Hemolytic Streptococci from the Throat of Normal Monkeys

Abstract

In November 14, 1938, a shipment of 500 Rhesus monkeys arrived in San Juan from India. These animals came, on the average, from 300 miles inland from Calcutta. The period of time they remained in this city awaiting shipment varied with different animals from a few days to 3 weeks. The shipment left Calcutta, September 30, 1938. The ports touched enroute were: Colombo, Ceylon, one day; Boston Mass., 2 days; and New York City, 2 days.

We studied the throat flora of 172 of these monkeys soon after arrival, over a period from November 20 to December 12, 1938, and the beta-hemolytic streptococci recovered were studied in considerable detail. The materials and methods used were the same as those employed in a previous investigation. 1

During the second week of December, 1938, the monkeys were taken to Santiago∗ Primate Colony, where they were set free. Throat cultures from 309 monkeys which were in apparent good health were taken again over a period from January 16 to February 22, 1940, and the hemolytic streptococci recovered were studied, utilizing media and methods similar to those employed before.

Seegal, Heller and Joblanowitz 2 studied the normal bacterial flora of 48 monkeys in New York City and recovered beta-hemolytic streptococci in 28 instances. Of these, 19 were Group A, 4 Group C, 5 Group G, and one, a minute streptococcus belonging to Group F.

Of the 172 monkeys examined in 1938, 22 (12.7%) harbored hemolytic streptococci in their throat, of which 10 (45.6%) were Group A, 8 (35.9%) were Group C, and 4 (18.5%) were Group G.

Of the 309 monkeys examined in 1940, 39 (12.5%) harbored hemolytic streptococci in their throat. None of them were Group A. Twenty-six (66.6%) were Group C, and 13 (33.3%) were Group G. It is interesting to note that, though the incidence of beta-hemolytic streptococci is the same in both cases, about one-half of the streptococci recovered from the throats of the monkeys soon after arrival, belonged to Group A, while no streptococci belonging to this serological group were encountered among the strains obtained after the monkeys had been in Santiago Island for about 14 months.