title: The influence of reduced oxygen availability on gene expression in laboratory (H37Rv) and clinical strains (S7 and S10) of Mycobacterium tuberculosis.
abstract: Mycobacterium tuberculosis has the ability to persist within the host in a dormant stage. One important condition believed to contribute to dormancy is reduced access to oxygen known as hypoxia. However, the response of M. tuberculosis to such hypoxia condition is not fully characterized. Virtually all dormant models against tuberculosis tested in animals used laboratory strain H37Rv or Erdman strain. But major outbreaks of tuberculosis (TB) occur with the strains that have widely different genotypes and phenotypes compared to H37Rv. In this study, we used a custom oligonucleotide microarray to determine the overall transcriptional response of laboratory strain (H37Rv) and most prevalent clinical strains (S7 and S10) of M. tuberculosis from South India to hypoxia. Analysis of microarray results revealed that a total of 1161 genes were differentially regulated (≥1.5 fold change) in H37Rv, among them 659 genes upregulated and 502 genes down regulated. Microarray data of clinical isolates showed that a total of 790 genes were differentially regulated in S7 among which 453 genes were upregulated and 337 down regulated. Interestingly, numerous genes were also differentially regulated in S10 (total 2805 genes) of which 1463 genes upregulated and 1342 genes down regulated during reduced oxygen condition (Wayne's model). One hundred and thirty-four genes were found common and upregulated among all three strains (H37Rv, S7, and S10) and can be targeted for drug/vaccine development against TB.
authors.affiliation: Department of Immunology, National Institute for Research in Tuberculosis (ICMR), (Formerly Tuberculosis Research Centre), No. 1, Mayor Sathiyamoorthy Road, Chetpet, Chennai 600 031, India.
authors.forename: Santhi
authors.initials: S
authors.lastname: Devasundaram
authors.affiliation: Department of Molecular Reproduction, Development and Genetics Biological Sciences Building, Indian Institute of Science, Bangalore 560 012, India.
authors.forename: Imran
authors.initials: I
authors.lastname: Khan
authors.affiliation: Department of Molecular Reproduction, Development and Genetics Biological Sciences Building, Indian Institute of Science, Bangalore 560 012, India.
authors.forename: Neeraj
authors.initials: N
authors.lastname: Kumar
authors.affiliation: Department of Immunology, National Institute for Research in Tuberculosis (ICMR), (Formerly Tuberculosis Research Centre), No. 1, Mayor Sathiyamoorthy Road, Chetpet, Chennai 600 031, India.
authors.forename: Sulochana
authors.initials: S
authors.lastname: Das
authors.affiliation: Department of Immunology, National Institute for Research in Tuberculosis (ICMR), (Formerly Tuberculosis Research Centre), No. 1, Mayor Sathiyamoorthy Road, Chetpet, Chennai 600 031, India. Electronic address: alameluraja@gmail.com.
authors.forename: Alamelu
authors.initials: A
authors.lastname: Raja
mesh_terms: D000332:Aerobiosis; D000693:Anaerobiosis; D001426:Bacterial Proteins / Q000235:genetics*; D020869:Gene Expression Profiling / Q000379:methods; D015964:Gene Expression Regulation, Bacterial; D007194:India; D009169:Mycobacterium tuberculosis / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods; D010100:Oxygen / Q000494:pharmacology
chemical_list: D001426:Bacterial Proteins; D010100:Oxygen
keywords: Clinical strains; Dormancy; Gene regulation; Hypoxia; Tuberculosis