Different resistance patterns of reference and field strains of Brucella abortus

The aim of this study was to evaluate the growth of the B. abortus reference strains and field isolates on media containing different inhibitor agents. Reference strains were seeded on tryptose agar containing: i-erythritol (1.0 mg/mL), fuchsin (20 μg/mL and 80 μg/mL), thionin (2.5 μg/mL and 10 μg/mL), rifampicin (200 μg/mL) and safranin O (200 μg/mL). Field isolates were tested only on media containing i-erythritol, rifampicin and thionin. Furthermore, each suspension was also inoculated on tryptose agar incubated in air, to test its ability to grow without CO2. Sensitivity to fuchsin was similar among reference strains evaluated. Growth of S19, 544 and 2308 but not RB51 were inhibited on media containing rifampicin. Medium with safranin O showed no inhibition for RB51, 544 and 2308, but it partially inhibited the S19 growth as well as medium containing i-erythritol. Treatment/control growth ratio for 2308 on tryptose agar containing thionin (2.5 μg/mL) was approximatelly 1.0, whereas S19 and RB51 showed 0.85 and 0.89 ratios, respectively. Growth of 544, S19 and RB51 but not 2308 was completely inhibited on medium with thionin (10 μg/mL). All field strains grew on medium containing i-erythritol, but were completelly inhibited by rifampicin. With exception of A1 (B. abortus biovar 3) all field isolates grew on medium with thionin, although some strains showed a treatment/control growth ratio of 0.75–0.80 (10 μg/mL). These results showed that tryptose agar with thionin, i-erythritol or rifampicin could be useful for differentiating vaccine, challenge and field strains of B. abortus.

The serological response of adult cattle after vaccination with Brucella abortus strain 19 and RB51

Adult cattle vaccinated once or twice with 2x109 viable B. abortus strain RB51 bacteria did not seroconvert in the rose bengal, serum agglutination and mercaptoethanol tests. Animals vaccinated while pregnant did not abort and no B. abortus was isolated from their vaginal mucus and milk

Brucelose canina: relato de caso / Canine brucellosis: a case report

Relata-se a ocorrência de casos de brucelose em animais de um canil da cidade de Uruguaiana, Rio Grande do Sul. Devido a registros de aborto nesta criação, suspeitou-se desta enfermidade. O isolamento da Brucella canis foi realizado através da cultura de materiais obtidos dos fetos abortados, placenta e neonatos. O teste sorológico de imunodifusão em gel de ágar demonstrou que 72,7% (8/11) dos animais deste canil haviam se infectado com esta bactéria. Neste relato são descritos e discutidos os dados clínicos e sorológicos, assim como o isolamento da Brucella canis.

The ocurrence of canine brucellosis is described in a kennel from Uruguaiana city. Due to abortion registered at the kennel the suspected disease was brucellosis. The isolation of Bucella canis was realized by culturing the material collected from aborted fetuses, placenta and neonatos. The agar gel immunodiffusion test was used for sorological evaluation and showed that 72.7% (8/11) of the dogs were infected wifh the bactéria. The authors describe also the clinical signs, serological findings and also the isolation of the Brucella canis.

Evaluation of different meat peptones as culture media for Brucella abortus 19 vacine production

Quatro marcas comerciais de peptonas foram usadas para o cultivo de Brucella abortus amostra 19. Um estudo comparativo entre as quatro diferentes peptonas, usando-se procedimentos de fermentaçäo, revelou que houve uma significativa variaçäo no crescimento da Brucella abortus. Uma das quatro marcas testadas apresentou resultado superior às demais