Departments of Population Health, University of Georgia, Athens, Georgia, USA.
Appl Environ Microbiol. 2012 Oct;78(20):7290-8. doi: 10.1128/AEM.01408-12. Epub 2012 Aug 10.
Salmonella enterica subsp. enterica serovar Typhimurium is responsible for the majority of salmonellosis cases worldwide. This Salmonella serovar is also responsible for die-offs in songbird populations. In 2009, there was an S. Typhimurium epizootic reported in pine siskins in the eastern United States. At the time, there was also a human outbreak with this serovar that was associated with contaminated peanuts. As peanuts are also used in wild-bird food, it was hypothesized that the pine siskin epizootic was related to this human outbreak. A comparison of songbird and human S. Typhimurium pulsed-field gel electrophoresis (PFGE) patterns revealed that the epizootic was attributed not to the peanut-associated strain but, rather, to a songbird strain first characterized from an American goldfinch in 1998. This same S. Typhimurium strain (PFGE type A3) was also identified in the PulseNet USA database, accounting for 137 of 77,941 total S. Typhimurium PFGE entries. A second molecular typing method, multiple-locus variable-number tandem-repeat analysis (MLVA), confirmed that the same strain was responsible for the pine siskin epizootic in the eastern United States but was distinct from a genetically related strain isolated from pine siskins in Minnesota. The pine siskin A3 strain was first encountered in May 2008 in an American goldfinch and later in a northern cardinal at the start of the pine siskin epizootic. MLVA also confirmed the clonal nature of S. Typhimurium in songbirds and established that the pine siskin epizootic strain was unique to the finch family. For 2009, the distribution of PFGE type A3 in passerines and humans mirrored the highest population density of pine siskins for the East Coast.
鼠伤寒沙门氏菌亚种肠炎血清型鼠伤寒是世界范围内大多数沙门氏菌病病例的罪魁祸首。这种沙门氏菌血清型也是鸣禽种群死亡的原因。2009 年，在美国东部的松雀中报告了一场鼠伤寒血清型的爆发。当时，也有人与人之间的爆发与此血清型有关，与受污染的花生有关。由于花生也用于野生鸟类的食物，因此有人假设松雀的爆发与这次人类爆发有关。对鸣禽和人类鼠伤寒沙门氏菌脉冲场凝胶电泳（PFGE）模式的比较表明，此次爆发并非与花生相关的菌株所致，而是与 1998 年首次从美国金翅雀中分离出的鸣禽菌株有关。同样的鼠伤寒沙门氏菌（PFGE 型 A3）也在美国脉冲网 USA 数据库中被识别，占总鼠伤寒沙门氏菌 PFGE 条目数 77941 的 137 个。第二种分子分型方法，多位点可变数目串联重复分析（MLVA），证实了同一菌株是导致美国东部松雀爆发的原因，但与从明尼苏达州松雀中分离出的遗传上相关的菌株不同。松雀 A3 菌株于 2008 年 5 月首次在一只金翅雀中发现，随后在松雀爆发开始时在一只红衣主教鸟中发现。MLVA 还证实了鸣禽中鼠伤寒沙门氏菌的克隆性质，并确定了松雀 A3 菌株是雀形目鸟类特有的。2009 年，PFGE 型 A3 在雀形目鸟类和人类中的分布与东海岸松雀的最高种群密度相吻合。
