scholarly journals Isolation and identification of biological characteristics of porcine circovirus type 2 (PCV2) from pigs in southern Vietnam

2018 ◽  
Vol 17 (04) ◽  
pp. 68-75
Author(s):  
Phuong T. T. Le
Keyword(s):  
Porcine Circovirus Type ◽  
Postweaning Multisystemic Wasting Syndrome ◽  
Biological Characteristics ◽  
Porcine Circovirus ◽  
Isolation And Identification ◽  
Southern Vietnam ◽  
The Third ◽  
Wasting Syndrome ◽  
Viral Titers

This study aimed to isolate and examine the biological characteristics of PCV2 field strains circulating in Vietnam for further study in producing vaccine against PMWS (postweaning multisystemic wasting syndrome). Eighteen PCV2 strains were successfully isolated and belonged to genotype PCV2b (9 strains), PCV2d (6 strains) and recombinant (3 strains). The viral titers of PCV2 isolates at the third passages in PK15A cells were in the range from 1.67 to 5,50 log10TCID50/mL. Three PCV2 field strains with stable viral titers (≥ 5,0 log10TCID50/mL) through passages, which belonged to different genotypes, were selected as master seed for studying of PCV2 vaccines

scholarly journals Two Amino Acid Mutations in the Capsid Protein of Type 2 Porcine Circovirus (PCV2) Enhanced PCV2 Replication In Vitro and Attenuated the Virus In Vivo

2004 ◽  
Vol 78 (24) ◽  
pp. 13440-13446 ◽  
Author(s):  
M. Fenaux ◽  
T. Opriessnig ◽  
P. G. Halbur ◽  
F. Elvinger ◽  
X. J. Meng
Keyword(s):  
Capsid Protein ◽  
Vaccine Development ◽  
Porcine Circovirus Type ◽  
Postweaning Multisystemic Wasting Syndrome ◽  
Porcine Circovirus ◽  
Entire Genome ◽  
Wasting Syndrome

ABSTRACT Porcine circovirus type 2 (PCV2) is the primary causative agent of postweaning multisystemic wasting syndrome (PMWS) in pigs. To identify potential genetic determinants for virulence and replication, we serially passaged a PCV2 isolate 120 times in PK-15 cells. The viruses harvested at virus passages 1 (VP1) and 120 (VP120) were biologically, genetically, and experimentally characterized. The PCV2 VP120 virus replicated in PK-15 cells to a titer similar to that of the PK-15 cell line-derived nonpathogenic PCV1 but replicated more efficiently than PCV2 VP1 with a difference of about 1 log unit in the titers. The complete genomic sequences of viruses at passages 0, 30, 60, 90, and 120 were determined. After 120 passages, only two nucleotide mutations were identified in the entire genome, and both were located in the capsid gene: the mutations were located at nucleotide positions 328 (C328G) and 573 (A573C). The C328G mutation, in which a proline at position 110 of the capsid protein changed to an alanine (P110A), occurred at passage 30 and remained in the subsequent passages. The second mutation, A573C, resulting in a change from an arginine to a serine at position 191 (R191S), appeared at passage 120. To experimentally characterize the VP120 virus, 31 specific-pathogen-free pigs were randomly divided into three groups. Ten pigs in group 1 received phosphate-buffered saline as negative controls. Each pig in group 2 (11 pigs) was inoculated intramuscularly and intranasally with 104.9 50% tissue culture infective doses (TCID50) of PCV2 VP120. Each pig in group 3 (10 pigs) was similarly inoculated with 104.9 TCID50 of PCV2 VP1. Viremia was detected in 9 of 10 pigs in the PCV2 VP1 group with a mean duration of 3 weeks, but in only 4 of 11 pigs in the PCV2 VP120 group with a mean duration of 1.6 weeks. The PCV2 genomic copy numbers in serum in the PCV2 VP1 group were significantly higher than those in the PCV2 VP120 group (P < 0.0001). Gross and histopathologic lesions in pigs inoculated with PCV2 VP1 were more severe than those inoculated with PCV2 VP120 at both day 21 and 42 necropsies (P = 0.0032 and P = 0.0274, respectively). Taken together, the results from this study indicated that the P110A and R191S mutations in the capsid of PCV2 enhanced the growth ability of PCV2 in vitro and attenuated the virus in vivo. This finding has important implications for PCV2 vaccine development.

Porcine circovirus type 2 and associated diseases in Romania — Short communication

2007 ◽  
Vol 55 (1) ◽  
pp. 151-156 ◽  
Author(s):  
D. Cadar ◽  
A. Cságola ◽  
Á. Dán ◽  
Z. Deim ◽  
Marina Spînu ◽  
...  
Keyword(s):  
Clinical Signs ◽  
Porcine Circovirus Type ◽  
Postweaning Multisystemic Wasting Syndrome ◽  
Porcine Circovirus Type 2 ◽  
Porcine Circovirus ◽  
Serum Samples ◽  
Associated Diseases ◽  
Wasting Syndrome

Porcine circovirus type 2 (PCV2) has been demonstrated to be the causal agent for postweaning multisystemic wasting syndrome (PMWS) and porcine dermatitis and nephropathy syndrome (PDNS). This report describes the first detection of PCV2 and associated diseases in a Romanian swine herd located in Transylvania. The clinical signs, pathological and histopathological changes observed in affected pigs were similar to those previously described for PDNS and PMWS. Polymerase chain reaction and in situ hybridisation were used for the detection of PCV2 nucleic acids from tissues and serum samples. Complete PCV2 genomes of both PMWS and PDNS cases were sequenced and analysed, and by comparing them with each other no genomic differences could be detected. The sequence analysis showed that the Romanian PCV2 was closely related to PCV2 identified in France and in Hungary.

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