Evaluation of brucellosis RB51 vaccine for domestic water buffalo (Bubalus bubalis) in Trinidad

Comparative study on responses of cattle and water buffalo (Bubalus bubalis) to experimental inoculation of Brucella abortus biovar 1 by the intraconjunctival route—a preliminary report

“…For the first time in Trinidad, following vaccination studies on the efficacy of SRB51 vaccine in domestic water buffalo (Fosgate et al 2003a;Diptee et al 2007;Ramnanan 2009), the current study established infection with a local strain of B. abortus that was demonstrated serologically and by culture. This is important because this had hampered vaccination trials due to the non-availability of the standard challenge S2308 and the failure of local isolates of B. abortus at different dosages to cause experimentally induced infection.…”

“…There are however published reports on the use of calves of cattle and water buffalo in vaccine trials or challenge studies (Meador et al 1988;Olsen et al 1996Olsen et al , 2003Fosgate et al 2003a;Diptee 2004).…”

“…However, at that time, there were no published reports on the efficacy of the vaccine in the domestic water buffalo. A study conducted by Fosgate et al (2003a) on young water buffalo calves aged 5 to 20 months demonstrated that the vaccine did not offer protection to vaccinated study animals following exposure to naturally infected herds. In another investigation, Diptee et al (2007), using local strains of B. abortus, in the absence of the standard challenge strain 2308, at the recommended standard dosage of 1.0×10 7 colony forming units (cfu; Olsen et al 2003) and dosages as high as 1.2×10 8 cfu to challenge B. abortus RB51-vaccinated and non-vaccinated using the recommended intraconjunctival route failed to establish demonstrable infection or induce seroconversion.…”

“…It was therefore hypothesized that the domestic water buffalo is either more resistant than cattle to infection by B. abortus following intraconjunctival exposure or that the local strains of the organism were avirulent. In a recent study (unpublished), 19 strains of B. abortus isolated from apparently normal and diseased tissues of cattle and water buffalo in three different studies (Fosgate et al 2002a(Fosgate et al , 2003aDiptee et al 2007;Ramnanan 2009) were inoculated intraperitoneally into BALB/cByJ mice, using the protocol described by Mukherjee et al (2005). The BALB/c mouse strain has been suggested to be an appropriate model to study the virulence of B. abortus strains for cattle (Montaraz and Winter 1986).…”

Brucellosis at the animal/ecosystem/human interface at the beginning of the 21st century

“…RB51 does not protect sheep against either B. melitensis or B. ovis (Moriyon et al, 2004). Furthermore, it has been tested in water buffaloes (Fosgate et al, 2003), pigs (Stoffregen et al, 2006), bisons (Davis and Elzer, 2002) and cervids (Cook et al, 2002) with negative results.…”