Behaviour of a high-temperature-requirement A (Htr A) deletion mutant of Brucella abortus in goats

• Published in: Research in veterinary science Vol. 60; no. 1; pp. 48 - 50
• Main Authors: Elzer, P.H, Hagius, S.D, Robertson, G.T, Phillips, R.W, Walker, J.V, Fatemi, M.B, Enright, F.M, Roop, R.M
• Format: Journal Article
• Language: English
• Published: England Elsevier India Pvt Ltd 1996
• Subjects: Abortion, Veterinary; Animals; Bacterial Proteins - genetics; Brucella abortus; Brucella abortus - genetics; Brucella abortus - isolation & purification; Brucella abortus - physiology; Brucellosis - physiopathology; Female; Gene Deletion; Goats; Heat-Shock Proteins; Macrophages - microbiology; Mice; Mice, Inbred BALB C; Periplasmic Proteins; Pregnancy; Pregnancy Complications, Infectious - physiopathology; Serine Endopeptidases - genetics; Temperature
• ISSN: 0034-5288; 1532-2661
• DOI: 10.1016/S0034-5288(96)90130-7

Previous studies have shown that high-temperature-requirement
A (Htr
A) mutants of
Brucella abortus are more sensitive to oxidative killing in vitro, are less able to survive in cultured murine macrophages and are attenuated in BALE/c mice. To measure the effect of an Htr
A mutation on the virulence of B abortus in ruminants, pregnant goats in late gestation were exposed to infection by the conjunctival route with
B abortus 2308 or an isogenic
htrA mutant,
phe1. Infection with either 2308 or
phe1 resulted in abortion, but the serological responses to infection were consistent with 2308 but variable with
phe1. Strain 2308 was recovered post mortem both from aborted fetuses and infected dams, whereas
phe1 was recovered from neither. Nevertheless, short term studies revealed that
phe1 could be recovered from infected goats for up to two weeks after infection, suggesting that although the Htr
A mutation may change the colonising ability of
B abortus, the virulence of the mutant in pregnant goats is not reduced.