Cherry John J, Ley David H, Altizer Sonia
Population Biology, Ecology and Evolution, Graduate School of Arts and Sciences, Emory University, Atlanta, Georgia 30322, USA.
J Wildl Dis. 2006 Apr;42(2):421-8. doi: 10.7589/0090-3558-42.2.421.
Mycoplasma gallisepticum (MG) conjunctivitis emerged in 1994 as a disease of free-ranging house finches (Carpodacus mexicanus) in North America and has also been isolated from other songbirds with conjunctivitis. Random amplification of polymorphic DNA (RAPD) of house finch and other songbird isolates has suggested that a single 'strain' initiated this outbreak. To explore the possibility of genomic variability among house finch isolates of MG and to evaluate the utility of a second technique for MG genotyping, we selected samples from our archive of reference strains and wild songbird isolates to analyze using both RAPD and amplified-fragment length polymorphism (AFLP); this is a newer technique that has been successfully used to explore the genomic variability of several Mycoplasma species. Both RAPD and AFLP results confirmed previous observations that during the initial stages of the MG epidemic in songbirds, isolates from different geographic locations and songbird species had genotypes that appeared to be highly similar, further supporting a single point source of origin. One 2001 isolate from New York was clearly different from the other songbird samples and clustered together with the vaccine and reference strains, indicating that substantial molecular evolution or a separate introduction has occurred.
鸡败血支原体（MG）结膜炎于1994年在北美洲作为一种自由放养的家朱雀（Carpodacus mexicanus）疾病出现，并且也从患有结膜炎的其他鸣禽中分离出来。对家朱雀和其他鸣禽分离株的多态性DNA随机扩增（RAPD）表明，单一“菌株”引发了此次疫情。为了探索MG在家朱雀分离株中基因组变异的可能性，并评估另一种MG基因分型技术的实用性，我们从参考菌株和野生鸣禽分离株档案中选取样本，使用RAPD和扩增片段长度多态性（AFLP）进行分析；AFLP是一种较新的技术，已成功用于探索几种支原体物种的基因组变异。RAPD和AFLP结果均证实了先前的观察结果，即在鸣禽MG疫情的初始阶段，来自不同地理位置和鸣禽物种的分离株具有看似高度相似的基因型，进一步支持单一来源点。一株2001年来自纽约的分离株明显不同于其他鸣禽样本，并与疫苗和参考菌株聚集在一起，表明发生了显著的分子进化或单独引入。
