Hua Chang Min, Cheminade Yves, Perret Jean-Luc, Weynants Vincent, Lobet Yves, Gern Lise
Institut de Zoologie, University of Neuchâtel, Neuchâtel, Switzerland.
Int J Med Microbiol. 2003 Dec;293(6):421-6. doi: 10.1078/1438-4221-00285.
In Europe, Borrelia burgdorferi is transmitted by Ixodes ricinus to animals and human. When infected and uninfected ticks co-feed on a host, spirochetes are transmitted from ticks to animal and also to uninfected ticks. Here, we used uninfected ticks to co-feed with infected ticks on mice to evaluate this method to detect early infection in mice. A total of 128 mice were challenged by infected nymphs placed in capsules glued on the back of the mice. Three days later uninfected larvae were added in the capsule to co-feed with infected nymphs and were examined for Borrelia infection after natural detachment. Infection in mice was also determined by xenodiagnosis and by spirochete isolation from ear skin biopsy and back skin biopsy taken at the tick attachment site one month after infection. A total of 111 mice were found to be infected by at least one of these four methods. Borrelia infection was observed in 95% of mice by the co-feeding method, in 92% of mice by xenodiagnosis, in 69% and in 68% of mice by cultivation of ear and back skin biopsies, respectively. Our results demonstrate that the co-feeding method is a very sensitive method which can be used to detect very early infection in mice infected by tick bites.
在欧洲，伯氏疏螺旋体通过蓖麻硬蜱传播给动物和人类。当受感染和未受感染的蜱同时叮咬一个宿主时，螺旋体会从蜱传播给动物，也会传播给未受感染的蜱。在此，我们使用未受感染的蜱与受感染的蜱同时叮咬小鼠，以评估这种检测小鼠早期感染的方法。总共128只小鼠被放置在粘在其背部的胶囊中的受感染若蜱叮咬。三天后，将未受感染的幼虫放入胶囊中与受感染的若蜱同时叮咬，并在自然脱落之后检查是否感染伯氏疏螺旋体。小鼠的感染情况也通过接种诊断以及在感染后一个月从蜱附着部位采集的耳部皮肤活检和背部皮肤活检中分离螺旋体来确定。通过这四种方法中的至少一种，总共发现111只小鼠受到感染。通过同时叮咬法，95%的小鼠被观察到感染伯氏疏螺旋体；通过接种诊断法，92%的小鼠被观察到感染；通过培养耳部和背部皮肤活检，分别有69%和68%的小鼠被观察到感染。我们的结果表明，同时叮咬法是一种非常灵敏的方法，可用于检测被蜱叮咬感染的小鼠的极早期感染。
