Newton J R, Laxton R, Wood J L N, Chanter N
Centre for Preventive Medicine, Animal Health Trust, Newmarket, Suffolk, UK.
Vet J. 2008 Mar;175(3):338-45. doi: 10.1016/j.tvjl.2007.02.018. Epub 2007 Apr 11.
The objective of the study was to characterise the molecular epidemiology of Streptococcus zooepidemicus infection among isolates collected sequentially from recently weaned, pasture maintained Welsh mountain ponies with naturally occurring respiratory disease. Weekly nasopharyngeal and tracheal lavage samplings over a 10-week period were conducted in 29 ponies. Two PCR typing methods based on characterisation of the M-protein hypervariable (HV) region and the 16S-23S rRNA gene intergenic spacer were then applied to isolates of S. zooepidemicus recovered from nasopharyngeal swab and tracheal wash samples. S. zooepidemicus infection was highly prevalent during the study, being isolated from 94% of tracheal washes and 88% of nasopharyngeal swabs. Among 39 different S. zooepidemicus types isolated, more were isolated from the trachea (n=33) than the nasopharynx (n=27). There was evidence from temporal patterns of infection for clonal succession over time by the more prevalent S. zooepidemicus types. Novel S. zooepidemicus types were identified, including previously untyped HV regions and intra-strain multiples of both the HV region and intergenic spacer types.
本研究的目的是对从近期断奶、在牧场饲养且患有自然发生的呼吸道疾病的威尔士山地小马中连续采集的分离株进行兽疫链球菌感染的分子流行病学特征分析。在29匹小马中进行了为期10周的每周一次鼻咽和气管灌洗采样。然后将基于M蛋白高变（HV）区特征和16S - 23S rRNA基因间隔区的两种PCR分型方法应用于从鼻咽拭子和气管冲洗样本中分离出的兽疫链球菌分离株。在研究期间，兽疫链球菌感染非常普遍，从94%的气管冲洗样本和88%的鼻咽拭子中分离出该菌。在分离出的39种不同的兽疫链球菌类型中，从气管分离出的（n = 33）比从鼻咽分离出的（n = 27）更多。从感染的时间模式来看，有证据表明较常见的兽疫链球菌类型随时间发生了克隆演替。鉴定出了新型兽疫链球菌类型，包括以前未分型的HV区以及HV区和间隔区类型的菌株内多个拷贝。
