배양조건이 질트리코모나스의 병원성에 미치는 영향

Abstract

[한글]

질트리코모나스(Trichomonas vaginalis)는 병원성 편모충으로서 그 크기가 다양하며(Winston,1974), 실험실내 배양에 있어 배지의 pH가 적합치 않은 경우 충체의 크기가 커지고 편모의 길이는 짧아짐이 보고되었다(문등, 1983). 또한 크기가 작은 충체를 가진 환자

군에서 증상이 심한 것으로 알려지고 있다(Winston, 1974). 그러나 본 원충의 병원성이 단순히 충체의 크기나 주(株)에 따라 다른 것인지 또는 배양조건에 따라서도 병원성이 달라지는지에 대해서는 아직 확실하지 않다.

본 실험에서는 배지의 pH가 다른 조건에서 배양된 질트리코모나스에 있어서 충체의 크기와 병원성의 변화를 관찰하기 위해서 일부 수정한 TPS-1배지(Diamond, 1986)의 pH를 5.5, 7.0, 8.5로 조정하여 각각 3, 5, 2회 계대배양하였다. 충체의 크기를 개인용 컴퓨터에 부착된 세포크기 측정장치를 이용하여 충체의 길이, 폭, 면적을 계측하였다. 또한 병원성을 관찰하기 위해서 pH5.5, 7.0, 8.5에서 배양된 1×10**6마리의 충체를 마우스 피하에 감염시키고 감염 6일 후 피하에 생긴 농양의 크기로 병원성을 판별하여 아래와 같은 결론을 얻었다.

1. 배지의 pH7.0에서 배양된 질트리코모나스가 pH5.5나 pH8.5에서 배양된 충체에 비해 크기가 유의하게 작았다.

2. 배지의 pH7.0에서 배양된 충체가 pH5.5나 pH8.5에서 배양된 충체에 비해 병원성이 강하였다.

이상의 결과로 보아 질트리코모나스 배양에 있어서 배지내 pH가 적합치 않을 경우 충체의 크기가 커지며 병원성이 약화되는 것으로 생각된다.

[영문]

Trichomonas vaginalis is the pathogenic flagellate parasitizing in the human vagina. It has been known that these vaginal trichomonads are natually distinguished with two different populations; large and small race(Winston, 1974). Moon et al.(1983) reported that the sizes of trichomonads cultured under

unfavorable pH conditions were significantly greater than those of trichomonads cultured at the optimum pH value, while the lengths of flagella of trichomonads were shortened under unfavorable pH conditions as compared with those cultured in

normal condition. Moreover, Woinston(1974) concluded that the patients with the small-size T. vaginalis showed more severe symptoms. However, there is an open question whether culturing conditions in addition to the size of the flagellates affect the pathogenicity of T. vaginalis.

All stocks of T. vaginalis were axenically cultured in TPS-1 media(Diamond, 1968) with minor modification. for the present experiments, culture systems were divided into three groups in which TP-broths were controlled with different pH values; 5.5,

7.0 and 8.5. Three culture systems controlled at pH 5.5, 7.0 and 8.5. were subcultured 3, 5 and 2 times, respectively. After subculturing under different pH conditions, the lengths, widths and sizes of the flagellates in each system were measured with cell-measuring device attached at a personal computer. On the other hand, the 6-day subcutaneous lesion assaying method applied by Honigberg(1966) was employed in this study in order to figure out the degrees of pathogenicity of T. vaginalis cultured in the different culture systems. About 1 x 10**6 trophozoties in each group were subcutaneously inoculated into each mouse. The sizes of abscess formed due to the inoculation of trichomonads were measured by a dial caliper 6 days later, and compared by mean values with confidence intervals(95% significance level).

The results obtained in this study were as follows;

1. The sizes of T. vaginalis cultured at pH 7.0 were significantly smaller than those cultured at pH 5.5 or 8.5.

2. The pathogenicity of T. vaginalis cultured at pH 7.0 was more severe than those cultured at pH 5.5 or 8.5.

In sumarizing the above results, it is considered that T. vaginalis culturing under unfavable pH conditions is greater in size, and weaker in its pathogenicity as compared with those cultured at optimum pH value.