Abstract
Presence of peritrichal fimbriae in the 2 strains of Aeromonas hydrophila isolated from the blood of two cases of sepsis was confirmed by electron microscopy and antigenicity of the fimbriae of these strains were studied. At the same time, comparison was made with reference to serological specificity of fimbrial antigens with fimbriated strains of several other species. Then the fimbriae of A. hydrophila were purified and subjected to amino acid analysis. From these results, the following conclusions were drawn. 1) Agglutination tests and agglutinin absorption tests were carried out using the antisera produced in the rabbits immunized by 2 strains of A. hydrophila and the antisera absorbed by given antigens. The tests revealed that Aeromonas has a thermostable antigen (O antigen) and thermolabile antigens. The latter consists of flagellar antigen and fimbrial antigen. Each of these 3 kinds of antigens has its own antigenic specificity. 2) Fimbrial antiserum was prepared by absorption of the O and H antibodies from the Aeromonas antiserum by a nonfimbriated variant of the same strain as employed in the production of the antiserum. Agglutination tests were conducted using such fimbrial antiserum and organisms of several strains of different species. It was shown that the Aeromonas fimbriae have species-specific antigenicity. 3) Fimbriae of strain YN of A. hydroρhila were purified and the degree of purity was examined by electron microscopy, immunodiffusion, immunoelectrophoresis, and polyacrylamide gel electrophoresis. These examinations proved that the fimbrial preparation was fairly well purified. Then they were subjected to amino acid analysis. It was found that the content of glycine was the largest which was followed by alanine, glutamic acid, aspartic acid, and valine in this order. This indicated much difference from the amino acid composition of Escherichia coli.
