Isolation and molecular characterization of Clostridium perfringens from healthy Merino lambs in Patagonia region, Argentina.

The presence and molecular characterization of Clostridium perfringens in healthy Merino lambs over a six-month period was investigated in this study. Overall, a high prevalence of C. perfringens was detected, even in day-old lambs. Even though the majority of the isolates were characterized as being of type A, types C and D were also isolated. Furthermore, a high genetic diversity was observed by PFGE among the type A isolates.

Early protection against foot-and-mouth disease virus in cattle using an inactivated vaccine formulated with Montanide ESSAI IMS D 12802 VG PR adjuvant.

Foot and mouth disease is an acute disease of cattle with a broad distribution around the world. Due to the fast spread of FMDV infections, control measures must be applied immediately after an outbreak, such as the use of vaccines that induce fast protection. Previously, it was shown that mice vaccinated with FMD inactivated virus (iFMDV) formulated with Montanide™ ESSAI IMS D 12802 VG PR adjuvant (802-iFMDV) were protected when they were challenged 4 and 7 days post-vaccination (dpv) with homologous virus. In this work, we describe the successful use of this formulation in cattle. In addition, adjuvant Montanide™ IMS 1313 VG NPR was also tested. 802-iFMDV vaccine was able to confer 100% protection against viral challenge at 4 and 7 dpv, while eliciting low antibody levels, at 7 dpv. 1313-iFMDV vaccine induced protection in 60% of cattle. At 4 dpv, 1313-iFMDV vaccinated animals presented increased levels of IFNγ but not of macrophages. At 4 and 7 dpv, macrophages, IFNγ, nasal IgA and IgG1 antibodies against FMDV, and opsonophagocytosis were increased in animals vaccinated with 802-iFMDV indicating that these phenomena could be involved in protection.It is the first time that total protection against FMDV at early stages post-vaccination is reported using a single dose of the formulation iFMDV plus Montanide™ ESSAI D IMS 12802 VG PR adjuvant.

Role of macrophages in early protective immune responses induced by two vaccines against foot and mouth disease.

Foot and Mouth Disease (FMD) is an acute disease of cloven-hoofed species. We studied the protection and early immune response induced in the murine model by vaccines formulated with inactivated virus and two different adjuvants. The presence of IMS12802PR or ISA206VG adjuvants yielded protection against viral challenge at early times post vaccination and induced FMDV-specific, but non neutralizing, antibody titers. In vivo macrophage depletion in vaccinated mice severely decreased the protection levels after virus challenge, indicating a central role of this cell population in the response elicited by the vaccines. Accordingly, opsonophagocytosis of FITC-labelled virus was augmented in 802-FMDVi and 206-FMDVi vaccinated mice. These results demonstrate the ability of the studied adjuvants to enhance the protective responses of these inactivated vaccines without the increase in seroneutralizing antibodies and the main role of opsonization and phagocytosis in the early protective immune responses against FMD infection in the murine model.

Induction of specific cytotoxic activity for bovine herpesvirus-1 by DNA immunization with different adjuvants.

It is well documented that adjuvants improve the immune response generated by traditional viral vaccines; however, less is known about their effects on the immune response elicited by DNA vaccines. In this study, we have investigated the use of adjuvants, and have analyzed the humoral and cellular specific immune responses elicited by DNA vaccines based on the BoHV-1 glycoprotein D (secreted version) in pCIneo vector with and without Montanide ISA25 (O/W), ISA206 VG (SEPPIC) and Cliptox™ (natural microparticles of clinoptilolite). The comparison of the immune response induced in mice by pCIgD formulated with or without adjuvants showed that the immunomodulators affect the total specific humoral and cellular response. The isotypes induced by these adjuvants were of the type Th1/Th2. A significant increase in the mac-3+ and F4/80+ populations of the groups receiving pCIneo with ISA25, ISA206; and an increase in CD4+ populations of the group receiving pCIneo ISA25, in comparison with the pCIneo group was observed. On the other hand, mice vaccinated with pCIgD/ISA25, pCIgD/ISA206, or pCIgD/Cliptox developed a significantly higher specific cytotoxic activity against BoHV-1 than the pCIgD and pCIneo groups. In this report we propose the use of ISA25, ISA206 or Cliptox as adjuvants in a DNA vaccine since they are able to induce not only a specific humoral immune response but also a specific cellular immune response.

Adjuvant effect of Cliptox on the protective immune response induced by an inactivated vaccine against foot and mouth disease virus in mice.

Foot and Mouth Disease (FMD) is an acute disease caused by Foot and Mouth Disease Virus (FMDV) which causes important economy losses, this is why it is necessary to obtain a vaccine that stimulates a rapid and long-lasting protective immune response. Cliptox is a mineral microparticle that in earlier studies has shown adjuvant activity against different antigens. In this study we have examined the effects of Cliptox on the magnitude and type of immunity elicited in response to inactivated FMDV (iFMDV) vaccine. It was demonstrated that iFMDV-Cliptox stimulates a specific antibody response detected in mucosal and in sera. The different isotype profiles elicited by inoculation with this vaccine indicate a Th1/Th2 response. Also, an increase in dendritic cells and macrophages in the spleen in comparison with the iFMDV vaccine iFMDV-Cliptox was detected. The Cliptox-iFMDV formulation was non toxic by using egg embryos and yielded increased protection against challenge with FMDV in the murine model. Our results show that the incorporation of Cliptox into FMDVi vaccine induces an increase of the specific protective immune response in mice and clearly indicate that Cliptox TM exert an (important) up-regulation on DC and MPhi. Additionally, Cliptox TM adjuvant can be used in vaccines for induction of mucosal immune response.