Detection of varicella-zoster virus genome having a PstI site in the ocular sample from a patient with acute retinal necrosis.

We detected the virus genome in ocular samples from a 65-year-old woman with clinically diagnosed acute retinal necrosis using DNA amplification. She exhibited occlusive retinal vasculitis, confluent necrotizing retinitis, mainly peripheral, and iridocyclitis. For DNA amplification, we used recently published primers specific for varicella-zoster virus (VZV) and herpes simplex virus. Using VZV primers, we detected the VZV genome in the aqueous humor, but not in the vitreous, by amplifying a DNA fragment 642 base pairs in length. HSV DNA was not detected. After detecting the VZV genome, PstI restriction endonuclease was used because an epidemiological study found that about 25% of the VZV strains in Japan carry a mutation lacking a PstI recognition site. The VZV genome from the patient had a PstI cleavage pattern, while the positive control had a VZV genome that carried a PstI-site-less mutation. We considered our patient with acute retinal necrosis to be infected with VZV having a PstI site.