Alterations in the mitochondrial physiology of Biomphalaria glabrata (Mollusca: Gastropoda) after experimental infection by Angiostrongylus cantonensis (Nematoda: Metastongylidae).

The effect of infection by Angiostrongylus cantonensis on the mitochondrial physiology of Biomphalaria glabrata was investigated after exposure to 1200 L1 larvae. The snails were dissected one, two and three weeks after infection for collection and mechanical permeabilization of the gonad-digestive gland (DGG) complex. The results obtained indicate that prepatent infection by this nematode fluke significantly suppresses the phosphorylation state (respiratory state 3) and basal oxygen consumption of B. glabrata, demonstrating that the infection reduces the ability of the intermediate host to carry out aerobic oxidative reactions. Additionally, relevant variations related to the uncoupled mitochondrial (state 3u) of B. glabrata infected by A. cantonensis were observed. One week after exposure, a significant reduction in mitochondrial oxygen consumption after addition of ADP (2.91 ± 0.36 pmol O2/mg of tissue) was observed in the infected snails in comparison with the respective control group (5.14 ± 0.25 O2/mg of tissue). In the uncoupled state, the infected snails consumed about 62% less oxygen than the infected snails (7.39 ± 0.69 pmol O2/mg of tissue) in the same period. These results demonstrate a reduction in oxidative decarboxylation rate of the tricarboxylic acid cycle and faster anaerobic degradation of carbohydrates in the infected snails. The possible mechanisms that explain this new metabolic condition in the infected organisms are discussed.