克拉玛依地区的利什曼病 Ⅲ.大沙鼠体内利什曼原虫的形态及其对实验动物致病力的研究

Leishmanias is In Karamay Ⅲ: Study on the Morphology of Leishmania from Big Gerbil and Its Pathogenicity in Laboratory Animals

在新疆克拉玛依的小拐和白碱滩两地,从20只大沙鼠的耳组织徐片上查出9只有利什曼原虫的感染。经测量69个原虫,平均大小为4.71±0.71×2.35±0.44μm,t试验结果显示,该地大沙鼠体内的利什曼原虫较沙鼠利什曼明显为小,与硕大利什曼原虫的形态比较,也有显著不同。 动物实验感染结果表明,该地大沙鼠体内的利什曼原虫在接种到BALB/c小鼠的足垫皮下后。可使小鼠产生皮肤溃疡和转移性皮肤损害,小鼠最后死于全身性感染。在远交系小鼠(昆明株)的足垫组织内,利什曼原虫可引起足垫局部短期肿胀,旋后消退,在外观正常的足垫皮下组织内,原虫可持续7个月以上。当原虫被注入黑线仓鼠的睾丸内后,产生睾丸局部感染,利什曼原虫主要寄生在鼠睾间质部位的巨噬细胞内,在曲细精管内的一些塞氏细胞中也有原虫寄生,偶而也发生转移性皮损。在长爪沙鼠耳组织内,原虫能持续14个月以上,并且可使鼠耳发生溃疡。 上述各项观察和实验结果表明,克拉玛依大沙鼠体内的利什曼原虫在形态大小、对4种实验动物所致的病变都与沙鼠利什曼原虫不同,对自然宿主大沙鼠的耳组织和远交系小鼠的致病力又与硕大利什曼原虫相异。作者认为,该地大沙鼠耳组织感染的利什曼原虫可能是一个新种(或新亚种),宜通过进一步的实验研究,来确定它分类上的地位。

In Karamay, Xinjiang Uyger Autonomus Region where big gerbil (Rhombomys opimus) were present, ear tissue smears taken from 20 R. opimus were made, and amastigotes were detected in 9 of them, however, no ulceration was revealed in the infected animals. Based on measurements of 69 amastigotes from naturally infected R. opimus, it was found that the avarage size was 4.71 ± 0.71× 2.35 ± 0.44μm, being smaller than Leishmania gerbilli and different from that of the Leishmania maj or reported previously. Promastigotes of 6 Leishmania isolates from Karamay gerbils (KGL) were injected subcutaneously into footpads of BALB / c mice, consequently, swelling followed by ulceration was presented at the inoculation sites of 88.2% animals. Leishmania was found in all of these lesions. Metastasis occurred on tails and other sites. Finally, the mice died from generalized infection. When KGL isolates were injected into footpads of outbred mice (Kun-ming strain), transient swelling was observed at the site of inoculation, but no ulceration was revealed. Leishmania still concealed in subcutaneous tissue of footpads with normal appearance for more than 7 months. When Chinese hamsters (Cricetulus barabensis) were inoculated intratestically with KGL isolates, the parasites were engulfed in macrophages lying in intertubular spaces, and a few number of parasites were also presented in sertoli's cells of seminiferous tubules. When inoculation was performed on the ear of Mongolian jird (Meriones unguiculatus), local swelling and ulceration could be viewed, and the parasites could be recovered in situ for 14 months. The morphological features of KGL isolates and the pathological changes post its inoculation in 4 experimental animals were different from those of L. gerbilli. And the pathogenicity was diverse from that of L. maj or in the natural host big gerbils or in experimental outbred mice. In the light of the preceding consequences, it was suggested that referring the KGL parasite concerned to a new species (or subspecies) of Leishmania should betaken into consideration.