| 1. |
- Das, Sarbashis, et al.
(författare)
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Characterization of three Mycobacterium spp. with potential use in bioremediation by genome sequencing and comparative genomics
- 2015
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Ingår i: Genome Biology and Evolution. - : Oxford University Press (OUP). - 1759-6653. ; 7:7, s. 1871-1886
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Tidskriftsartikel (refereegranskat)abstract
- We provide the genome sequences of the type strains of the polychlorophenol-degrading Mycobacterium chlorophenolicum (DSM43826), the degrader of chlorinated aliphatics Mycobacterium chubuense (DSM44219) and Mycobacterium obuense (DSM44075) that has been tested for use in cancer immunotherapy. The genome sizes of M. chlorophenolicum, M. chubuense and M. obuense are 6.93, 5.95 and 5.58 Mbps with GC-contents of 68.4, 69.2 and 67.9%, respectively. Comparative genomic analysis revealed that 3254 genes are common and we predicted approximately 250 genes acquired through horizontal gene transfer from different sources including proteobacteria. The data also showed that the biodegrading Mycobacterium spp. NBB4, also referred to as M. chubuense NBB4, is distantly related to the M. chubuense type strain and should be considered as a separate species, we suggest it to be named M. ethylenense NBB4. Among different categories we identified genes with potential roles in: biodegradation of aromatic compounds, and copper homeostasis. These are the first non-pathogenic Mycobacterium spp. found harboring genes involved in copper homeostasis. These findings would therefore provide insight into the role of this group of Mycobacterium spp. in bioremediation as well as the evolution of copper homeostasis within the Mycobacterium genus.
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| 2. |
- Das, Sarbashis, et al.
(författare)
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The Mycobacterium phlei Genome : Expectations and Surprises
- 2016
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Ingår i: Genome Biology and Evolution. - : Oxford University Press (OUP). - 1759-6653. ; 8:4, s. 975-985
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Tidskriftsartikel (refereegranskat)abstract
- Mycobacterium phlei, a nontuberculosis mycobacterial species, was first described in 1898-1899. We present the complete genome sequence for the IV, phlei CCUG21000(T) type strain and the draft genomes for four additional strains. The genome size for all five is 5.3 Mb with 69.4% Guanine-Cytosine content. This is approximate to 0.35 Mbp smaller than the previously reported M. phlei RIVM draft genome. The size difference is attributed partly to large bacteriophage sequence fragments in the M. phlei RIVM genome. Comparative analysis revealed the following: 1) A CRISPR system similar to Type 1E (cas3) in M. phiei RIVM; 2) genes involved in polyamine metabolism and transport (potAD, potT) that are absent in other mycobacteria, and 3) strain specific variations in the number of sigma-factor genes. Moreover, M. phlei has as many as 82 mce (mammalian cell entry) homologs and many of the horizontally acquired genes in M. phlei are present in other environmental bacteria including mycobacteria that share similar habitat. Phylogenetic analysis based on 693 Mycobacterium core genes present in all complete mycobacterial genomes suggested that its closest neighbor is Mycobacterium smegmatis JS623 and Mycobacterium rhodesiae NBB3, while it is more distant to M. smegmatis mc2 155.
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| 3. |
- Ghosh, Jaydip, et al.
(författare)
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Sporulation in mycobacteria
- 2009
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - 0027-8424 .- 1091-6490. ; 106:26, s. 10781-10786
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Tidskriftsartikel (refereegranskat)
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| 4. |
- Ghosh, Jaydip, et al.
(författare)
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Sporulation in mycobacteria
- 2009
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 106:26, s. 10781-10786
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Tidskriftsartikel (refereegranskat)abstract
- Mycobacteria owe their success as pathogens to their ability to persist for long periods within host cells in asymptomatic, latent forms before they opportunistically switch to the virulent state. The molecular mechanisms underlying the transition into dormancy and emergence from it are not clear. Here we show that old cultures of Mycobacterium marinum contained spores that, upon exposure to fresh medium, germinated into vegetative cells and reappeared again in stationary phase via endospore formation. They showed many of the usual characteristics of well-known endospores. Homologues of well-known sporulation genes of Bacillus subtilis and Streptomyces coelicolor were detected in mycobacteria genomes, some of which were verified to be transcribed during appropriate life-cycle stages. We also provide data indicating that it is likely that old Mycobacterium bovis bacillus Calmette-Guérin cultures form spores. Together, our data show sporulation as a lifestyle adapted by mycobacteria under stress and tempt us to suggest this as a possible mechanism for dormancy and/or persistent infection. If so, this might lead to new prophylactic strategies.
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| 5. |
- Kirsebom, Leif A, et al.
(författare)
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New Vaccines
- 2009
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Patent (populärvet., debatt m.m.)
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| 6. |
- Kirsebom, Leif A., et al.
(författare)
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Pleiomorphism in Mycobacterium
- 2012
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Ingår i: Advances in Applied Microbiology, Vol 80. - : ELSEVIER ACADEMIC PRESS INC. - 9780123943811 ; , s. 81-112
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Bokkapitel (refereegranskat)abstract
- Morphological variants in mycobacterial cultures under different growth conditions, including aging of the culture, have been shown to include fibrous aggregates, biofilms, coccoids, and spores. Here we discuss the diversity in shape and size changes demonstrated by bacterial cells with special reference to pleiomorphism observed in Mycobacterium spp. in response to nutritional and other environmental stresses. Inherent asymmetry in cell division and compartmentalization of cell interior under different growth conditions might contribute toward the observed pleiomorphism in mycobacteria. The regulatory genes comprising the bacterial signaling pathway responsible for initiating morphogenesis are speculated upon from bioinformatic identifications of genes for known sensors, kinases, and phosphatases existing in mycobacterial genomes as well as on the basis of what is known in other bacteria.
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| 7. |
- Pettersson, B. M. Fredrik, et al.
(författare)
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Comparative Sigma Factor-mRNA Levels in Mycobacterium marinum under Stress Conditions and during Host Infection
- 2015
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 10:10
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Tidskriftsartikel (refereegranskat)abstract
- We have used RNASeq and qRT-PCR to study mRNA levels for all s-factors in different Mycobacterium marinum strains under various growth and stress conditions. We also studied their levels in M. marinum from infected fish and mosquito larvae. The annotated s-factors were expressed and transcripts varied in relation to growth and stress conditions. Some were highly abundant such as sigA, sigB, sigC, sigD, sigE and sigH while others were not. The s-factor mRNA profiles were similar after heat stress, during infection of fish and mosquito larvae. The similarity also applies to some of the known heat shock genes such as the a-crystallin gene. Therefore, it seems probable that the physiological state of M. marinum is similar when exposed to these different conditions. Moreover, the mosquito larvae data suggest that this is the state that the fish encounter when infected, at least with respect to s-factor mRNA levels. Comparative genomic analysis of s-factor gene localizations in three M. marinum strains and Mycobacterium tuberculosis H37Rv revealed chromosomal rearrangements that changed the localization of especially sigA, sigB, sigD, sigE, sigF and sigJ after the divergence of these two species. This may explain the variation in species-specific expression upon exposure to different growth conditions.
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| 8. |
- Pettersson, B M Fredrik, et al.
(författare)
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Draft Genome Sequence of Saccharopolyspora rectivirgula.
- 2014
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Ingår i: Genome Announcements. - 2169-8287. ; 2:1
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Tidskriftsartikel (refereegranskat)abstract
- We have sequenced the genome of Saccharopolyspora rectivirgula, the causative agent of farmer's lung disease. The draft genome consists of 182 contigs totaling 3,977,051 bp, with a GC content of 68.9%.
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| 9. |
- Pettersson, B. M. Fredrik, et al.
(författare)
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Identification and expression of stressosomal proteins in Mycobacterium marinum under various growth and stress conditions
- 2013
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Ingår i: FEMS Microbiology Letters. - : Oxford University Press (OUP). - 0378-1097 .- 1574-6968. ; 342:2, s. 98-105
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Tidskriftsartikel (refereegranskat)abstract
- Like other bacteria, Mycobacterium spp. have developed different strategies in response to environmental changes such as nutrient limitations and other different stress situations. We have identified candidate genes (rsb genes) from Mycobacterium marinum involved in the regulation of the activity of the alternative sigma factor, sigma F. This is a homolog of the master regulator of general stress response, sigma B, and the sporulation-specific sigma factor, sigma F, in Bacillus subtilis. The organization of these genes in M.marinum and B.subtilis is similar. Transcriptome and qRT-PCR data show that these genes are indeed expressed in M.marinum and that the levels of expression vary with growth phase and exposure to stress. In particular, cold stress caused a significant rise in the expression of all identified rsb and sigF genes. We discuss these data in relation to what is currently known for other Mycobacterium spp.
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| 10. |
- Ramesh, Malavika, et al.
(författare)
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Age-dependent pleomorphism in Mycobacterium monacense cultures
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Annan publikation (populärvet., debatt m.m.)abstract
- Changes in cell shape and pleomorphism have been shown to be an integral part of the mycobacterial life cycle, however, systematic investigations into its patterns of pleomorphic behaviour in connection with stages or conditions of growth is scarce. We have studied the complete growth-cycle of Mycobacterium monacense cultures, a Non-Tuberculous Mycobacterium (NTM), in solid as well as liquid media. We provide data showing changes in cell shape from rod to coccoid and occurrence of refractive cells ranging from Phase Grey to phase Bright (PGB) in appearance upon ageing. Data further showed that changes in cell shape observed under the microscope could be correlated to the biphasic nature of the growth curves for M. monacense (as well as the NTM Mycobacterium boenickei) as measured by the absorbance of liquid cultures. Using the complete M. monacense genome we identified genes involved in cell morphology, and transcriptome analyses at different stages of growth revealed changes in their mRNA levels. One gene of interest, dnaK_3, that showed strong upregulation during stationary phase, was identified as an MreB-like homolog based on the protein domain architecture. Exogenous overexpression of M. monacense dnaK_3 in Mycobacterium marinum resulted in morphological changes with an impact on the frequency of occurrence of PGB cells. However, the introduction of an anti-sense "gene" targeting M. marinum dnaK_3 did not show such effects. Using dnaK_3-lacZ reporter constructs we provide data that these differences could be attributed to differences in the regulation of dnaK_3 in the two species. Together, this suggests that although its regulation may vary between mycobacterial species, dnaK_3 might be involved in the mechanism influencing mycobacterial cell shape.
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