Olsen B, Gylfe A, Bergström S
Department of Infectious Diseases, University of Umeå, Sweden.
Microb Pathog. 1996 Jun;20(6):319-24. doi: 10.1006/mpat.1996.0030.
To investigate if passerine birds can be used as an avian model for Lyme borreliosis, the Borrelia burgdorferi sensu stricto strain Sh2-82 was inoculated subcutaneously on Canary finches (Serinus canaria). Spirochaetes could be detected in the blood by direct microscopy and an immunofluorescence assay (IFA) up to 2 weeks after the inoculation. DNA amplification (PCR) revealed B. burgdorferi DNA in the serum for up to 3 weeks, in the faeces up to 4 weeks, and from several internal organs at autopsy 3 months after the inoculation. Of particular interest was the finding of B. burgdorferi DNA in the liver of all birds at the end of the experiment, indicating a persistent infection. Four weeks after the primary infection, all infected birds showed an increase in anti Borrelia IgG antibodies and after 6 weeks all birds had seroconverted. Except for a brief episode of diarrhoea, none of the birds showed any signs of disease. This study shows that passerine birds experience short-term spirochaetemia after infection with B. burgdorferi, but show few clinical symptoms. This suggests that, although these birds can act as reservoirs of B. burgdorferi s.s., they may be of less importance as long lasting amplifiers for this pathogen.
为了研究雀形目鸟类是否可作为莱姆病疏螺旋体病的鸟类模型，将狭义伯氏疏螺旋体菌株Sh2-82皮下接种于金丝雀（Serinus canaria）。接种后长达2周，可通过直接显微镜检查和免疫荧光试验（IFA）在血液中检测到螺旋体。DNA扩增（PCR）显示，接种后3周内血清中可检测到伯氏疏螺旋体DNA，粪便中4周内可检测到，接种后3个月尸检时在几个内部器官中也可检测到。特别值得关注的是，在实验结束时所有鸟类的肝脏中均发现了伯氏疏螺旋体DNA，表明存在持续性感染。初次感染4周后，所有感染鸟类的抗伯氏疏螺旋体IgG抗体均有所增加，6周后所有鸟类均发生血清转化。除了短暂的腹泻发作外，没有一只鸟表现出任何疾病迹象。这项研究表明，雀形目鸟类感染伯氏疏螺旋体后会经历短期螺旋体血症，但临床症状很少。这表明，尽管这些鸟类可作为狭义伯氏疏螺旋体的宿主，但作为该病原体的长期扩增宿主，其重要性可能较低。
