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Implementation of In Vitro Drug Resistance Assays: Maximizing the Potential for Uncovering Clinically Relevant Resistance Mechanisms
08:46

Implementation of In Vitro Drug Resistance Assays: Maximizing the Potential for Uncovering Clinically Relevant Resistance Mechanisms

Published on: December 9, 2015

[Resistance studies: when are they indicated?]

M Angeles Marcos1

  • 1Servicio de Microbiología, Hospital Clínic de Barcelona, Barcelona, España. mmarcos@clinic.ub.es

Enfermedades Infecciosas Y Microbiologia Clinica
|May 1, 2012
PubMed

Insights

Cytomegalovirus (CMV) drug resistance is a growing concern due to viral mutations. Early detection of resistance, particularly UL97 and UL54 mutations, is crucial for effective treatment and preventing multi-drug resistance.

Area of Science:

  • Virology
  • Infectious Diseases
  • Pharmacology

Context:

  • Antiviral drug resistance in Cytomegalovirus (CMV) is an increasing clinical challenge.
  • Resistance arises from mutations in the CMV genome, affecting all antiviral agents, with ganciclovir resistance being most studied.
  • Risk factors include lack of immunity, specific transplant types, high viral loads, and prolonged/suboptimal antiviral exposure.

Purpose:

  • To highlight the emerging problem of Cytomegalovirus (CMV) antiviral drug resistance.
  • To identify risk factors and clinical indicators for suspecting CMV resistance.
  • To emphasize the importance of early detection and confirmation of resistance mutations.

Summary:

  • CMV resistance develops through mutations, primarily in UL97 (ganciclovir resistance) and UL54 genes, with combined mutations leading to high-grade, multi-drug resistance.
  • Suspect resistance if viral load increases or disease progresses despite 2 weeks of adequate treatment.
  • Phenotypic and genotypic testing are required for confirmation; alternative antivirals like foscarnet and cidofovir may be used.

Impact:

  • Early detection of CMV resistance is essential to prevent poor clinical outcomes and the development of multi-drug resistant strains.
  • Investigating plasma drug levels and immune status is important for patients with slow responses lacking resistance mutations.
  • Understanding resistance mechanisms guides therapeutic strategies and improves patient management in CMV infections.

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