GENETIC DIVERSITY AMONG MYCOBACTERIUM-AVIUM COMPLEX STRAINS RECOVEREDFROM CHILDREN WITH AND WITHOUT HUMAN-IMMUNODEFICIENCY-VIRUS INFECTION

The genetic diversity and molecular epidemiology of Mycobacterium aviu m complex (MAC) infections in children with and without human immunode ficiency virus (HIV) infection were evaluated. Isolates recovered from 136 children were subtyped by sequence analysis of a 360-bp region of the gene (hsp65) encoding a 65-kDa heat-shock protein. Twenty-one dis tinct hsp65 alleles were identified. On the basis of hsp65 genotype, 6 isolates were not MAC organisms. Of the remaining 130 samples, 61% we re M, avium, 37% were Mycobacterium intracellulare, and 2% were specie s nonspecific MAC. Eighty-eight percent of the isolates obtained from HIV-infected children were M. avium. In contrast, only 38% of the isol ates obtained from children without HIV infection were M, avium (chi(2 ) test, P <.0131), M, avium isolates were further subtyped by Southern blot analysis with insertion element IS1245. Taken together, no evide nce for a single clonal M, avium strain causing infection was detected .