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Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria
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Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria

Published on: May 8, 2013

Regulation of penicillin-binding protein activity: description of a methicillin-inducible penicillin-binding protein

L Rossi, E Tonin, Y R Cheng

    Antimicrobial Agents and Chemotherapy
    |May 1, 1985
    PubMed

    Insights

    Methicillin-resistant Staphylococcus aureus strains R1 and R2 exhibit altered penicillin-binding proteins (PBPs). Strain R2 develops novel PBP-2a, while R1 increases PBP-3, both showing low methicillin affinity.

    Area of Science:

    • Microbiology
    • Molecular Biology
    • Biochemistry

    Background:

    • Methicillin-resistant Staphylococcus aureus (MRSA) poses a significant public health threat.
    • Understanding the molecular mechanisms of beta-lactam resistance in MRSA is crucial for developing effective treatments.

    Purpose of the Study:

    • To analyze the penicillin-binding protein (PBP) profiles of two distinct MRSA strains (R1 and R2).
    • To investigate how methicillin exposure affects PBP expression and characteristics in these strains.
    • To correlate PBP alterations with methicillin resistance levels.

    Main Methods:

    • Analysis of penicillin-binding proteins (PBPs) in MRSA strains R1 and R2.
    • Comparison of PBP patterns in cells grown with and without methicillin.
    • Determination of PBP affinity for methicillin and correlation with Minimum Inhibitory Concentrations (MICs).

    Main Results:

    • Strain R2, under methicillin pressure, uniquely synthesized a novel PBP (PBP-2a) with low methicillin affinity.
    • Strain R1, under methicillin pressure, showed increased production of PBP-3, also exhibiting low methicillin affinity.
    • These PBP alterations in both strains correlated with their observed methicillin resistance (MICs).

    Conclusions:

    • Specific alterations in penicillin-binding proteins (PBPs), such as the emergence of PBP-2a in strain R2 and increased PBP-3 in strain R1, are key mechanisms conferring methicillin resistance in Staphylococcus aureus.
    • The low affinity of these altered PBPs for methicillin explains the resistance phenotype observed in these MRSA strains.

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