Isolation and characterisation of Rhodococcus equi from submaxillary lymph nodes of wild boars (Sus scrofa)
Isolation and characterisation of Rhodococcus equi from submaxillary lymph nodes of wild boars (Sus scrofa)
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DOI：
10.1016/j.vetmic.2008.04.009
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发表时间：
2008-10-15
影响因子：
3.3
通讯作者：
Takai, Shinji
中科院分区：
文献类型：
--
作者：
Makrai, Laszlo;Kobayashi, Ayumi;Takai, Shinji
马红球菌已从家猪的颌下淋巴结中分离到，但对马红球菌的存在知之甚少。野猪中的马本研究的目的是评估R.野猪中的马及其特征。在匈牙利39个定居点的482个野猪颌下淋巴结中，从60个标本中分离出马立克次体，并对82个分离株的质粒类型进行了检查。通过聚合酶链反应（PCR）检测分离株是否存在15-17-kDa（VapA）和20-kDa毒力相关蛋白抗原（VapB）基因。分离质粒DNA，并通过限制性内切酶消化进行分析，以估计大小并比较它们的多态性。82株分离株均不含vapA基因，但21株（25.6%）vapB基因阳性，PCR扩增产物为827 bp，与预期大小相符。61株（74.4%）不含质粒。21株中等毒力的分离株含有毒力质粒，分别鉴定为I型（1株）、5型（16株）、21型（1株）和3种新的不同质粒变体（1-1-1分离株）。根据质粒DNA的限制性酶切图谱，我们初步将新的变异体分别命名为25-27型。感染率分别为100%和100%。来自野猪颌下淋巴结的菌株中，中等毒力的马属菌株（25.6%）与来自匈牙利家猪的菌株（26.8%）非常相似，两组中质粒5型均占优势。这是首次分离到VapB阳性R.野猪中分离出的最多的一种。(C)2008 Elsevier B. V.保留所有权利。
Rhodococcus equi has been isolated from the submaxillary lymph nodes of domesticated pigs, but little is known about the presence of R. equi in wild boars. The aim of the study was the evaluation of the incidence of R. equi in wild boars and the characterisation of them. Of 482 submaxillary lymph nodes of wild boars shot in 39 settlements throughout Hungary, R, equi was isolated from 60 specimens, and plasmid types of 82 isolates were examined. The isolates were tested for the presence of 15-17-kDa (VapA) and 20-kDa virulence-associated protein antigen (VapB) genes by polymerase chain reaction (PCR). Plasmid DNAs were isolated and analysed by digestion with restriction endonucleases to estimate size and compare their polymorphisms. None of the 82 isolates contained vapA gene but 21 isolates (25.6%) were positive for vapB gene showing 827 bp product of the expected size in the PCR amplification. Sixty-one strains (74.4%) did not contain plasmid. The 21 isolates of intermediate virulence contained virulence plasmids that were identified as types I (1 isolate), 5 (16 isolates), 21 (1 isolate), and three new distinct plasmid variants (1-1-1 isolate), respectively. On the basis of restriction digestion patterns of plasmid DNAs, we tentatively designated the new variants as types 25-27, respectively. The prevalence of R. equi strains of intermediate virulence among the isolates originated from the submaxillary lymph nodes of wild boars (25.6%) is very similar to those of domestic pigs (26.8%) in Hungary, and plasmid type 5 is the predominating one in both groups. This is the first report of isolation of VapB-positive R. equi from wild boars in the world. (C) 2008 Elsevier B.V. All rights reserved.