DETECTION AND IDENTIFICATION OF MYCOBACTERIUM-AVIUM IN THE BLOOD OF AIDS PATIENTS BY THE POLYMERASE CHAIN-REACTION

One hundred fifty-three blood samples from patients positive for the h uman immunodeficiency virus (HIV) were analyzed by polymerase chain re action (PCR) to detect the presence of Mycobacterium avium. Samples we re collected from patients who also had blood cultures performed by a radiometric method, Blood samples were centrifuged on a Ficoll-Hypaque gradient to purify peripheral blood mononuclear cells, The purified c ells were washed and incubated with a resin, boiled to release mycobac terial DNA, and then amplified, Polymerase chain reaction products wer e detected by a nonisotopic method, A 123 base-pair (bp) insertion seq uence, namely IS6110, from Mycobacterium tuberculosis complex was also included in the reaction as an internal control of Tag polymerase act ivity to exclude the presence of enzyme inhibitors, This IS6110 fragme nt can be distinguished from the 383 bp target product on ethidium bro mide-stained agarose gel and may also be used in a colorimetric assay. Such results were compared with the results of culture and indicated that the assay is as sensitive as bacteriological methods, though fast er.