Restriction map of mycobacteriophage D29 and its deletion mutant F5.

A physical map of mycobacteriophage D29 was constructed, including positions for 25 restriction sites for 9 endunocleasic enzymes. D29 DNA contains about 48 150 bp. Analysis of a deletion mutant (F5) has allowed to determine the location of two non essential regions in the genome, allowing further insertion of foreign genes and construction of cosmids.

Methionine as methyl-group donor in the synthesis of Mycobacterium avium envelope lipids, and its inhibition by DL-ethionine, D-norleucine and DL-norleucine.

The radioactivity from 3H-methyl methionine was rapidly incorporated into the surface lipids of Mycobacterium avium. The transmethylation reaction was efficiently inhibited by DL-ethionine, D-norleucine and DL-norleucine. The structure of the outerlayer of the M. avium envelope was profoundly altered in the bacteria treated with DL-norleucine.

Abortive infection of Mycobacterium leprae by the mycobacteriophage D29.

The interactions of mycobacteriophage D29 and Mycobacterium leprae were examined. It was demonstrated that after adsorption D29 injected its DNA in M. leprae. While the synthesis of host proteins and lipids were inhibited in M. tuberculosis and in M. smegmatis during infection by D29, the results were inconclusive in the case of M. leprae because these bacteria did not incorporate the appropriate substrates.

Taxonomy of mycobacterial strains isolated from the tissues of leprosy patients.

Thirty-six slowly growing mycobacteria isolated from the tissues of leprosy patients were studied using 40 characteristics as well as susceptibility to 27 distinct mycobacteriophages. The composition in mycolic acids of selected strains was also studied. According to the data, the strains formed 5 clusters. Some of the clusters were possibly as yet undescribed species; however, comparison of the data with the known properties of Mycobacterium leprae leads to the conclusion that none of the strains were identical to the leprosy bacillus.

Adsorption of mycobacteriophages on Mycobacterium leprae: taxonomic significance.

The following bacteriophages were shown to adsorb on Mycobacterium leprae: BK1, Clark, Sedge, Baits, Watson and D29. Bacteriophages that did not adsorb on the leprosy bacilli were Bg1, Legendre, Marshall, Panetti, Leo and Wiseman. The taxonomic significance of these findings and some prospective consequences of these investigations are discussed.

[Lipidic constituents of "Mycobacterium leprae" isolated from experimentally infected armadillo (author's transl)]. / Constituants lipidiques de Mycobacterium leprae isolé de tatou infecté expérimentalement.

Mycobacterium leprae (obtained from experimentally infected armadillo) was submitted to saponification. The liposoluble part was methylated and fractionated by chromatographic methods. Each fraction was studied by gas-liquid chromatography. Cholesterol (from the infected host) and the main fatty acids were identified. Mycolic acids were isolated, and their structures determined, using mass spectrometry. These structures are useful to make a comparison of M. leprae with some other mycobacteria. Some of these comparisons are discussed here. The absence-or, at least, the very low level-of tuberculostearate suggests comparative studies of M. leprae and M. gordonae.

Paracrystalline inclusions in Mycobacterium leprae.

The occurrence of paracrystalline inclusions of Mycobacterium leprae infected with the mycobacteriophage D29 or treated with mitomycin C was reported before [5, 6]. In pursuing these studies we have now documented by electron micrography a number of paracrystals we thought sufficient to further describe these inclusions, and to show that they appeared to be formed in association with the intracellular membranous structures of the leprosy bacilli.

Effects of antituberculosis and antileprosy drugs on mycobacteriophage D29 growth.

The minimal inhibitory concentrations of antituberculosis and antileprosy drugs were determined for Mycobacterium aurum. The concentrations that reduced the final yield of bacteriophage D29R1 by 50% and the time during the replication cycle at which the drugs completely inhibited phage production were estimated. THe 50% inhibitory concentration/minimal inhibitory concentration ratios were close to 1.0 for clofazimine, colistin, rifampin, and streptomycin; these ratios were high for dapsone (diaminodiphenylsulfone) and isoniazid. Ethambutol (minimal inhibitory concentration, 1.0 micrograms/ml) was without effect on viral growth.

Interaction of Mycobacterium leprae and mycobacteriophage D29.

This study of the interaction between Mycobacterium leprae and the mycobacteriophage D29 showed that the viruses caused a patchy damage of cell wall structure and the accumulation in the host of internal crystalline structures. Whether the observed ultrastructural alterations were caused by the replication of D29 was not clear. Mitomycin C also caused the accumulation of crystalline structures in M. leprae.