Soares S C, Dorella F A, Pacheco L G C, Hirata R, Mattos-Guaraldi A L, Azevedo V, Miyoshi A
Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brasil.
Genet Mol Res. 2011 Jun 28;10(2):1290-4. doi: 10.4238/vol10-2gmr1211.
Despite the existence of a vaccine against diphtheria, this disease remains endemic and is reemerging in several regions due to many factors, including variations in genes coding for virulence factors. One common feature of virulence factors is their high concentration in pathogenicity islands (PAIs), very unstable regions acquired via horizontal gene transfer, which has lead to the emergence of various bacterial pathogens. The 13 putative PAIs in Corynebacterium diphtheriae NCTC 13129 and the reemergence of this disease point to the great variability in the PAIs of this species, which may reflect on bacterial life style and physiological versatility. We investigated the relationships between the large number of PAIs in C. diphtheriae and the possible implications of their plasticity in virulence. The GenoFrag software was used to design primers to analyze the genome plasticity of two pathogenicity islands of the reference strain (PiCds 3 and 8) in 11 different strains. We found that PiCd 3 was absent in only two strains, showing genes playing putative important roles in virulence and that only one strain harbored PiCd 8, due to its location in a putative "hotspot" for horizontal gene transfer events.
尽管存在白喉疫苗，但由于多种因素，包括编码毒力因子的基因变异，这种疾病仍然是地方性疾病，并且在几个地区再次出现。毒力因子的一个共同特征是它们在致病岛（PAIs）中高度集中，致病岛是通过水平基因转移获得的非常不稳定的区域，这导致了各种细菌病原体的出现。白喉棒状杆菌NCTC 13129中的13个假定致病岛以及这种疾病的再次出现表明该物种致病岛的巨大变异性，这可能反映了细菌的生活方式和生理多功能性。我们研究了白喉棒状杆菌中大量致病岛之间的关系以及它们的可塑性对毒力的可能影响。使用GenoFrag软件设计引物，以分析参考菌株的两个致病岛（PiCds 3和8）在11个不同菌株中的基因组可塑性。我们发现PiCd 3仅在两个菌株中不存在，显示出在毒力中起假定重要作用的基因，并且由于PiCd 8位于水平基因转移事件的假定“热点”中，只有一个菌株含有它。
