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Orgeur M, Sous C, Madacki J, Brosch R. Evolution and emergence of Mycobacterium tuberculosis. FEMS Microbiol Rev 2024; 48:fuae006. [PMID: 38365982 PMCID: PMC10906988 DOI: 10.1093/femsre/fuae006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 01/12/2024] [Accepted: 02/13/2024] [Indexed: 02/18/2024] Open
Abstract
Tuberculosis (TB) remains one of the deadliest infectious diseases in human history, prevailing even in the 21st century. The causative agents of TB are represented by a group of closely related bacteria belonging to the Mycobacterium tuberculosis complex (MTBC), which can be subdivided into several lineages of human- and animal-adapted strains, thought to have shared a last common ancestor emerged by clonal expansion from a pool of recombinogenic Mycobacterium canettii-like tubercle bacilli. A better understanding of how MTBC populations evolved from less virulent mycobacteria may allow for discovering improved TB control strategies and future epidemiologic trends. In this review, we highlight new insights into the evolution of mycobacteria at the genus level, describing different milestones in the evolution of mycobacteria, with a focus on the genomic events that have likely enabled the emergence and the dominance of the MTBC. We also review the recent literature describing the various MTBC lineages and highlight their particularities and differences with a focus on host preferences and geographic distribution. Finally, we discuss on putative mechanisms driving the evolution of tubercle bacilli and mycobacteria in general, by taking the mycobacteria-specific distributive conjugal transfer as an example.
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Affiliation(s)
- Mickael Orgeur
- Institut Pasteur, Université Paris Cité, CNRS UMR 6047, Unit for Integrated Mycobacterial Pathogenomics, 75015 Paris, France
| | - Camille Sous
- Institut Pasteur, Université Paris Cité, CNRS UMR 6047, Unit for Integrated Mycobacterial Pathogenomics, 75015 Paris, France
| | - Jan Madacki
- Institut Pasteur, Université Paris Cité, CNRS UMR 6047, Unit for Integrated Mycobacterial Pathogenomics, 75015 Paris, France
- Institut Pasteur, Université Paris Cité, CNRS UMR 2000, Unit for Human Evolutionary Genetics, 75015 Paris, France
| | - Roland Brosch
- Institut Pasteur, Université Paris Cité, CNRS UMR 6047, Unit for Integrated Mycobacterial Pathogenomics, 75015 Paris, France
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A Polymorphic Gene within the Mycobacterium smegmatis esx1 Locus Determines Mycobacterial Self-Identity and Conjugal Compatibility. mBio 2022; 13:e0021322. [PMID: 35297678 PMCID: PMC9040860 DOI: 10.1128/mbio.00213-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Mycobacteria mediate horizontal gene transfer (HGT) by a process called distributive conjugal transfer (DCT) that is mechanistically distinct from oriT-mediated plasmid transfer. The transfer of multiple, independent donor chromosome segments generates transconjugants with genomes that are mosaic blends of their parents. Previously, we had characterized contact-dependent conjugation between two independent isolates of Mycobacterium smegmatis. Here, we expand our analyses to include five independent isolates of M. smegmatis and establish that DCT is both active and prevalent among natural isolates of M. smegmatis. Two of these five strains were recipients but exhibited distinct conjugal compatibilities with donor strains, suggesting an ability to distinguish between potential donor partners. We determined that a single gene, Msmeg0070, was responsible for conferring mating compatibility using a combination of comparative DNA sequence analysis, bacterial genome-wide association studies (GWAS), and targeted mutagenesis. Msmeg0070 maps within the esx1 secretion locus, and we establish that it confers mycobacterial self-identity with parallels to kin recognition. Similar to other kin model systems, orthologs of Msmeg0070 are highly polymorphic. The identification of a kin recognition system in M. smegmatis reinforces the concept that communication between cells is an important checkpoint prior to DCT commitment and implies that there are likely to be other, unanticipated forms of social behaviors in mycobacteria. IMPORTANCE Conjugation, unlike other forms of HGT, requires direct interaction between two viable bacteria, which must be capable of distinguishing between mating types to allow successful DNA transfer from donor to recipient. We show that the conjugal compatibility of Mycobacterium smegmatis isolates is determined by a single, polymorphic gene located within the conserved esx1 secretion locus. This gene confers self-identity; the expression of identical Msmeg0070 proteins in both donor-recipient partners prevents DNA transfer. The presence of this polymorphic locus in many environmental mycobacteria suggests that kin identification is important in promoting beneficial gene flow between nonkin mycobacteria. Cell-cell communication, mediated by kin recognition and ESX secretion, is a key checkpoint in mycobacterial conjugation and likely plays a more global role in mycobacterial biology.
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Abstract
Current models of horizontal gene transfer (HGT) in mycobacteria are based on “distributive conjugal transfer” (DCT), an HGT type described in the fast-growing, saprophytic model organism Mycobacterium smegmatis, which creates genome mosaicism in resulting strains and depends on an ESX-1 type VII secretion system. In contrast, only few data on interstrain DNA transfer are available for tuberculosis-causing mycobacteria, for which chromosomal DNA transfer between two Mycobacterium canettii strains was reported, a process which, however, was not observed for Mycobacterium tuberculosis strains. Here, we have studied a wide range of human- and animal-adapted members of the Mycobacterium tuberculosis complex (MTBC) using an optimized filter-based mating assay together with three selected strains of M. canettii that acted as DNA recipients. Unlike in previous approaches, we obtained a high yield of thousands of recombinants containing transferred chromosomal DNA fragments from various MTBC donor strains, as confirmed by whole-genome sequence analysis of 38 randomly selected clones. While the genome organizations of the obtained recombinants showed mosaicisms of donor DNA fragments randomly integrated into a recipient genome backbone, reminiscent of those described as being the result of ESX-1-mediated DCT in M. smegmatis, we observed similar transfer efficiencies when ESX-1-deficient donor and/or recipient mutants were used, arguing that in tubercle bacilli, HGT is an ESX-1-independent process. These findings provide new insights into the genetic events driving the pathoevolution of M. tuberculosis and radically change our perception of HGT in mycobacteria, particularly for those species that show recombinogenic population structures despite the natural absence of ESX-1 secretion systems.
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Draft Genome Sequence of MKD8, a Conjugal Recipient Mycobacterium smegmatis Strain. GENOME ANNOUNCEMENTS 2013; 1:e0014813. [PMID: 23618714 PMCID: PMC3636542 DOI: 10.1128/genomea.00148-13] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We report an annotated draft genome sequence of the Mycobacterium smegmatis strain MKD8. This strain acts as a recipient during conjugation with the reference M. smegmatis strain mc(2)155. While the genomes of the two strains are colinear and have similar sizes, extensive genome-wide sequence variation suggests rich diversity within the M. smegmatis clade.
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Prozorov AA, Zaichikova MV, Danilenko VN. Systems of genes and proteins affecting mycobacteria virulence and their homologs participation in conjugation of Mycobacterium smegmatis. RUSS J GENET+ 2013. [DOI: 10.1134/s1022795413010092] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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6
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Jacobs-Sera D, Marinelli LJ, Bowman C, Broussard GW, Guerrero Bustamante C, Boyle MM, Petrova ZO, Dedrick RM, Pope WH, Modlin RL, Hendrix RW, Hatfull GF. On the nature of mycobacteriophage diversity and host preference. Virology 2012; 434:187-201. [PMID: 23084079 DOI: 10.1016/j.virol.2012.09.026] [Citation(s) in RCA: 140] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Revised: 09/19/2012] [Accepted: 09/23/2012] [Indexed: 11/29/2022]
Abstract
The complete genome sequences of over 220 mycobacteriophages reveal them to be highly diverse, with numerous types sharing little or no nucleotide sequence identity with each other. We have determined the preferences of these phages for Mycobacterium tuberculosis and for other strains of Mycobacterium smegmatis, and find there is a correlation between genome type (cluster, subcluster, singleton) and host range. For many of the phages, expansion of host range occurs at relatively high frequencies, and we describe several examples in which host constraints occur at early stages of infection (adsorption or DNA injection), and phages have the ability to expand their host range through mutations in tail genes. We present a model in which phage diversity is a function of both the ability of phages to rapidly adapt to new hosts and the richness of the diversity of the bacterial population from which those phages are isolated.
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Affiliation(s)
- Deborah Jacobs-Sera
- Pittsburgh Bacteriophage Institute, Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
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Abstract
Molecular genetics is one of the most rational approaches to determine particular gene functions. Inactivation of putative virulence genes is a powerful tool not only for characterization of pathogenic bacteria. This review summarizes recently described strategies for DNA transfer and gene inactivation in mycobacteria.
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Affiliation(s)
- Christian Morsczeck
- Stiftung caesar, Center of Advanced European Studies And Research, Bonn, Germany.
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9
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Vijaya S. The genetics ofMycobacterium tuberculosis. J Genet 1998. [DOI: 10.1007/bf02966598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Parsons LM, Jankowski CS, Derbyshire KM. Conjugal transfer of chromosomal DNA in Mycobacterium smegmatis. Mol Microbiol 1998; 28:571-82. [PMID: 9632259 DOI: 10.1046/j.1365-2958.1998.00818.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The genus Mycobacterium includes the major human pathogens Mycobacterium tuberculosis and Mycobacterium leprae. The development of rational drug treatments for the diseases caused by these and other mycobacteria requires the establishment of basic molecular techniques to determine the genetic basis of pathogenesis and drug resistance. To date, the ability to manipulate and move DNA between mycobacterial strains has relied on the processes of transformation and transduction. Here, we describe a naturally occurring conjugation system present in Mycobacterium smegmatis, which we anticipate will further facilitate the ability to manipulate the mycobacterial genome. Our data rule out transduction and transformation as possible mechanisms of gene transfer in this system and are most consistent with conjugal transfer. We show that recombinants are not the result of cell fusion and that transfer occurs from a distinct donor to a recipient. One of the donor strains is mc(2)155, a highly transformable derivative that is considered the prototype laboratory strain for mycobacterial genetics; the demonstration that it is conjugative should increase its genetic manipulability dramatically. During conjugation, extensive regions of chromosomal DNA are transferred into the recipient and then integrated into the recipient chromosome by multiple recombination events. We propose that DNA transfer is occurring by a mechanism similar to Hfr conjugation in Escherichia coli.
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Affiliation(s)
- L M Parsons
- Wadsworth Center, New York State Department of Health and School of Public Health, State University of New York at Albany, David Axelrod Institute, 12201-2002, USA
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Bardarov S, Kriakov J, Carriere C, Yu S, Vaamonde C, McAdam RA, Bloom BR, Hatfull GF, Jacobs WR. Conditionally replicating mycobacteriophages: a system for transposon delivery to Mycobacterium tuberculosis. Proc Natl Acad Sci U S A 1997; 94:10961-6. [PMID: 9380742 PMCID: PMC23545 DOI: 10.1073/pnas.94.20.10961] [Citation(s) in RCA: 237] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/1997] [Indexed: 02/05/2023] Open
Abstract
Transposon mutagenesis provides a direct selection for mutants and is an extremely powerful technique to analyze genetic functions in a variety of prokaryotes. Transposon mutagenesis of Mycobacterium tuberculosis has been limited in part because of the inefficiency of the delivery systems. This report describes the development of conditionally replicating shuttle phasmids from the mycobacteriophages D29 and TM4 that enable efficient delivery of transposons into both fast- and slow-growing mycobacteria. These shuttle phasmids consist of an Escherichia coli cosmid vector containing either a mini-Tn10(kan) or Tn5367 inserted into a nonessential region of the phage genome. Thermosensitive mutations were created in the mycobacteriophage genome that allow replication at 30 degrees C but not at 37 degrees C (TM4) or 38.5 degrees C (D29). Infection of mycobacteria at the nonpermissive temperature results in highly efficient transposon delivery to the entire population of mycobacterial cells. Transposition of mini-Tn10(kan) occurred in a site-specific fashion in M. smegmatis whereas Tn5367 transposed apparently randomly in M. phlei, Bacille Calmette-Guérin (BCG), and M. tuberculosis. Sequence analysis of the M. tuberculosis and BCG chromosomal regions adjacent to Tn5367 insertions, in combination with M. tuberculosis genomic sequence and physical map data, indicates that the transpositions have occurred randomly in diverse genes in every quadrant of the genome. Using this system, it has been readily possible to generate libraries containing thousands of independent mutants of M. phlei, BCG, and M. tuberculosis.
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Affiliation(s)
- S Bardarov
- Howard Hughes Medical Institute, Department of Microbiology and Immunology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY, 10461, USA
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Taniguchi H, Chang B, Abe C, Nikaido Y, Mizuguchi Y, Yoshida SI. Molecular analysis of kanamycin and viomycin resistance in Mycobacterium smegmatis by use of the conjugation system. J Bacteriol 1997; 179:4795-801. [PMID: 9244267 PMCID: PMC179326 DOI: 10.1128/jb.179.15.4795-4801.1997] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
We examined the molecular mechanisms of resistance to kanamycin and viomycin in Mycobacterium smegmatis. All of the M. smegmatis strains with high-level kanamycin resistance had a nucleotide substitution from A to G at position 1389 of the 16S rRNA gene (rrs). This position is equivalent to position 1408 of Escherichia coli, and mutation at this position is known to cause aminoglycoside resistance. Mutations from G to A or G to T at position 1473 of the M. smegmatis rrs gene were found in viomycin-resistant mutants which had been designated vicB mutants in our earlier studies. Using the M. smegmatis conjugation system, we confirmed that these mutations indeed contributed to kanamycin and viomycin resistance, and kanamycin susceptibility was dominant over resistance in a heterogenomic strain. Additional experiments showed that three of four Mycobacterium tuberculosis strains with high-level kanamycin resistance had a mutation from A to G at position 1400, which was equivalent to position 1389 of M. smegmatis.
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MESH Headings
- Base Sequence
- Capreomycin/pharmacology
- Conjugation, Genetic
- DNA, Bacterial
- Drug Resistance, Microbial/genetics
- Drug Resistance, Multiple/genetics
- Genes, Dominant
- Genes, Recessive
- Genome, Bacterial
- Kanamycin Resistance/genetics
- Molecular Sequence Data
- Mutation
- Mycobacterium/drug effects
- Mycobacterium/genetics
- Mycobacterium tuberculosis/genetics
- Mycobacterium tuberculosis/isolation & purification
- RNA, Bacterial
- RNA, Ribosomal, 16S
- Sequence Analysis, RNA
- Viomycin/pharmacology
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Affiliation(s)
- H Taniguchi
- Department of Microbiology, School of Medicine, University of Occupational and Environmental Health, Yahatanishiku, Kitakyusyu, Japan.
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Balasubramanian V, Pavelka MS, Bardarov SS, Martin J, Weisbrod TR, McAdam RA, Bloom BR, Jacobs WR. Allelic exchange in Mycobacterium tuberculosis with long linear recombination substrates. J Bacteriol 1996; 178:273-9. [PMID: 8550428 PMCID: PMC177649 DOI: 10.1128/jb.178.1.273-279.1996] [Citation(s) in RCA: 127] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Genetic studies of Mycobacterium tuberculosis have been greatly hampered by the inability to introduce specific chromosomal mutations. Whereas the ability to perform allelic exchanges has provided a useful method of gene disruption in other organisms, in the clinically important species of mycobacteria, such as M. tuberculosis and Mycobacterium bovis, similar approaches have thus far been unsuccessful. In this communication, we report the development of a shuttle mutagenesis strategy that involves the use of long linear recombination substrates to reproducibly obtain recombinants by allelic exchange in M. tuberculosis. Long linear recombination substrates, approximately 40 to 50 kb in length, were generated by constructing libraries in the excisable cosmid vector pYUB328. The cosmid vector could be readily excised from the recombinant cosmids by digestion with PacI, a restriction endonuclease for which there exist few, if any, sites in mycobacterial genomes. A cosmid containing the mycobacterial leuD gene was isolated, and a selectable marker conferring resistance to kanamycin was inserted into the leuD gene in the recombinant cosmid by interplasmid recombination in Escherichia coli. A long linear recombination substrate containing the insertionally mutated leuD gene was generated by PacI digestion. Electroporation of this recombination substrate containing the insertionally mutated leuD allele resulted in the generation of leucine auxotrophic mutants by homologous recombination in 6% of the kanamycin-resistant transformants for both the Erdman and H37Rv strains of M. tuberculosis. The ability to perform allelic exchanges provides an important approach for investigating the biology of this pathogen as well as developing new live-cell M. tuberculosis-based vaccines.
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Affiliation(s)
- V Balasubramanian
- Howard Hughes Medical Institute, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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Quinn FD, Newman GW, King CH. Virulence determinants of Mycobacterium tuberculosis. Curr Top Microbiol Immunol 1996; 215:131-56. [PMID: 8791712 DOI: 10.1007/978-3-642-80166-2_6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- F D Quinn
- Division of AIDS, STD, and TB Laboratory Research, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA
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15
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Mizuguchi Y, Suga K, Yamada T. Interactions between viomycin resistance and streptomycin resistance on ribosomes of Mycobacterium smegmatis. Microbiol Immunol 1979; 23:581-94. [PMID: 228160 DOI: 10.1111/j.1348-0421.1979.tb00499.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Mizuguchi Y, Suga K, Yamada T. Interaction between 30 S ribosomal components in a viomycin resistant mutant of Mycobacterium smegmatis. Microbiol Immunol 1979; 23:595-604. [PMID: 228161 DOI: 10.1111/j.1348-0421.1979.tb00500.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A high level viomycin resistant mutant of Mycobacterium smegmatis ATCC 14468 (AC16) was analyzed genetically and biochemically in an attempt to understand the mechanisms of expression of high level viomycin resistance and co-resistance to kanamycin and streptomycin. Genetic analysis has shown that at least three different genes (vicC, str, and kan) were involved in the phenotypic expression of drug resistance in AC16, and high level resistance to viomycin was due to interactions between the products of these genes.
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Abstract
A procedure for preparing sodium dodecyl sulfate-salt-cleared lysates of mycobacteria was developed. Standard techniques were employed to demonstrate covalently closed circular deoxyribonucleic acid in lysates of nine strains of Mycobacterium avium-intracellulare.
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Slosárek M, Konícková-Radochová M, Konícek J. Genetic transfers in Mycobacteria. Folia Microbiol (Praha) 1978; 23:140-51. [PMID: 417980 DOI: 10.1007/bf02915315] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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20
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Norgard MV, Imaeda T. Physiological factors involved in the transformation of Mycobacterium smegmatis. J Bacteriol 1978; 133:1254-62. [PMID: 641008 PMCID: PMC222159 DOI: 10.1128/jb.133.3.1254-1262.1978] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Transfer of streptomycin resistance and changes from methionine and leucine auxotrophy to prototrophy were achieved in Mycobacterium smegmatis by transformation. Recipient cells were more resistant to mitomycin C and methyl methlanesulfonate treatments than were wild-type cells. A high level of calcium ions was essential for transformation, especially during DNA adsorption, whereas the presence of magnesium ions and the exposure of recipient cells to mild doses of UV light enhanced recombination frequencies. Transformants were not isolated when recipient cell-DNA mixtures were first treated with deoxyribonuclease. Recipient cells at various stages of growth showed similar transformabilities. Transformation was successful only when recipient cells were incubated on rich agar medium after mixture with DNA. Exposure of recipient cells to Pronase before treatment with donor DNA did not affect transformation, suggesting the absence of a protein competence factor. Throughout the present experiments, cotransformation frequencies were very low and unselected-marker segregation patterns were independent, indicating that the methionine, leucine, and streptomycin markers are not closely linked in M. smegmatis.
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Mizuguchi Y, Suga K, Tokunaga T. Multiple mating types of Mycobacterium smegmatis. JAPANESE JOURNAL OF MICROBIOLOGY 1976; 20:435-43. [PMID: 994349 DOI: 10.1111/j.1348-0421.1976.tb01009.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Multiple mating systems were found in the strains of Mycobacterium smegmatis. Nineteen wild type strains were classified into five different groups according to their mating behavior. All crosses between substrains derived from the same wild type strain or between substrains belonging to the same group were infertile, while eight different intergroup crosses were fertile. It was suggested that in most of the fertile crosses, chromosome transfer was unidirectional. Genes controlling matings were resistant to curing by acridine dye, sodium dodecyl sulfate and higher temperature suggesting that they were chromosomal genes. However, the location of these genes could not be demonstrated because none of the chromosomal markers tested was found to be linked to these mating genes.
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Yamada T, Masuda K, Mizuguchi Y, Suga K. Altered ribosomes in antibiotic-resistant mutants of Mycobacterium smegmatis. Antimicrob Agents Chemother 1976; 9:817-23. [PMID: 182073 PMCID: PMC429627 DOI: 10.1128/aac.9.5.817] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Two alleles for viomycin-capreomycin resistance (vic) in Mycobacterium smegmatis affect ribosome structures. One (vicA) affects a component of 50S subunits and the other (vicB) affects a component of 30S subunits. The locus for neomycin-kanamycin resistance (nek), which is linked to vicA and vicB, affects a component of 30S subunits. Although the erythromycin resistance locus (ery) is linked to vic and nek, no ribosomal alterations could be detected. Mutations at the streptomycin locus (str) not linked to vic and nek caused alterations of 30S subunits.
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Abstract
The genus Mycobacterium, despite its medical importance, has so far received relatively little attention from bacterial geneticists. Nevertheless examples of the transfer of genes from one strain to another by means of transformation, phage-mediated transduction and direct cellular contact have been reported. The modification of strains by experimental or naturally occurring lysogeny has been studied in some detail and there is evidence that phage may contribute significantly to variation within species. Mycobacteriophages have been the subject of genetic analyses and have proved of value in the study of certain aspects of host-induced phage modification. In addition phages are being used to develop typing systems for use in epidemiological studies. It is evident that much of interest and value awaits discovery by means of genetic analysis of the mycobacteria and their phages and hopefully the next decade or so will bring great advances in this subject.
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Konícek J, Konícková-Radochová M. Possibilities of the conjugation process in mycobacteria. Folia Microbiol (Praha) 1975; 20:382-8. [PMID: 1104423 DOI: 10.1007/bf02877039] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Results obtained when studying conjugation in mycobacteria by means of different methods are summarized. The method of conjugation on surface of a solid complete medium was tested with different auxotrophic mutants of different strains of Mycobacterium smegmatis. It was not possible to obtain positive results even by means of the above method. This was probably due to unsuitability of the chosen strains of Mycobacterium smegmatis. Preparation of the donor strain by transfer of the F factor from Escherichia coli F'ORF 1 ade+ lac+ pro+ to Mycobacterium phlei PA ade Stmr by means of sexduction is described. Frequency of the phenotype PA ade+ Stmr increased in the average by two and a half orders of magnitude with respect to the control, however, a further transfer from cultures of the cells ade+ Stmr to cells ade could not be demonstrated. Experiments aimed at transferring the R factor from strains Escherichia coli K-12 to Mycobacterium phlei were unsuccessful.
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Mizuguchi Y, Suga K, Masuda K, Yamada T. Genetic and biochemical studies on drug-resistant mutants in Mycobacterium smegmatis. JAPANESE JOURNAL OF MICROBIOLOGY 1974; 18:457-62. [PMID: 4141739 DOI: 10.1111/j.1348-0421.1974.tb00834.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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28
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Suga K, Mizuguchi Y. Mapping of antibiotic resistance markers in Mycobacterium smegmatis. JAPANESE JOURNAL OF MICROBIOLOGY 1974; 18:139-47. [PMID: 4139295 DOI: 10.1111/j.1348-0421.1974.tb00802.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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29
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Mizuguchi Y. Effect of ultraviolet-sensitive mutants on gene inheritance in mycobacterial matings. J Bacteriol 1974; 117:914-6. [PMID: 4811552 PMCID: PMC285592 DOI: 10.1128/jb.117.2.914-916.1974] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Evidence is presented suggesting that a rec mutation in one strain (presumably female) of a mating pair of Mycobacterium smegmatis strains prevented the appearance of recombinants, whereas a rec mutation in the other strain (presumably male) did not.
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Saroja D, Gopinathan KP. Transduction of isoniazid susceptibility-resistance and streptomycin resistance in mycobacteria. Antimicrob Agents Chemother 1973; 4:643-5. [PMID: 4793884 PMCID: PMC444611 DOI: 10.1128/aac.4.6.643] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Transduction of resistance to isoniazid and streptomycin as well as susceptibility to isoniazid in Mycobacterium smegmatis SN2 has been demonstrated. A method has been described for the selection of isoniazid-susceptible variants after transduction of susceptibility.
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