Studies on the Applicability of Furazolidone to the Silkworm Rearing Industry as a Useful Remedy for Certain Silkworm Diseases (Report I)

푸라졸리돈의 누에병치료약으로서의 응용가능성에 관한 연구 (제1보)

The author studied the applicability of Furazolidone to the silkworm rearing industry as a useful remedy for certain silkworm diseases, at the silkworm rearing house of the college of agriculture, Seoul national university, during both the spring and the autumn silkworm rearing season of 1972. Discovering the fact that Furazolidone, when put on the mulberry leaves in a powdered form, is eaten along with the leaves by silkworms and thus the systematic administration of Furazolidone to silkworms is possible, the experimenter carried on a series of experiments (1. determining the in vitro antibacterial activity of Furazolidone to four pathogens of silkworm diseases-Bacillus thuringiensis, Aspergillus oryzae, Aspergillus flavus, and Isaria farinosa, 2. observing the prophylactic and therapeutic effect of Furazolidone against the experimental flacherie caused by inoculation of B. thuringiensis, and 3. examining the toxicity of Furazolidone to silkworm larvae). As the results of the experiments the investigator found out the fundamental fact that Furazolidone exerts a good prophylactic and therapeutic effect against flacherie which is the most common and important silkworm disease: Furazolidone, in in vitro test, inhibited completely the growth of B. thuringiensis, the pathogen of bacterial flacherie, at the concentration of 1 ${\mu}$g/mι. with the tube method and at the concentration of 5 ${\mu}$g/mι. with the plate method, and the drug showed an excellent prophylactic effect and a considerably good therapeutic effect, depending on the time of administration, on the 5th instar silkworms inoculated B. thuringiensis, at the tentative dose of 150mg. per 10 silkworms administered once a day for 2 days. For the practical administration of Furazolidone against flacherie, the dose, the time and duration of administration, and the form of preparation, will be investigated more closely.

본인은 1972년 춘잠기와 추잠기에 걸쳐서 서울대학교농과대학 잠실에서 FZD의 누에병치료약으로서의 응용가능성을 검토한바 있다. 첫째로 FZD의 누에에의 경구적투약이 가능함을 알아낸 본인은 FZD의 4가지 누에병병원체 (Bacillus thuringiensis, Aspergillus flavus, Aspergillus oryzae, Isaria farinosa)에 대한 시험관내 항균력 측정, B.thuringiensis 로써 일으킨 실험적연화병에 대한 FZD의 발병억제효과 내지는 치료효과 관찰 등 일련의 실험을 거쳐, FZD은 실험적세균성연화병에 대해서 발병 억제효과와 치료효과를 겸해서 발휘한다는 기본적 사실을 밝혔다. 즉, 푸라졸리돈은 시험관내항균력측정에 있어서 세균성 연화병의 병원체인 Bacillus thuringiensis에 대해서는 시험관법으로써는 1$\mu\textrm{g}$/mι의 농도로써 그리고 한천평판법으로써는 $\mu\textrm{g}$/mι의 농도로써 완전한 발육억제효과를 발휘했으며, 한편 B. thuringiensis가 접종된 5령기 누에에 대해서는 잠정적인 용량인 누에 10마리당 150mg. 비율의 용량(누에체액 1ml당 약 2.2mg. 비율의 용량)에 있어서 1일 1회색 2일(2회)투여할 때 거의 완전한발병억제효과와 상당히 좋은 치료효과를 발휘했다. FZD의 임상적 응용에 따르는 용량, 투약시기, 제제형태 등의 여러가지 문제는 앞으로 세밀히 검토되어야 할 것으로 안다.