Mem Inst Oswaldo Cruz, Rio de Janeiro, 112(11) November 2017
Construction of Mycobacterium tuberculosis cdd knockout and evaluation of invasion and growth in macrophages
1Pontifícia Universidade Católica do Rio Grande do Sul, Centro de Pesquisas em Biologia Molecular e Funcional, Instituto Nacional de Ciência e Tecnologia em Tuberculose, Porto Alegre, RS, Brasil
2Pontifícia Universidade Católica do Rio Grande do Sul, Programa de Pós-Graduação em Biologia Celular e Molecular, Porto Alegre, RS, Brasil
3Pontifícia Universidade Católica do Rio Grande do Sul, Programa de Pós-Graduação em Medicina e Ciências da Saúde, Porto Alegre, RS, Brasil
Cytidine deaminase (MtCDA), encoded by cdd gene (Rv3315c), is the only enzyme identified in nucleotide biosynthesis pathway of Mycobacterium tuberculosis that is able to recycle cytidine and deoxycytidine. An M. tuberculosis knockout strain for cdd gene was obtained by allelic replacement. Evaluation of mRNA expression validated cdd deletion and showed the absence of polar effect. MudPIT LC-MS/MS data indicated thymidine phosphorylase expression was decreased in knockout and complemented strains. The cdd disruption does not affect M. tuberculosis growth both in Middlebrook 7H9 and in RAW 264.7 cells, which indicates that cdd is not important for macrophage invasion and virulence.