Related Experiment Video

Updated: Aug 19, 2026

Identification of Virulence Markers of Mycobacterium abscessus for Intracellular Replication in Phagocytes
08:34

Identification of Virulence Markers of Mycobacterium abscessus for Intracellular Replication in Phagocytes

Published on: September 27, 2018

Characterization of plasmids from strains of Mycobacterium avium-intracellulare

J T Crawford, M D Cave, J H Bates

    Reviews of Infectious Diseases
    |September 1, 1981
    PubMed

    Insights

    Plasmids were found in some Mycobacterium avium-intracellulare strains, including a large one in strain LR25. This research identifies plasmid presence in specific serovars of this bacterium.

    Area of Science:

    • Microbiology
    • Molecular Biology
    • Genetics

    Background:

    • Mycobacterium avium-intracellulare is an opportunistic pathogen.
    • Plasmids can influence bacterial virulence and antibiotic resistance.

    Purpose of the Study:

    • To investigate the presence and characteristics of plasmids in Mycobacterium avium-intracellulare strains.
    • To determine if plasmid carriage varies among different serovars.

    Main Methods:

    • Bacterial cultures were treated to facilitate cell lysis.
    • Plasmid DNA was purified using cesium chloride-ethidium bromide density gradients.
    • DNA was analyzed by agarose gel electrophoresis and electron microscopy.

    Main Results:

    • Strain LR25 contained three plasmids, one exceeding 10^8 molecular weight.
    • Plasmids were detected in strains of serovars 2 (three plasmids), 4, 12, and 18 (one plasmid each).
    • Plasmids were absent in strains of serovars 1, 3, and 5.

    Conclusions:

    • Plasmids are present in a subset of Mycobacterium avium-intracellulare strains.
    • Plasmid carriage is not universal and appears to be serovar-dependent.
    • Further research is needed to understand the role of these plasmids.

    More Related Videos

    Analysis of the Lipid Composition of Mycobacteria by Thin Layer Chromatography07:42

    Analysis of the Lipid Composition of Mycobacteria by Thin Layer Chromatography

    Published on: April 16, 2021

    Intradermal Inoculation of Mycobacterium avium in the Mouse Ear09:20

    Intradermal Inoculation of Mycobacterium avium in the Mouse Ear

    Published on: July 3, 2025

    Related Concept Videos

    Plasmids01:28

    Plasmids

    Plasmids are extrachromosomal DNA molecules found in bacteria, archaea, and some eukaryotic microbes like yeast. These small, circular DNA structures typically contain fewer than 30 genes, although some may exist linearly. Plasmids vary in their number within a cell, known as copy number. Single-copy plasmids are present in one copy per cell and multi-copy plasmids are present in multiple copies, reaching over 100 copies per cell.Plasmids usually replicate independently of the chromosomal DNA...
    Bacterial Phylum Actinobacteria01:30

    Bacterial Phylum Actinobacteria

    Coryneform bacteria are gram-positive, aerobic, nonmotile rods that exhibit irregular, club-shaped, or V-shaped arrangements. Their V-shape results from snapping division, where the inner cell wall layer forms the cross-wall, while the outer layer remains intact until it ruptures on one side, causing the daughter cells to bend away.The primary genera are Corynebacterium and Arthrobacter. Corynebacterium includes diverse species, ranging from saprophytes to pathogens like Corynebacterium...
    Bacterial Phylum Tenericutes01:24

    Bacterial Phylum Tenericutes

    The phylum Tenericutes, which includes the single class Mollicutes, comprises bacteria that lack cell walls. The term "Mollicutes" derives from the Latin word mollis, meaning "soft." These organisms are among the smallest known and are commonly referred to as mycoplasmas due to the prominence of the genus Mycoplasma, which includes well-known human pathogens. Despite their inability to stain gram-positively (a result of their lack of cell walls), mycoplasmas are phylogenetically related to the...