Excretion of Brucella abortus vaccine B19 strain during a reproductive cycle in dairy cows

This paper aimed to determine the excretion period of B19 vaccine strain during a complete reproductive cycle (from estrus synchronization, artificial insemination, pregnancy and until 30 days after parturition) of dairy cows from 3 to 9 years old that were previously vaccinated from 3 to 8 months. Three groups were monitored with monthly milk and urine collection during 12 months: G1 with seven cows from 3 to 4 years old; G2 with three cows from 5 to 6 years old; and G3 with four cows from 7 to 9 years old. Urine and milk samples were submitted to bacteriological culture and urine and PCR reactions for detection of Brucella spp. and PCR-multiplex for B19 strain identification. Ring test (RT) was also performed in the milk samples, and serum samples were tested by buffered acidified plate antigen test (BAPA). All animals were serologically negative at BAPA and Brucella spp. was not isolated from both urine and milk samples. RT revealed 13/210 (6.2%) positive milk samples. PCR reactions detected DNA of Brucella spp. in 86/420 (20.5%) samples. In urine it was found a significantly higher frequency (35.2%; 74/210) than in milk (5.7%; 12/210), more frequently from the estrus to 150 days of pregnancy and after parturition (6.7%; 10/150), and from 150 days of pregnancy to parturition (3.4%; 2/60), and they were all identified as B19 strain. In three groups, intermittent excretion of B19 strain was detected mainly in urine samples, which confirmed its multiplication and persistence in cows for until 9 years.

Excretion of Brucella abortus vaccine B19 strain during a reproductive cycle in dairy cows.

This paper aimed to determine the excretion period of B19 vaccine strain during a complete reproductive cycle (from estrus synchronization, artificial insemination, pregnancy and until 30 days after parturition) of dairy cows from 3 to 9 years old that were previously vaccinated from 3 to 8 months. Three groups were monitored with monthly milk and urine collection during 12 months: G1 with seven cows from 3 to 4 years old; G2 with three cows from 5 to 6 years old; and G3 with four cows from 7 to 9 years old. Urine and milk samples were submitted to bacteriological culture and urine and PCR reactions for detection of Brucella spp. and PCR-multiplex for B19 strain identification. Ring test (RT) was also performed in the milk samples, and serum samples were tested by buffered acidified plate antigen test (BAPA). All animals were serologically negative at BAPA and Brucella spp. was not isolated from both urine and milk samples. RT revealed 13/210 (6.2%) positive milk samples. PCR reactions detected DNA of Brucella spp. in 86/420 (20.5%) samples. In urine it was found a significantly higher frequency (35.2%; 74/210) than in milk (5.7%; 12/210), more frequently from the estrus to 150 days of pregnancy and after parturition (6.7%; 10/150), and from 150 days of pregnancy to parturition (3.4%; 2/60), and they were all identified as B19 strain. In three groups, intermittent excretion of B19 strain was detected mainly in urine samples, which confirmed its multiplication and persistence in cows for until 9 years.

Isolation and identification of bovine tuberculosis in a Brazilian herd (São Paulo).

Mycobacterium was verified in animals from a Brazilian dairy herd, a total of 42 samples from 30 cows were submitted to culture and the isolated strains were analyzed by two polymerase chain reaction (PCR), the first specific for species belonging to the Mycobacterium complex (MTBC) and the other for differentiating M. tuberculosis from M. bovis. Twenty seven samples (64.3%) from 18 animals (60%) were positive for mycobacteria by culture, including samples from 15 retrofaryngeal lymphnodes (55.5%), 9 prescapular lymphnodes (33.3%), 2 lungs (7.4%), and 1 liver (3.7%). All isolated colonies were confirmed by PCR to contain MTBC organisms, and were identified as M. bovis by the same methodology.

Isolation and identification of bovine tuberculosis in a Brazilian herd (São Paulo)

Mycobacterium was verified in animals from a Brazilian dairy herd, a total of 42 samples from 30 cows were submitted to culture and the isolated strains were analyzed by two polymerase chain reaction (PCR), the first specific for species belonging to the Mycobacterium complex (MTBC) and the other for differentiating M. tuberculosis from M. bovis. Twenty seven samples (64.3 percent) from 18 animals (60 percent) were positive for mycobacteria by culture, including samples from 15 retrofaryngeal lymphnodes (55.5 percent), 9 prescapular lymphnodes (33.3 percent), 2 lungs (7.4 percent), and 1 liver (3.7 percent). All isolated colonies were confirmed by PCR to contain MTBC organisms, and were identified as M. bovis by the same methodology.