Experimental exposure of llamas (Lama glama) to Brucella abortus: humoral antibody response

Positive antibody reactions to brucella were observed in the sera of four l lamas receiving Bruccella abortus Strain 19 subcutaneously at 2-3 weeks pos t-exposure (PE) using five of eight conventional brucella serologic tests a nd an ISU-ELISA. Positive brucella antibody reactions were detected in sera of four llamas exposed by intraocular instillation (IOI) of 1.02 x 10(8) ( high dose) B. abortus Strain 2308 at 16-35 days PE using seven of eight ser ologic tests or an ISU-ELISA. Brucella antibody was also detected in sera o f four llamas exposed by IOI of 9 x 10(5) (low dose) B. abortus using each of four agglutination tests, Complement Fixation test, PCFIA, the rivanol t est and the ISU-ELISA at 16-35 days PE. Positive reactions were observed us ing the Card test, PAPA, SPT, STT, the rivanol test, the PCFIA, and the ISU -ELISA on sera collected on days 42-70 PE, except on one llama, given the l ow dose; that llama was negative on the PCFIA on day 42. Positive or suspic ious reactions were not detected in sera of controls, receiving saline subc utaneously, using the routine tests, with the exception of the CFT. The B. abortus Strain 2308 was isolated from tissues of seven of eight llamas expo sed to virulent B. abortus Strain 2308. (C) 2001 Elsevier Science B.V. All rights reserved.