双芽巴贝斯虫在长角血蜱肠内发育的形态学研究

以耳袋法将长角血蜱(Haemaphysalis longicornis)幼虫饲于实验感染双芽巴贝斯虫(Babesia bigemina)牛,幼虫饱血后24h内,其肠管内容物中红细胞内、外见有单梨子型(3.5～4.5μm×1.2～2.6μm)和双梨子型(4.1～4.8μm×1.8～3.0μm)两种裂殖体.饱血后24～48h,随着裂殖体细胞膜及核变性而发生形态变化.48～72h,绝大多数裂殖体出现溶解.72h后,这些裂殖体从肠道消失.其后,在蜱肠上皮及血淋巴中也未能找到双芽巴贝斯虫体.本实验从形态学上证明双芽巴贝斯虫在长角血蜱若虫肠道内不能发育.

Development of Babesia bigemina in the Gut of Haemaphysalis longicornis

Studies were made on the development of Babesia bigemina in the gut of the nymph of Haemaphysalis longicornis. It was shown that the single and paired pyriform merozoites appeared outside or inside the erythrocytes in the gut contents of the ticks infected with B. bigemma within 24 h post-repletion (with blood). However, within 24-48 h the nuclei and plasma membranes of the merozoites have undergone degeneration and resulted in morphological alterations. The majority of merozoites have been lysed within 48-72 h and were not found in the gut epithe-lia and haemolymph of ticks later on. Based on the findings above-mentioned, it was morphologically substantiated that B. bigemina may not exhibit development in the nymphal stage of Haema-physalis longicornis.