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Papers by Luis Gómez Núñez
In swine production systems, one of the critical points that must be strictly attended to is the ... more In swine production systems, one of the critical points that must be strictly attended to is the health of the pigs. Health is a structural component of animal welfare and reflects an optimal state of the animals, which has a direct impact on a higher productive performance and better development conditions. Infectious diseases are one of the greatest threats to the health of pigs and can cause losses of up to 100 % of production; therefore, it requires constant attention and continuous monitoring by the veterinarian and producers, in perfect coordination with the official health authorities. Currently, the implementation of best practices in the production chain is of interest to both producers and consumers. The control of infectious diseases requires collaboration between the various actors in the environment Rev Mex Cienc Pecu 2021;12(Supl 3):149-185 151 and must be considered a public good, since their negative repercussions can range from the local to the global level. This re...
Virus Genes, 2017
In Mexico, the first outbreaks suggestive of the circulation of the porcine epidemic diarrhea vir... more 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 (232 LGL 234) 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.
Virus Research, 2017
The objective of this study was to evaluate the clinical disease, humoral response and viral dist... more The objective of this study was to evaluate the clinical disease, humoral response and viral distribution of recent Porcine rubulavirus (PorPV) isolates in experimentally infected pigs. Four, 6-piglet (5-days old) groups were employed (G1-84, G2-93, G3-147, and G4-T). Three viral strains were used for the experimental infection: the reference strain LPMV-1984 (Michoacán 1984) and two other strains isolated in 2013, one in Queretaro (Qro/93/2013) and the other in Michoacán (Mich/147/2013). Each strain was genetically characterized by amplification and sequencing of the gene encoding hemagglutinin-neuroamidase (HN). The inoculation was performed through the oronasal and ocular routes, at a dose of 1×10(6)TCID50/ml. Subsequently, the signs were evaluated daily and necropsies were performed on 3 different days post infection (dpi). We recorded all micro- and macroscopic lesions. Organs from the nervous, lymphatic, and respiratory system were analyzed by quantifying the viral RNA load and the presence of the infectious virus. The presence of the viral antigen in organs was evidenced through immunohistochemistry. Seroconversion was evaluated through the use of a hemagglutination inhibition test. In the characterization of gene HN, only three substitutions were identified in strain Mich/147/2013, two in strain LPMV/1984 (fourth passage) and one in strain Qro/93/2013, with respect to reference strain LPMV-84, these changes had not been identified as virulence factors in previously reported strains. Neurological alterations associated with the infection were found in all three experimental groups starting from 3dpi. Groups G1-84 and G3-147 presented the most exacerbated nervous signs. Group G2-93 only presented milder signs including slight motor incoordination, and an increased rectal temperature starting from day 5 post infection (PI). The main histopathological findings were the presence of a mononuclear inflammatory infiltrate (lymphocytic/monocytic) surrounding the ventricles in the brain and focal interstitial pneumonitis with distention of the alveolar sacs in the lungs. PorPV and RNA distribution were identified in the organs of the nervous, lymphatic, and respiratory systems of the piglets analyzed at different times (days 5, 10, and 15 PI). The viral antigen was detected in the brain and lungs in most of the assessed groups. Seroconversion was evident in groups G1-84 and G2-93. Groups G1-84 and G3-147 were the most clinically affected by the experimental infection. Both strains were isolated in the state of Michoacán. The virulence of the new isolates maintains similar characteristics to those reported more than 30 years ago.
Small Ruminant Research, 2021
Small ruminant lentiviruses (SRLVs) are one of the main viral agents affecting goats worldwide. T... more Small ruminant lentiviruses (SRLVs) are one of the main viral agents affecting goats worldwide. They cause a systemic, chronic, incurable, degenerative disease. In Mexico, the B1 genotype of SRLV has been detected as endemic in goats and sheep; however, its pathological characteristics have not yet been evaluated. In this study, sampling was performed to identify the percentage of SRLV positivity in different farms in Mexico. Prevalence rates of 19.6 % and 11.6 % were detected through PCR and serology, respectively. Through a real-time PCR differential test, the prevalence of genotype B was identified. From a chosen case, an SRLV strain was isolated (which was called SRLV/B1/Goat/Mx/INIFAP-1/2013). The phylogenetic analysis revealed that the strain SRLV/B1/Goat/Mx/INIFAP-1/2013 shares a great homology with an American and Asiatic strains of the B1 genotype. Virulence of the isolated strain was analyzed during an experimental infection in kids. The kids did not present clinical disea...
Cloning and heterologue expression of antigens to pathogenic agents which affect humans and anima... more Cloning and heterologue expression of antigens to pathogenic agents which affect humans and animals is an effective way of producing subunitary vaccines. An analysis was done of stable expression of the E gene coding for the West Nile Virus (WNV) envelope (E) glycoprotein in corn type II embryogenic callus transformed with biobalistics using the constitutive CAMV35S promoter. This protein is responsible for WNV immunity induction. Transgene expression in transformed calluses with the WNV E glycoprotein was identified by RT-PCR. Western Blot was used to verify protein expression with total soluble protein (TSP) extracts from the transformed calluses. A 68 kDa protein was identified and 0.86 % TSP attained. This WNV E glycoprotein production system allows production of this protein in almost half the time of conventional techniques, a significant advance in experimental immunological design. This is the first time that this kind of evaluation was done. We suggest evaluating the transf...
Revista Mexicana de Ciencias Pecuarias
La importancia de las cabras en México radica en que su producción se concentra en zonas áridas y... more La importancia de las cabras en México radica en que su producción se concentra en zonas áridas y semiáridas del norte y el centro del país, y particularmente en la región de la Mixteca en los estados de Oaxaca, Guerrero y Puebla, donde prevalece la pobreza y donde la especie, es capaz de sobrevivir y producir leche y cabritos. El estudio de las enfermedades de las cabras en México es escaso; el INIFAP se ha caracterizado por nunca haber dejado de lado la investigación en esta especie. En esta revisión, se abordan las principales enfermedades que afectan a las cabras en México y se describen las investigaciones que sobre ellas ha desarrollado el INIFAP. Los problemas de salud que enfrentan la mayoría de los rebaños caprinos en los que se ha realizado investigación, demuestran que algunos trastornos reproductivos son causados por enfermedades como brucelosis, leptospirosis y clamidiasis, todas éstas consideradas endémicas y con potencial zoonótico. Por otra parte, los problemas de ti...
Revista Mexicana de Ciencias Pecuarias
En los sistemas de producción porcina, uno de los puntos críticos que deben ser atendidos con est... more En los sistemas de producción porcina, uno de los puntos críticos que deben ser atendidos con estricto rigor, es la salud de los cerdos. La salud, es un componente estructural del bienestar animal y refleja un estado óptimo de los animales, lo que repercute directamente en un mayor desempeño productivo y mejores condiciones de desarrollo. Uno de los eslabones más frágiles de la salud de los cerdos, es la presencia de enfermedades infecciosas más importantes, las cuales pueden representar pérdidas hasta del 100 % de la producción, por lo cual, debe ser un tema de atención constante, y continuamente vigilado por el Médico Veterinario Zootecnista y los productores, en perfecta coordinación con las autoridades sanitarias oficiales. En la actualidad, la implementación de mejores prácticas en la cadena productiva es de interés para productores y consumidores. El control de las enfermedades infecciosas debe ser un tema de colaboración entre los diferentes actores del entorno y ser consider...
RA RIÓ GUENDARUYUBI
The SARS-CoV-2 virus is an emerging coronavirus identified in 2019 and is responsible for the dis... more The SARS-CoV-2 virus is an emerging coronavirus identified in 2019 and is responsible for the disease called COVID-19, which was declared a global pandemic, in 2020 by the World Health Organization (WHO). At the beginning of May 2020, more than 4 million infected people have been confirmed in the world and more than 278 thousand deaths, estimating an economic impact of more than 3 billion dollars. In Mexico, a total of 36,327 positive cases have been confirmed. The impact of this disease is mainly associated with the rapid spread among the human population and the severity of the clinical signs, which, if not treated, can lead to death. Currently, there is no vaccine available to prevent the disease and its control is based on the clinical diagnosis, which must be carried out by a specialist. This diagnosis must be confirmed by laboratory tests, which are of two types, mainly: for the detection of the etiological agent (virological and molecular) and serological (detection of antibo...
In swine production systems, one of the critical points that must be strictly attended to is the ... more In swine production systems, one of the critical points that must be strictly attended to is the health of the pigs. Health is a structural component of animal welfare and reflects an optimal state of the animals, which has a direct impact on a higher productive performance and better development conditions. Infectious diseases are one of the greatest threats to the health of pigs and can cause losses of up to 100 % of production; therefore, it requires constant attention and continuous monitoring by the veterinarian and producers, in perfect coordination with the official health authorities. Currently, the implementation of best practices in the production chain is of interest to both producers and consumers. The control of infectious diseases requires collaboration between the various actors in the environment Rev Mex Cienc Pecu 2021;12(Supl 3):149-185 151 and must be considered a public good, since their negative repercussions can range from the local to the global level. This re...
Virus Genes, 2017
In Mexico, the first outbreaks suggestive of the circulation of the porcine epidemic diarrhea vir... more 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 (232 LGL 234) 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.
Virus Research, 2017
The objective of this study was to evaluate the clinical disease, humoral response and viral dist... more The objective of this study was to evaluate the clinical disease, humoral response and viral distribution of recent Porcine rubulavirus (PorPV) isolates in experimentally infected pigs. Four, 6-piglet (5-days old) groups were employed (G1-84, G2-93, G3-147, and G4-T). Three viral strains were used for the experimental infection: the reference strain LPMV-1984 (Michoacán 1984) and two other strains isolated in 2013, one in Queretaro (Qro/93/2013) and the other in Michoacán (Mich/147/2013). Each strain was genetically characterized by amplification and sequencing of the gene encoding hemagglutinin-neuroamidase (HN). The inoculation was performed through the oronasal and ocular routes, at a dose of 1×10(6)TCID50/ml. Subsequently, the signs were evaluated daily and necropsies were performed on 3 different days post infection (dpi). We recorded all micro- and macroscopic lesions. Organs from the nervous, lymphatic, and respiratory system were analyzed by quantifying the viral RNA load and the presence of the infectious virus. The presence of the viral antigen in organs was evidenced through immunohistochemistry. Seroconversion was evaluated through the use of a hemagglutination inhibition test. In the characterization of gene HN, only three substitutions were identified in strain Mich/147/2013, two in strain LPMV/1984 (fourth passage) and one in strain Qro/93/2013, with respect to reference strain LPMV-84, these changes had not been identified as virulence factors in previously reported strains. Neurological alterations associated with the infection were found in all three experimental groups starting from 3dpi. Groups G1-84 and G3-147 presented the most exacerbated nervous signs. Group G2-93 only presented milder signs including slight motor incoordination, and an increased rectal temperature starting from day 5 post infection (PI). The main histopathological findings were the presence of a mononuclear inflammatory infiltrate (lymphocytic/monocytic) surrounding the ventricles in the brain and focal interstitial pneumonitis with distention of the alveolar sacs in the lungs. PorPV and RNA distribution were identified in the organs of the nervous, lymphatic, and respiratory systems of the piglets analyzed at different times (days 5, 10, and 15 PI). The viral antigen was detected in the brain and lungs in most of the assessed groups. Seroconversion was evident in groups G1-84 and G2-93. Groups G1-84 and G3-147 were the most clinically affected by the experimental infection. Both strains were isolated in the state of Michoacán. The virulence of the new isolates maintains similar characteristics to those reported more than 30 years ago.
Small Ruminant Research, 2021
Small ruminant lentiviruses (SRLVs) are one of the main viral agents affecting goats worldwide. T... more Small ruminant lentiviruses (SRLVs) are one of the main viral agents affecting goats worldwide. They cause a systemic, chronic, incurable, degenerative disease. In Mexico, the B1 genotype of SRLV has been detected as endemic in goats and sheep; however, its pathological characteristics have not yet been evaluated. In this study, sampling was performed to identify the percentage of SRLV positivity in different farms in Mexico. Prevalence rates of 19.6 % and 11.6 % were detected through PCR and serology, respectively. Through a real-time PCR differential test, the prevalence of genotype B was identified. From a chosen case, an SRLV strain was isolated (which was called SRLV/B1/Goat/Mx/INIFAP-1/2013). The phylogenetic analysis revealed that the strain SRLV/B1/Goat/Mx/INIFAP-1/2013 shares a great homology with an American and Asiatic strains of the B1 genotype. Virulence of the isolated strain was analyzed during an experimental infection in kids. The kids did not present clinical disea...
Cloning and heterologue expression of antigens to pathogenic agents which affect humans and anima... more Cloning and heterologue expression of antigens to pathogenic agents which affect humans and animals is an effective way of producing subunitary vaccines. An analysis was done of stable expression of the E gene coding for the West Nile Virus (WNV) envelope (E) glycoprotein in corn type II embryogenic callus transformed with biobalistics using the constitutive CAMV35S promoter. This protein is responsible for WNV immunity induction. Transgene expression in transformed calluses with the WNV E glycoprotein was identified by RT-PCR. Western Blot was used to verify protein expression with total soluble protein (TSP) extracts from the transformed calluses. A 68 kDa protein was identified and 0.86 % TSP attained. This WNV E glycoprotein production system allows production of this protein in almost half the time of conventional techniques, a significant advance in experimental immunological design. This is the first time that this kind of evaluation was done. We suggest evaluating the transf...
Revista Mexicana de Ciencias Pecuarias
La importancia de las cabras en México radica en que su producción se concentra en zonas áridas y... more La importancia de las cabras en México radica en que su producción se concentra en zonas áridas y semiáridas del norte y el centro del país, y particularmente en la región de la Mixteca en los estados de Oaxaca, Guerrero y Puebla, donde prevalece la pobreza y donde la especie, es capaz de sobrevivir y producir leche y cabritos. El estudio de las enfermedades de las cabras en México es escaso; el INIFAP se ha caracterizado por nunca haber dejado de lado la investigación en esta especie. En esta revisión, se abordan las principales enfermedades que afectan a las cabras en México y se describen las investigaciones que sobre ellas ha desarrollado el INIFAP. Los problemas de salud que enfrentan la mayoría de los rebaños caprinos en los que se ha realizado investigación, demuestran que algunos trastornos reproductivos son causados por enfermedades como brucelosis, leptospirosis y clamidiasis, todas éstas consideradas endémicas y con potencial zoonótico. Por otra parte, los problemas de ti...
Revista Mexicana de Ciencias Pecuarias
En los sistemas de producción porcina, uno de los puntos críticos que deben ser atendidos con est... more En los sistemas de producción porcina, uno de los puntos críticos que deben ser atendidos con estricto rigor, es la salud de los cerdos. La salud, es un componente estructural del bienestar animal y refleja un estado óptimo de los animales, lo que repercute directamente en un mayor desempeño productivo y mejores condiciones de desarrollo. Uno de los eslabones más frágiles de la salud de los cerdos, es la presencia de enfermedades infecciosas más importantes, las cuales pueden representar pérdidas hasta del 100 % de la producción, por lo cual, debe ser un tema de atención constante, y continuamente vigilado por el Médico Veterinario Zootecnista y los productores, en perfecta coordinación con las autoridades sanitarias oficiales. En la actualidad, la implementación de mejores prácticas en la cadena productiva es de interés para productores y consumidores. El control de las enfermedades infecciosas debe ser un tema de colaboración entre los diferentes actores del entorno y ser consider...
RA RIÓ GUENDARUYUBI
The SARS-CoV-2 virus is an emerging coronavirus identified in 2019 and is responsible for the dis... more The SARS-CoV-2 virus is an emerging coronavirus identified in 2019 and is responsible for the disease called COVID-19, which was declared a global pandemic, in 2020 by the World Health Organization (WHO). At the beginning of May 2020, more than 4 million infected people have been confirmed in the world and more than 278 thousand deaths, estimating an economic impact of more than 3 billion dollars. In Mexico, a total of 36,327 positive cases have been confirmed. The impact of this disease is mainly associated with the rapid spread among the human population and the severity of the clinical signs, which, if not treated, can lead to death. Currently, there is no vaccine available to prevent the disease and its control is based on the clinical diagnosis, which must be carried out by a specialist. This diagnosis must be confirmed by laboratory tests, which are of two types, mainly: for the detection of the etiological agent (virological and molecular) and serological (detection of antibo...