Ceria-vesicle nanohybrid therapeutic for modulation of innate and adaptive immunity in a collagen-induced arthritis model.

Commencing with the breakdown of immune tolerance, multiple pathogenic factors, including synovial inflammation and harmful cytokines, are conjointly involved in the progression of rheumatoid arthritis. Intervening to mitigate some of these factors can bring a short-term therapeutic effect, but other unresolved factors will continue to aggravate the disease. Here we developed a ceria nanoparticle-immobilized mesenchymal stem cell nanovesicle hybrid system to address multiple factors in rheumatoid arthritis. Each component of this nanohybrid works individually and also synergistically, resulting in comprehensive treatment. Alleviation of inflammation and modulation of the tissue environment into an immunotolerant-favourable state are combined to recover the immune system by bridging innate and adaptive immunity. The therapy is shown to successfully treat and prevent rheumatoid arthritis by relieving the main symptoms and also by restoring the immune system through the induction of regulatory T cells in a mouse model of collagen-induced arthritis.

Comparative growth performance of 3 types of combination vaccines containing porcine circovirus 2 and Mycoplasma hyopneumoniae under field conditions.

The objective of this field trial was to compare the effect of 3 different types of combination vaccines on growth performance in pigs under field conditions. The vaccines compared were: a trivalent vaccine containing porcine circovirus type 2a and 2b (PCV-2a/b); and Mycoplasma hyopneumoniae; a mixable bivalent vaccine containing PCV-2a and M. hyopneumoniae; and a ready-to-use bivalent vaccine containing PCV-2a and M. hyopneumoniae. Two farms were selected on the basis of their history of subclinical PCV-2d infection and enzootic pneumonia. A total of 120 pigs on each farm was randomly divided into 4 groups of 30 pigs each. The trivalent-vaccinated group from both farms outperformed each bivalent-vaccinated group in terms of growth performance. Growth performance was significantly improved during the fattening period (70 to 175 d of age) in the mixable bivalent-vaccinated group compared with the ready-to-use bivalent-vaccinated group on 1 farm. The trivalent-vaccinated group elicited higher levels of neutralizing antibodies and interferon-γ secreting cells (IFN-γ-SC) against PCV-2d, while simultaneously decreasing the levels of PCV-2d load in blood when compared with the mixable and ready-to-use bivalent-vaccinated groups. The trivalent-vaccinated group also elicited higher levels of IFN-γ-SC against M. hyopneumoniae and lower levels of M. hyopneumoniae load in the larynx when compared with the mixable and ready-to-use bivalent-vaccinated groups. The results of the present study demonstrated that a trivalent vaccine containing PCV-2a/b and M. hyopneumoniae resulted in a more productive parameter, higher immune responses, and less blood-viral and mycoplasmal larynx-loads when compared with the mixable and ready-to-use bivalent vaccines despite the presence of ongoing subclinical PCV-2d infection and enzootic pneumonia on the farms.

L'objectif de cet essai de terrain était de comparer l'effet de trois différents types de vaccins combinés sur les performances de croissance chez les porcs dans des conditions de terrain. Les vaccins comparés étaient : un vaccin trivalent contenant des circovirus porcins de type 2a et 2b (PCV-2a/b) et Mycoplasma hyopneumoniae; un vaccin bivalent mélangeable contenant PCV-2a et M. hyopneumoniae; et un vaccin bivalent prêt à l'emploi contenant le PCV-2a et M. hyopneumoniae. Deux fermes ont été sélectionnées sur la base de leurs antécédents d'infection subclinique par le PCV-2d et de pneumonie enzootique. Un total de 120 porcs dans chaque ferme a été divisé au hasard en quatre groupes de 30 porcs chacun. Le groupe vacciné par les trivalents des deux fermes a surpassé chaque groupe vacciné par les bivalents en termes de performances de croissance. Les performances de croissance ont été significativement améliorées pendant la période d'engraissement (70 à 175 jours d'âge) dans le groupe vacciné bivalent mélangeable par rapport au groupe vacciné bivalent prêt à l'emploi sur une ferme. Le groupe vacciné par trivalent a suscité des niveaux plus élevés d'anticorps neutralisants et de cellules sécrétant de l'interféron-γ (IFN-γ-SC) contre le PCV-2d, tout en diminuant simultanément les niveaux de charge de PCV-2d dans le sang par rapport aux vaccins mélangeables et prêts à l'emploi. Le groupe vacciné trivalent a également provoqué des niveaux plus élevés d'IFN-γ-SC contre M. hyopneumoniae et des niveaux inférieurs de charge de M. hyopneumoniae dans le larynx par rapport aux groupes vaccinés bivalents mélangeables et prêts à l'emploi. Les résultats de la présente étude ont démontré qu'un vaccin trivalent contenant du PCV-2a/b et M. hyopneumoniae entraînait un paramètre plus productif, des réponses immunitaires plus élevées et moins de charges sanguines virales et mycoplasmiques dans le larynx par rapport aux vaccins mélangeables et prêts à l'emploi malgré la présence d'une infection subclinique par le PCV-2d et d'une pneumonie enzootique dans les élevages.(Traduit par Docteur Serge Messier).

Multiplex polymerase chain reaction for the detection and differentiation of 4 porcine circovirus 2 genotypes (PCV-2a, -2b, -2d, and -2e) in clinical samples.

The objective of this study was to develop multiplex polymerase chain reaction (PCR) for the simultaneous detection of porcine circovirus 2 (PCV-2) and differentiation among 4 PCV-2 genotypes (2a, 2b, 2d, and 2e) in collected clinical lymph node samples. The multiplex PCR detected each of 4 PCV-2 genotypes (2a, 2b, 2d, and 2e) to a dilution of 2 × 101 copies/µL. PCV-2a, PCV-2b, PCV-2d, and PCV-2e were propagated in tissues prior to DNA extraction for use in multiplex PCR for the simultaneous detection and differentiation of 4 PCV-2 genotypes. The designed multiplex PCR effectively detected and differentiated various combinations of multiple infection, such as PCV-2a+2b, PCV-2a+2d, PCV-2b+2d, PCV-2a+2e, and PCV-2a+2b+2d, in clinical lymph node samples. The results of this study demonstrated that multiplex PCR testing of clinical samples developed herein was able to simultaneously detect and differentiate among the 4 PCV-2 genotypes (PCV-2a, 2b, 2d, and 2e).

L'objectif de cette étude était de développer une réaction en chaîne par la polymérase multiplex (PCR) pour la détection simultanée du circovirus porcin 2 (PCV-2) et la différenciation entre quatre génotypes PCV-2 (2a, 2b, 2d et 2e) dans des échantillons cliniques de noeuds lymphatique. La PCR multiplex a détecté chacun des quatre génotypes PCV-2 (2a, 2b, 2d et 2e) à une dilution de 2 × 101 copies/µL. Le PCV-2a, le PCV-2b, le PCV-2d et le PCV-2e ont été propagés dans les tissus avant l'extraction de l'ADN pour être utilisés dans la PCR multiplex pour la détection et la différenciation simultanées de quatre génotypes du PCV-2. La PCR multiplex conçue a efficacement détecté et différencié diverses combinaisons d'infections multiples, telles que PCV-2a+2b, PCV-2a+2d, PCV-2b+2d, PCV-2a+2e et PCV-2a+2b+2d, dans les échantillons cliniques de ganglions lymphatiques. Les résultats de cette étude ont démontré que le test PCR multiplex des échantillons cliniques développés ici était capable de détecter et de différencier simultanément les quatre génotypes PCV-2 (PCV-2a, 2b, 2d et 2e).(Traduit par Docteur Serge Messier).

A field efficacy trial of a trivalent vaccine containing porcine circovirus type 2a and 2b, and Mycoplasma hyopneumoniae in three herds.

BACKGROUND: This field trial was designed to evaluate the efficacy of a new trivalent vaccine containing porcine circovirus type 2a and 2b (PCV2a/b), and Mycoplasma hyopneumoniae at three independent locations. METHODS: Three farms were selected based on their history of PCV2 and M. hyopneumoniae co-infection. Each farm housed a total of 60, 3-day-old pigs that were randomly allocated to one of three treatment groups. Pigs were administered the trivalent vaccine intramuscularly with either a 1.0 ml dose at 3 and 24 days of age or a 2.0 ml dose at 21 days of age in accordance with the manufacturer's recommendations. RESULTS: Clinically, the average daily weight gain of the one-dose and two-dose vaccinated groups within all three farms was significantly higher (p < 0.05) than those of unvaccinated animals during the growing (70-112 days of age), finishing (112-175 days of age) and overall (3-175 days of age) stages of production. One-dose and two-dose vaccinated animals elicited neutralizing antibodies and interferon-γ-secreting cells (IFN-γ-SC), which reduced the amount of PCV2 in terms of blood load and reduced the severity of lymphoid lesions when compared with unvaccinated animals. Similarly, one-dose and two-dose vaccinated animals elicited IFN-γ-SC, which reduced the amount of M. hyopneumoniae in terms of laryngeal load and reduced the severity of lung lesions. CONCLUSIONS: The intramuscular administration of either one or two doses of trivalent vaccine was not significantly different in any of the evaluated parameters. The results of field trial demonstrated that the trivalent vaccine was efficacious in the protection of swine herds where PCV2d and M. hyopneumoniae were in active circulation.

Pathogenicity of Porcine Circovirus Type 2d (PCV2d) in Pigs Infected with PCV2d or Co-infected with Mycoplasma hyopneumoniae and PCV2d or with Porcine Reproductive and Respiratory Syndrome Virus and PCV2d.

The objective of this study was to determine the pathogenicity of porcine circovirus type 2d (PCV2d) in pigs inoculated intranasally with PCV2d alone, PCV2d in combination with Mycoplasma hyopneumoniae or PCV2d in combination with porcine reproductive and respiratory syndrome virus (PRRSV). Pigs infected with PCV2d alone were asymptomatic. All pigs inoculated with either M. hyopneumoniae and PCV2d or with PCV2d and PRRSV developed porcine circovirus-associated disease (PCVAD), as characterized by a sudden onset of clinical signs and disseminated granulomatous inflammation. Inflammation was mainly present in lymph nodes and spleen, and occasionally in liver and kidney. Pigs in both of these dually infected groups also had significantly higher (P <0.05) microscopic lymphoid lesion scores and a significantly higher (P <0.05) number of PCV2-positive cells in lymph node tissue than did pigs inoculated with PCV2d alone. The M. hyopneumoniae and PRRSV combination potentiated the PCV2d load in the blood. Co-infection with PRRSV and PCV2d resulted in a significantly higher blood load of PCV2d compared with the M. hyopneumoniae and PCV2d combination. Successful reproduction of PCVAD in pigs appears to require PCV2d with at least one additional infectious agent, such as M. hyopneumoniae or PRRSV, for the full manifestation of disease.

A Comparison of Pathogenicity and Virulence of Three Porcine Circovirus Type 2 (PCV2) Genotypes (a, b, and d) in Pigs Singularly Inoculated with PCV2 and Dually Inoculated with Mycoplasma hyopneumoniae and PCV2.

The objective of this study was to compare the virulence of three different porcine circovirus type 2 (PCV2) genotypes (PCV2a, PCV2b, and PCV2d) in pigs infected with either one of these three PCV2 genotypes versus pigs dually inoculated with Mycoplasma hyopneumoniae and PCV2. Pigs were inoculated intratracheally with M. hyopneumoniae at 4 weeks of age followed by another intranasal inoculation at 6 weeks of age with one of three PCV2 genotypes. Dual infection with two pathogens produced moderate and severe dyspnea, lethargy, and reduced weight gain in pigs regardless of the PCV2 genotype evaluated compared with pigs only inoculated with PCV2. The overall levels of PCV2d viremia and severity of lymphoid lesions, and PCV2-antigen within lymphoid lesions were significantly higher in pigs dually inoculated with M. hyopneumoniae/PCV2d when compared with all other dually inoculated groups. The level of PCV2 viremia and the production of PCV2-associated lymphoid lesions did not differ significantly among PCV2a, PCV2b, and PCV2d single-inoculated pig groups. The results of this study demonstrated that M. hyopneumoniae potentiated the replication of PCV2d more than it did with the other PCV2 genotypes as measured by lymphoid lesion severity.

A Comparison of Virulence of Three Porcine Circovirus Type 2 (PCV2) Genotypes (a, b, and d) in Pigs Singularly Inoculated with PCV2 and Dually Inoculated with PCV2 and Porcine Reproductive and Respiratory Syndrome Virus.

The aim of this study was to compare the virulence of porcine circovirus type 2 (PCV2) genotypes in dually inoculated pigs with both three genotypes (a, b, and d) of PCV2 and porcine reproductive and respiratory syndrome virus-2 (PRRSV-2) versus pigs singularly inoculated with the same three PCV2 genotypes (a, b, and d). Differences in this comparison were found in PCV2 viremia levels, lung and lymphoid lesion severity, and the amount of PCV2 antigen within the lymphoid lesions. Regardless of PCV2 genotypes, pigs that were dually inoculated with PCV2/PRRSV had significantly higher clinical scores, less average daily weight gain, higher levels of PCV2 viremia, and more severe lug and lymphoid lesions compared to pigs singularly inoculated with PCV2. Among the dually infected pig groups, pigs infected with PCV2d/PRRSV-2 had significantly higher levels of PCV2 viremia, more severe lung and lymphoid lesions, and more PCV2-positive cells within lymphoid lesions compared to pigs dually inoculated with PCV2a/PRRSV-2 and PCV2b/PRRSV-2. The results of this study demonstrated significant differences in the virulence among dual inoculation of PCV2a/PRRSV-2, PCV2b/PRRSV-2, and PCV2d/PRRSV-2. A significant difference in the virulence among PCV2a, PCV2b, and PCV2d single-inoculated pig groups was not found with respect to the levels of PCV2 viremia and production of PCV2-associated lymphoid lesions.

Comparative Evaluation of Growth Performance between Bivalent and Trivalent Vaccines Containing Porcine Circovirus Type 2 (PCV2) and Mycoplasma hyopneumoniae in a Herd with Subclinical PCV2d Infection and Enzootic Pneumonia.

The present field trial compared two combined vaccines of porcine circovirus type 2 (PCV2) and Mycoplasma hyopneumoniae, each administered in herd with subclinical PCV2d infection and enzootic pneumonia. One vaccine was a bivalent containing PCV2a and M. hyopneumoniae and the other was a trivalent vaccine containing PCV2a and 2b (PCV2a/b), and M. hyopneumoniae. The defining difference between these two vaccines was the inclusion or absence of PCV2b antigen. A total of 480, 21day-old pigs were randomly allocated to one of four treatment groups (120 pigs per group, male = 60 and female = 60). These groups included; one-dose trivalent-vaccinated, two-dose trivalent-vaccinated, one-dose bivalent-vaccinated, and unvaccinated. The one- and two-dose trivalent vaccinated pigs exhibited significantly better growth performance when compared with those vaccinated with the bivalent vaccine. The one- and two-dose trivalent vaccinated pigs also reduced the amount of PCV2d loads in the blood and feces, and resulted in a lower M. hyopneumoniae load in the larynx when compared with one-dose bivalent vaccinated pigs. Statistical differences were not observed between the one- and two-dose trivalent-vaccinated groups in terms of growth performance, serology, amount of PCV2d loads in the blood and feces, amount of M. hyopneumoniae load in larynx, and pathological lesions. The results of the present study will provide swine practitioners and producer with comparative clinical field data to select the proper vaccine and vaccination regiment for herds suffering from subclinical PCV2d infection and enzootic pneumonia.

Efficacy Evaluation of a Bivalent Vaccine Containing Porcine Circovirus Type 2b and Mycoplasma hyopneumoniae Against an Experimental Dual Challenge.

The purpose of this study was to evaluate the efficacy of a new, single-dose bivalent vaccine containing porcine circovirus type 2b (PCV2b) and Mycoplasma hyopneumoniae against a dual PCV2b and M. hyopneumoniae challenge. At -25 days post challenge (dpc, 10 days of age), one pig group (designated as the vaccinated/challenged group) received a single, 1.0 ml dose of bivalent vaccine. Pigs in both the vaccinated/challenged and unvaccinated/challenged groups were then inoculated intranasally with PCV2b and M. hyopneumoniae at 0 dpc (35 days of age). Pigs in vaccinated/challenged group induced significantly higher levels of neutralizing antibodies against PCV2b and cell-mediated immunity against PCV2b and M. hyopneumonia when compared with pigs in unvaccinated/challenged group. The vaccination of pigs with a bivalent vaccine also reduced PCV2b viremia, reduced mycoplasmal nasal shedding, and decreased the severity of both lung and lymphoid lesions for PCV2b and M. hyopneumoniae infection, respectively. The results of this study demonstrated that the evaluated bivalent vaccine was effective in protecting pigs against PCV2b and M. hyopneumoniae infection.

Experimental efficacy of a trivalent vaccine containing porcine circovirus types 2a/b (PCV2a/b) and Mycoplasma hyopneumoniae against PCV2d and M. hyopneumoniae challenges.

The purpose of this experimental study was to evaluate the efficacy of a new trivalent vaccine containing porcine circovirus types 2a/b (PCV2a/b) and Mycoplasma hyopneumoniae. Pigs were administered the vaccine intramuscularly as either at 3 and 24 days of age with 1.0 mL or at 21 days of age with 2.0 mL according to the manufacturer's recommendations. The pigs were challenged at 42 days of age with either PCV2d (intranasal route) or M. hyopneumoniae (intratracheal route), or both. No statistical differences were observed between the one-dose and two-dose experiments based on clinical (growth performance), immunological (protective immunity), microbiological (viremia and laryngeal swab), and pathological (pulmonary and lymphoid lesion) outcomes. Pigs in vaccinated/challenged and unvaccinated/unchallenged groups showed significant difference in growth performance compared to pigs in the unvaccinated/challenged group in both dosage experiments. Vaccinated pigs elicited a significant amount of protective immunity for PCV2d-specific neutralizing antibodies and interferon-γ secreting cells (IFN-γ-SC) as well as M. hyopneumoniae-specific IFN-γ-SC significantly post-challenge compared to unvaccinated/challenged pigs. Vaccination and challenge reduced the viral load amount of PCV2d in the blood and reduced the M. hyopneumoniae load in laryngeal swab, while simultaneously reducing both pulmonary and lymphoid lesion severity when compared to unvaccinated/challenged pigs. Trivalent vaccination provided good protection against a single PCV2d challenge, single M. hyopneumoniae challenge, and a PCV2d/M. hyopneumoniae dual challenge.

Field evaluation of a sing-dose bivalent vaccine of porcine circovirus type 2b and Mycoplasma hyopneumoniae.

BACKGROUND: The field efficacy of a bivalent vaccine containing porcine circovirus type 2b (PCV2b) and Mycoplasma hyopneumoniae was evaluated on three pig farms. METHODS: Three pig farms were used, two of which had a history of subclinical PCV2 and clinical M. hyopneumoniae infections between 84 and 126 days of age while concurrent porcine circovirus-associated disease and clinical M. hyopneumoniae infection between 70 and 105 days of age. Each farm vaccinated pigs with a single dose of a bivalent vaccine at 10 days of age while unvaccinated pigs were administered a single dose of phosphate buffered-saline at the same age. RESULTS: Vaccination improved growth performance and reduced clinical scores significantly (p < .05) when compared with unvaccinated animals. The amount of PCV2d loads in blood and M. hyopneumoniae loads in nasal swabs of vaccinated animals were also significantly lower (p < .05) when compared with unvaccinated animals. Immunologically, vaccinated groups elicited a significantly higher (p < .05) level of protective immunity against PCV2d such as neutralizing antibodies and interferon-γ secreting cells (IFN-γ-SC), as well as protective immunity against M. hyopneumoniae such as IFN-γ-SC when compared with unvaccinated animals. Pathologically, vaccination significantly lowered (p < .05) the scores of M. hyopneumoniae-induced pneumonia and PCV2-associated lymphoid lesions when compared with unvaccinated animals. CONCLUSIONS: The evaluated bivalent vaccine provided good protection against PCV2d and M. hyopneumoniae infection under field conditions.

Experimental evaluation of Mycoplasma hyopneumoniae bacterin against a Korean M. hyopneumoniae challenge.

The objective of this study was to evaluate the efficacy of a new Mycoplasma hyopneumoniae bacterin against a Korean M. hyopneumoniae challenge under experimental conditions. Fifteen pigs were allocated randomly into 3 groups (5 pigs per group) that were designated in 1 of 3 ways: vaccinated-challenged, unvaccinated-challenged, or unvaccinated-unchallenged. The pigs in the vaccinated-challenged group were immunized with an M. hyopneumoniae whole-cell bacterin at a 1.0 mL dose-level at 21 d old. At 42 d old (0 d post-challenge), the pigs in the vaccinated-challenged and unvaccinated-challenged groups were inoculated intranasally with a strain of Korean M. hyopneumoniae. Vaccinated-challenged pigs elicited a strong cell-mediated immunity as measured by M. hyopneumoniae-specific interferon-γ secreting cells when compared with unvaccinated-challenged pigs. Vaccination of pigs with this new M. hyopneumoniae bacterin reduced nasal shedding and lung lesions. The evaluated vaccine was therefore considered effective in controlling M. hyopneumoniae infection.

L'objectif de cette étude était d'évaluer l'efficacité d'une nouvelle bactérine de Mycoplasma hyopneumoniae contre une infection défi avec une souche coréenne de M. hyopneumoniae dans des conditions expérimentales. Quinze porcs ont été répartis au hasard en trois groupes (5 porcs par groupe) qui ont été désignés de l'une des trois façons suivantes : vaccinés-infectés, non vaccinés-infectés, non vaccinésnon infectés. Les porcs du groupe vacciné-infectés ont été immunisés avec 1,0 mL d'une bactérine à cellules entières de M. hyopneumoniae à 21 jours d'âge. A l'âge de 42 jours (0 jour après la provocation), les porcs dans les groupes vaccinés-infectés et non vaccinés-infectés ont été inoculés par voie intranasale avec une souche coréenne de M. hyopneumoniae. Les porcs vaccinés-infectés ont manifesté une forte immunité à médiation cellulaire telle que mesurée par les cellules sécrétant l'interféron-γ spécifique à M. hyopneumoniae par rapport aux porcs non vaccinés-infectés. La vaccination des porcs avec cette nouvelle bactérine de M. hyopneumoniae a réduit l'excrétion nasale et les lésions pulmonaires. Le vaccin évalué a donc été considéré comme efficace pour maitriser l'infection à M. hyopneumoniae.(Traduit par Docteur Serge Messier).

Experimental reproduction of porcine respiratory disease complex in pigs inoculated porcine reproductive and respiratory syndrome virus and Mycoplasma hyopneumoniae and followed by inoculation with porcine circovirus type 2.

The aim of this study was to reproduce severe pneumonic lesions, similar to those during naturally-occurring porcine respiratory disease complex, in pigs dually inoculated with porcine reproductive and respiratory syndrome virus and Mycoplasma hyopneumoniae at 6 weeks of age, followed by inoculation with porcine circovirus type 2 at two weeks after. Time and sequence of infection with three pathogens mirror Asian field conditions. Microscopically, interstitial pneumonia and peribronchiolar lymphoid hyperplasia are considered the most characteristic lung lesions in infected pigs. The results of the present study demonstrate that inoculation of pigs with these three pathogens can lead to severe interstitial pneumonia with peribronchial or peribronchiolar lymphoid hyperplasia and fibrosis.

The first isolation of porcine circovirus type 2e from a Korean pig.

This study describes the first isolation and genetic characterization of the newly emerging porcine circovirus type 2e (PCV2e) from Korean pigs. The PCV2e isolate did not produce a cytopathic effect in PCV-free PK-15 cells; therefore, PCV2e infection was demonstrated by immunohistochemistry with polyclonal PCV2a antibodies and polymerase chain reaction with primers specific for PCV2e. As the infected PCV-free PK-15 cells were passaged, the amount of infectious virus correlated with an increase in the amount of viral DNA (i.e., a decrease in the cycle threshold values. A full genomic analysis of the PCV2e strain SNUVR199711 was performed and showed that the genome is 1,777 nucleotides in length.

Efficacy comparison of commercial porcine circovirus type 2 (PCV2) and Mycoplasma hyopneumoniae monovalent and bivalent vaccines against a dual challenge.

The objective of this study was to compare the efficacy of commercially available porcine circovirus type 2 (PCV2) and Mycoplasma hyopneumoniae vaccines. A total of 80 pigs was randomly divided into 6 treatment groups; 4 of the groups each received a different vaccine as well as a dual challenge. The remaining 2 groups were used as controls, 1 of which also received a dual challenge. Two of the 4 groups of pigs were administered 2 monovalent vaccines (designated as either monovalent vaccine A or B) of PCV2 at 7 days old and of M. hyopneumoniae at 21 days old. The remaining 2 vaccinated groups of pigs received a bivalent vaccine (designated as either bivalent vaccine A or B) of PCV2 and M. hyopneumoniae at 21 days old. All 4 vaccinated groups were challenged with M. hyopneumoniae at 42 days old [-14 d post-challenge (dpc)], followed by a PCV2d challenge at 56 days old (0 dpc). All 4 vaccinated/challenged groups displayed a reduction in clinical signs, PCV2d viremia, nasal shedding of M. hyopneumoniae, and lung lesions compared with pigs in the unvaccinated and challenged groups. Vaccination and challenge improved growth performance and increased the immunologic responses (M. hyopneumoniae- and PCV2-specific antibodies and interferon-γ-secreting cells) when compared to pigs in the unvaccinated/challenged groups. Pigs in groups vaccinated with either a monovalent or bivalent vaccine A treatment and challenge produced a larger amount of M. hyopneumoniae- and PCV2d-specific interferon-γ-secreting cells within the pigs and simultaneously reduced the nasal shedding of M. hyopneumoniae and PCV2d viremia compared with groups vaccinated with either a monovalent or bivalent vaccine B treatment and challenge. Both the bivalent vaccines and the respective monovalent vaccines were efficacious against a dual challenge of M. hyopneumoniae and PCV2d.

L'objectif de la présente étude était de comparer l'efficacité de vaccins commercialement disponibles contre le circovirus porcin de type 2 (PCV2) et Mycoplasma hyopneumoniae. Un total de 80 porcs ont été divisés de manière aléatoire en six groupes de traitement; quatre des groupes ont chacun reçu un vaccin différent ainsi qu'une infection défi double. Les deux groupes restants ont servi de témoin, un des deux recevant l'infection défi double. Deux des quatre groupes de porcs ont reçu deux vaccins monovalents (désigné comme étant vaccin monovalent A ou B) de PCV2 à 7 jours d'âge et de M. hyopneumoniae à 21 jours d'âge. Les deux autres groupes de porcs vaccinés ont reçu un vaccin bivalent (désigné comme étant vaccin bivalent A ou B) de PCV2 et de M. hyopneumoniae à 21 jours d'âge. Les quatre groupes vaccinés furent challengés avec M. hyopneumoniae à 42 jours d'âge [−14 j post-défi (dpc)], suivi d'une infection défi avec PCV2 à 56 j d'âge (0 dpc). Les quatre groupes vaccinés/infectés ont montré une réduction des signes cliniques, de la virémie à PCV2d, de l'excrétion nasale de M. hyopneumoniae et de lésions pulmonaires comparativement aux porcs dans les groupes non-vaccinés et infectés. La vaccination et l'infection défi ont amélioré les performances de croissance et augmenté les réponses immunologiques (anticorps spécifiques contre M. hyopneumoniae et PCV2d et les cellules secrétant l'interféron-γ) lorsque comparé aux porcs dans les groupes non-vaccinés/infectés. Les porcs dans les groupes vaccinés avec soit le vaccin A monovalent ou bivalent et infectés ont produit de plus grandes quantités de cellules secrétant de l'interféron-γ spécifique à M. hyopneumoniae et PCV2d chez les porcs et ont simultanément réduit l'excrétion nasale de M. hyopneumoniae et la virémie de PCV2d comparativement aux groupes vaccinés avec le vaccin monovalent ou bivalent B et infectés. Autant les vaccins bivalents que les vaccins monovalents respectifs étaient efficaces à une infection défi double par M. hyopneumoniae et PCV2d.(Traduit par Docteur Serge Messier).

A Dual Swine Challenge With Porcine Circovirus Type 2 (PCV2) and Mycoplasma hyopneumoniae Used to Compare a Combination of Mixable Monovalent PCV2 and Monovalent M. hyopneumoniae Vaccines With a Ready-to Use PCV2 and M. hyopneumoniae Bivalent Vaccine.

The present study evaluated the efficacy of swine vacciation using a combination of mixable monovalents for porcine circovirus type 2 (PCV2) and Mycoplasma hyopneumoniae against a ready-to-use bivalent vaccine under experimental conditions. Pigs at 21 days of age were administered either a combination of two mixable monovalent vaccines or a bivalent vaccine containing PCV2 and M. hyopneumoniae. Vaccination was followed with an M. hyopneumoniae challenge at 42 days of age (-14 days post challenge, dpc) and a PCV2d challenge at 56 days of age (0 dpc). Each vaccinated and challenged group was compared with the unvaccinated and challenged group for clinical, microbiological, immunologic, and pathologic differences. Clinically, two vaccinated and challenged groups showed minimal respiratory diseases that was characterized by occasionally coughing and sneezing. A significant difference was not calculated in the average daily weight gain, nasal shedding of M. hyopneumoniae, and pathological lesions between two vaccinated and challenged groups. A combination of two monovalent vaccines mixed into a combo prior to vaccination followed by challenge resulted in increased numbers of PCV2d-specific interferon-γ secreting cells at 21 dpc and a significant reduction in PCV2d viremia at 14 dpc when compared with the ready-to-use bivalent-vaccinated and challenged groups. These results offer supporting evidence that vaccination during the weaning to finishing period against M. hyopneumoniae and PCV2 is efficacious for controlling diseases caused by these two pathogens.

A modified-live porcine reproductive and respiratory syndrome virus (PRRSV) vaccine protects late-term pregnancy gilts against a heterologous PRRSV-2 challenge.

The objective of this study was to evaluate the efficacy of a modified-live virus (MLV) porcine reproductive and respiratory syndrome virus (PRRSV) vaccine against a heterologous PRRSV-2 challenge in late-term pregnancy gilts under experimental conditions. Eighteen gilts were randomly assigned to vaccinated-challenged, unvaccinated-challenged, and unvaccinated-unchallenged groups (n = 6 gilts per group). Pregnant gilts in the vaccinated-challenged and unvaccinated-unchallenged groups were able to carry their pregnancies to full term and farrowed after 114 to 115 days of gestation. In contrast, pregnant gilts in the unvaccinated-challenged group did not reach full term and farrowed early, after 104 to 108 days of gestation. Pregnant gilts vaccinated with the PRRSV-2 MLV vaccine exhibited a reduction in PRRSV-2 viremia. At the time of challenge with PRRSV-2, vaccinated gilts had relatively low levels of neutralizing antibody titers (≤ 1:16 titer), whereas the number of interferon-γ-secreting cells (IFN-γ-SC) was consistently at protective levels (IFN-γ-SC, ≥ 150 per million). Induction of cell-mediated immunity, as measured by PRRSV-2-specific IFN-γ-SC, correlated with a reduction in PRRSV-2 viremia. Duration of immunity was a minimum of 19 wk. Taken together, the results presented here suggest that vaccination of gilts with a PRRSV-2 MLV vaccine can protect against a heterologous PRRSV-2 challenge and improve the reproductive performance of late-term pregnancy gilts.

L'objectif de la présente étude était d'évaluer dans des conditions expérimentales l'efficacité d'un vaccin à virus vivant modifié (MLV) du virus du syndrome reproducteur et respiratoire porcin (PRRSV) contre une infection défi avec un PRRSV-2 hétérologue chez des cochettes en fin de gestation. Dix-huit cochettes furent assignées de manière aléatoire à un des groupes suivants: vaccinées-infectées, non-vaccinées-infectées et non-vaccinées-non-infectées (n = 6 cochettes par groupe). Les cochettes gestantes dans les groupes vaccinées-infectées et non-vaccinées-non-infectées furent en mesure de mener leur gestation à terme et ont mis-bas après 114 à 115 jours de gestation. À l'opposé, les cochettes gestantes du groupe (témoin) non-vaccinées-infectées ne se sont pas rendues à terme et ont mis-bas plus tôt, après 104 à 108 jours de gestation. Les cochettes gestantes vaccinées avec le vaccin PRRSV-2 MLV ont montré une réduction de la virémie à PRRSV-2. Au moment de l'infection-défi avec le PRRSV-2, les cochettes vaccinées avaient des titres relativement bas d'anticorps neutralisants (titre ≤ 1:16), alors que le nombre de cellules secrétant de l'interféron-γ (IFN-γ-SC) était constamment à des niveaux de protection (IFN-γ-SC, ≥ 150 par million). L'induction de l'immunité à médiation cellulaire, telle que mesurée par l'IFN-γ-SC spécifique à PRRSV-2, corrélait avec une réduction de la virémie à PRRSV-2. La durée de l'immunité était d'un minimum de 19 sem. Pris dans son ensemble, les résultats présentés ici suggèrent que la vaccination des cochettes avec un vaccin PRRSV-2 MLV peut protéger contre une infection-défi avec un PRRSV-2 hétérologue et améliorer les performances de reproduction des cochettes en fin de gestation.(Traduit par Docteur Serge Messier).

Comparative study of the virulence of 3 major Korean porcine circovirus type 2 genotypes (a, b, and d).

The objective of this study was to compare the virulence of 3 major Korean porcine circovirus type 2 (PCV2) genotypes in terms of clinical signs, PCV2 viremia and antibody titers, lymphoid lesions, and PCV2-antigen within lymphoid lesions in experimentally infected pigs. Pigs were infected at 7 weeks with PCV2a, PCV2b, and PCV2d strains and necropsied at 28 days post-infection. No statistical differences were observed in clinical signs, PCV2 viremia and antibody titers, lymphoid lesions scores, and numbers of PCV2 antigens among the 3 major Korean PCV2 genotypes. The results of this study indicate that the 3 major Korean PCV2 genotypes, PCV2a, PCV2b, and PCV2d, have similar virulence.

L'objectif de la présente étude était de comparer la virulence de trois génotypes majeurs de circovirus porcine de type 2 (PCV2) coréens en termes de signes cliniques, virémie de PCV2 et titres d'anticorps, lésions lymphoïdes et antigènes de PCV2 à l'intérieur des lésions lymphoïdes chez des porcs infectés expérimentalement. Les porcs furent infectés à 7 semaines d'âge avec les souches PCV2a, PCV2b et PCV2d et soumis à une nécropsie 28 jours post-infection. Aucune différence significative ne fut observée dans les signes cliniques, la virémie de PCV2 et les titres d'anticorps, les pointages de lésions lymphoïdes et les nombres d'antigènes de PCV2 pour les trois génotypes majeurs de PCV2 coréens. Les résultats de cette étude indiquent que les trois génotypes majeurs de PCV2 coréens, PCV2a, PCV2b et PCV2d ont une virulence similaire.(Traduit par Docteur Serge Messier).

Optimal vaccination strategy against Mycoplasma hyopneumoniae, porcine reproductive and respiratory syndrome virus, and porcine circovirus type 2 in case of early M. hyopneumoniae infection.

BACKGROUND: The aim of this study was to determine the optimal vaccination strategies for the control of porcine respiratory disease complex (PRDC) caused by Mycoplasma hyopneumoniae, porcine reproductive and respiratory syndrome virus (PRRSV), and porcine circovirus type 2 (PCV2) in case of early mycoplasmal infection. METHODS: A total of 120 pigs were randomly divided into 6 groups (20 pigs per group). Four separate vaccine regimen groups were selected. Pigs from the four vaccinated groups were challenged with M. hyopneumoniae at 28 days old followed by a challenge of PRRSV or PCV2 at 49 days old. RESULTS: Regardless of PRRSV or PCV2 vaccination, pigs vaccinated with one of the M. hyopneumoniae vaccines at 7 days old had a significantly better growth performance over the whole length of the study compared to pigs vaccinated with a second M. hyopneumoniae vaccine at 21 days old. Vaccination of pigs with M. hyopneumoniae at 7 days and PRRSV at either 7, 14 or 21 days old resulted in significantly reduced PRRSV viremia and lung lesions compared to vaccination of pigs with M. hyopneumoniae and PRRSV at 21 days old. CONCLUSIONS: The efficacy of the PRRSV MLV vaccine is influenced by the different timing of M. hyopneumoniae vaccination whereas the efficacy of the PCV2 vaccine is not. This experiment study demonstrated that early vaccination with a M. hyopneumoniae vaccine should be the highest priority in order to control M. hyopneumoniae and PRRSV infection in cases of early M. hyopneumoniae infection.