Reclassification, genotypes and virulence of Paenibacillus larvae, the etiological agent of American foulbrood in honeybees -: a review

American foulbrood, a worldwide bacterial disease of honeybee brood caused by the grampositive bacterium Paenibacillus larvae, is one of the most serious bee diseases. This review will focus on recent achievements in the study of Paenibacillus larvae brought about by molecular methods introduced into the field over the last fifteen years. One topic will be the classification of the etiological agent, which has changed several times since the first description in 1906 and was most recently modified again. Different genetic and biochemical methods for subtyping Paenibacillus larvae, the analysis of differences in virulence and the implications of these differences will also be covered.