scholarly journals Diagnostic Characteristics of Circovirus Infection in Pigs

2015 ◽  
Vol 38 (1) ◽  
pp. 73-78
Author(s):  
Ivica Gjurovski ◽  
Branko Angelovski ◽  
Toni Dovenski ◽  
Dine Mitrov ◽  
Trpe Ristoski

Abstract The aim of this study is to compare the results from the histopathology and the immunohistochemical method in the diagnostic of Porcine circovirus type 2 (PCV2) infection in pigs. The circovirus infection is a pig disease that is caused by a small, spherical, nonenveloped virus with a single stranded DNA genome which is spread throughout the pig industry worldwide. The circovirus is the etiological agent of a several pig diseases which today are thought to be the cause of the greatest economical loses in pig production. The most important of these diseases is the PMWS (post-weaning multisystemic wasting syndrome). In this article we have performed an investigation of four farms on which there had been a previous clinical diagnosis of the Post-weaning multisystemic wasting syndrome. The examination was performed on thirty pigs from these farms, from two to five months old, which had the most severe symptoms of the disease. Necropsy, histopathology and immunohistochemical diagnostic methods were performed. The most significant necropsy findings were the enlarged lymph nodes (especially the inguinal, mediasinal and the mesenteric lymph nodes). The main histopathological changes were located in the lymphatic organs presented by B and T lymphocyte depletion and increase in the number of the macrophages. PCV2 antigen and nucleic acid were detected in almost all of the examined tissues. The examination showed that the histopathological and immunohistochemical methods provide complementary results in diagnosing PCV2 in pigs.

2016 ◽  
Vol 19 (3) ◽  
pp. 471-476 ◽  
Author(s):  
Wang Nai Dong ◽  
Li Jing Jun ◽  
Wang Ai Bing ◽  
Zhu Zhe ◽  
Chang Yan ◽  
...  

Abstract In order to investigate whether PCV2b can be transmitted across the placenta in sows thereby causing vertical infection of fetuses, six sows in 75 day of pregnancy were either intramuscularly inoculated with a PCV2b culture supernatant (n = 4) or mock infected with cell culture supernatant (n = 2). At parturition, 3 newborn piglets from each litter were randomly selected and euthanatized prior to suckling. Samples of the mesenteric lymph nodes, spleens, kidneys, hearts and lungs were collected for PCR, histopathological and immunohistochemical assays. The results showed that the newborn piglets from PCV2b-infected sows had histopathological lesions in the tested tissues. Moreover, PCV2b antigen and DNA were detected as well. These findings therefore suggested that porcine circovirus type 2b can be transmitted across the placenta of sows, thereby leading to PCV2b vertical infection of the fetuses.


2008 ◽  
Vol 28 (6) ◽  
pp. 313-318 ◽  
Author(s):  
Priscila Zlotowski ◽  
André M.R. Corrêa ◽  
David E.S.N. Barcellos ◽  
Cláudio E.F. Cruz ◽  
William Asanome ◽  
...  

Samples of mesenteric lymph nodes and intestines from 79 unthrifty 3- to 5-month-old postweaning pigs, confirmed as naturally affected with postweaning multisystemic wasting syndrome (PMWS), were studied. Pigs originated from 12 farms in southern Brazil and were selected on the basis of clinical signs and/or gross lesions suggestive of enteric disorder. Lymphohistiocytic infiltrates of varying intensity were associated with anti-porcine circovirus type 2 (anti-PCV2) immunostaining (IS) in samples of intestines and mesenteric lymph nodes from all pigs. Although most findings were similar to those described in PCV2-associated enteritis, anti-PCV2 IS in association with depletion of the goblet cell mucin stores (24 pigs), diffuse ileal villous atrophy and fusion (18 pigs), and dilatation of the lymphatic vessels (11 pigs) combined or not with lymphangitis were also observed. PCV2 antigen was immunohistochemically demonstrated in the cytoplasm and nuclei from intralesional epithelial cells, histiocytes, and endothelial-like cells in intestinal tissues. Together these findings imply an association with PCV2. The presence of co-infections by Lawsonia intracellularis, Brachyspira spp., Mycobacterium spp., Salmonella spp., rotavirus, parvovirus, coronavirus and enteric calicivirus with PCV2 in the intestinal lesions was investigated.


2008 ◽  
Vol 28 (12) ◽  
pp. 601-605 ◽  
Author(s):  
André Mendes Ribeiro Corrêa ◽  
Priscila Zlotowsk ◽  
David Emilio Santos Neves de Barcellos ◽  
Cláudio Estêvão Farias da Cruz ◽  
David Driemeier

Samples of gastric lymph nodes and the stomachs from 24 pigs selected from herds affected by postweaning multisystemic wasting syndrome (PMWS) and sudden death associated with gastric ulcers were studied. Pigs were selected on the basis of unthriftiness, decreased feed intake, and wasting. The stomachs were opened, inverted, and classified into 0-3 score according the severity of the gross lesions present in pars oesophagica (non-glandulargastric mucosa). Selected samples were processed for paraffin embedding and stained with hematoxylin and eosin. Immunohistochemistry using anti-PCV2 (porcine circovírus type 2) antibody, anti-Helicobacter pylori antibody and a wide-spectrum anti-cytokeratin antibody was performed. Gross changes in pars oesophagea were classified according to the severity of lesions as score 3, 2, and 1 in 8, 6, 5 stomachs respectivelly. Microscopically, hyperplastic lymphoid follicles, lymphohistiocytic inflammatory infiltrates and focci of necrosis in the gastric mucosa were common findings. Large amounts of PCV2 antigen were observed in the cytoplasm and nuclei from intralesional cells and debris from the gastric glandular mucosal zone; however, in the fundus, anti-PCV2 immunostaining was restricted to the surface mucosal cells and foveolar compartment. All gastric lymph nodes were positive for PCV2 antigen. Anti-H. pylori immunostaining was seen in eleven cases, mainly in the antrum, on the mucosal surface and foveolar compartment. The association of the anti-PCV2 immunostaining with the glandular mucus-producing cells suggests a role for PCV2 as an additional factor for the swine ulcer development.


2003 ◽  
Vol 55 (5) ◽  
pp. 522-527 ◽  
Author(s):  
J.R. Ciacci-Zanella ◽  
N. Morés

This report describes the first preliminary characterization of porcine circovirus type 2 (PCV2) isolates from pigs affected with post-weaning multisystemic wasting syndrome (PMWS) in Brazil. Diseased pigs were examined at necropsy and by histopathology. Macroscopic and microscopic analyses revealed lesions reported to be typical of PMWS, which included, respectively, emaciation, enlargement of lymph nodes, thymus atrophy and interstitial pneumonia, and granulomatous lymphadenitis with syncytial cells, among others. Using nested polymerase chain reaction (PCR) or imunoperoxidase it was possible to detected DNA or antigen of PCV2, respectively. The PCR' s amplified fragment could be differentiated from PCV1 and PCV2 from one another by restriction fragment length polymorphism (RFLP) analysis. PCV2 DNA was detected in 70% (14/20) of samples of pigs with clinical signs and lesions associated with PMWS. This study shows that PCV2 is associated with lesions and symptoms indicative of PMWS in pigs. It is also shown that the Brazilian PCV2 isolates may have variation in their genome.


2004 ◽  
Vol 78 (24) ◽  
pp. 13440-13446 ◽  
Author(s):  
M. Fenaux ◽  
T. Opriessnig ◽  
P. G. Halbur ◽  
F. Elvinger ◽  
X. J. Meng

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.


2009 ◽  
Vol 135 (3-4) ◽  
pp. 272-282 ◽  
Author(s):  
Llorenç Grau-Roma ◽  
Charlotte K. Hjulsager ◽  
Marina Sibila ◽  
Charlotte S. Kristensen ◽  
Sergio López-Soria ◽  
...  

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