Ho B C, Chew L M, Yap E H, Singh M
Department of Microbiology, Faculty of Medicine, National University of Singapore.
J Helminthol. 1987 Sep;61(3):203-12. doi: 10.1017/s0022149x00010026.
The kinetics of Breinlia booliati infection in 3 inbred rat strains (Lewis, Wistar and Sprague Dawley) were investigated. One group of rats was infected as neonates (less than 24 hours of age) with third-stage larvae of B. booliati and the other group was infected as juveniles (4 weeks of age). The results showed that infection in the neonates were significantly different from the infection in the juveniles. The 60 rats infected as neonates, when necropsied between 8 to 10 months postinfection, yielded adult worms. The 2 neonatal infection groups of Lewis and Wistar strains showed highest susceptibility to the infections. The mean prepatent period was 85 days. Ninety to 95% of the infected rats were patent with microfilaraemia and a large percentage (33 to 47%) of them had high microfilaraemia counts exceeding 3000 mff/20 mm3 of blood and larger sizes (mean 157.11 mm for female adult worms and 61.88 mm for male adult worms. The adult worms were distributed equally in both the pleural (57%) and peritoneal cavity (43%). In most aspects, the neonatal infection group of the Sprague-Dawley strain was intermediate in susceptibility between the 2 neonatal infection groups of the Lewis and Wistar strains and the 3 juvenile infection groups. In contrast to neonatal infection groups, the 3 juvenile infection groups exhibited low infection rates (37%, 58% and 47% for the Lewis, Wistar and Sprague Dawley strains respectively), longer prepatent periods (mean 101 days), lower recovery rates (2 to 4%), lower adult worm loads (mean 0.4 to 0.8 female worms, and 0.2 to 0.8 male worms per rat), and smaller sizes (mean 141.24 mm for female adult worms and 53.75 mm for male adult worms). Forty-four to 57% of these infected rats harboured either single male or single female adult worms in the body cavity. Most (92%) of the adult worms recovered from the juvenile infection groups resided in the pleural cavity and the remaining 8% were recovered from the peritoneal cavity. Microfilaraemia could be detected in only 3/20 Lewis rats, 5/20 Wistar rats and 5/20 Sprague Dawley rats. The mean peak microfilaraemia of the 3 pooled juvenile infection groups was 632 mff/20 mm3 of blood, ranging from 7 mff/20 mm3 to 1856 mmf/20 mm3. Our results indicate that the susceptibility to B. booliati infection in white rats is both genetic and age-associated. The responses of the 2 distinct infection groups to B. booliati infections are discussed.
研究了3种近交系大鼠（刘易斯大鼠、Wistar大鼠和斯普拉格-道利大鼠）感染布氏布氏线虫的动力学。一组大鼠在新生期（小于24小时龄）感染布氏布氏线虫的第三期幼虫，另一组在幼年期（4周龄）感染。结果表明，新生期感染与幼年期感染有显著差异。60只新生期感染的大鼠在感染后8至10个月进行尸检时，发现了成虫。刘易斯大鼠和Wistar大鼠的2个新生期感染组对感染表现出最高的易感性。平均潜伏期为85天。90%至95%的感染大鼠出现微丝蚴血症，其中很大一部分（33%至47%）微丝蚴血症计数高，超过3000条微丝蚴/20立方毫米血液，成虫尺寸较大（雌性成虫平均长157.11毫米，雄性成虫平均长61.88毫米）。成虫在胸腔（57%）和腹腔（43%）中分布均匀。在大多数方面，斯普拉格-道利品系的新生期感染组在易感性上介于刘易斯大鼠和Wistar大鼠的2个新生期感染组与3个幼年期感染组之间。与新生期感染组相比，3个幼年期感染组的感染率较低（刘易斯大鼠、Wistar大鼠和斯普拉格-道利大鼠分别为37%、58%和47%），潜伏期较长（平均101天），回收率较低（2%至4%），成虫负荷较低（每只大鼠平均有0.4至0.8条雌虫和0.2至0.8条雄虫），尺寸较小（雌性成虫平均长141.24毫米，雄性成虫平均长53.75毫米）。这些感染大鼠中有44%至57%在体腔内仅怀有单只雄虫或单只雌虫。从幼年期感染组回收的成虫大多数（92%）位于胸腔，其余8%从腹腔回收。仅在3/20的刘易斯大鼠、5/20的Wistar大鼠和5/20的斯普拉格-道利大鼠中检测到微丝蚴血症。3个合并的幼年期感染组的平均微丝蚴血症峰值为632条微丝蚴/20立方毫米血液，范围为7条微丝蚴/20立方毫米至1856条微丝蚴/20立方毫米。我们的结果表明，白色大鼠对布氏布氏线虫感染的易感性与遗传和年龄相关。讨论了2个不同感染组对布氏布氏线虫感染的反应。
