Neospora caninum: infection induces high lysosomal activity.

Neospora caninum is a protozoan that causes abortion in cattle and neuromuscular lesions in dogs, making it an important target of veterinary medicine. Lysosomes are cellular organelles responsible for important biological functions as cellular defense mechanisms. The aim of this work was to evaluate the lysosomal stability of rat gliocytes infected in vitro with N. caninum. Rat glial cultures were infected at a ratio of 1:1 (cell/parasite). The enzymatic activity of acid phosphatase (orthophosphoric-monoester phosphohydrolase, EC 3.1.3.2) was assayed in the medium of control and infected cell cultures. The activity observed at 24h of incubation was 0.4±0.08mU/mg/min for control cells and 1.3±0.5mU/mg/min for infected cells. After 72h, control and infected cells exhibited activities of 1.3±0.5 and 4.1±0.9mU/mg/min, respectively. These results suggested that lysosomal compartment plays an important role in the mechanisms of cellular infection by N. caninum.
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