Rickettsia amblyommatis has been reported infecting various tick species throughout the western hemisphere, including Amblyomma cajennense sensu stricto (s.s.). The present study aimed to evaluate whether R. amblyommatis can be maintained by transovarial transmission and transstadial passage in A. cajennense s.s. ticks, and whether these ticks are competent vectors of this rickettsial agent. We selected engorged females that were naturally infected or uninfected by R. amblyommatis, and reared their offspring (infected and control groups, respectively). Immature ticks were allowed to feed on guinea pigs, whereas adults fed on rabbits. All stages and individuals of each generation of the infected group yielded rickettsial DNA, which was not detected in any tick from the control group. No host from the control group seroconverted to R. amblyommatis. Among 16 guinea pigs and eight rabbits infested with R. amblyommatis-infected ticks, only one guinea pig seroconverted to R. amblyommatis. Some unfed adult ticks of the infected group were dissected, and DNA was extracted from their salivary glands and from their carcasses. DNA of R. amblyommatis was detected in all carcasses, but not in the salivary glands. Results of this study indicate very low vector competence of A. cajennense s.s. for R. amblyommatis. Previous studies reported domestic animals with high titers to R. amblyommatis in areas where these animals are naturally infested chiefly by A. cajennense s.s. ticks. One may consider that the vector competence of A. cajennense s.s. for R. amblyommatis could vary among tick populations and/or rickettsial strains.

中文翻译：

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维持弱吸收性立克次体在弱吸虫中的感染，并评估载体能力。

据报道，立克次体弱视菌感染了整个西半球的各种壁虱物种，包括细盲膜弱视菌（Aslyomma cajennense sensu stricto，ss）。本研究旨在评估是否可以通过cajennense s壁虱的经卵巢传播和跨性别传代来维持弱视杆状杆菌，以及这些壁虱是否是这种立克次体的有效载体。我们选择了自然感染或未感染过弱视红球菌的饱腹女性，并饲养其后代（分别为感染组和对照组）。未成熟的tick被允许以豚鼠为食，而成年动物以兔子为食。感染组每一代的所有阶段和个体都产生了立克次体DNA，在对照组的任何tick中均未检测到。对照组没有宿主血清转化为弱视杆状菌。在16只豚鼠和8只兔子中感染了肺炎双球菌感染的tick，只有一只豚鼠血清转化为肺炎双球菌。解剖了感染组的一些未喂食的成年tick，并从唾液腺和尸体中提取了DNA。肺炎衣原体的DNA在所有car体中均检出，但在唾液腺中未检出。这项研究的结果表明，A。cajennense ss对弱视杆状杆菌的载体能力很低。先前的研究报道，在主要被A. cajennense s虱自然感染的地区，这些动物对amdlyommatis的滴度很高。人们可能会认为，A。cajennense ss对棉铃虫的载体能力可能会在tick种群和/或立克次氏菌株之间发生变化。