Elimination of Porcine Epidemic Diarrhea Virus in an Animal Feed Manufacturing Facility

Citation: Huss AR, Schumacher LL, Cochrane RA, Poulsen E, Bai J, Woodworth JC, et al. (2017) Elimination of Porcine Epidemic Diarrhea Virus in an Animal Feed Manufacturing Facility. PLoS ONE 12(1): e0169612. doi:10.1371/journal.pone.0169612Porcine Epidemic Diarrhea Virus (PEDV) was the first virus of wide scale concern to be linked to possible transmission by livestock feed or ingredients. Measures to exclude pathogens, prevent cross-contamination, and actively reduce the pathogenic load of feed and ingredients are being developed. However, research thus far has focused on the role of chemicals or thermal treatment to reduce the RNA in the actual feedstuffs, and has not addressed potential residual contamination within the manufacturing facility that may lead to continuous contamination of finished feeds. The purpose of this experiment was to evaluate the use of a standardized protocol to sanitize an animal feed manufacturing facility contaminated with PEDV. Environmental swabs were collected throughout the facility during the manufacturing of a swine diet inoculated with PEDV. To monitor facility contamination of the virus, swabs were collected at: 1) baseline prior to inoculation, 2) after production of the inoculated feed, 3) after application of a quaternary ammonium-glutaraldehyde blend cleaner, 4) after application of a sodium hypochlorite sanitizing solution, and 5) after facility heat-up to 60°C for 48 hours. Decontamination step, surface, type, zone and their interactions were all found to impact the quantity of detectable PEDV RNA (P < 0.05). As expected, all samples collected from equipment surfaces contained PEDV RNA after production of the contaminated feed. Additionally, the majority of samples collected from non-direct feed contact surfaces were also positive for PEDV RNA after the production of the contaminated feed, emphasizing the potential role dust plays in cross-contamination of pathogen throughout a manufacturing facility. Application of the cleaner, sanitizer, and heat were effective at reducing PEDV genomic material (P < 0.05), but did not completely eliminate it

Pulmonary adenocarcinoma with osseous metastasis and secondary paresis in a blue and gold macaw (Ara ararauna)

A 16-yr-old female blue and gold macaw (Ara ararauna) was presented with an acute history of lethargy, inappetance, ataxia, and paralysis. The bird had rapidly progressed from a normal state to complete inability to perch or ambulate within a 48-hr period. Neurologic examination revealed bilateral hind limb paresis with upper motor neuron signs present in both legs and the vent. Radiographs identified multiple nodular soft-tissue opacities within the cranial coelomic cavity and a single nodule superimposed with the thoracic spine. The bird was euthanized and submitted for necropsy, which revealed a primary pulmonary adenocarcinoma with multiple sites of osseous metastasis, including the vertebrae, and subsequent spinal cord compression. This is the first report of pulmonary adenocarcinoma in this species, although reports of similar tumors in other psittacines have been published. This report, along with others previously published, suggests that vertebral metastasis of primary pulmonary tumors may be more common in psittacine species than previously recognized and, as such, should be considered as a differential diagnosis in psittacine birds exhibiting signs of neurologic dysfunction attributed to a spinal cord lesion

Primer and probe sequences used in the duplex real-time RT-PCR (RT-qPCR) assay for the detection and quantification of environmental swabs for PEDV.

<p>Primer and probe sequences used in the duplex real-time RT-PCR (RT-qPCR) assay for the detection and quantification of environmental swabs for PEDV.</p

Number of swabs with detectable PEDV RNA compared to the number of swabs collected, based on surface characteristic and type, collection zone and decontamination step done immediately prior to sample collection.

<p>Number of swabs with detectable PEDV RNA compared to the number of swabs collected, based on surface characteristic and type, collection zone and decontamination step done immediately prior to sample collection.</p

Main effects and interactions of factors considered for building decontamination.

<p>Main effects and interactions of factors considered for building decontamination.</p

Percent PCR-positive for PEDV from environmental samples collected during decontamination as a function of step of the decontamination protocol followed after processing PEDV-inoculated mash feed into pellets.

<p>Percent PCR-positive for PEDV from environmental samples collected during decontamination as a function of step of the decontamination protocol followed after processing PEDV-inoculated mash feed into pellets.</p

Percent PCR-positive for PEDV from environmental samples collected based on surface type (equipment or structural) during decontamination as a function of step of the decontamination protocol followed after processing PEDV-inoculated mash feed into pellets.

<p>Percent PCR-positive for PEDV from environmental samples collected based on surface type (equipment or structural) during decontamination as a function of step of the decontamination protocol followed after processing PEDV-inoculated mash feed into pellets.</p

In Vivo and In Vitro Characterization of the Recently Emergent PRRSV 1-4-4 L1C Variant (L1C.5) in Comparison with Other PRRSV-2 Lineage 1 Isolates

The recently emerged PRRSV 1-4-4 L1C variant (L1C.5) was in vivo and in vitro characterized in this study in comparison with three other contemporary 1-4-4 isolates (L1C.1, L1A, and L1H) and one 1-7-4 L1A isolate. Seventy-two 3-week-old PRRSV-naive pigs were divided into six groups with twelve pigs/group. Forty-eight pigs (eight/group) were for inoculation, and 24 pigs (four/group) served as contact pigs. Pigs in pen A of each room were inoculated with the corresponding virus or negative media. At two days post inoculation (DPI), contact pigs were added to pen B adjacent to pen A in each room. Pigs were necropsied at 10 and 28 DPI. Compared to other virus-inoculated groups, the L1C.5-inoculated pigs exhibited more severe anorexia and lethargy, higher mortality, a higher fraction of pigs with fever (>40 °C), higher average temperature at several DPIs, and higher viremia levels at 2 DPI. A higher percentage of the contact pigs in the L1C.5 group became viremic at two days post contact, implying the higher transmissibility of this virus strain. It was also found that some PRRSV isolates caused brain infection in inoculation pigs and/or contact pigs. The complete genome sequences and growth characteristics in ZMAC cells of five PRRSV-2 isolates were further compared. Collectively, this study confirms that the PRRSV 1-4-4 L1C variant (L1C.5) is highly virulent with potential higher transmissibility, but the genetic determinants of virulence remain to be elucidated

Effect of contamination on animal food-contact zone and their types after porcine epidemic diarrhea virus (PEDV) inoculated animal food manufacturing^†.

<p>Effect of contamination on animal food-contact zone and their types after porcine epidemic diarrhea virus (PEDV) inoculated animal food manufacturing^{<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0187309#t002fn002" target="_blank">†</a>}.</p

Diet composition of porcine epidemic diarrhea virus (PEDV) inoculated animal food, as fed basis.

<p>Diet composition of porcine epidemic diarrhea virus (PEDV) inoculated animal food, as fed basis.</p