Free Access
Vet. Res.
Volume 35, Number 1, January-February 2004
Page(s) 1 - 38
How to cite this article Vet. Res. (2004) 1-38
Vet. Res. 35 (2004) 1-38
DOI: 10.1051/vetres:2003037

Rough vaccines in animal brucellosis: Structural and genetic basis and present status

Ignacio Moriyóna, María Jesús Grillób, Daniel Monreala, David Gonzáleza, Clara Marínb, Ignacio López-Goñib, Raúl C. Mainar-Jaimec, Edgardo Morenod and José María Blascob

a  Departamento de Microbiología, Universidad de Navarra, Aptdo. 177, 31080 Pamplona, Spain
b  Unidad de Sanidad Animal SIA/DGA. Aptdo. 727, 50080 Zaragoza, Spain
c  Dpto. of Veterinary Microbiology, WCVM, University of Saskatchewan, 52 Campus Drive, Saskatoon, SK, S7N 5B4, Canada
d  Programa de Investigación en Enfermedades Tropicales (PIET), Escuela de Medicina Veterinaria, Universidad Nacional, Aptdo 304-3000 Heredia, Costa Rica

(Received 13 March 2003, accepted 4 July 2003)

Abstract - Brucellosis control and eradication requires serological tests and vaccines. Effective classical vaccines (S19 in cattle and Rev 1 in small ruminants), however, induce antibodies to the O-polysaccharide of the lipopolysaccharide which may be difficult to distinguish from those resulting from infection and may thus complicate diagnosis. Rough attenuated mutants lack the O-polysaccharide and would solve this problem if eliciting protective immunity; the empirically obtained rough mutants 45/20 and RB51 have been used as vaccines. Strain 45/20 is reportedly unstable and it is not presently used. RB51 is increasingly used instead of S19 in some countries but it is rifampicin resistant and its effectiveness is controversial. Some controlled experiments have found good or absolute protection in adult cattle vaccinated orally (full dose) or subcutaneously (reduced dose) and in one field experiment, RB51 was reported to afford absolute protection to calves and to perform better than S19. Controlled experiments in calves, however, have shown reduced doses of RB51 to be ineffective, full doses only partially effective, and RB51 less effective than S19 against severe challenges. Moreover, other observations suggest that RB51 is ineffective when prevalence is high. RB51 is not useful in sheep and evidence in goats is preliminary and contradictory. Rough mutants obtained by molecular biology methods on the knowledge of the genetics and structure of Brucella lipopolysaccharide may offer alternatives. The B. abortus manBcore (rfbK) mutant seems promising in cattle, and analyses in mice suggest that mutations affecting only the O-polysaccharide result in better vaccines than those affecting both core and O-polysaccharide. Possible uses of rough vaccines also include boosting immunity by revaccination but solid evidence on its effectiveness, safety and practicality is not available.

Key words: Brucella / brucellosis / vaccines / lipopolysaccharide / genetics

Corresponding author: Ignacio Moriyón

© INRA, EDP Sciences 2004