Different biological characteristics of wild-type porcine reproductive and respiratory syndrome viruses and vaccine viruses and identification of the corresponding genetic determinants.
نویسندگان
چکیده
Two attenuated vaccines, Ingelvac PRRS MLV and Ingelvac PRRS ATP, derived from VR2332 and JA142, respectively, have been used to control porcine reproductive and respiratory syndrome (PRRS) virus. However, there have been several field reports concerning the reversion of the vaccine virus to virulence. Furthermore, viruses genetically indistinguishable from the vaccines and wild-type parental viruses have been detected in clinical PRRS cases, raising the need for a better differential tool. As the vaccine viruses replicated better and produced bigger plaques in MARC-145 cells than did the wild-type parental strains, the following study was conducted to determine if the growth difference in MARC-145 cells can be utilized to differentiate a vaccine-like virus (VLV) from a wild-type virus and to identify genetic markers corresponding to such phenotype of the vaccine viruses. The relatedness of 83 field isolates collected between 1996 and 2005 to VR2332 and JA142 was classified genetically and antigenically. Thirteen of 25 VR2332-related viruses and 9 of 10 JA142-related viruses were determined as VLVs, since those viruses produced plaques similar to those by the vaccine viruses. Four unique amino acids each were identified throughout structural genes for MLV and ATP. Among those, F(10) in open reading frame 2 (ORF2) of MLV and E(85) and Y(165) in ORF3 of ATP were stable during pig passages. When the sequences unique for MLV were incorporated into an infectious clone constructed based on VR2332, the virus growth and resultant plaque size in MARC-145 cells were increased, suggesting that these sequences can be used as genetic markers for VLVs.
منابع مشابه
Different biological characteristics between wild - type PRRS viruses and vaccine viruses and identification of the corresponding genetic determinants
متن کامل
Evaluation of the use of non-pathogenic porcine circovirus type 1 as a vaccine delivery virus vector to express antigenic epitopes of porcine reproductive and respiratory syndrome virus.
We previously demonstrated that the C-terminus of the capsid gene of porcine circovirus type 2 (PCV2) is an immune reactive epitope displayed on the surface of virions. Insertion of foreign epitope tags in the C-terminus produced infectious virions that elicited humoral immune responses against both PCV2 capsid and the inserted epitope tags, whereas mutation in the N terminus impaired viral rep...
متن کاملGenetic and antigenic analysis of type O and A FMD viruses isolated in Iran
FMD is one of the most highly contagious diseases of animals, caused by RNA virus belong to Picornaviridae family and Aphtovirus genus. A broad host range and occurrence of FMDV as seven serotypes and also intratypic antigenic variation without clear cut demarcations, which interferes with a concept of sub typing these factors make difficult conditions to diagnosis, control and eradication of...
متن کاملA Synthetic Porcine Reproductive and Respiratory Syndrome Virus Strain Confers Unprecedented Levels of Heterologous Protection.
UNLABELLED Current vaccines do not provide sufficient levels of protection against divergent porcine reproductive and respiratory syndrome virus (PRRSV) strains circulating in the field, mainly due to the substantial variation of the viral genome. We describe here a novel approach to generate a PRRSV vaccine candidate that could confer unprecedented levels of heterologous protection against div...
متن کاملRestriction fragment length polymorphism of ORF6 and ORF7 genes of porcine reproductive and respiratory syndrome virus (PRRSV) vaccine strains registered in the Czech Republic
Restriction fragment length polymorphism (RFLP) of open reading frames 6 and 7 was applied to comparative genetic analysis of live attenuated vaccine strains (Amervac-PRRS/A3, Porcilis PRRS, Ingelvac PRRS) of porcine reproductive and respiratory syndrome virus (PRRSV), registered in the Czech Republic, six field viruses (L-588, L-1606, L-2053, L-3305, L-6558, L-6791), and three PRRSV local fiel...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Journal of clinical microbiology
دوره 46 5 شماره
صفحات -
تاریخ انتشار 2008