Mycobacterium avium is the most frequent cause of disseminated bacterial infection in patients with human immunodeficiency virus type 1 infection and in rhesus macaques with simian immunodeficiency virus (SIV) infection. This animal model of AIDS was used to test the hypothesis that this frequent association is the result of reciprocal enhancement of replication of both microorganisms. The replication of M. avium and SIV was analyzed in lymphatic tissues obtained from rhesus macaques experimentally inoculated with SIVmac who developed or remained free of overt M. avium infection. In situ hybridization, quantitative image analysis, and staining of M. avium and of macrophages were used to assess the effects of coinfection on the replication of SIV and M. avium in vivo. There was no correlation between virus load and M. avium load in coinfected lymph nodes, and, with one exception, there was no evidence that M. avium coinfection of macrophages increased SIV replication.
Bibliographical noteFunding Information:
Received 28 May 1999; revised 12 November 1999; electronically published 7 March 2000. Financial support: National Institutes of Health grants RR00168 and AI 38565. All experiments were performed in accordance with National Institutes of Health guidelines on the care and use of laboratory animals. Reprints or correspondence: Dr. Ashley T. Haase, Dept. of Microbiology, University of Minnesota, Box 196 Mayo Bldg., 420 Delaware St. S.E., Minneapolis, MN 55455 (firstname.lastname@example.org).