Contrasting Geographic Distribution Profiles of the Herpes Simplex Virus Type 1 BgO L and BgK L Variants in Japan Suggest Dispersion and Replacement

Abstract

ABSTRACT Thelifelong latent infection-reactivation mode of infection of herpes simplex virus type 1 (HSV-1) transmitted by close contact has allowed a diversity of restriction fragment length polymorphism (RFLP) variations to accumulate in human populations. Whether and how the variants of the HSV-1 that is ubiquitous worldwide spread to different human populations is not clear. In our previous study the geographically gradient distribution of the HSV-1 BgK L variant, which is a good marker for the BgK L :SaCFJ M :SaGH M :SaD/E L :KpM S variant, suggested that BgK L dispersed geographically. Southern hybridization analyses showed that in BgK L the BglII cleavage site between the BglII K and small “Q/#13” fragments is lost, the SalI cleavage sites between the SalI J and C and between SalI F and J fragments are lost, and the SalI E fragment is abnormally large (SaE L variation). The RFLP and geographic distribution of one more HSV-1 RFLP variant, BgO L , were comparatively analyzed. The BglII cleavage site between the BglII O and Q/#13 fragments is lost in BgOL. BgO L clinical isolates were not associated with any of the SaCFJ M , SaE L , SaGH M , or KpM S variations, whereas one-fourth of the non-BgO L :non-BgK L isolates was associated with SaCFJ M and SaGH M , indicating that BgK L and BgO L are distant in terms of diversification. BgO L is distributed highly in the northeastern region and the southwestern island of Kyushu but is rare between the two regions in Japan, in a remarkable contrast to BgK L . These are the first epidemiologic data to show contrasting geographic distribution profiles of two HSV-1 variants and suggest the gradual dispersion and replacement of HSV-1 variants.