Rónai Zsuzsanna, Csivincsik Ágnes, Dán Ádám, Gyuranecz Miklós
Veterinary Diagnostic Directorate, National Food Chain Safety Office (NFCSO), P.O. Box 2, 1581 Budapest, Hungary.
University of Kaposvar, Diagnostic Imaging and Radiation Oncology, Guba Sándor u. 40., 7400 Kaposvár, Hungary.
Infect Genet Evol. 2016 Jun;40:192-199. doi: 10.1016/j.meegid.2016.03.004. Epub 2016 Mar 7.
Besides Mycobacterium avium subsp. paratuberculosis (MAP), M. avium subsp. avium (MAA), M. avium subsp. silvaticum (MAS), and 'M. avium subsp. hominissuis' (MAH) are equally important members of M. avium complex, with worldwide distribution and zoonotic potential. Genotypic discrimination is a prerequisite to epidemiological studies which can facilitate disease prevention through revealing infection sources and transmission routes. The primary aim of this study was to identify the genetic diversity within 135 MAA, 62 MAS, and 84 MAH strains isolated from wild and domestic mammals, reptiles and birds. Strains were tested for the presence of large sequence polymorphism LSP(A)17 and were submitted to Mycobacterial interspersed repetitive units-variable-number tandem repeat (MIRU-VNTR) analysis at 8 loci, including MIRU1, 2, 3, and 4, VNTR25, 32, and 259, and MATR9. In 12 strains hsp65 sequence code type was also determined. LSP(A)17 was present only in 19.9% of the strains. All LSP(A)17 positive strains belonged to subspecies MAH. The discriminatory power of the MIRU-VNTR loci set used reached 0.9228. Altogether 54 different genotypes were detected. Within MAH, MAA, and MAS strains 33, 16, and 5 different genotypes were observed. The described genotypes were not restricted to geographic regions or host species, but proved to be subspecies specific. Our knowledge about MAS is limited due to isolation and identification difficulties. This is the first study including a large number of MAS field strains. Our results demonstrate the high diversity of MAH and MAA strains and the relative uniformity of MAS strains.
除了副结核分枝杆菌鸟型亚种（MAP）外，鸟分枝杆菌鸟型亚种（MAA）、鸟分枝杆菌森林亚种（MAS）和“鸟分枝杆菌人亚种”（MAH）也是鸟分枝杆菌复合群中同样重要的成员，它们分布于全球，具有人畜共患病传播的可能性。基因型鉴别是流行病学研究的前提条件，通过揭示感染源和传播途径有助于疾病预防。本研究的主要目的是鉴定从野生和家养哺乳动物、爬行动物及鸟类中分离出的135株MAA、62株MAS和84株MAH菌株的遗传多样性。对菌株进行大序列多态性LSP(A)17检测，并在8个位点进行分枝杆菌散布重复单元-可变数目串联重复序列（MIRU-VNTR）分析，包括MIRU1、2、3和4、VNTR25、32和259以及MATR9。对12株菌株还测定了hsp65序列编码类型。仅19.9%的菌株存在LSP(A)17。所有LSP(A)17阳性菌株均属于MAH亚种。所使用的MIRU-VNTR位点组合的鉴别力达到0.9228。共检测到54种不同基因型。在MAH、MAA和MAS菌株中分别观察到33种、16种和5种不同基因型。所描述的基因型并不局限于地理区域或宿主物种，而是具有亚种特异性。由于分离和鉴定困难，我们对MAS的了解有限。这是第一项纳入大量MAS野外菌株的研究。我们的结果表明MAH和MAA菌株具有高度多样性，而MAS菌株相对较为单一。
