“The results of attempts to cultivate trypanosomes from frogs.” A preliminary report

Abstract

During the year 1904 an effort was made in the pathological laboratory of the University of Buffalo to make studies on hematozoa in the lower animals. In a considerable number of normal cats, dogs, rabbits and guinea-pigs no hematozoa were found. The results of other examinations were as follows: 51 English sparrows {Passer domesticus), half in the winter, half in the spring, all negative; 27 mud-puppies (Necturus maculatus) in March, all negative; 40 toads in the summer, all negative. In 140 frogs from the Niagara river there occurred the following infections: 14 with Trypanosoma, 5 with Drepanidium, 1 with Filaria. Drepanidium was found both in the summer and fall. The infections with Trypanosoma were distributed as follows:

In July, of 15 frogs, 2 showed trypanosomes.

In August, of 26 frogs, 10 showed trypanosomes.

In September, of 14 frogs, 2 showed trypanosomes.

From October to December, of 85 frogs, none showed trypanosomes.

In one case Trypanosoma and Drapanidium occurred in the same blood. The trypanosomes had the usual characters of Trypanosoma rotatarium (ranarum). They were in no case numerous; two were rarely seen in one low-power field. The frogs appeared healthy. Eight attempts to inoculate normal frogs by way of the peritoneum with the blood of infected frogs gave negative results.

Attemps ad cultivation.— The blood of frogs and toads was taken to make blood-agar (used by Novy and MacNeal for the cultivation of trypanosomes). The blood was first examined carefully to see that it was free from parasites. The animal was etherized and placed in HgCl₂ solution I to 1,000 for 15 minutes, rinsed with distilled water, opened with a11 precautions, the blood from the heart taken wit11 a sterile pipette, and mixed rapidly with the water of condensation on slanted agar tubes (made with meat extract and peptone, and slightly alkaline to litmus).