Comparison between enzyme-linked immunosorbent assay, indirect fluorescent antibody and rapid conglutination tests in detecting antibodies against Babesia bovis.

The performance of an enzyme-linked immunosorbent assay (ELISA), an indirect fluorescent antibody test (IFAT) and a rapid conglutination test (RCT) for the detection of antibodies against Babesia bovis, was evaluated with 462 cattle sera from Bahia State; Brazil. The results showed a concordance of 96.6% between the ELISA and IFAT, 90.5% between the ELISA and RCT, and 91.8% between the IFAT and RCT. Although the prevalence rates determined by ELISA (97.2%) and IFAT (96.8%) were higher than that indicated by the RCT (92.9%), performances of the three serological tests were very similar and characterized the region studied as enzootically stable to B. bovis.

Análise de testes de conglutinaçäo rápida para detecçäo de anticorpos contra Babesia bovis e Babesia bigemina / Evaluation of rapid conglutination tests for detection of antibodies against Babesia bovis and Babesia bigemina

Testes de conglutinaçäo rápida foram desenvolvidos para detecçäo de anticorpos contra Babesia bovis e B. bigemina. O primeiro (TCR-B. bovis) apresentou resultados idênticos à imunofluorescência indireta (IFI), na detecçäo de anticorpos resultantes da vacinaçäo com cepas atenuadas de B. bovis, enquanto que o segundo teste de conglutinaçäo (TCR-B. bigemina) divergiu em três dos seis animais na fase inicial da soroconversäo. Aos 28 e 56 dias pós-vacinaçäo (PV) houve coincidência total de resultados. A correlaçäo entre os TCR-B. bovis e IFI no exame dos soros de bovinos de sete estados brasileiros foi de 86,2 por cento, enquanto que a correlaçäo entre TCR-B. bigemina e a prova de imunofluorescência foi de 95,6 por cento. Os resultados demonstraram que os testes de conglutinaçäo podem ser empregados em estudos epidemiológicos com eficiência comparável à imunofluorescência indireta

In vitro cultivation of Anaplasma marginale: growth pattern and morphologic appearance.

Anaplasma marginale propagated in vitro showed an increasing rate of replication in a sequence of three experiments. The changes in the percentage of parasitized erythrocytes and identification of the organism in culture were monitored by the Giemsa-staining and the direct fluorescent antibody techniques. The ultrastructure of the organism in culture also was determined. The percentage of parasitized erythrocytes increased more than three times in the first experiment during a period of 8 days, and about ten times in the second experiment during a period of 14 days. After 8 days of observation of the primary culture in the third experiment, the trend of growth was more rapid than in the first and second experiment. The viability of the organism was verified by inoculation of susceptible calves, using 13- and 33-day cultures of the first and the second experiments, respectively. The primary cultures were subcultured twice by dilution with normal bovine erythrocytes.

In vitro cultivation of Anaplasma marginale: invasion of and development in noninfected erythrocytes.

Ovine erythrocytes infected with attenuated Anaplasma marginale organisms were cultured in a suspension of normal ovine erythrocytes and normal bovine erythrocytes for 42 days. In each system, the organism showed an initial period of rapid growth followed by a gradual decrease in the percentage of parasitized erythrocytes accompanied by cyclic peaks. The percentage of infection of ovine erythrocytes were not different when normal ovine or bovine erythrocytes were added to the cultures. In vitro transmission of the organism from infected ovine cells to normal bovine cells was demonstrated by use of a two-step direct fluorescent antibody method, which allowed for specific identification of the two cell types and the organism.

Direct effects of salicylate on renal function in the dog.

Sodium salicylate was administered to anesthetized dogs in doses sufficient to produce concentrations in plasma comparable to those common in human salicylate toxicity. Salicylate administration increased the rates of excretion of water, sodium, and chloride in the urine. Salicylate administration also increased the rate of excretion of potassium so that its clearance often exceeded that of creatinine. This enhancement of potassium excretion was dissociated from the alkalosis that accompanies salicyate toxicity. Administration of 5% CO(2) in inspired gas did not attenuate the excretion of potassium; injection of salicylate into one renal artery caused a unilateral kaliuresis. Phosphate excretion increased progressively after administration of salicylate. On several occasions the clearance of phosphate equalled that of creatinine. Salicylate reduced renal tubular glucose reabsorption. When salicylate was injected into a renal artery, a glycosuria occurred ipsilaterally at filtered loads of glucose far below the reabsorptive capacity of the dog kidney. Salicylate administration also was associated with early elevation of glucose, phosphate, and potassium concentration in plasma. Salicylate administration reduced the content of adenosine triphosphate in the renal medulla. Salicylate was concentrated within the medulla between 1.5 and 3 times that of the cortex, a gradient equal to that for chloride.