Rajasekariah G R, Deb B N, Dhage K R, Bose S
Acta Trop. 1985 Dec;42(4):333-40.
Resistance to the development of human hookworm, Necator americanus was examined in 3- to 6-week-old young adult hamsters. Only 3% of N. americanus infective third stage larvae (NaL3) reached maturity in the intestines of young adults as opposed to as many as 60% in 2-day-old baby hamsters. This seemingly effective resistance prevailing in young adults was investigated in some detail. The skin, the first site of contact for the invading NaL3, was bypassed during the infection process. Completely in vitro exsheathed NaL3 (ExNaL3) were used, and young adult hamsters were infected parenterally, by-passing the skin. Even after exsheathing the larvae artificially before infection and by-passing the skin, no improvement was seen in the development of N. americanus in the intestines of young adults. Higher infection doses also did not increase the worm burden. Some of the factors limiting the development of parasites in young adults were examined. N. americanus were monitored in lungs and intestines during various intervals after infection. Similar parasite burdens were apparent in lungs of baby as well as young adult hamsters. In the intestines, a significantly lower burden of N. americanus was seen during various intervals in young adults compared to the baby hamsters. Moreover, N. americanus were expelled soon after reaching the intestine. This comparative monitoring revealed the intestine as the seat of resistance against the establishment of N. americanus in young adult hamsters.
在3至6周龄的成年幼龄仓鼠中检测了对美洲板口线虫（Necator americanus）发育的抗性。与2日龄幼龄仓鼠中多达60%的美洲板口线虫感染性第三期幼虫（NaL3）在肠道内发育成熟相比，只有3%的NaL3在成年幼龄仓鼠的肠道内发育成熟。对成年幼龄仓鼠中普遍存在的这种看似有效的抗性进行了较为详细的研究。在感染过程中绕过了入侵的NaL3首先接触的部位——皮肤。使用完全在体外脱鞘的NaL3（ExNaL3），通过非经皮肤的方式对成年幼龄仓鼠进行肠道外感染。即使在感染前人工脱鞘幼虫并绕过皮肤，美洲板口线虫在成年幼龄仓鼠肠道内的发育也未见改善。更高的感染剂量也没有增加虫负荷。研究了一些限制成年幼龄仓鼠体内寄生虫发育的因素。在感染后的不同时间段对美洲板口线虫在肺部和肠道中的情况进行了监测。幼龄仓鼠和成年幼龄仓鼠肺部的寄生虫负荷相似。在肠道中，与幼龄仓鼠相比，成年幼龄仓鼠在不同时间段内美洲板口线虫的负荷明显较低。此外，美洲板口线虫在进入肠道后不久就被排出。这种对比监测表明，肠道是成年幼龄仓鼠抵抗美洲板口线虫定植的部位。
