Development of symbionts in triatomine bugs and the effects of infections with trypanosomatids
Development of symbionts in triatomine bugs and the effects of infections with trypanosomatids
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DOI：
10.1006/expr.2001.4653
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发表时间：
2002-01-01
影响因子：
2.1
通讯作者：
Schaub, GA
中科院分区：
文献类型：
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作者：
Eichler, S;Schaub, GA
在五龄食血红球菌肠道内，摄入血红球菌和染红三角瘤菌分别导致各自的共生细菌红红球菌和诺卡菌的浓度最初下降，然后在10天内，总数/虫增加15或18倍，在染红红球菌中约为0.8 × 10(9)个菌落形成单位，在染红红球菌中约为1.8 × 10(9)个菌落形成单位。这两种共生体的总种群中约有95-99%发育在前中肠区域，即心和胃。从储存血液的胃到正在消化的小肠的通道导致了大量共生体的分解，只有大约0.01%的共生体存在于直肠中。这些主要在血餐后4小时内排泄。3种锥虫感染后，长尾锥虫的共生体红锥虫受兰氏锥虫感染，而不受三角胚锥虫和克氏锥虫感染。另一方面，感染三角螺旋体后，诺卡氏菌的浓度降低，而感染兰氏和克氏螺旋体后，诺卡氏菌的浓度没有降低。与未感染的对照组相比，在长期感染牛角双歧杆菌的大肠杆菌中，这种减少和进食后利尿活性的降低协同降低了单次沉积的粪便/尿液中的共生体浓度。这些数据有力地支持了兰氏T虫和三角b虫分别对长毛霉和感染T虫致病机制的理论，即主要攻击点分别是宿主特异性共生体罗氏r虫和诺卡迪亚sp.。(C) 2002 Elsevier Science （USA）。
In the intestinal tract of fifth instars of the hematophagous reduviid bugs Rhodnius prolixus and Triatoma infestans blood ingestion induced an initial decrease of the concentration of the respective symbiotic bacteria Rhodococcus rhodnii and Nocardia sp. and then within 10 days a 15- or 18-fold increase of the total population/bug to about 0.8 x 10(9) colony-forming units in R. prolixus and 1.8 x 10(9) colony-forming units in T. infestans. About 95-99% of the total populations of both symbionts developed in the anterior midgut regions, i.e., cardia and stomach. The passage from the blood-storing stomach to the digesting small intestine caused a considerable breakdown of symbiont populations, and only about 0.01% of the total population was present in the rectum. These were excreted mainly within 4 h after a blood meal. After infection with three species of trypanosomatids, R. rhodnii, the symbiont of R. prolixus, was affected by Trypanosoma rangeli, but not by Blastocrithidia triatomae or Trypanosoma cruzi. On the other hand, in T. infestans the concentration of Nocardia sp. was reduced after infection with B. triatomae, but not by T. rangeli nor T. cruzi. In long-term B. triatomae-infected T. infestans, this reduction and a reduced diuretic activity after feeding synergistically lowered the symbiont concentration in the singly deposited feces/urine drops drastically compared to uninfected controls. These data strongly support the theory of the mechanisms of pathogenicity of T rangeli and B. triatomae for R. prolixus and T. infestans, respectively, that the primal point of attack is the host-specific symbiont, R. rhodnii and Nocardia sp., respectively. (C) 2002 Elsevier Science (USA).