Kapoor Pratibha, Hayes Yumiko O, Jarrell Leslie T, Bellinger Dwight A, Thomas Rhiannon D, Lawson Gregory W, Arkema Jaclyn D, Fletcher Craig A, Nielsen Judith N
Division of Laboratory Animal Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina;, Email:
Division of Laboratory Animal Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
J Am Assoc Lab Anim Sci. 2017 May 1;56(3):273-289.
The entry of infectious agents in rodent colonies occurs despite robust sentinel monitoring programs, strict quarantine measures, and stringent biosecurity practices. In light of several outbreaks with Aspiculuris tetraptera in our facilities, we investigated the presence of anthelmintic resistance and the use of exhaust air dust (EAD) PCR for early detection of A. tetraptera infection. To determine anthelmintic resistance, C57BL/6, DBA/2, and NCr nude mice were experimentally inoculated with embryonated A. tetraptera ova harvested from enzootically infected mice, followed by treatment with 150 ppm fenbendazole in feed, 150 ppm fenbendazole plus 5 ppm piperazine in feed, or 2.1 mg/mL piperazine in water for 4 or 8 wk. Regardless of the mouse strain or treatment, no A. tetraptera were recovered at necropsy, indicating the lack of resistance in the worms to anthelmintic treatment. In addition, 10 of 12 DBA/2 positive-control mice cleared the A. tetraptera infection without treatment. To evaluate the feasibility of EAD PCR for A. tetraptera, 69 cages of breeder mice enzootically infected with A. tetraptera were housed on a Tecniplast IVC rack as a field study. On day 0, 56% to 58% of the cages on this rack tested positive for A. tetraptera by PCR and fecal centrifugation flotation (FCF). PCR from EAD swabs became positive for A. tetraptera DNA within 1 wk of placing the above cages on the rack. When these mice were treated with 150 ppm fenbendazole in feed, EAD PCR reverted to pinworm-negative after 1 mo of treatment and remained negative for an additional 8 wk. The ability of EAD PCR to detect few A. tetraptera positive mice was investigated by housing only 6 infected mice on another IVC rack as a field study. The EAD PCR from this rack was positive for A. tetraptera DNA within 1 wk of placing the positive mice on it. These findings demonstrate that fenbendazole is still an effective anthelmintic and that EAD PCR is a rapid, noninvasive assay that may be a useful diagnostic tool for antemortem detection of A. tetraptera infection, in conjunction with fecal PCR and FCF.
尽管有完善的哨兵监测计划、严格的检疫措施和严格的生物安全措施，感染源仍会进入啮齿动物群落。鉴于我们设施中多次爆发四翼无刺线虫感染，我们调查了驱虫抗性的存在情况以及利用废气灰尘（EAD）PCR技术早期检测四翼无刺线虫感染的情况。为了确定驱虫抗性，将从地方流行性感染小鼠体内采集的四翼无刺线虫胚胎卵分别接种到C57BL/6、DBA/2和NCr裸鼠体内，然后分别用饲料中含150 ppm芬苯达唑、饲料中含150 ppm芬苯达唑加5 ppm哌嗪或饮水中含2.1 mg/mL哌嗪的方式进行处理，持续4周或8周。无论小鼠品系或处理方式如何，尸检时均未发现四翼无刺线虫，这表明线虫对驱虫治疗没有抗性。此外，12只DBA/2阳性对照小鼠中有10只未经治疗便清除了四翼无刺线虫感染。为了评估EAD PCR检测四翼无刺线虫的可行性，作为一项现场研究，将69笼地方流行性感染四翼无刺线虫的繁殖小鼠饲养在Tecniplast IVC饲养架上。在第0天，通过PCR和粪便离心浮选法（FCF）检测发现，该饲养架上56%至58%的笼子四翼无刺线虫检测呈阳性。将上述笼子放置在饲养架上1周内，EAD拭子PCR检测到四翼无刺线虫DNA呈阳性。当用饲料中含150 ppm芬苯达唑的方式对这些小鼠进行治疗时，治疗1个月后EAD PCR检测结果恢复为蛲虫阴性，并在接下来的8周内一直保持阴性。作为一项现场研究，在另一个IVC饲养架上仅饲养6只感染小鼠，以此来研究EAD PCR检测少量四翼无刺线虫阳性小鼠的能力。将阳性小鼠放置到该饲养架上1周内，该饲养架的EAD PCR检测到四翼无刺线虫DNA呈阳性。这些研究结果表明，芬苯达唑仍然是一种有效的驱虫药，并且EAD PCR是一种快速、非侵入性的检测方法，与粪便PCR和FCF结合使用时，可能是生前检测四翼无刺线虫感染的一种有用的诊断工具。
