The virulence of seven geographic isolates of white spot syndrome virus (WSSV; genus
Whispovirus; China [strain CH1995], Nicaragua [strain N2000], Honduras [strain H2000], Ecuador [strains EL1999
and E-LT2002], and Mexico [strains M-M2001 and M-LP2001]) was compared using a series of
challenge experiments, each lasting 10 d. For each isolate, four quantified dilutions (10 ˉ⁶, 10 ˉ⁷, 10 ˉ⁸, and
10 ˉ⁹) of a viral inoculum were prepared from WSSV-infected shrimp tissue. Each viral inoculum was injected
into 10 specific pathogen-free juvenile Pacific white shrimp Litopenaeus vannamei (0.25–1.50 g); controls
received injections of marine crustacean physiological saline (3.2%). The minimum dose of viral inoculum
that killed 50% of injected shrimp (LD50) was calculated for dilution, tissue concentration, and viral DNA
amount. The CH1995 and M-M2001 isolates were the least virulent, with LD50 values of 10 ˉ⁶ to 10 ˉ⁷ of
viral inoculum. The isolates could be grouped into three virulence clusters (CH1995 and M-M2001; N2000
and E-LT2002; and H2000, E-L1999, and M-LP2001). Virulence clusters were not altered by LD50 values
based on viral DNA concentration, although a slight shifting of order in regards to virulence was seen among
the three most virulent isolates (E-L1999, H2000, and M-LP2001). Overall, results indicate that there is a measurable virulence difference among WSSV isolates, which may correspond to geographical region.
Member of
Contributors
Publisher
American Fisheries Society.
Date Issued
2009
Note
Language
Type
Genre
Form
Extent
10 p.
Subject (Topical)
Identifier
FA00007162
Additional Information
The virulence of seven geographic isolates of white spot syndrome virus (WSSV; genus
Whispovirus; China [strain CH1995], Nicaragua [strain N2000], Honduras [strain H2000], Ecuador [strains EL1999
and E-LT2002], and Mexico [strains M-M2001 and M-LP2001]) was compared using a series of
challenge experiments, each lasting 10 d. For each isolate, four quantified dilutions (10 ˉ⁶, 10 ˉ⁷, 10 ˉ⁸, and
10 ˉ⁹) of a viral inoculum were prepared from WSSV-infected shrimp tissue. Each viral inoculum was injected
into 10 specific pathogen-free juvenile Pacific white shrimp Litopenaeus vannamei (0.25–1.50 g); controls
received injections of marine crustacean physiological saline (3.2%). The minimum dose of viral inoculum
that killed 50% of injected shrimp (LD50) was calculated for dilution, tissue concentration, and viral DNA
amount. The CH1995 and M-M2001 isolates were the least virulent, with LD50 values of 10 ˉ⁶ to 10 ˉ⁷ of
viral inoculum. The isolates could be grouped into three virulence clusters (CH1995 and M-M2001; N2000
and E-LT2002; and H2000, E-L1999, and M-LP2001). Virulence clusters were not altered by LD50 values
based on viral DNA concentration, although a slight shifting of order in regards to virulence was seen among
the three most virulent isolates (E-L1999, H2000, and M-LP2001). Overall, results indicate that there is a measurable virulence difference among WSSV isolates, which may correspond to geographical region.
Whispovirus; China [strain CH1995], Nicaragua [strain N2000], Honduras [strain H2000], Ecuador [strains EL1999
and E-LT2002], and Mexico [strains M-M2001 and M-LP2001]) was compared using a series of
challenge experiments, each lasting 10 d. For each isolate, four quantified dilutions (10 ˉ⁶, 10 ˉ⁷, 10 ˉ⁸, and
10 ˉ⁹) of a viral inoculum were prepared from WSSV-infected shrimp tissue. Each viral inoculum was injected
into 10 specific pathogen-free juvenile Pacific white shrimp Litopenaeus vannamei (0.25–1.50 g); controls
received injections of marine crustacean physiological saline (3.2%). The minimum dose of viral inoculum
that killed 50% of injected shrimp (LD50) was calculated for dilution, tissue concentration, and viral DNA
amount. The CH1995 and M-M2001 isolates were the least virulent, with LD50 values of 10 ˉ⁶ to 10 ˉ⁷ of
viral inoculum. The isolates could be grouped into three virulence clusters (CH1995 and M-M2001; N2000
and E-LT2002; and H2000, E-L1999, and M-LP2001). Virulence clusters were not altered by LD50 values
based on viral DNA concentration, although a slight shifting of order in regards to virulence was seen among
the three most virulent isolates (E-L1999, H2000, and M-LP2001). Overall, results indicate that there is a measurable virulence difference among WSSV isolates, which may correspond to geographical region.
Florida Atlantic University. Harbor Branch Oceanographic Institute contribution 1714
This manuscript is an author version with the final
publication available and may be cited as: Laramore, S. E., Scarpa, J., Laramore, C. R., & Lin, J. (2009).
Virulence variation of white spot syndrome virus in Pacific white shrimp Litopenaeus vannamei.
Journal of Aquatic Animal Health, 21(2), 82-90. doi: 10.1577/H08-012.1
publication available and may be cited as: Laramore, S. E., Scarpa, J., Laramore, C. R., & Lin, J. (2009).
Virulence variation of white spot syndrome virus in Pacific white shrimp Litopenaeus vannamei.
Journal of Aquatic Animal Health, 21(2), 82-90. doi: 10.1577/H08-012.1
Date Backup
2009
Date Text
2009
DOI
10.1577/H08-012.1
Date Issued (EDTF)
2009
Extension
FAU
IID
FA00007162
Person Preferred Name
Laramore, Susan E.
slaramo1@fau.edu
Physical Description
10 p.
Title Plain
Virulence variation of white spot syndrome virus in Pacific white shrimp Litopenaeus vannamei
Origin Information
2009
American Fisheries Society.
Kissimmee, FL
Place
Kissimmee, FL
Title
Virulence variation of white spot syndrome virus in Pacific white shrimp Litopenaeus vannamei
Other Title Info
Virulence variation of white spot syndrome virus in Pacific white shrimp Litopenaeus vannamei