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Porcine reproductive and respiratory syndrome (PRRS), characterized by reproductive failure in sows and respiratory distress in pigs of all ages, causes substantial economic loss to the worldwide swine industry. PRRS [...]

To the Editor: Senecavirus A (SVA; formerly known as Seneca Valley virus [SVV] belongs to the genus Senecavirus, family Picornaviridae (1,2). SVA was first isolated in 2001 as a contaminant [...]

In the past decade, different members of the genus Mamastrovirus have been associated with outbreaks of neurologic disease in humans, cattle, sheep, mink, and, most recently, porcine astrovirus 3 (PoAstV3) in swine. We performed a retrospective analysis of 50 cases of porcine neurologic disease of undetermined cause but with microscopic lesions compatible with a viral encephalomyelitis to better understand the role and pathogenesis of PoAstV3 infection. Nucleic acid was extracted from formalin-fixed paraffin-embedded (FFPE) tissue for reverse transcription quantitative polymerase chain reaction (RT-qPCR) testing for PoAstV3. In addition, 3 cases with confirmed PoAstV3-associated disease were assayed by RT-qPCR to investigate PoAstV3 tissue distribution. PoAstV3 was detected in central nervous system (CNS) tissue via RT-qPCR and in situ hybridization in 13 of 50 (26%) FFPE cases assayed. PoAstV3 was rarely detected in any tissues outside the CNS. Positive cases from the retrospective study included pigs in various production categories beginning in 2010, the earliest year samples were available. Based on these results, PoAstV3 appears to be a recurring putative cause of viral encephalomyelitis in swine that is rarely detected outside of the CNS at the time of clinical neurologic disease, unlike other common viral causes of neurologic disease in swine. [ABSTRACT FROM AUTHOR]

Since 2014, pelvic organ prolapse (POP) has become a growing concern in the U.S. swine industry. Pelvic organ prolapse is one of the three leading causes of sow mortality today. While research has increased over the years investigating the cause and occurrence of POP, the reason for the increase in POP is not fully understood. Trace mineral status is one area of interest proposed to be associated with POP. We conducted a study to determine if there was a difference in serum trace minerals and tumor necrosis factor alpha (TNF-a) concentration between prolapsed and non-prolapsed sows. The study utilized 44 prolapsed sows and 44 nonprolapsed sows of the same parity, location, management, and stage of production. Blood was collected from the prolapsed and non-prolapsed sows upon discovery and processed at a local lab where serum was collected and stored until further analyses were performed. Serum samples were analyzed using inductively coupled plasma mass spectrometry (ICP-MS) for trace mineral content (Ca, Cu, Fe, K, Mg, Mn, Mo, P, Se, and Zn). Additionally, TNF-a concentration was determined from the serum using ELISA testing. Data were analyzed using the PROC GLIMMIX procedure in SAS. Prolapsed sows had decreased (P < 0.05) Fe (2.77 vs 3.76 ppm), Mo (9.22 vs 13.02 ppb), and Zn (1.07 vs 1.19 ppm) trace mineral concentration in the serum compared with the non-prolapsed sows. However, Mg was greater (P < 0.05) in prolapsed sows compared with non-prolapsed sows (23.24 vs 21.36 ppm). Selenium was marginally (P = 0.08) less in prolapsed sows compared with non-prolapsed sows (191 vs 206 ppb). There were no differences (P > 0.10) between prolapsed and non-prolapsed sows trace mineral concentrations for Ca (97.1 vs 99.1 ppm), Cu (2.07 vs 2.03 ppm), Mn (3.77 vs 3.72 ppb), P (52.5 vs 50.2 ppm), and K (264 vs 264 ppm). There was a difference (P < 0.05) in TNF-α concentration between the prolapsed and non-prolapsed sows (233.1 vs 178.9 pg/mL). This study suggests that there is a decreased concentration of various serum trace minerals found in prolapsed sows compared with non-prolapsed sows and an increased TNF-a response in prolapsed sows. [ABSTRACT FROM AUTHOR]

Teschovirus encephalomyelitis is a sporadic disease associated with Teschovirus A (PTV) serotype 1 and, less frequently, other serotypes. In recent years, the number of cases submitted to the Iowa State University Veterinary Diagnostic Laboratory with a history of posterior paresis has increased. Submission histories from various regions of the United States suggest a trend for clinical disease to persist in herds and affect a wider age-range of pigs than historically reported. Polioencephalitis and/or myelitis was consistently present and PTV was detected in affected neural tissue by PCR in a portion of cases. Sequencing from two clinical cases identified PTV-2 and PTV-11. To assess neuropathogenicity of these isolates, 5-week-old cesarean derived and colostrum-deprived pigs were assigned to three groups: negative control (n = 4), PTV-2-inoculated (n = 7), and PTV-11-inoculated (n = 7). Three PTV-2-inoculated pigs developed mild incoordination of the hind limbs, one of which progressed to posterior ataxia. While all PTV-11-inoculated pigs showed severe neurological signs consistent with Teschovirus encephalomyelitis, no evidences of neurological signs were observed in sham-inoculated animals. All PTV-2- and PTV-11-inoculated pigs had microscopic lesions consistent with Teschovirus encephalomyelitis. To our knowledge, this is the first description of PTV-11 and experimental study demonstrating the neuropathogenicity of PTV-11 in the United States. [ABSTRACT FROM AUTHOR]

We isolated and plaque purified IA76950-WT and IA70388-R, 2 porcine reproductive and respiratory syndrome viruses from pigs in the same herd in Iowa, USA, that exhibited coughing and had interstitial pneumonia. Phylogenetic and molecular evolutionary analysis indicated that IA70388-R is a natural recombinant from Fostera PRRSV vaccine and field strain IA76950-WT. [ABSTRACT FROM AUTHOR]

Mycoplasma (M.) hyosynoviae is known to colonize and cause disease in growing-finishing pigs. In this study, two clinical isolates of M. hyosynoviae were compared by inoculating cesarean-derived colostrum-deprived and specific-pathogen-free growing pigs. After intranasal or intravenous inoculation, the proportion and distribution pattern of clinical cases was compared in addition to the severity of lameness. Tonsils were found to be the primary site of colonization, while bacteremia was rarely detected prior to the observation of clinical signs. Regardless of the clinical isolate, route of inoculation, or volume of inocula, histopathological alterations and tissue invasion were detected in multiple joints, indicating an apparent lack of specific joint tropism. Acute disease was primarily observed 7 to 10 days post-inoculation. The variability in the severity of synovial microscopic lesions and pathogen detection in joint cavities suggests that the duration of joint infection may influence the diagnostic accuracy. In summary, these findings demonstrate that diagnosis of M. hyosynoviae-associated arthritis can be influenced by the clinical isolate, and provides a study platform to investigate the colonization and virulence potential of field isolates. This approach can be particularly relevant to auxiliate in surveillance and testing of therapeutic and/or vaccine candidates. [ABSTRACT FROM AUTHOR]

Background: At least two genetically different porcine epidemic diarrhea virus (PEDV) strains have been identified in the United States (U.S. PEDV prototype and S-INDEL-variant strains). The current serological assays offered at veterinary diagnostic laboratories for detection of PEDV-specific antibody are based on the U.S. PEDV prototype strain. The objectives of this study were: 1) isolate the U.S. PEDV S-INDEL-variant strain in cell culture; 2) generate antisera against the U.S. PEDV prototype and S-INDEL-variant strains by experimentally infecting weaned pigs; 3) determine if the various PEDV serological assays could detect antibodies against the U.S. PEDV S-INDEL-variant strain and vice versa. Results: A U.S. PEDV S-INDEL-variant strain was isolated in cell culture in this study. Three groups of PEDV-negative, 3-week-old pigs (five pigs per group) were inoculated orally with a U.S. PEDV prototype isolate (previously isolated in our lab), an S-INDEL-variant isolate or virus-negative culture medium. Serum samples collected at 0, 7, 14, 21 and 28 days post inoculation were evaluated by the following PEDV serological assays: 1) indirect fluorescent antibody (IFA) assays using the prototype and S-INDEL-variant strains as indicator viruses; 2) virus neutralization (VN) tests against the prototype and S-INDEL-variant viruses; 3) PEDV prototype strain whole virus based ELISA; 4) PEDV prototype strain S1-based ELISA; and 5) PEDV S-INDEL-variant strain S1-based ELISA. The positive antisera against the prototype strain reacted to and neutralized both prototype and S-INDEL-variant viruses, and the positive antisera against the S-INDEL-variant strain also reacted to and neutralized both prototype and S-INDEL-variant viruses, as examined by IFA antibody assays and VN tests. Antibodies against the two PEDV strains could be detected by all three ELISAs although detection rates varied to some degree. Conclusions: These data indicate that the antibodies against U.S. PEDV prototype and S-INDEL-variant strains cross-reacted and cross-neutralized both strains in vitro. The current serological assays based on U.S. PEDV prototype strain can detect antibodies against both U.S. PEDV strains. [ABSTRACT FROM AUTHOR]