Zumárraga M J, Bernardell A, Bastida R, Quse V, Loureiro J, Cataldi A, Bigi F, Alito A, Castro Ramos M, Samper S, Otal I, Martin C, Romano M I
Instituto de Biotecnologı́a, CICV/INTA, Buenos Aires, Argentina1.
Departamento de Micobacterias, DILAB SENASA, C. C. 77 Morón (1708), Buenos Aires, Argentina2.
Microbiology (Reading). 1999 Sep;145 ( Pt 9):2519-2526. doi: 10.1099/00221287-145-9-2519.
Tuberculosis (TB) was diagnosed in 10 seals from three species (Arctocephalus australis, Arctocephalus tropicalis and Otaria flavescens) found in South America. The mycobacteria isolated from these cases belonged to the Mycobacterium tuberculosis complex, as determined by RFLP using an IS6110 probe, spoligotyping, analysis of the 16S rRNA gene sequence and by PCR-restriction analysis of hsp65. Polymorphisms in gyrA, katG, oxyR and pncA were investigated in some of the isolates, as well as the presence of the MPB70 antigen. The insertion sequence IS6110 was present in three to seven copies in the genome of the mycobacteria isolated from seals. Using the IS6110 probe, six patterns (designated A, B, C, D, E and F) were identified from 10 different isolates. Patterns A and B were found for the mycobacteria isolated from two and four seals, respectively, indicating an epidemiological relationship between isolates grouped according to their IS6110 RFLP. The mycobacteria isolated from seals shared the majority of their IS6110 DNA-containing restriction fragments, and nine isolates had an identical spoligotype; only one isolate showed a minor difference in its spoligotype. In addition, none of these spoligotypes were found in other M. tuberculosis complex strains. These results suggest that the isolates from seals constitute a unique group of closely related strains. The mycobacteria isolated from seals showed polymorphisms at gyrA codon 95 and katG codon 463, as do group 1 M. tuberculosis, and M. bovis. Group 1 mycobacteria are associated with cluster cases. The spoligotypes found in the mycobacteria isolated from seals lack spacers 39-43, as does M. bovis, but the MPB70 antigen, which is highly expressed in M. bovis and minimally expressed in M. tuberculosis, was not detected in these mycobacteria. The mycobacteria isolated from seals also showed oxyR and pncA polymorphisms specific to M. tuberculosis. In conclusion, the mycobacteria that cause TB in seals in the South-Western Atlantic are a related group, and based on the combination of genetic characteristics, belong to a unique genotypic group within the M. tuberculosis complex.
在南美洲发现的来自三种海豹物种（南极毛皮海狮、热带毛皮海狮和南美海狗）的10只海豹中诊断出患有结核病。通过使用IS6110探针的RFLP、间隔寡核苷酸分型、16S rRNA基因序列分析以及hsp65的PCR-限制性分析确定，从这些病例中分离出的分枝杆菌属于结核分枝杆菌复合群。在一些分离株中研究了gyrA、katG、oxyR和pncA的多态性，以及MPB70抗原的存在情况。从海豹分离出的分枝杆菌基因组中IS6110插入序列存在3至7个拷贝。使用IS6110探针，从10个不同分离株中鉴定出6种模式（分别命名为A、B、C、D、E和F）。模式A和B分别在从两只和四只海豹分离出的分枝杆菌中发现，这表明根据其IS6110 RFLP分组的分离株之间存在流行病学关系。从海豹分离出的分枝杆菌共享其大多数含IS6110 DNA的限制性片段，并且9个分离株具有相同的间隔寡核苷酸分型；只有一个分离株在其间隔寡核苷酸分型上有微小差异。此外，在其他结核分枝杆菌复合群菌株中未发现这些间隔寡核苷酸分型中的任何一种。这些结果表明，从海豹分离出的分离株构成了一组独特的密切相关菌株。从海豹分离出的分枝杆菌在gyrA密码子95和katG密码子463处显示多态性，与1型结核分枝杆菌和牛分枝杆菌相同。1型分枝杆菌与聚集病例相关。从海豹分离出的分枝杆菌中发现的间隔寡核苷酸分型缺少间隔区39 - 43，与牛分枝杆菌相同，但在这些分枝杆菌中未检测到在牛分枝杆菌中高表达而在结核分枝杆菌中低表达的MPB70抗原。从海豹分离出的分枝杆菌还显示出结核分枝杆菌特有的oxyR和pncA多态性。总之，在西南大西洋海豹中引起结核病的分枝杆菌是一个相关群体，基于遗传特征的组合，属于结核分枝杆菌复合群内的一个独特基因型群体。
