scholarly journals Comparative Pathogenicity of Nine US Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) Isolates in a Five-Week-Old Cesarean-Derived, Colostrum-Deprived Pig Model

1996 ◽  
Vol 8 (1) ◽  
pp. 11-20 ◽  
Author(s):  
Patrick G. Halbur ◽  
Prem S. Paul ◽  
Xiang-Jin Meng ◽  
Melissa A. Lum ◽  
John J. Andrews ◽  
...  
Keyword(s):  
Lymph Node ◽  
Respiratory Disease ◽  
Mononuclear Cells ◽  
Lung Lesion ◽  
Pig Model ◽  
Respiratory Syndrome Virus ◽  
Lung Lesions ◽  
Follicular Hyperplasia ◽  
Lung Lobes

One hundred forty-six 5-week-old cesarean-derived, colostrum-deprived (CDCD) pigs were inoculated intranasally with 1 of 9 US porcine reproductive and respiratory syndrome virus (PRRSV) isolates. Differences were found in severity of clinical respiratory disease, rectal temperatures ( P ≤0.001), gross lung lesions ( P ≤ 0.001), and microscopic lung lesions ( P ≤ 0.05). Gross lung lesions were generally most severe 10 days postinoculation and were distributed primarily in the cranial, middle, and accessory lobes and ventromedial portion of the caudal lung lobes. Mean gross lung lesion scores estimating the percentage of lung affected by pneumonia at 10 days postinoculation ranged from 16.7% ± 2.8% (x X ± SEM, n = 10) for isolate ISU-51 to 62.4% ± 5.7% ( n = 10) for isolate ISU-28. Microscopic lung lesions were characterized by hyperplastic and hypertrophied type 2 pneumocytes, septal infiltration by mononuclear cells, and accumulation of necrotic alveolar exudate. Lymph node follicular hyperplasia and focal necrosis was seen with all 9 isolates. This CDCD pig model was useful for demonstration of significant differences in pathogenicity among US PRRSV isolates. This difference in pathogenicity may help explain the variation in severity of clinical disease observed in field outbreaks of porcine reproductive and respiratory syndrome and should provide for meaningful comparison of PRRSV genotypes.

Comparison of the Pathogenicity of Two US Porcine Reproductive and Respiratory Syndrome Virus Isolates with that of the Lelystad Virus

1995 ◽  
Vol 32 (6) ◽  
pp. 648-660 ◽  
Author(s):  
P. G. Halbur ◽  
P. S. Paul ◽  
M. L. Frey ◽  
J. Landgraf ◽  
K. Eernisse ◽  
...  
Keyword(s):  
Mononuclear Cells ◽  
Inflammatory Cells ◽  
Lung Lesion ◽  
Respiratory Syndrome Virus ◽  
Major Site ◽  
Lelystad Virus ◽  
Follicular Lesions ◽  
Virus Isolates ◽  
Necrotic Debris

The Lelystad virus or one of two US isolates (VR2385, VR2431) of porcine reproductive and respiratory syndrome virus were given intranasally to 25 4-week-old cesarian-derived colostrum-deprived pigs. Pigs from these groups were necropsied at 1, 2, 3, 5, 7, 10, 15, 21, or 28 days postinoculation. The Lelystad virus and VR2431 induced mild transient pyrexia, dyspnea, and tachypnea. VR2385 induced labored and rapid abdominal respiration, pyrexia, lethargy, anorexia, and patchy dermal cyanosis. All three isolates induced multifocal tan-mottled consolidation involving 6.8% ( n = 9, SEM = 3.4) of the lung for Lelystad, 9.7% ( n = 9, SEM = 2.7) of the lung for VR2431, and 54.2% ( n = 9, SEM = 4.4) of the lung for VR2385 at 10 days postinoculation. Characteristic microscopic lung lesions consisted of type 2 pneumocyte hypertrophy and hyperplasia, necrotic debris and increased mixed inflammatory cells in alveolar spaces, and alveolar septal infiltration with mononuclear cells. Lymphadenopathy with follicular hypertrophy, hyperplasia, and necrosis was consistently seen. Similar follicular lesions were also seen in Peyer's patches and tonsils. Lymphohistiocytic myocarditis and encephalitis were reproduced with all three isolates. Clinical respiratory disease and gross and microscopic lung lesion scores were considerably and significantly more severe in the VR2385-inoculated pigs. All three viruses were readily isolated from sera, lungs, and tonsils throughout the 28 days of the study. The lymphoid and respiratory systems have the most remarkable lesions and appear to be the major site of replication of these viruses. This work demonstrated a marked difference in pathogenicity of porcine reproductive and respiratory syndrome isolates.

scholarly journals Assessment of Lung Disease in Finishing Pigs at Slaughter: Pulmonary Lesions and Implications on Productivity Parameters

Animals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3604
Author(s):  
Yania Paz-Sánchez ◽  
Pedro Herráez ◽  
Óscar Quesada-Canales ◽  
Carlos G. Poveda ◽  
Josué Díaz-Delgado ◽  
...  
Keyword(s):  
Respiratory Disease ◽  
Lung Parenchyma ◽  
Porcine Circovirus Type ◽  
Daily Weight Gain ◽  
Porcine Circovirus ◽  
Respiratory Syndrome Virus ◽  
Finishing Pigs ◽  
Negative Impacts ◽  
The Impact

Swine respiratory disease is associated with productive losses. We evaluated the prevalence of lung lesions with an emphasis on Mycoplasma hyopneumoniae (Mh), porcine circovirus type 2 (PCV2) and porcine reproductive and respiratory syndrome virus (PRRSV), as well as the impact on productive parameters in 108 finishing pigs at slaughter. Pathologic, immunohistochemical (IHC) and serologic analyses were performed. Pneumonic processes were observed in 73.1% of the animals. They mainly consisted of cranioventral bronchopneumonia (CBP) (46.3%) and pleuritis (17.6%). Microscopically, bronchointerstitial pneumonia (67.4%) was common and was occasionally combined (27.9%) with interstitial pneumonia (IP). Mh and PCV2-antigens were detected in bronchointerstitial pneumonia (70.7%) and IP cases (33.3%). There were low titers against Mh (18%) and high titers against PRRSV (100%) and PCV2 (65%). Animals with CBP remained at the farm longer; those with >10% of lung parenchyma involvement were sent later (208.8 days old) and had a lower average carcass weight (74.1 kg) and a lower daily weight gain (500.8 gr/day) compared with animals without lesions (567.2 gr/day, 77.7 kg, 200.8 days old). We suggest that animals that do not reach the weight at slaughter should be sent to slaughter regardless to avoid further negative impacts of respiratory disease in productive parameters.

scholarly journals Comparison of Two Commercial Type 1 Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) Modified Live Vaccines against Heterologous Type 1 and Type 2 PRRSV Challenge in Growing Pigs

2015 ◽  
Vol 22 (6) ◽  
pp. 631-640 ◽  
Author(s):  
Taeyeon Kim ◽  
Changhoon Park ◽  
Kyuhyung Choi ◽  
Jiwoon Jeong ◽  
Ikjae Kang ◽  
...  
Keyword(s):  
Nucleic Acids ◽  
Interleukin 10 ◽  
Growing Pigs ◽  
Respiratory Syndrome Virus ◽  
Lung Lesions ◽  
Live Vaccines ◽  
Immunological Responses ◽  
Ifn Γ

ABSTRACTThe objective of the present study was to compare the efficacy of two commercial type 1 porcine reproductive and respiratory syndrome virus (PRRSV) modified live vaccines against heterologous type 1 and type 2 PRRSV challenge in growing pigs. Vaccination with a type 1 PRRSV vaccine reduced the level of viremia after type 1 PRRSV challenge but did not reduce the level of viremia after the type 2 PRRSV challenge in pigs. Increased levels of interleukin-10 (IL-10) stimulated by type 2 PRRSV coincided with the low numbers of type 2 PRRSV-specific interferon gamma-secreting cells (IFN-γ-SC) in vaccinated pigs after type 2 PRRSV challenge, whereas low levels of IL-10 stimulated by type 1 PRRSV coincided with high numbers of type 1 PRRSV-specific IFN-γ-SC in vaccinated pigs after type 1 PRRSV challenge. Additionally, vaccination with the type 1 PRRSV vaccine effectively reduced the lung lesions and type 1 PRRSV nucleic acids in type 1 PRRSV-challenged pigs but did not reduce lung lesions and type 2 PRRSV nucleic acids in type 2 PRRSV-challenged pigs. There were no significant differences between two commercial type 1 PRRSV vaccines against type 1 and type 2 PRRSV challenge based on virological results, immunological responses, and pathological outcomes. This study demonstrates that vaccinating pigs with the type 1 PRRSV vaccine provides partial protection against respiratory disease with heterologous type 1 PRRSV challenge but no protection with heterologous type 2 PRRSV challenge.

scholarly journals Comparison of Four Commercial One-Dose Porcine Circovirus Type 2 (PCV2) Vaccines Administered to Pigs Challenged with PCV2 and Porcine Reproductive and Respiratory Syndrome Virus at 17 Weeks Postvaccination To Control Porcine Respiratory Disease Complex under Korean Field Conditions

2014 ◽  
Vol 21 (3) ◽  
pp. 399-406 ◽  
Author(s):  
Changhoon Park ◽  
Hwi Won Seo ◽  
Kiwon Han ◽  
Chanhee Chae
Keyword(s):  
Respiratory Disease ◽  
Porcine Circovirus Type ◽  
Porcine Circovirus Type 2 ◽  
Field Conditions ◽  
Porcine Circovirus ◽  
Respiratory Syndrome Virus ◽  
Disease Complex ◽  
Associated Lesions ◽  
Porcine Respiratory

ABSTRACTUnder Korean field conditions, coinfection with porcine circovirus type 2 (PCV2) and porcine reproductive and respiratory syndrome virus (PRRSV) is most commonly observed in porcine respiratory disease complex (PRDC). Despite the wide use of PCV2 vaccination, PRDC remains a serious respiratory problem. Thus, the objective of this study was to determine and compare the efficacy of 4 one-dose PCV2 vaccines on 3-week-old pigs with an experimental PCV2-PRRSV challenge at 17 weeks postvaccination. Regardless of which commercial PCV2 vaccine was used, the vaccination of piglets at 3 weeks of age was efficacious against cochallenge of PCV2 and PRRSV, on the basis of growth performance and PCV2-associated lesions. However, the inactivated chimeric PCV1-2 and the PCV2 vaccines induced higher PCV2-specific neutralizing antibody (NA) titers and PCV2-specific gamma interferon-secreting cells and lower PCV2 viremia levels than the two PCV2 subunit vaccines. The vaccination of piglets against PCV2 at 3 weeks of age was effective in reducing PCV2 viremia and PCV2-associated lesions during the finishing period, which is an age at which pigs are frequently affected by PRDC caused by coinfection with PCV2 and PRRSV under Korean field conditions.

scholarly journals Cytokine Profiles in Peripheral Blood Mononuclear Cells and Lymph Node Cells from Piglets Infected In Utero with Porcine Reproductive and Respiratory Syndrome Virus

2002 ◽  
Vol 9 (6) ◽  
pp. 1229-1234 ◽  
Author(s):  
B. Aasted ◽  
P. Bach ◽  
J. Nielsen ◽  
P. Lind
Keyword(s):  
Lymph Node ◽  
Peripheral Blood Mononuclear Cells ◽  
Peripheral Blood ◽  
Mononuclear Cells ◽  
Respiratory Syndrome Virus ◽  
Peripheral Blood Mononuclear ◽  
Tnf Α ◽  
Blood Mononuclear Cells ◽  
Lymph Node Cells ◽  
Bronchial Lymph Node

ABSTRACT The aim of the present study was to investigate at 2, 4, and 6 weeks after birth cytokine expression by peripheral blood mononuclear cells and bronchial lymph node cells from piglets infected in utero with porcine reproductive and respiratory syndrome virus (PRRSV). Technically, by flow cytometry we were able to measure gamma interferon (γ-IFN), tumor necrosis factor alpha (TNF-α), interleukin-4 (IL-4), and IL-8 levels. In general, we found increases in the percentages of IL-4-, γ-IFN-, and TNF-α-producing lymphocytes in the infected piglets compared to the percentages in the uninfected control animals, while there was a decrease in the percentage of IL-8-producing monocytes. We believe that these findings reflect a general lymphocyte activation stage that is created due to the infection and that occurs in combination with impairment of the monocyte function, possibly due to the ongoing viral replication in these cells. Single-cell bronchial lymph node preparations exhibited very much the same cytokine profiles as peripheral blood mononuclear cells except for a lack of IL-8 production. When the levels of the individual cytokines in the three groups of PRRSV-infected piglets were compared, the levels of cytokine expression at 4 weeks diverged from those at 2 and 6 weeks, in that there was a significant decrease in the numbers of lymphocytes producing γ-IFN and TNF-α. This tendency was also observed among blood monocytes and lymph node macrophages. Possible reasons for this temporary immunosuppression in the piglets at 4 weeks are discussed.

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