Complete genome sequence of a novel sub-subgenotype 2.1g isolate of classical swine fever virus from China

Abstract

Current subgenotype 2.1 isolates of classical swine fever virus (CSFV) play a dominant role in CSF outbreaks in China, and a novel sub-subgenotype 2.1g of CSFV was recently identified, but the complete genome sequence of this new sub-subgenotype has not been reported. In this study, complete genome of 2.1g isolate GD19/2011 collected from Guangdong province of China in 2011 was sequenced. It was found to be 12,298 nucleotides (nt) in length, including a 375-nt 5'UTR, a 11,697-nt opening reading frame (ORF), and a 227-nt 3'UTR. GD19/2011 shared 91.0-93.7 % and 95.6-97.5 % nt and amino acid sequence identity, respectively, with other subgenotype 2.1 isolates. The topology of a phylogenetic tree constructed based on complete genome sequences of GD19/2011 and other CSFV isolates was identical to that obtained with full-length E2 gene sequences, but it was significantly different from those obtained with the 5'UTR and core sequences. Serial passages of GD9/2011 in PK-15 cells generated a highly cell-adapted virus stock with an infectious titer of 10(7.8) TCID50/ml at the 12(th) passage in which two amino acid substitutions, S476R and N2494S, were observed in comparison with the complete polyprotein sequence of the original isolate from kidney tissue, GD19/2011. This is the first report of the complete genome sequence of a 2.1g isolate, and the GD19/2011 isolate will be useful for further analysis of the evolution and virulence of CSFV isolates.

Efficiency Comparison of a Novel E2 Subunit Vaccine and a Classic C-Strain Vaccine against Classical Swine Fever

“…Hence, C-vac is still a good choice for farmers. However, CSF was recently demonstrated to occur sporadically or endemically in many regions in China [ 16 , 41 , 42 , 43 , 44 ]. To completely control CSF, an elimination program is the only option.…”

Characterization of monoclonal antibodies that specifically differentiate field isolates from vaccine strains of classical swine fever virus

“…Highly virulent CSFV reference SM, HCLV strain, and 106 CSFV field isolates (sub-genotypes 1.1, 2.1, 2.2, and 2.3) and bovine viral diarrheic virus 1 (BVDV1) strain 32 were stored in our laboratory. These field isolates were collected between 1990 and 2017 from 23 provinces of China ( 30 – 32 ) and adapted in PK-15 cells following isolation ( 31 , 33 ). The growth and replication of CSFV in PK-15 cells were confirmed by indirect fluorescent antibody assay (IFA) using CSFV-specific mAb WH303 ( 34 ) as the primary antibody and Alexa Fluor 488 donkey anti-mouse IgG (H+L) (Life Technologies, MA, USA) as the secondary antibody ( 33 ).…”

“…These field isolates were collected between 1990 and 2017 from 23 provinces of China ( 30 – 32 ) and adapted in PK-15 cells following isolation ( 31 , 33 ). The growth and replication of CSFV in PK-15 cells were confirmed by indirect fluorescent antibody assay (IFA) using CSFV-specific mAb WH303 ( 34 ) as the primary antibody and Alexa Fluor 488 donkey anti-mouse IgG (H+L) (Life Technologies, MA, USA) as the secondary antibody ( 33 ). Full E2 and E rns genes of various CSFV strains were synthesized at Jilin Comate Biotech Company (Changchun, Jilin, China).…”

Complete Genome Sequence of a Sub-Subgenotype 2.1i Isolate of Classical Swine Fever Virus from China

“…To obtain the entire genome sequence of this 2.1i isolate, total RNA was extracted from a 10% homogenate of the kidney sample using the TRIzol reagent (Invitrogen, Carlsbad, CA), according to the manufacturer’s instructions. Reverse transcription, PCR amplification, and sequencing of the whole genome were conducted as previously described (8, 9). The entire genome sequence of GD317/2011 was assembled using the SeqMan program of Lasergene (DNAStar, Inc., Madison, WI).…”