In Mexico, the first outbreaks suggestive of the circulation of the porcine epidemic diarrhea virus (PEDV) were identified at the beginning of July 2013. To identify the molecular characteristics of the PEDV Spike (S) gene in Mexico, 116 samples of the intestine and diarrhea of piglets with clinical signs of porcine epidemic diarrhea (PED) were obtained. Samples were collected from 14 farms located in six states of Mexico (Jalisco, Puebla, Sonora, Veracruz, Guanajuato, and Michoacán) from 2013 to 2016. To identify PEDV, we used real-time RT-PCR to discriminate between non-INDEL and INDEL strains. We chose samples according to state and year to characterize the S gene. After amplification of the S gene, the obtained products were sequenced and assembled. The complete amino acid sequences of the spike protein were used to perform an epitope analysis, which was used to determine null mutations in regions SS2, SS6, and 2C10 compared to the sequences of G2. A phylogenetic analysis determined the circulation of G2b and INDEL strains in Mexico. However, several mutations were recorded in the collagenase equivalent (COE) region that were related to the change in polarity and charge of the amino acid residues. The PEDV strain circulating in Jalisco in 2016 has an insertion of three amino acids (LGL) and one change in the antigenic site of the COE region, and strains from the years 2015 and 2016 changed the index of the surface probability, which could be related to the re-emergence of disease outbreaks.

Blue eye disease (BED) is a swine viral infection that affects the pork industry of Mexico. Porcine orthorubulavirus (PRV) is the etiological agent, and the hemagglutinin-neuraminidase protein (HN) is characterized as the best antigen for serological tests, although other structural proteins, including the nucleoprotein (NP) and the matrix (M) protein, have been investigated during the infection of members of the Paramyxoviridae family, generating promising results. Herein, for the first time, we successfully produced and characterized both the NP and M proteins of PRV by using a recombinant strategy in the E. coli heterologous system. The ORF of the NP and M genes were cloned in-frame with the pET-SUMO expression vector. Recombinant proteins proved to be a sensitive target to detect seroconversion at 7 days until 28 days in vaccinated mice (BALB/c) by indirect ELISAs. Immunoreactivity was also tested using porcine serum samples, in which antibodies were recognized from early stages to a persistence of PRV infection, which is indicative that these proteins contain properties similar to native antigens. The predicted tertiary structure showed that both proteins have a conserved structure that resembles those found in others Paramyxovirus. Our results pave the way for developing biotechnological tools based on these proteins for the control and prevention of BED.

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Porcine rubulavirus (PRV) is a contagious virus that affects the Mexican swine industry. This work aimed to evaluate the immunogenicity of an rHN-PorPV candidate vaccine on pregnant sows, and the protective efficacy afforded to their 7-day-old suckling piglets against PRV lethal challenge. Three sows were immunized with rHN-PorPV formulated with immunestimulating complex (ISCOMs) and two sows with rHN-PorPV protein alone as well as a mock-immunized pregnant sow (negative control). Quantitative ELISA detected a high concentration of anti-rHN-PorPV Immunoglobulin G (IgG) antibodies in sow sera after the second dose of vaccine administered on day 14 until farrowing, showing viral-neutralizing and cross-neutralization activity against different variants of PRV. Sera samples from piglets of immunized sows (with or without adjuvant), showed high concentrations of IgG antibodies.As expected, piglets from the negative control sow (n=5), exhibited severe signs of disease and 100% of mortality after PRV challenge study. Conversely, 75% and 87.5% of the piglets born from the rHN-PorPV and the rHN-PorPV-ISCOMs-immunized sows (n=8), survived, respectively, showing milder PRV clinical signs. Our data indicate that rHN-PorPV candidate vaccine produced in E. coli induces efficient humoral response in pregnant sows and that the maternally derived immunity provides high protection to suckling piglets against PRV lethal challenge.