Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA.
Vet Microbiol. 2012 Feb 24;155(1):53-61. doi: 10.1016/j.vetmic.2011.08.003. Epub 2011 Aug 7.
Mycoplasma gallisepticum (MG) has become a common cause of conjunctivitis in free-living house finches (Carpodacus mexicanus) since its emergence in the early 1990s. To date, temporal and spatial genotypic variation in MG has been documented, but phenotypic variation in pathogenicity and immunogenicity has not been examined. House finches were inoculated with MG isolates Virginia (VA)1994, California (CA)2006, or North Carolina (NC)2006, which were cultured from free-living house finches with conjunctivitis in 1994, 2006, and 2006, respectively. Infection with NC2006 resulted in the most severe eye lesions, highest pathogen loads, and highest levels of pathogen-specific lachrymal and serum antibodies. Infection with CA2006 caused the least severe eye lesions, lowest pathogen load, and lowest levels of antibodies. A small number of birds in each group developed protracted, severe disease in spite of robust antibody responses, suggesting that immunopathology may contribute to the lesions. Immunoblot analyses indicated that isolates are antigenically similar; thus, there may be partial cross-protection if a house finch encounters two or more strains of MG throughout the course of its lifetime. This study provides evidence that MG strains or strain variants circulating in house finch populations vary in their ability to cause disease, induce antibody responses, and persist in the host.
自从 20 世纪 90 年代初支原体（MG）出现以来，它已成为自由生活的北美红雀（Carpodacus mexicanus）结膜炎的常见病因。迄今为止，已经记录了 MG 在时间和空间上的基因型变异，但尚未研究其致病性和免疫原性的表型变异。将 MG 分离株弗吉尼亚（VA）1994、加利福尼亚（CA）2006 或北卡罗来纳（NC）2006 接种给北美红雀，这些分离株分别是从 1994 年、2006 年和 2006 年患有结膜炎的自由生活的北美红雀中培养出来的。感染 NC2006 会导致最严重的眼部病变、最高的病原体载量和最高水平的病原体特异性泪液和血清抗体。感染 CA2006 会导致最轻微的眼部病变、最低的病原体载量和最低的抗体水平。尽管存在强烈的抗体反应，但每组中的少数鸟类仍会出现迁延性、严重疾病，这表明免疫病理学可能导致病变。免疫印迹分析表明分离株具有相似的抗原性；因此，如果北美红雀在其一生中遇到两种或更多种 MG 菌株，可能会有部分交叉保护。本研究提供了证据表明，在北美红雀种群中循环的 MG 菌株或菌株变体在引起疾病、诱导抗体反应和在宿主中持续存在的能力上存在差异。
