Conjunctival vaccination of young goats with Brucella melitensis strain Rev 1

Three groups each of 15 four-month old female kids were vaccinated with Brucella melitensis strain Rev 1 either conjunctivally (1.1 x 10(7) or 1.1 x 10(9) CFU) or subcutaneously (1.1 x 10(9) CFU). One group of 15 kids remained unvaccinated as control. All kids were mated when 9.5 month old. Three months later, they were challenged conjunctivally with B melitensis strain H38 at a dose of 5.1 x 10(6) CFU. Blood samples collected before vaccination and throughout the experiment were subjected to Rose Bengal (RBPT) and Complement Fixation (CFT) tests. Allergy was tested both after vaccination and after challenge. Milk, uterine discharge as well as tissues from aborted foetuses and dead kids and from goats slaughtered 4-6 weeks after abortion or full-term kidding, were cultured on Farrell's medium. A serological response was shown in most kids vaccinated conjunctivally. However, 4 months after vaccination with either 1.1 x 10(7) or 1.1 x 10(9) CFU Rev 1, all animals were negative whereas some positive RBPT or CFT titres were still observed after the classical subcutaneous vaccination. There were more allergic reactions among subcutaneously than conjunctivaly vaccinated animals, but sensitization was shown long-lasting in all vaccinated groups, excluding allergic testing as a screening method in vaccinated flocks. Against a challenge which led all controls to abort, conjunctival vaccination was slightly better with 1.1 x 10(9) than with 1.1 x 10(7) CFU and almost as effective than that given by the subcutaneous one. These differences however were not statistically significant. These results quite agree with those previously recorded for ewes.(ABSTRACT TRUNCATED AT 250 WORDS)