title: Transcriptome analysis of mycobacteria in sputum samples of pulmonary tuberculosis patients.
abstract: Pulmonary tuberculosis, the disease caused by Mycobacterium tuberculosis, still retains a top rank among the deadliest communicable diseases. Sputum expectorated during the disease continues to be a primary diagnostic specimen and also serves as a reservoir of bacteria. The expression pattern of mycobacteria in sputum will lead to an insight into bacterial adaptation at the most highly transmissible stage of infection and can also help in identifying newer diagnostic as well as drug targets. Thus, in the present study, a whole genome microarray of Mycobacterium tuberculosis was used to elucidate the transcriptional profile of mycobacteria in the sputum samples of smear positive pulmonary tuberculosis patients. Overall, the mycobacteria in sputum appeared to be in a low energy and low replicative state as compared to in vitro grown log phase M. tb with downregulation of genes involved in ATP synthesis, aerobic respiration and translational machinery. Simultaneously, downregulation was also seen in the genes involved in secretion machinery of mycobacteria along with the downregulation of genes involved in the synthesis of phthiocerol dimycocerosate and phenol glycolipids. In contrast, the majority of the genes which showed an upregulation in sputum mycobacteria were of unknown function. Further identification of these genes may provide new insights into the mycobacterial behavior during this phase of infection and may help in deciphering candidates for development of better diagnostic and drug candidates.
authors.affiliation: Department of Biochemistry, Post Graduate Institute of Medical Education and Research, Chandigarh, India.
authors.forename: Sumedha
authors.initials: S
authors.lastname: Sharma
authors.affiliation: Department of Pathology, New York University Langone Medical Center, New York, New York, United States of America.
authors.forename: Michelle B
authors.initials: MB
authors.lastname: Ryndak
authors.affiliation: Department of Pulmonary Medicine, Post Graduate Institute of Medical Education and Research, Chandigarh, India.
authors.forename: Ashutosh N
authors.initials: AN
authors.lastname: Aggarwal
authors.affiliation: Department of Medical Microbiology, Post Graduate Institute of Medical Education and Research, Chandigarh, India.
authors.forename: Rakesh
authors.initials: R
authors.lastname: Yadav
authors.affiliation: Department of Medical Microbiology, Post Graduate Institute of Medical Education and Research, Chandigarh, India.
authors.forename: Sunil
authors.initials: S
authors.lastname: Sethi
authors.affiliation: Molecular Diagnostic and Research Laboratory (MDRL) Pvt. Ltd., Chandigarh, India.
authors.forename: Shet
authors.initials: S
authors.lastname: Masih
authors.affiliation: Department of Pathology, New York University Langone Medical Center, New York, New York, United States of America.|Veterans Affairs New York Harbor Healthcare System, New York, New York, United States of America.
authors.forename: Suman
authors.initials: S
authors.lastname: Laal
authors.affiliation: Department of Biochemistry, Post Graduate Institute of Medical Education and Research, Chandigarh, India.
authors.forename: Indu
authors.initials: I
authors.lastname: Verma
mesh_terms: D005260:Female; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D008297:Male; D009169:Mycobacterium tuberculosis / Q000378:metabolism*; D013183:Sputum / Q000382:microbiology*; D059467:Transcriptome; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis / Q000382:microbiology*