On Direct Cultivation of Bacterium Tularense

抄録

Since McCoy and Chopin succeeded in 1912 in isolating Bacterium tularense using egg-yolk as medium, many contributions have been made towards securing better media for cultivating this organism. Among them, Foshay¹⁾²⁾ and his associates, Gibby, Nicholes and Tamura³⁾, succeeded recentlyy in, getting more suitable; liquid media. They are at present making further efforts to elucidate the effects of the components of the media upon the growths.
In this country, though some amount of contribution has been made in this field of medicine, it is still difficult to directly cultivate Bacterium tularense from any given pathologic source, and egg-yolk has been considered to be the most suitable medium for this purpose.
Pig-liver medium was devised, by Hiwatashi a short time ago and has hitherto been valued as suitable for subculture; but, as the one to be used for first isolation of the organisms got from human pathologic materials, it has not been given much credit.
T. Ota, ⁴⁾ after an attempt to isolate Bacterium tularense using the Hiwatashi medium in nine cases out of more than forty of tularemia which occurred 1949 in Chiba Prefecture, had to confess his failure.
In the latest outbreak of Yato-byo in this part of Japan, we at first used egg-yolk medium for direct cultivation. But, since the spring of 1950, we have come to find a far better, medium in pig-liver. It certainly enables us to make further study of the morphology of the organism more easily, of which the present work is only a part.
And it may well be stated that the direct isolation of Bacterium tularense from human lymph nodes presents a considerably good result and has its diagnostical value in case the materials can be secured within about a month after onsets and inoculated onto suitable media; though it will be difficult to do so after the lapse of over a month of the clinical course, even if animal examination is performed immediately after operation.