豚型流産菌

抄録

Abortion of swine due to Brucella-bacillus occurs in various countries of Europe and America, especially in the United States of America, very frequently. In Japan, however, it has not been reported as yet. Whereas, several years ago, a sow for breeding, imported from Great Britain, aborted seven fetuses on a certain farm, 2 months after it had been fecundated. Using the viscera of these aborted fetuses and the amniotic fluid, we carried out the isolation by means of ordinary agar slants and in 3 days we were able to obtain, in almost pure state, macroscopically visible numerous, transparent, minute colonies.
As we could not distinguish this isolated bacillus from Brucella abortus, used as a control, either morphologically, serologically. biologically or by animal experiment, we decided the former to be of the Brucella group.
Hereupon we carried out a test, following Huddleson's and the hydrogen sulfide (H₂S) methods, in order to decide whether it was Br. abortus suis or Br. abortus Bang.
According to the results of comparative tests with the isolated bacillus and the bovine type of Br. abortus, as regards to growth in media, each of which contained different kind of dye in various concentration, e. g., thionin, pyronin, basic fuchsin, methylviolet, 1) the isolated bacillus grew very well in the medium containing thionin, while the bacillus, used as a control, failed to develop in this medium at dilutions of 1:10, 000 and 1:15, 000.
2) As regards medium containing pyronin, the isolated bacillus did not grow at a dilution of 1:1, 000 at all, and we could distinguish it from the control-bacillus at the dilutions of 1:1, 000-1:10, 000.
3) In the medium containing basic fuchsin, the isolated bacillus was weak in reducing power, and the dilutions, at which we could distinguish it from the control-bacillus, were between 1:15, 000 and 1:30, 000.
4) In the medium containing methyl-violet, the isolated bacillus was weak in reducing power and could not develop completely even at dilutions of 1:50, 000. We could, however, distinguish it from the control-bacillus in the sphere of dilutions between 1:25, 000-1:1(10, 000.
5) In the medium containing gentian-violet, the isolated ba
cillus did not develop completely at aa dilution of 1:25, 000. The
most suitable dilution for distinguishig it from the control-bacillus
extended from 1:25, 000 to 1:50, 000.
In the next differential test, in which the hydrogen sulfide method was followed, either in solid or in liquid media, the iso-lated bacillus produced hydrogen sulfide rather remarkably in comparison with the controlbacillus, with the exception that one of the control-strains produced hydrogen sulfide to a considerable degree.
According to the above mentioned tests, in which the Huddleson's and the hydrogen sulfide method was followed, we decided that the bacillus isolated by us from the fetuses is B. abortus suis, and conclude that the abortion in this case was caused by this bacillus.