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

• Published in: Journal of clinical microbiology Vol. 45; no. 7; pp. 2183 - 2190
• Main Authors: Ozawa, Shigeru, Eda, Hiroyuki, Ishii, Yasuyuki, Ban, Fumihiko, Funabashi, Toshiyuki, Hata, Seiichiro, Hayashi, Kozaburo, Iga, Hiroki, Ikushima, Takao, Ishiko, Hiroaki, Itagaki, Tomoo, Kawana, Rinji, Kobayashi, Shunsaku, Ogino, Takeo, Sekizawa, Tsuyoshi, Shimomura, Yoshikazu, Shiota, Hiroshi, Mori, Ryoichi, Nakakita, Takashi, Numazaki, Yoshio, Ozaki, Yoshikatsu, Yamamoto, Shigeru, Yoshino, Kamesaburo, Yanagi, Kazuo
• Format: Journal Article
• Language: English
• Published: 01-07-2007
• ISSN: 0095-1137; 1098-660X
• DOI: 10.1128/JCM.02472-06

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 (α0 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.