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

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.

The Betacoronavirus PHEV Replicates and Disrupts the Respiratory Epithelia and Upregulates Key Pattern Recognition Receptor Genes and Downstream Mediators, Including IL-8 and IFN-λ

The neurotropic betacoronavirus porcine hemagglutinating encephalomyelitis virus (PHEV) primarily infects and replicates in the swine upper respiratory tract, causing vomiting and wasting disease and/or encephalomyelitis in suckling pigs. This study investigated the modulation of key early innate immune genes at the respiratory epithelia in vivo, on tracheal tissue sections from experimentally infected pigs, and in vitro , on air-liquid interface porcine respiratory cell cultures.

Control integral del PRRSv mediante el concepto de las 5 fases: revisión crítica

El Síndrome Reproductivo y Respiratorio Porcino (PRRSV) es una enfermedad viral que causa importantes pérdidas económicas y productivas, afectando la reproducción en cerdas gestantes, la calidad del semen en verracos y, ocasionando enfermedad respiratoria en lechones en transición y cebo, reduciendo el crecimiento de los cerdos y provocando un aumento de la mortalidad. Este síndrome cuenta con diversas cepas patógenas, muchas de ellas no incluidas en las actuales vacunas. En consecuencia, los cerdos nunca estarán completamente protegidos frente a esta enfermedad, debido a la capacidad permanente de recombinación y mutación propia del virus. El proceso de las 5 fases surge fruto de la experiencia y la búsqueda de desarrollar metodologías que unifiquen criterios y herramientas de diagnóstico, prevención y bioseguridad para el control de esta enfermedad. En conclusión, la plataforma de las 5 fases hace posible el abordaje en conjunto de la enfermedad, sirviendo como herramienta integral de utilidad para el control exitoso de esta enfermedad. Porcine Respiratory and Reproductive Syndrome is a viral disease, which causes important economic and productive losses, affecting reproduction in pregnant sows, semen quality in boars and, causing respiratory disease in growing and fattening piglets, reducing pig growth and causing increased mortality. This syndrome is caused by several pathogenic strains, many of which are not included in current vaccines. Consequently, pigs will never be completely protected against this disease, due to the permanent recombination and mutation capacity of the virus. The five-phase process is the result of experience and the search to develop methodologies that unify criteria and tools for diagnosis, prevention and biosecurity for the control of this disease. In conclusion, the 5-phases platform makes it possible to approach the disease as a whole, providing it as an integral tool for success on this disease.

Electroceutical fabric lowers zeta potential and eradicates coronavirus infectivity upon contact

Coronavirus with intact infectivity attached to PPE surfaces pose significant threat to the spread of COVID-19. We tested the hypothesis that an electroceutical fabric, generating weak potential difference of 0.5 V, disrupts the infectivity of coronavirus upon contact by destabilizing the electrokinetic properties of the virion. Porcine respiratory coronavirus AR310 particles (105) were placed in direct contact with the fabric for 1 or 5 min. Following one minute of contact, zeta potential of the porcine coronavirus was significantly lowered indicating destabilization of its electrokinetic properties. Size-distribution plot showed appearance of aggregation of the virus. Testing of the cytopathic effects of the virus showed eradication of infectivity as quantitatively assessed by PI-calcein and MTT cell viability tests. This work provides the rationale to consider the studied electroceutical fabric, or other materials with comparable property, as material of choice for the development of PPE in the fight against COVID-19.

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

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.

Application of Methods to Assess Animal Welfare and Suffering Caused by Infectious Diseases in Cattle and Swine Populations

Control of infectious diseases in livestock has often been motivated by food safety concerns and the economic impact on livestock production. However, diseases may also affect animal welfare. We present an approach to quantify the effect of five infectious diseases on animal welfare in cattle (three diseases) and pigs (two diseases). We grouped clinical manifestations that often occur together into lists of clinical entities for each disease based on literature reviews, and subsequently estimated “suffering scores” based on an aggregation of duration, frequency, and severity. The duration and severity were based on literature reviews and expert knowledge elicitation, while frequency was based mainly on estimates from the literature. The resulting suffering scores were compared to scores from common welfare hazards found under Danish conditions. Most notably, the suffering scores for cattle diseases were ranked as: bovine viral diarrhoea and infection with Mycobacterium avium subsp. paratuberculosis > infectious bovine rhinotracheitis, and for pigs as: porcine respiratory and reproductive syndrome > Aujeszky’s disease. The approach has limitations due to the limited data available in literature and uncertainties associated with expert knowledge, but it can provide decision makers with a tool to quantify the impact of infections on animal welfare given these uncertainties.

Isolasi dan Identifikasi Bakteri Streptococcus spp. pada Babi Penderita Porcine Respiratory Disease Complex

Streptococcus sp. merupakan salah satu penyebab primer terjadinya Porcine Respiratory Disease Complex (PRDC). Penelitian ini dilakukan untuk mendeteksi bakteri Streptococcus sp. di saluran pernapasan babi penderita PRDC serta distribusi bakteri Streptococcus sp. pada babi pra sapih dan pasca sapih. Sebanyak 43 sampel swab rongga hidung dikumpulkan dari babi yang menunjukkan gejala penyakit PRDC seperti depresi, anorexia, dyspnea, adanya eksudat dari rongga hidung, batuk/bersin, dan pembengkakan pada persendian. Sampel berasal dari peternakan babi di kabupaten Tabanan, kabupaten Badung, dan kabupaten Gianyar. Semua sampel ditanam pada media sheep blood agar dilanjutkan dengan uji pewarnaan Gram. Koloni yang dicurigai kemudian dilakukan uji primer berupa uji katalase dan uji oksidase serta uji biokimia dengan MRPV, TSIA, SIM, uji koagulase dan uji gula – gula . Hasil penelitian menunjukkan 23 sampel (tiga belas dari babi pra sapih dan sepuluh dari babi pasca sapih) telah terdeteksi positif Streptococcus sp. ? hemolitik (20 isolat) dan Streptococcus sp. ? hemolitik (3 isolat).

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

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.

Environmental stability of porcine respiratory coronavirus in aquatic environments

Coronaviruses (CoVs) are a family of viruses that are best known as the causative agents of human diseases like the common cold, Middle East Respiratory Syndrome (MERS), Severe Acute Respiratory Syndrome (SARS) and COVID-19. CoVs spread by human-to-human transmission via droplets or direct contact. There is, however, concern about potential waterborne transmission of SARS-CoV-2, the virus responsible for COVID-19, as it has been found in wastewater facilities and rivers. To date, little is known about the stability of SARS-CoV-2 or any other free coronavirus in aquatic environments. The inactivation of terrestrial CoVs in seawater is rarely studied. Here, we use a porcine respiratory coronavirus (PRCV) that is commonly found in animal husbandry as a surrogate to study the stability of CoVs in natural water. A series of experiments were conducted in which PRCV (strain 91V44) was added to filtered and unfiltered fresh- and saltwater taken from the river Scheldt and the North Sea. Virus titres were then measured by TCID50-assays using swine testicle cell cultures after various incubation times. The results show that viral inactivation of PRCV in filtered seawater can be rapid, with an observed 99% decline in the viral load after just two days, which may depend on temperature and the total suspended matter concentration. PRCV degraded much slower in filtered water from the river Scheldt, taking over 15 days to decline by 99%, which was somewhat faster than the PBS control treatment (T99 = 19.2 days). Overall, the results suggest that terrestrial CoVs are not likely to accumulate in marine environments. Studies into potential interactions with exudates (proteases, nucleases) from the microbial food web are, however, recommended.