The Herpes Simplex Virus Type 1 BgK_LVariant, Unlike the BgO_LVariant, Shows a Higher Association with Orolabial Infection than with Infections at Other Sites, Supporting the Variant-Dispersion-Replacement Hypothesis

Abstract

The identification and geographic distribution of the herpes simplex virus type 1 (HSV-1) BglII restriction fragment length polymorphism (RFLP) variants named BgK L and BgO L in clinical isolates from orolabial and cutaneous sites were described in our previous reports, in which the dispersion and replacement of HSV-1 variants were proposed. The base substitution sites deduced from the BgK L multiple RFLP variations were mapped to the U L 12 (DNase), R L 2 (␣0 transactivator), and latency-associated transcript genes in the present study. The results show that the relative frequencies (RFs) of BgK L are significantly higher in orolabial and cutaneous HSV-1 infections than in ocular infections. For the BgO L variant, the opposite was found; i.e., the RF of BgO L was significantly lower in orolabial and cutaneous infections than in ocular infections. No significant differences in the RFs of non-BgK L :non-BgO L isolates were observed. The ratio of the BgK L RF to the BgO L RF was much higher for the orolabial and cutaneous infection groups than for the ocular infection group, whereas the BgK L RF-to-non-BgK L :non-BgO L RF ratios for the former groups were slightly higher than those for the latter group. The higher efficiency of orolabial and cutaneous infections caused by BgK L compared to the efficiency of infections caused by BgO L allows BgK L to spread more efficiently in human populations and to displace BgO L , because the mouth and lips are the most common HSV-1 infection sites in children. The present study supports our HSV-1 dispersion-and-replacement hypothesis and suggests that HSV-1, the latency-reactivation of which allows variants to accumulate in human populations, has evolved under competitive conditions, providing a new perspective on the polymorphism or variation of HSV-1.

Analysis of herpes simplex virus type 1 restriction fragment length polymorphism variants associated with herpes gladiatorum and Kaposi's varicelliform eruption in sumo wrestlers

“…Future studies in this laboratory will analyse the genome sequences of these BgK L clinical isolates. As far as we are aware, the present study is the first to suggest that the efficiency of HSV-1 reactivation/ recurrence in humans may depend on the HSV-1 variant or strain and it supports the BgK L dispersion hypothesis Ozawa et al, 2006Ozawa et al, , 2007. …”

Cutaneous lumbosacral Herpes Simplex virus among patients hospitalized for an advanced disease

“…Two sub‐types exist. Sub‐type 1 (HSV‐1) is most frequently found on the oral mucosa and other localizations above the waist, mainly cephalic; and HSV‐2, more frequently found on genital and other localizations below‐the‐waist 4 . Once the virus has infected the neural ganglia of the posterior roots of the spinal cord, recurrences of the infection occur with various triggering factors, including general immune host‐related as well as environmental factors.…”