Immunization With Recombinant Haemonchus contortus Y75B8A.8 Partially Protects Local Crossbred Female Goats From Haemonchus contortus Infection

Abstract

Haemonchus contortus Y75B8A.8 (Hc8) derived from H. contortus excretory–secretory (ES) products was identified as a functional inhibitor of goat interleukin 2 (IL-2). It may act as a vaccine candidate for the development of therapeutic strategies against H. contortus infection. In this research, recombinant Hc8 (rHc8) and goat anti-rHc8 polyclonal antibodies were employed to evaluate the protective capacities of Hc8 antigen against H. contortus infections via active and passive immunization trials, respectively. In both trials, local crossbred female goats aged 9–12 months old were randomly divided into three groups, five in each group, respectively. Parasitological examinations, including fecal egg counts (FEC), cumulative FEC (cFEC), and worm burdens, were performed. In addition, antibody levels in mucosal homogenate (MH) samples and hematological and immunological parameters were detected. In the passive trial, goats were intravenously immunized with 5 mg total IgG containing anti-rHc8 goat polyclonal antibodies. After twice immunization, compared with the challenged control group, cFEC was reduced by 39%. In addition, there was a 46% reduction of worm burdens compared with the challenged controls. In the active immunization trials, 500 μg of recombinant Hc8 protein was given subcutaneously twice to 9–12-month-old local crossbred female goats with a 2-week interval, resulting in the generation of high levels of antigen-specific circulating antibodies. Besides, cFEC and abomasal worm burden were reduced by 70 and 55%, respectively, compared with the challenged control group. In addition, immunized goats had higher mucosal homogenate IgA and hemoglobin levels than the challenged controls in both passive and active immunization trials. These preliminary results demonstrated the immunoprophylactic effects of Hc8 antigen and will inform new studies on ES proteins in developing subunit recombinant vaccines against H. contortus.

Arthrobotrys musiformis (Orbiliales) Kills Haemonchus contortus Infective Larvae (Trichostronylidae) through Its Predatory Activity and Its Fungal Culture Filtrates

“…A predatory activity higher than 70% is a very good activity; if we consider that, using NF for the control of animal parasitic nematodes should be considered only as a tool of control together with other control measures, or even using a combined method with two or more fungal genera/species to achieve a more effective control [ 26 ]. It is important to consider that the use of nematode natural antagonists is only part of an integrated control system that can involve different strategies of control [ 27 ]; for example, the use of a high protein and energy-based diet, which promotes immune self-defence mechanisms [ 28 , 29 ], grazing management [ 30 , 31 ], vaccines [ 32 , 33 ] and the use of plants/plant metabolites [ 34 , 35 ].…”

A Review on The Clinical Efficacy of Antitetanic Hyperimmune Serum Prepared in Equine ‎Using Freund Adjuvants in Response to Toxoid and Toxin Immunization

“…This is owing to the tetanospasmin toxin's extreme potency. Tetanospasmin will almost certainly be lethal before it triggers an immunological response (Iqbal andShahid, 2004 andTian et al, 2022). Immunity to tetanus is a vaccine-avoidable illness for which both tetanus toxin and toxoid were introduced as vaccines to animals and humans to elicit an active immunization by forming tetanus immune globulin (antitoxin) to cure or fight against toxin-based diseases (Sonobe et al, 2007).…”

Recent Advances in the Control of Endoparasites in Ruminants from a Sustainable Perspective

“…Some of these strategies include vaccination to enhance the immunological status of animals against parasite infection [ 39 , 40 ], focusing on the use of antigens obtained from the intestine cells of adult parasitic nematodes such as H. contortus to induce immune responses that provide protection [ 41 ]. Furthermore, the use of recombinant antigen technologies has also achieved a solid immune protection of flocks against this important parasite [ 42 ]. Another alternative is the use of biological control strategies employing natural antagonists of nematodes, such as nematophagous fungi, to control parasitic nematodes affecting crops of high commercial value [ 43 ] and ruminant parasitic nematodes, using the fungus Duddingtonia flagrans [ 44 ].…”