Characteristics of Escherichia coli serotypes in the yanomama, a primitive indian tribe of South America.

From stool samples of isolated subjects from members of the Yanomama tribe of South America, 432 isolates of Escherichia coli were obtained from 72 individuals. Two hundred and four of these strains were typable with a standard panel of 147 O antisera; included in the above were eight enteropathogenic strains. From the untypable strains, antisera were produced, and 13 serologically distinct O serotypes were identified. These data substantiate the ubiquity of known strains of E. coli as microhabitants of man's internal environment. The finding of 13 new O serotypes suggests that, in efforts to understand the ecosystem of primitive man, the internal milieu must also be investigated.