Characterization of isolates of Paenibacillus larvae subsp. larvae from diverse geographical origin by the polymerase chain reaction and BOX primers

Ninety-nine strains of Paenibacillus larvae subsp. larvae, the causal agent of American Foulbrood disease (AFB) of honeybees, were isolated from different regions of Argentina and other countries. The isolates were characterized on the basis of DNA fingerprints by a polymerase chain reaction technique (PCR) with BOX sequence-specific primers. Isolates from Argentina generated three groups of patterns (designated A, B, and C), while P. larvae subsp. larvae strains obtained from other countries yielded two distinguishable patterns (coincident with A and B). Strains from U.S. A. and Germany were identical and related to Group A, while all Czech and English isolates belonged to Group B. Strains from France, Poland, Italy, Sweden, and New Zealand showed two different patterns (A and B). Comparisons of the biochemical type and genotype of isolates rendered no obvious linkage between both features. These results suggest that AFB in Argentina resulted from multiple sources of contaminated material.