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Updated: Oct 2, 2026

Testing the Role of Multicopy Plasmids in the Evolution of Antibiotic Resistance
09:00

Testing the Role of Multicopy Plasmids in the Evolution of Antibiotic Resistance

Published on: May 2, 2018

Transferable chloramphenicol and ampicillin resistance in a strain of Haemophilus influenzae

L E Bryan

    Antimicrobial Agents and Chemotherapy
    |July 1, 1978
    PubMed

    Insights

    A strain of Haemophilus influenzae exhibits resistance to multiple antibiotics. This resistance was transferable to other bacteria, indicating a potential public health concern.

    Area of Science:

    • Microbiology
    • Infectious Diseases
    • Antimicrobial Resistance

    Background:

    • Haemophilus influenzae is a significant human pathogen.
    • Antibiotic resistance in H. influenzae poses a growing threat to effective treatment.
    • Multidrug resistance complicates therapeutic options.

    Purpose of the Study:

    • To characterize antibiotic resistance in a clinical isolate of Haemophilus influenzae.
    • To investigate the transferability of multiple antibiotic resistances within H. influenzae.

    Main Methods:

    • Isolation and identification of Haemophilus influenzae from sputum.
    • Antimicrobial susceptibility testing against chloramphenicol, ampicillin, and tetracycline.
    • Bacterial conjugation experiments to assess resistance transfer.

    Main Results:

    • The isolated H. influenzae strain demonstrated resistance to chloramphenicol, ampicillin, and tetracycline.
    • All three resistances were co-transferred to recipient strains.
    • Resistance transfer occurred irrespective of the selecting antibiotic used (ampicillin, chloramphenicol, or tetracycline).

    Conclusions:

    • This study highlights the presence of multidrug-resistant Haemophilus influenzae.
    • The co-transferability of chloramphenicol, ampicillin, and tetracycline resistance suggests a common genetic element, such as a plasmid.
    • Findings underscore the importance of monitoring and managing antibiotic resistance in H. influenzae infections.

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