Moroccan Journal of Agricultural and Veterinary Sciences

Vol. 13 No. 2 (2025): (June 2025)
Animal Production and Health

Activity tests of the bivalent vaccine against bovine colibacillosis on circulating Escherichia coli

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  • Louis Valentin RANDRIANAMBININTSOA,
  • H.H.C. RAKOTONIRINA,
  • M. RAHERIMANDIMBY,
  • O. F. MAMINIAINA
Louis Valentin RANDRIANAMBININTSOA Institut Malgache des Vaccins Vétérinaires, Madagascar
H.H.C. RAKOTONIRINA Laboratoire de Contrôle Qualité des Vaccins Vétérinaires, Institut Malgache des Vaccins Vétérinaires, Antananarivo, Madagascar
M. RAHERIMANDIMBY Mention Biochimie Appliquée, Faculté des Sciences, Université d’Antananarivo, Madagascar
O. F. MAMINIAINA Centre National de la Recherche Appliquée au Développement Rural (FOFIFA), Département de recherche Zootechnique Vétérinaire et Piscicole, Antananarivo, Madagascar
colibacillose

Published 2025-04-10

Keywords

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Abstract

The objective of this study is to determine the activity of an anti-colibacillosis vaccine against circulating coliform strains. From cattle droppings, 16 samples are collected in different regions of Madagascar. They contain 8 types of bacteria including 7 coliform strains, noted F1, V1, V5, VH1D, VH2, A1 and A2. After their isolation, the coliforms are injected intraperitoneally into adult guinea pigs at doses between 108 and 109 CFU/ml. Most strains are pathogenic, but only the VH1 strain is not at a concentration of 1.21 x 108 CFU/ml. The 50% lethal doses of each strain are determined using Reed and Muench, Boyd and graph methods; to find the 100% lethal dose or LD100. The LD100 is used when testing the activity of the anti-colibacillosis vaccine on these coliform strains. At a dose ranging from 0.0093 x 108 to 27.4 x 108 CFU/ml, the vaccine protects guinea pigs against strains F1, V1, V5, VH1D and VH2. However, it does not protect them against strains A1 and A2 at doses between 0.51 x 107 to 3.44 x 108 CFU/ml. These strains differ in their growth rate and pathogenicity.

Keywords: Circulating strains, LD100, activity, vaccine

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References