A phenotypic characterization of two isolates of a multidrug-resistant outbreak strain of mycobacterium tuberculosis with opposite epidemiological fitness

Tuberculosis (TB) is an infectious disease, caused by Mycobacterium tuberculosis, primarily affecting the lungs. The M. tuberculosis strain of the Haarlem family named M was responsible for a large multidrug-resistant TB (MDR-TB) outbreak in Buenos Aires. This outbreak started in the early 1990s and in the mid 2000s still accounted for 29% of all MDR-TB cases in Argentina. By contrast, a clonal variant of strain M, named 410, has caused a single tuberculosis case since the onset of the outbreak. The molecular bases of the high epidemiological fitness of the M strain remain unclear. To assess its unique molecular properties, herein, we performed a comparative protein and lipid analysis of a representative clone of the M strain (Mp) and the nonprosperous M variant 410. We also evaluated their growth in low pH. The variant 410 had higher levels of latency proteins under standard conditions and delayed growth at low pH, suggesting that it is more sensitive to stress stimuli than Mp. Moreover, Mp showed higher levels of mycolic acids covalently attached to the cell wall and lower accumulation of free mycolic acids in the outer layer than the 410 strain. The low expression of latency proteins together with the reduced content of surface mycolic acids may facilitate Mp to evade the host immune responses.

Instituto de Biotecnología

Fil: Bei, Jinlong. Guangdong Academy of Agricultural Sciences (GDAAS). AGRO-Biological Gene Research Center; China

Fil: Bigi, María Mercedes. Universidad de Buenos Aires. Facultad de Agronomía. Cátedra de Microbiología Agrícola; Argentina

Fil: Lima, Analía. Institut Pasteur de Montevideo; Uruguay. Instituto de Investigaciones Biológicas Clemente Estable; Uruguay

Fil: Zhang, Qi. Guangdong Academy of Agricultural Sciences (GDAAS). AGRO-Biological Gene Research Center; China

Fil: Blanco, Federico Carlos. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Fil: López, Beatriz. Administración Nacional de Laboratorios e Institutos de Salud. Instituto Nacional de Enfermedades Infecciosas “Dr. Carlos G. Malbrán”; Argentina

Fil: Yu, Ting. Guangdong Academy of Agricultural Sciences (GDAAS). AGRO-Biological Gene Research Center; China

Fil: Wang, Zhilin. Guangdong Academy of Agricultural Sciences (GDAAS). AGRO-Biological Gene Research Center; China

Fil: Dai, Zhangyan. Guangdong Academy of Agricultural Sciences (GDAAS). AGRO-Biological Gene Research Center; China

Fil: Chen, Zhuang. Guangdong Academy of Agricultural Sciences (GDAAS). AGRO-Biological Gene Research Center; China

Fil: Cataldi, Angel Adrian. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Fil: Sasiain, María del Carmen. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentina

Fil: Ritacco, Viviana. Administración Nacional de Laboratorios e Institutos de Salud. Instituto Nacional de Enfermedades Infecciosas “Dr. Carlos G. Malbrán”; Argentina

Fil: de la Barrera, Silvia Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentina

Fil: Soria, Marcelo Abel. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Biología Aplicada y Alimentos; Argentina

Fil: Durán, Rosario. Institut Pasteur de Montevideo; Uruguay. Instituto de Investigaciones Biológicas Clemente Estable; Uruguay

Fil: Bigi, Fabiana. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina