One thousand two hundred ninety-seven Erysipelothrix strains isolated from swine erysipelas cases between 1988 and 2004 in Japan were characterized by serotype, genotype, and acriflavine resistance. Thirty-eight, 67, 80 and 1,112 strains were isolated from acute septicemia, urticaria, chronic endocarditis and chronic arthritis cases, of which 635 isolates belonged to serotype 1a. Of the serotype 1a isolates, 75% were acriflavine-resistant and 81% showed a live vaccine strain-characteristic 253 bp band in randomly amplified polymorphic DNA analysis (RAPD), designated RAPD type 1-2. Almost all of these acriflavine-resistant strains or RAPD type 1-2 strains were isolated from cases of chronic arthritis. The incidence of acriflavine-resistant strains in the RAPD type 1-2 was markedly higher than in other RAPD types and serotypes. Furthermore, the mouse pathogenicity of the RAPD type 1-2 was lower than in other RAPD types of serotype 1a. Our results indicate that the RAPD typing is a useful method for the discrimination of avirulent strains of serotype 1a from virulent strains of serotype 1a.
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Reference:
Imada et al. (2004) J. Clin. Microbiol. 42:2121-2126.
