Further Note on the Salivary Gland Poison of Aëdes Aegypti.

Abstract

In a previous communication 1 we described the poisonous substance contained in the salivary glands of Aëdes aegypti and the types of reactions which are produced by introducing this substance intradermally into the human skin. This substance gives rise to a reaction which is practically identical to that following the bite of this insect. The poison is resistant to both freezing and boiling temperatures and contains no hemolytic or anticoagulant substances. It does not produce antitoxin when introduced intravenously into rabbits.

Further studies upon the properties of the salivary gland poison from Aëdes aegypti indicate that the poison does not deteriorate on standing for several months. Material tested after 8 months from the time of preparation is just as active as in the beginning. Furthermore the poison may be diluted with 5 volumes of 95% alcohol or ether, desiccated at room temperature over calcium chloride, redissolved in physiological saline, and still retain its full potency when tested by intradermal skin injection. The poison when shaken out several times in ether does not lose any of its strength. Exposure of the salivary gland poison in saline to the action of ultra violet light, at one foot distance, in quartz tubes, for a period of 20 minutes has no apparent effect. The saline extract of the salivary glands gives a negative biuret reaction, a negative Fehlings test but a definitely positive Molisch reaction. The chemical tests indicate the carbohydrate nature of the toxic substance and the skin reactions obtained (wheel, without pseudopods, surrounded by erythema) are quite similar to those obtained with carbohydrates isolated from certain microorganisms.