Republican Research and Practical Centre for Epidemiology and Microbiology, Immunoprophylaxis Laboratory, 23 Filimonova str., 220114 Minsk, Belarus.
Infect Genet Evol. 2011 Mar;11(2):518-21. doi: 10.1016/j.meegid.2010.11.004. Epub 2010 Nov 24.
Corynebacterium diphtheriae the causative pathogen of human diphtheria infects the nasopharynx or skin. Although diphtheria has been extensively studied, little is known about the two key aspects of C. diphtheriae invasiveness: colonization and invasion. The role of adhesive properties in establishing the infection of C. diphtheriae strains, independent of toxin production, still needs to be clarified. In this study, we describe a novel gene involved in adherence to epithelial cells. Transformation of C. diphtheriae 225, biotype gravis, ribotype St-Petersburg by EZ:TN(KAN-2)Tnp Transposome was undertaken. A C. diphtheriae 225 Tn5 insertion library of 2800 mutants was created. Five hundred and eighty five transformants were qualitatively screened for reduced adherence to HEp-2 cells by an adherence assay. One mutant strain consistently exhibiting 15.2% of the wild-type adherence was isolated. The DNA flanking the transposon was identified by inverse PCR and subsequent sequencing. The disrupted gene was 94% identical to the C. diphtheriae DIP1621 gene that belongs to unclassified genes. In conclusion, the disruption of the C. diphtheriae DIP1621 gene led to decreased adherence to epithelial cells; its exact function remains to be established.
白喉棒状杆菌是人类白喉的病原体，感染鼻咽部或皮肤。尽管对白喉进行了广泛的研究，但对于白喉棒状杆菌侵袭性的两个关键方面——定植和侵袭，人们知之甚少。粘附特性在建立白喉棒状杆菌菌株感染中的作用，独立于毒素产生，仍需要阐明。在本研究中，我们描述了一个参与粘附上皮细胞的新基因。通过 EZ:TN(KAN-2)Tnp 转座酶对 225 型白喉生物型、核糖体型圣彼得堡进行了转化。创建了一个包含 2800 个突变体的 225 型白喉 Tn5 插入文库。通过粘附测定法对 585 个转化体进行了定性筛选，以检测其对 HEp-2 细胞粘附能力的降低。分离出一株持续表现出野生型粘附率 15.2%的突变株。通过反向 PCR 和随后的测序确定了转座子侧翼的 DNA。该破坏的基因与白喉棒状杆菌 DIP1621 基因 94%相同，该基因属于未分类基因。总之，白喉棒状杆菌 DIP1621 基因的破坏导致对上皮细胞的粘附能力降低；其确切功能尚待确定。
