Related Experiment Video

Updated: Jun 30, 2026

System for Efficacy and Cytotoxicity Screening of Inhibitors Targeting Intracellular Mycobacterium tuberculosis
09:57

System for Efficacy and Cytotoxicity Screening of Inhibitors Targeting Intracellular Mycobacterium tuberculosis

Published on: April 5, 2017

Antibacterial activity of DL 473, a C3-substituted rifamycin derivative

H C Neu

    Antimicrobial Agents and Chemotherapy
    |September 1, 1983
    PubMed

    Insights

    DL 473, a novel rifamycin SV derivative, shows inhibitory activity against staphylococci and streptococci but is less potent than rifampin. Combinations with vancomycin or nafcillin demonstrated additive effects without antagonism.

    Area of Science:

    • Microbiology
    • Pharmacology
    • Medicinal Chemistry

    Background:

    • Rifamycin SV derivatives are investigated for antimicrobial properties.
    • The emergence of antibiotic resistance necessitates the development of new therapeutic agents.
    • Understanding the spectrum of activity of novel compounds is crucial for clinical application.

    Purpose of the Study:

    • To evaluate the antimicrobial activity of DL 473, a new rifamycin SV derivative.
    • To compare the efficacy of DL 473 with rifampin against various bacterial species.
    • To assess the potential synergistic or antagonistic effects of DL 473 in combination with other antibiotics.

    Main Methods:

    • In vitro susceptibility testing of DL 473 against a panel of Gram-positive and Gram-negative bacteria.
    • Comparative analysis of DL 473 and rifampin activity.
    • Checkerboard assays to evaluate drug combinations (DL 473 with vancomycin or nafcillin).

    Main Results:

    • DL 473 inhibited the growth of staphylococci, streptococci, Listeria, and Bacteroides species.
    • The compound exhibited lower activity compared to rifampin against the tested susceptible organisms.
    • DL 473 showed no significant activity against Enterobacteriaceae and most Pseudomonas species.
    • Combinations of DL 473 with vancomycin or nafcillin against staphylococci were primarily additive, with no antagonism observed.

    Conclusions:

    • DL 473 possesses a defined spectrum of activity, primarily targeting Gram-positive bacteria.
    • While less potent than rifampin, DL 473 may offer an alternative therapeutic option, particularly in combination regimens.
    • The additive effect in combination therapy suggests potential for enhanced treatment strategies against resistant staphylococcal infections.

    More Related Videos

    Visualization of Bacterial Resistance using Fluorescent Antibiotic Probes08:23

    Visualization of Bacterial Resistance using Fluorescent Antibiotic Probes

    Published on: March 2, 2020

    Assay Development for High-Throughput Drug Screening Against Mycobacteria07:50

    Assay Development for High-Throughput Drug Screening Against Mycobacteria

    Published on: October 25, 2024

    Related Concept Videos

    Inhibitors of Bacterial Protein Synthesis01:25

    Inhibitors of Bacterial Protein Synthesis

    Aminoglycosides constitute a highly potent class of bactericidal antibiotics that exert their antimicrobial effects by targeting the bacterial ribosome, specifically disrupting protein synthesis. These polycationic molecules consist of amino-modified sugars linked via glycosidic bonds to an aminocyclitol core such as 2-deoxystreptamine or streptamine. Their strong positive charges facilitate tight binding to the negatively charged phosphate backbone of ribosomal RNA (rRNA), primarily at the 16S...
    Inhibitors of Bacterial DNA Synthesis01:28

    Inhibitors of Bacterial DNA Synthesis

    Bacterial pathogens depend on precise and efficient DNA replication to sustain infection. Two type II topoisomerases—DNA gyrase and topoisomerase IV—are critical to this process, as they resolve DNA supercoiling and unlink chromosomes during replication. Fluoroquinolones, synthetic derivatives of quinolones, exploit this mechanism by stabilizing the transient DNA–enzyme cleavage complex, preventing strand religation, and causing lethal double-strand breaks. These antibiotics are selectively...
    Clinical Significance of Antibiotic Resistance01:25

    Clinical Significance of Antibiotic Resistance

    Methicillin-resistant Staphylococcus aureus (MRSA) presents a critical public health threat, arising from its capacity to resist β-lactam antibiotics due to acquisition of the mecA gene within the staphylococcal cassette chromosome mec (SCCmec). This gene encodes penicillin-binding protein 2a (PBP2a), which impairs binding efficacy of methicillin and other β-lactams. MRSA has evolved into distinct clonal lineages impacting humans and animals alike, reinforcing its significance within the One...