Acyclovir susceptibility of herpes simplex virus isolates at King Chulalongkorn Memorial Hospital, Bangkok.

ABSTRACT

OBJECTIVE: To determine the ACV susceptibility in Thai HSV clinical isolates. MATERIAL AND METHOD: One hundred thirty HSV isolates from the Virology Laboratory Unit, King Chulalongkorn Memorial Hospital, Bangkok Thailand had typing done by immunofluoresent assay using monoclonal antibody specific to either HSV-1 or HSV-2. Their sensitivity to ACV (IC50) was determined by plaque reduction assay. RESULTS: The IC50 of 77 HSV-1 isolates ranged from 0.07-0.97 microg/ml and that of 53 HSV-2 isolates was 0.13-1.66 microg/ml. The standard HSV-1 (KOS) and HSV-2 (Baylor 186) were included in each run. The mean + standard deviation (SD) of ACV IC50 among HSV-1 and HSV-2 isolates were 0.38 +/- 0.23 and 0.50 +/- 0.32 microg/ml while that of standard HSV-1 and HSV-2 were 0.45 +/- 0.13 and 0.57 +/- 0.04 microg/ml. Statistically significant difference between IC50 of HSV-1 and HSV-2 isolates was indicated (p = 0.02). CONCLUSION: No ACV(r) HSV has been detected and ACV susceptibility of HSV-2 has more resistance than that of HSV-1.