Biomedical subjects

L Lapchine

Publications and source records attributed to L Lapchine.

21 records · Page 2Linked to original sources

PubMedDate not supplied

Comparative studies of the strains PA and PN of Mycobacterium phlei leading to their reclassification: examination of lipids and DNA, biochemical tests and phage typing.

Study of lipid and DNA, biochemical tests and phage typing performed on the strain PA previously labelled Mycobacterium phlei, lead to the conclusion that this strain belongs to the species M. smegmatis. Parallel studies performed on strain PN, isolated from a culture of strain PA, as well as DNA homology percentage of the two strains, do not support the assumption that strain PN could have resulted from a mutation of strain PA Strain PN produces mycolic acids similar to those found in Rhodococcus bronchialis; the few biological tests applied quite agree with such a classification.

Bacteriophage Typing↗

PubMedDate not supplied

[Bacteriophage occurrence in "Mycobacterium phlei" (author's transl)].

Surface growth of synchronized bacteria was obtained by means of a suspension of Mycobacterium phlei cells in pentane, the dispersion of which resulted from passage through glass (Ballotini) column. By using standardized conditions, a series of identical cultures were obtained, suitable for studying their evolution as a function of time. By counting colonies every twenty minutes, during ten hours, two doublings were observed, with a generation time of five hours. At the end of a plateau, just before the next doubling, the curve exhibited a marked decrease. Bacteriophages were found in culture medium at the time corresponding to this decrease. In thin sections of the pellicles collected at this time, condensations resembling DNA from phage heads could be noticed within the bacterial cells, as well as free phages in th close neighbourhood of burst cells. The relations between phage and bacteria, and the possible relation between the presence of the phage and the synthesis of phleates has not been determined.

Deoxyribonucleases↗

PubMedDate not supplied

Reclassification of Mycobacterium phlei PN-bb as Rhodococcus bronchialis PN-bb.

Mycobacterium phlei PN-bb, induced in the parental strain PN by gamma-radiation and ethyl methanesulfonate, should be reclassified as Rhodococcus bronchialis PN-bb. The reclassification is based on the results of lipid analysis, DNA-DNA hybridization and several biochemical tests, performed in comparison with the parental strain PN, earlier reclassified as R. bronchialis, and R, bronchialis (N654).

Actinomycetales↗