American foulbrood in Japan and a B. larvae type strain (ATCC 9545T) were used. our B. larvae isolates had almost the same biological properties as the type strain. The isolates were more susceptible to penicillins, macrolides and lincomycin, a lincosamide, than other antimicrobials. Microsamicin among the macrolides and ampicillin among the penicillins appeared to be the most effective agents.