Western blot (immunoblot) analysis of sera from cattle vaccinated with
Brucella abortus S19 exhibit an elevated serologic response to Hsp62,
the GroEL homolog (BaGroEL). Serologic screening of individual cows v
accinated with B. abortus S19 revealed no correlation between the immu
ne response to BaGroEL and protection against a challenge with virulen
t organisms. The humoral immune response to BaGroEL was restricted to
a region of the mature protein which mapped to amino acids 317 to 355
and may represent a useful diagnostic tool for monitoring exposure to
B. abortus. Immunity to a challenge with virulent B. abortus S2308 was
not observed in the BaGroEL vaccinated mouse model.