Molecular Epidemiology of Streptococcus uberis Clinical Mastitis in Dairy Herds: Strain Heterogeneity and Transmission.
Molecular Epidemiology of Streptococcus uberis Clinical Mastitis in Dairy Herds: Strain Heterogeneity and Transmission.
复制标题
奶牛群乳房链球菌临床乳腺炎的分子流行病学：菌株异质性和传播。
DOI：
10.1128/jcm.01583-15
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发表时间：
2016-01
影响因子：
9.4
通讯作者：
Green MJ
中科院分区：
文献类型：
--
作者：
Davies PL;Leigh JA;Bradley AJ;Archer SC;Emes RD;Green MJ
从临床乳房炎病例中分离的494株Uberis链球菌在12个月的时间里对52个商业奶牛群进行了研究，成功地完成了多位点序列分型。共鉴定出195个序列类型(STS)。Uberis乳房炎病例发生在同一牛群内的不同奶牛中，并归因于共同的ST，被归类为潜在传播事件(PTE)。在这项研究中确定的195个STS中，有35个临床病例被归类为PTE。在63%的牛群中发现了PTE。与乳房炎相关的病例占所有临床乳房炎病例的40%，在63%的牛群中发生，其中包括在该牛群中首次记录的该乳房炎(指示病例)和该乳房炎的所有持续性感染。在33%的牛群中，PTE相关病例占所有葡萄球菌临床乳房炎病例的50%。9个STS(ST-5、-6、-20、-22、-24、-35、-233、-361和-512)在统计学上被过度表达，其中8个属于克隆复合体(共享至少4个等位基因)(OVR STS)。结果表明，奶牛群中38%的临床乳房炎病例和63%的可归因于Uberis的PTE可能是由9种最流行的菌株引起的。研究结果表明，STS的一小部分在英国Uberis乳房炎的流行病学中具有不成比例的重要性，在英国的大多数牛群中可能发生奶牛间的S.uberis传播，这可能是许多牛群中最重要的感染途径。
Multilocus sequence typing was successfully completed on 494 isolates of Streptococcus uberis from clinical mastitis cases in a study of 52 commercial dairy herds over a 12-month period. In total, 195 sequence types (STs) were identified. S. uberis mastitis cases that occurred in different cows within the same herd and were attributed to a common ST were classified as potential transmission events (PTEs). Clinical cases attributed to 35 of the 195 STs identified in this study were classified PTE. PTEs were identified in 63% of the herds. PTE-associated cases, which include the first recorded occurrence of that ST in that herd (index case) and all persistent infections with that PTE ST, represented 40% of all the clinical mastitis cases and occurred in 63% of the herds. PTE-associated cases accounted for >50% of all S. uberis clinical mastitis cases in 33% of the herds. Nine STs (ST-5, -6, -20, -22, -24, -35, -233, -361, and -512), eight of which were grouped within a clonal complex (sharing at least four alleles), were statistically overrepresented (OVR STs). The findings indicate that 38% of all clinical mastitis cases and 63% of the PTEs attributed to S. uberis in dairy herds may be caused by the nine most prevalent strains. The findings suggest that a small subset of STs is disproportionally important in the epidemiology of S. uberis mastitis in the United Kingdom, with cow-to-cow transmission of S. uberis potentially occurring in the majority of herds in the United Kingdom, and may be the most important route of infection in many herds.