Phage types of mycobacterium tuberculosis in cultures isolated from Eskimo patients.

The phage type of each of 3 colonies selected at random from cultures of mycobacterium tuberculosis isolated from 233 Eskimo patients was determined. In 33 cultures, colonies of different phage types were observed. In 22 cases, the differences in phage types paralleled differences in drug susceptibility of the bacteria. A comparative study with cultures of Mycobacterium tuberculosis isolated from while patients did not reveal differences in phage types among 3 colonies from the same culture. This observation suggests that some of the numerous reactivations of the disease in Eskimo patients may be due to exogenous reinfections.