A case of Rickettsia heilongjiangensis infection in Japan was identified in a 35-year-old man who had rash, fever, and eschars. Serum contained R. heilongjiangensis antibodies, and eschars contained R. heilongjiangensis DNA. R. heilongjiangensis was also isolated from ticks in the suspected geographic area of infection.

To clarify the taxonomic classification of Streptococcus suis serotype 33, we performed biochemical and molecular genetic analyses using isolates (GUT-183, GUT-184, GUT-185, GUT-186, GUT-187T, GUT-188, GUT-189, GUT-190, GUT-191, GUT-192 and GUT-193) from bovine endocarditis. A comparative sequence analysis showed 99.2-100 % sequence similarity among the reference strain of S. suis serotype 33 and our isolates for the 16S rRNA gene. These similarities were higher than those between the isolate GUT-187T and S. suis and other streptococci. Comparison of sodA genes also showed high degrees of similarities among the reference strain of S. suis serotype 33 and our isolates (99.7-100 %), which were higher than those between the GUT-187T and S. suis and other streptococci. DNA-DNA relatedness among three isolates (GUT-186, GUT-187T, the reference strain of S. suis serotype 33) was over 76.7 %. In contrast, the relatedness between GUT-187T and the other streptococcal species (S. suis, Streptococcus parasuis, Streptococcus acidominimus and Streptococcus porci) was 8.4-24.9 %. Phylogenetic analyses showed that the isolates did not affiliate closely to any known species of the genus Streptococcus. Moreover, GUT-187T could be distinguished from S. suis and other closely related species of genus Streptococcus using biochemical tests. On the basis of the phenotypic and molecular genetic data, we propose that the isolates of S. suis serotype 33 should be classified into the genus Streptococcus, Streptococcus ruminantium sp. nov. with the type strain GUT-187T (=DSM 104980T=JCM 31869T).

homology with other superantigens at the amino acid sequence level. The tertiary structure of SDM was predicted by modelling onto streptococcal pyrogenic exotoxin C and streptococcal mitogenic exotoxin Z-2, both of which share highly homologous structuredetermining regions. SDM showed overall structural similarity to both these superantigens. This is the first study to characterize fully a bacterial superantigen from S. dysgalactiae .

ABSTRACT. Bacterial isolation from slaughtered pigs with endocarditis was carried out from 1985 to 1994. A total of 495 (0.025%) out of 2,006,127 pigs were diagnosed as having endocarditis. Though bacteria were significantly isolated from 399 of the 495 pigs, bacteria could not be isolated in 96 pigs (19.4%). In 11 pigs, 2 bacterial species were isolated from heart lesion. Streptococcus suis was isolated from 127 cases (25.7%), Streptococcus dysgalactiae from 75 (15.2%), Erysipelothrix rhusiopathiae from 63 (12.7%), Actinomyces pyogenes from 39 (7.9%), Pasteurella multocida from 11 (2.2%), Staphylococcus aureus from 10 (2.0%), and Streptococcus porcinus from 8 (1.6%). Among the 99 isolates biochemically identified as S. suis, the major serotype was S. suis type 2 (35.4%). The remainder of the typable isolates were identified as serotypes 1/2 (2.0%) and 9 (1.0%). A total of 61 isolates (61.6%) were untypable. -KEY WORDS: bacterial endocarditis, swine (slaughtered), Streptococcus suis.

The nucleotide sequences of 16S and 23S rRNA genes (rDNA) were determined for 11 isolates of Streptococcus dysgalactiae subsp. equisimilis from slaughtered pigs with endocarditis, arthritis or lymphadenitis and strain ATCC 35666, designated as a strain of subspecies equisimilis. The sequences of each of the genes were compared phylogenetically with the corresponding sequences of S. dysgalactiae subsp. dysgalactiae ATCC 43078 T and ATCC 27957, which were also determined in this study. Based on the 16S rDNA analysis, the isolates of S. dysgalactiae subsp. equisimilis were divided into two distinct groups, designated groups 1 and 2. S. dysgalactiae subsp. equisimilis ATCC 35666 was closely related to the group 2 strains. The S. dysgalactiae subsp. dysgalactiae strains seemed to be associated with the group 1 strains, which was not consistent with the conventional subspecific classification of S. dysgalactiae. In contrast, the 23S rDNA analysis distinguished S. dysgalactiae subsp. dysgalactiae strains from subsp. equisimilis strains. This inconsistency between phylogenies based on 16S and 23S rDNA indicates that 23S rDNA is a more rigid marker for determining the phylogenetic relationships and taxonomic position of these organisms than is 16S rDNA.