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Toxocariasis is a zoonotic disease that affects humans and animals alike. Although recombinant proteins are widely used for its diagnosis in humans, their performance in companion and production animals remains unknown. This study aimed to investigate the serodiagnostic potential of the recombinant proteins rTES-30 and rTES-120 from Toxocara canis in an indirect ELISA for cattle, horses, and sheep. Serum samples collected from the animals were tested with indirect ELISA and Western Blotting using T. canis TES-30 and TES-120 recombinant proteins produced in Escherichia coli, as well as native-TES. In the ELISA, rTES-30 showed high serodiagnostic potential in sheep and horses (92.6% and 85.2%, respectively), while the sensitivity of rTES-120 was higher in cattle and horses (97.2% and 92.6%, respectively). Furthermore, a highly positive association was observed between native and recombinant proteins in seropositive samples, while a moderately positive association was observed in seronegative samples, probably due to the lower specificity of native TES. In conclusion, our study indicates that the use of recombinant proteins in an indirect ELISA is an effective tool for the serodiagnosis of toxocariasis in animals, with the choice of protein being species-dependent., Competing Interests: The authors have declared that no competing interests exist.

Toxocariasis is a neglected zoonosis that affects children and adults. Recombinant proteins have been widely investigated for diagnosis, achieving high sensitivity and specificity in an overall population; however, little is known about age as a factor in its application. This study aims to investigate the diagnostic potential of Toxocara canis TES-30 and TES-120 recombinant proteins in humans, differentiating between its performance in children and adults. Serum samples collected from children and adults seropositive to Toxocara spp. were tested with indirect ELISA using T. canis TES-30 and TES-120 recombinant proteins produced in Escherichia coli. While rTES-30 sensitivity was not affected by age (81.8% in children and 87% in adults), rTES-120 sensitivity severely decreased in children to only 63.6%, down from 95.7% in adults. Furthermore, the sensitivity of rTES-30 increased to 97.8% after Western blotting confirmation. High specificity (>94%) against other geohelminths was reported for both recombinant proteins. Our study favors the use of rTES-30 with total IgG as the primary antibody in an indirect ELISA assay as a tool for epidemiological human studies., Competing Interests: The authors have declared that no competing interests exist.

Clostridium perfringens is an anaerobic bacterium that produces several toxins. Of these, the alpha, beta, and epsilon toxins are responsible for causing the most severe C. perfringens-related diseases in farm animals. The best way to control these diseases is through vaccination. However, commercially available vaccines are based on inactivated toxins and have many production drawbacks, which can be overcome through the use of recombinant antigens. In this study, we produced recombinant alpha, beta, and epsilon toxins in Escherichia coli to formulate a trivalent vaccine. Its effectiveness was evaluated through a potency test in rabbits, in which the vaccine generated 9.6, 24.4, and 25.0 IU/mL of neutralizing antibodies against the respective toxins. Following this, cattle, sheep, and goats received the same formulation, generating, respectively, 5.19 ± 0.48, 4.34 ± 0.43, and 4.70 ± 0.58 IU/mL against alpha toxin, 13.71 ± 1.17 IU/mL (for all three species) against beta toxin, and 12.74 ± 1.70, 7.66 ± 1.69, and 8.91 ± 2.14 IU/mL against epsilon toxin. These levels were above the minimum recommended by international protocols. As such, our vaccine was effective in generating protective antibodies and, thus, may represent an interesting alternative for the prevention of C. perfringens-related intoxications in farm animals.

Enzootic pneumonia (EP), resulting from Mycoplasma hyopneumoniae infection is one of the most prevalent diseases in pigs and is a major cause of economic losses to the swine industry worldwide. EP is often controlled by vaccination with inactivated, adjuvanted whole-cell bacterin. However, these bacterins provide only partial protection and do not prevent M. hyopneumoniae colonization. Attempts to develop vaccines that are more efficient have made use of the recombinant DNA technology. The objective of this study was to assess the potential of recombinant M. hyopneumoniae heat shock protein P42 in vaccine preparations against EP, using piglets housed under field conditions in a M. hyopneumoniae-positive farm. The cellular and humoral immune responses were elicited after a single intramuscular inoculation of rP42 in an oil-based adjuvant, or in conjunction with whole-cell vaccine preparation. The production of INF-γ and IL-10 cytokines was quantified in the supernatant of the cultured mononuclear cells. The rP42 emulsified in oil-based adjuvant was able to trigger a strong humoral immune response. Further, it induced a cellular immune response, accompanied by the production of antibodies that reacted with the native M. hyopneumoniae protein. The rP42 mediated induction of cellular and humoral immune response in the host suggests that rP42 emulsified in an oil-based adjuvant holds promise as an effective recombinant subunit vaccine against EP., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Abstract: Aim: While the use of recombinant antigens is being widely investigated in the diagnosis of human toxocariasis, relatively little attention has been given to animal diagnostic models. For this reason, this study aimed to investigate the diagnosis potential of Toxocara canis TES‐30 and TES‐120 recombinant antigens in mice, the animal model for toxocariasis studies. Methods and results: Serum samples obtained from mice infected with T. canis or Toxocara cati were tested by indirect ELISA using T. canis TES‐30 and TES‐120 recombinant antigens produced in Escherichia coli. 90% of the samples reacted with rTES‐30, whereas there was almost no reactivity with rTES‐120. Conclusion: Despite rTES‐120 being a good antigen for diagnosis in humans, it could not reproduce its reactivity in this animal model. As rTES‐30 has good reactivity in mice, it is a valuable tool for diagnosis. [ABSTRACT FROM AUTHOR]

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