Acyclovir resistance/susceptibility in herpes simplex virus type 2 sequential isolates from an AIDS patient

Area of Science:

• Virology
• Immunology
• Infectious Diseases

Background:

• Herpes simplex virus type 2 (HSV-2) infections can be severe in patients with Acquired Immunodeficiency Syndrome (AIDS).
• Sequential antiviral treatments are sometimes necessary for managing prolonged HSV-2 lesions in immunocompromised individuals.
• Drug resistance is a significant concern in managing viral infections, particularly in patients with compromised immune systems.

Purpose of the Study:

• To biologically characterize sequential HSV-2 isolates from an AIDS patient receiving antiviral therapy.
• To investigate the mechanisms of antiviral resistance development in HSV-2 during treatment.
• To evaluate the impact of alternative antiviral therapies on resistant HSV-2 strains.

Main Methods:

• Isolation and biological characterization of sequential HSV-2 strains from patient lesions.
• Assessment of antiviral susceptibility, specifically to acyclovir (ACV).
• Phenotypic analysis of viral thymidine kinase (TK) activity.

Main Results:

• Acyclovir resistance in HSV-2 isolates was associated with a deficient thymidine kinase (TK-) phenotype.
• Discontinuation of ACV and treatment with foscarnet led to the recovery of an ACV-sensitive HSV-2 isolate.
• The recovered isolate demonstrated restored production of a functional TK enzyme.

Conclusions:

• Monitoring the chemosensitivity of HSV-2 isolates in AIDS patients is essential.
• Alternative antiviral treatments targeting different viral mechanisms may be beneficial for controlling resistant HSV-2 infections in AIDS patients.
• Understanding resistance mechanisms is key to optimizing therapeutic strategies for HSV-2 in immunocompromised individuals.