The authors present some data about the buccal and intestinal microflora of Ophidian Reptiles schooling in the vivaria of the Institute Pasteur of Tunis. They describe two cases of infestation and dead, chiefly symptomatology, of a horned Viper, Cerastes cerastes (L. 1758) and a lebetin Viper, Vipera lebetina (L., 1758) by Pseudomonas aeruginosa Schröeter, 1885.