scholarly journals Detection of respiratory viruses in cases of porcine respiratory disease in nurseries.

2021 ◽  
Author(s):  
Gerard Martín-Valls ◽  
Yanli Li ◽  
Ivan Díaz ◽  
Esmeralda Cano ◽  
Silvana Sosa Portugal ◽  
...  
Keyword(s):  
Respiratory Disease ◽  
Influenza A ◽  
Swine Influenza ◽  
Respiratory Syndrome Virus ◽  
Influenza B ◽  
Individual Level ◽  
Porcine Circoviruses ◽  
The One ◽  
Respiratory Coronavirus ◽  
Porcine Respiratory

Respiratory disease in weaned pigs is a common problem in the field, with a complex aetiology of both viruses and bacteria. In the present study, we investigated the presence of eleven viruses in nasal swabs collected from nurseries (fifty-five clinical outbreaks) under the suspicion of swine influenza A virus (swIAV) by cough and fever. The other ten viruses included influenza B (IBV) and influenza D viruses (IDV), Porcine reproductive and respiratory syndrome virus (PRRSV), Porcine respiratory coronavirus (PRCV), Porcine cytomegalovirus (PCMV), porcine circoviruses 2 (PCV2), 3 (PCV3) and 4 (PCV), Porcine parainfluenza 1 virus (PPIV1) and Swine orthopneumovirus (SOV). Twenty-nine swIAV-positive cases and twenty-six cases of swIAV-negative respiratory disease were primarily established. IBV, IBD, PCV4 and PPIV1 were not found in any case, while PRCV, SOV, and PCMV were more likely to be found in swIAV-positive nurseries with respiratory disease ( p<0.05) although, globally, PCV3, PRRSV, and PCMV were the most frequently detected agents on herd level. At an individual level, the prevalence of different viruses was: swIAV 48.6%; PRCV 48.0%; PRRSV 31.6%; SOV 33.8%; PCMV 48.3%, PCV2 36.0%; and PCV3 33.0%. Beyond that, it was common to find animals with low Ct values (< 30) for all agents except for PCV2 and PCV3. When analysed the association between different pathogens, PRCV was the one with the most associations. It positively interacted ( p < 0.05) with swIAV and SOV but was negatively associated ( p < 0.05) with PRRSV and PCVM. Besides these, swIAV and PRRSV were negatively related (p < 0.05). Further analysis of suckling pigs showed that circulation of PRCV, PCMV, SOV, and PCV3 started in the maternities, suggesting a role of the sows in the transmission. Overall, our data may contribute to a better understanding of the complex aetiology and the epidemiology of respiratory disease in weaners. This is the first report of SOV in Spain.

scholarly journals Successive Inoculations of Pigs with Porcine Reproductive and Respiratory Syndrome Virus 1 (PRRSV-1) and Swine H1N2 Influenza Virus Suggest a Mutual Interference between the Two Viral Infections

Viruses ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2169
Author(s):  
Juliette Bougon ◽  
Céline Deblanc ◽  
Patricia Renson ◽  
Stéphane Quéguiner ◽  
Stéphane Gorin ◽  
...  
Keyword(s):  
Influenza A ◽  
Viral Infections ◽  
Clinical Signs ◽  
Swine Influenza ◽  
Time Correlation ◽  
Respiratory Syndrome Virus ◽  
Cell Mediated Immune Response ◽  
Specific Pathogen ◽  
Porcine Respiratory

Porcine reproductive and respiratory syndrome virus (PRRSV) and swine influenza A virus (swIAV) are major pathogens of the porcine respiratory disease complex, but little is known on their interaction in super-infected pigs. In this study, we investigated clinical, virological and immunological outcomes of successive infections with PRRSV-1 and H1N2 swIAV. Twenty-four specific pathogen-free piglets were distributed into four groups and inoculated either with PRRSV at study day (SD) 0, or with swIAV at SD8, or with PRRSV and swIAV one week apart at SD0 and SD8, respectively, or mock-inoculated. In PRRSV/swIAV group, the clinical signs usually observed after swIAV infection were attenuated while higher levels of anti-swIAV antibodies were measured in lungs. Concurrently, PRRSV multiplication in lungs was significantly affected by swIAV infection, whereas the cell-mediated immune response specific to PRRSV was detected earlier in blood, as compared to PRRSV group. Moreover, levels of interferon (IFN)-α measured from SD9 in the blood of super-infected pigs were lower than those measured in the swIAV group, but higher than in the PRRSV group at the same time. Correlation analyses suggested an important role of IFN-α in the two-way interference highlighted between both viral infections.

scholarly journals Kinetics of single and dual simultaneous infection of pigs with swine influenza A virus and porcine reproductive and respiratory syndrome virus

2020 ◽  
Vol 34 (5) ◽  
pp. 1903-1913
Author(s):  
Małgorzata Pomorska‐Mól ◽  
Katarzyna Podgórska ◽  
Ewelina Czyżewska‐Dors ◽  
Hanna Turlewicz‐Podbielska ◽  
Maciej Gogulski ◽  
...  
Keyword(s):  
Influenza A Virus ◽  
Influenza A ◽  
Swine Influenza ◽  
Respiratory Syndrome Virus ◽  
Simultaneous Infection ◽  
Kinetics Of ◽  
Swine Influenza A Virus

THE USE OF GAMMA RADIATION FOR THE PREPARATION OF VIRUS VACCINES

1962 ◽  
Vol 8 (4) ◽  
pp. 455-459 ◽  
Author(s):  
John R. Polley
Keyword(s):  
Gamma Radiation ◽  
Hemagglutination Inhibition ◽  
Influenza A ◽  
Swine Influenza ◽  
Influenza B ◽  
Protective Agent ◽  
Live Virus ◽  
Precise Control ◽  
Neutralization Techniques ◽  
Hemagglutination Titer

A protective agent such as histidine or sodium p-aminohippurate was added to purified suspensions of influenza and mumps viruses. It was then possible to inactivate them in about an hour with gamma radiation while retaining most of the hemagglutination titer. It was demonstrated in mice that a vaccine prepared from a mouse-adapted virus (Shope's swine influenza strain of influenza A) conferred protection against challenge by the live virus and produced an antibody response as measured by the hemagglutination–inhibition technique. Vaccines prepared with the viruses of influenza A(PR8), influenza B, and mumps were shown to produce antibody responses in guinea pigs as measured by the hemagglutination–inhibition and serum neutralization techniques. With gamma radiation it was possible to prepare influenza and mumps virus vaccines quickly and with precise control of the inactivation. This work is being continued with other viruses.

scholarly journals Porcine Parvovirus 2 Is Predominantly Associated With Macrophages in Porcine Respiratory Disease Complex

2021 ◽  
Vol 8 ◽  
Author(s):  
April Nelsen ◽  
Chun-Ming Lin ◽  
Ben M. Hause
Keyword(s):  
Respiratory Disease ◽  
Alveolar Macrophages ◽  
Management Practices ◽  
Quantitative Polymerase Chain Reaction ◽  
Respiratory Syndrome Virus ◽  
Porcine Parvovirus ◽  
Metagenomic Sequencing ◽  
Disease Complex ◽  
Porcine Respiratory Disease Complex ◽  
Porcine Respiratory

Porcine respiratory disease complex (PRDC) is a significant source of morbidity and mortality, manifested by pneumonia of multiple etiologies, where a variety of pathogens and environment and management practices play a role in the disease. Porcine reproductive and respiratory syndrome virus (PRRSV), influenza A virus (IAV), and porcine circovirus 2 (PCV2) are well-established pathogens in PRDC. Porcine parvovirus 2 (PPV2) has been identified in both healthy and clinically diseased pigs at a high prevalence worldwide. Despite widespread circulation, the significance of PPV2 infection in PRDC and its association with other co-infections are unclear. Here, PPV2 was detected in the lung tissue in 39 of 100 (39%) PRDC-affected pigs by quantitative polymerase chain reaction (qPCR). Using in situ hybridization (ISH) in conjunction with tissue microarrays (TMA), PPV2 infection was localized in alveolar macrophages and other cells in the lungs with interstitial pneumonia in 28 of 99 (28.2%) samples. Viral load tended to correlate with the number of macrophages in the lungs. Assessment of the frequency, viral titers, and tissue distributions showed no association between infection of PPV2 and other major viral respiratory pathogens. In one-third of the PPV2-positive samples by qPCR, no other known viruses were identified by metagenomic sequencing. The genome sequences of PPV2 were 99.7% identical to the reference genomes. Although intensive intranuclear and intracytoplasmic signals of PPV2 were mainly detected in alveolar macrophages by ISH, no obvious virus replication was noted in in vitro cell culture. Together, these results suggest that PPV2 is associated, but may not be the sole causative agent, with PRDC, warranting the control and prevention of this underdiagnosed virus.

Sign in / Sign up

Export Citation Format

Share Document