Vet World Vol.16 January-2023 Article-8
Research Article
Veterinary World, 16(1): 68-75
https://doi.org/10.14202/vetworld.2023.68-75
Comparative protection of small ruminants against Mannheimia haemolytica infection by inactivated bacterin and toxoid vaccines
2. Department of Microbiology, Immunology and Contagious Diseases, Institute of Agronomy and Veterinary Medicine Hassan II, Rabat, Morocco.
Background and Aim: Mannheimia haemolytica causes respiratory infection and mortality in sheep and goats, similar to the effects in cattle, which causes major economic damage. Regular vaccinations alongside good management practices remain the most efficient tools for controlling this disease. Indeed, vaccines against pasteurellosis are available, but results on their efficacy have varied. Therefore, this study aimed to evaluate the efficacy of three vaccines against mannheimiosis in small ruminants.
Materials and Methods: We evaluated three vaccines developed from a local field isolate based on the inactivated bacterium, its toxoid, and a mixture of bacterin/toxoid, which we then tested on sheep and goats. Selected criteria that were evaluated were safety, antibody response, and protection through a challenge. Post-vaccination monitoring was carried out by enzyme-linked immunosorbent assay. The evaluation was based on antibody responses to vaccination in sheep and goats for both bacteria and leukotoxin. Protection was assessed by clinical and lesion scores after the challenge of vaccinated goats with a pathogenic strain.
Results: The three tested vaccines were completely safe, did not cause any adverse reactions, and induced significant antibody titers in immunized animals. Following M. haemolytica challenge, unvaccinated goats showed clinical signs with lesions typical of the disease. Meanwhile, the best protection was obtained with the inactivated combined bacterin/toxoid vaccine.
Conclusion: This study highlighted the effectiveness of adding a bacterial toxoid in the vaccine as a promising solution for preventing mannheimiosis in small ruminants. Because of the worldwide distribution of M. haemolytica infection, general prophylaxis based on a combined inactivated vaccine could greatly benefit. Keywords: efficacy, goats, leukotoxin, Mannheimia haemolytica, sheep, vaccination.
Keywords: efficacy, goats, leukotoxin, Mannheimia haemolytica, sheep, vaccination.
How to cite this article: Bkiri D, Elmejdoub S, Bamouh Z, Fassi Fihri O, and El-Harrak M (2023) Comparative protection of small ruminants against Mannheimia haemolytica infection by inactivated bacterin and toxoid vaccines, Veterinary World, 16(1): 68–75.
Received: 17-08-2022 Accepted: 28-11-2022 Published online: 10-01-2023
Corresponding author: Dounia Bkiri E-mail: d.bkiri@mci-santeanimale.com
DOI: 10.14202/vetworld.2023.68-75
Copyright: Bkiri, et al. This article is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http:// creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.