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Updated: Aug 18, 2026

Antibiotic Dereplication Using the Antibiotic Resistance Platform
10:49

Antibiotic Dereplication Using the Antibiotic Resistance Platform

Published on: October 17, 2019

Molecular genetics of resistance to macrolides, lincosamides and streptogramin B (MLS) in streptococci

T Horaud, C Le Bouguenec, K Pepper

    The Journal of Antimicrobial Chemotherapy
    |July 1, 1985
    PubMed

    Insights

    Macrolides-lincosamides-streptogramin B (MLS) resistance is common in human streptococci, found on plasmids and in plasmid-free strains. MLS resistance genes can be located on transposons and chromosome-borne elements, mediating broad or narrow host range resistance.

    Area of Science:

    • Microbiology
    • Genetics
    • Molecular Biology

    Background:

    • Macrolides-lincosamides-streptogramin B (MLS) resistance is prevalent across human-associated streptococcal species.
    • Resistance determinants are found on both extrachromosomal (plasmids) and chromosomal elements.

    Purpose of the Study:

    • To investigate the genetic basis and dissemination of MLS resistance in various streptococcal species.
    • To characterize MLS resistance plasmids and transposons in streptococci.

    Main Methods:

    • Plasmid analysis (size, host range, conjugation)
    • DNA hybridization studies using MLS resistance determinants as probes
    • Characterization of transposons and chromosome-borne elements

    Main Results:

    • Plasmids encoding MLS resistance (17-20 Mdal) were identified in multiple streptococcal groups (A, B, C, D, G) with broad host ranges.
    • MLS resistance genes were also found on multi-resistance plasmids and a transposon (Tn917) in Group D streptococci.
    • Chromosome-borne elements conferring MLS resistance were detected in plasmid-free strains of numerous streptococcal species.

    Conclusions:

    • MLS resistance in streptococci is mediated by diverse genetic elements, including plasmids, transposons, and chromosomal DNA.
    • These elements exhibit varying host ranges and contribute to the widespread dissemination of MLS resistance in human streptococci.

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