Diagnosis of disseminated mycobacterial infection: testing a simple and inexpensive method for use in developing countries.
With the development of the acquired immunodeficiency syndrome (AIDS) epidemic, the isolation of mycobacteria from blood has become a common problem for clinical laboratories. In this study two methods were used for the recovery of mycobacteria from blood specimens obtained from AIDS patients: (1) direct inoculation of a biphasic medium, and (2) a non-commercial lysis-centrifugation method. A total of 3 consecutive blood samples were taken at 15-minute intervals from each of 50 AIDS patients with clinical suspicion of disseminated mycobacterial disease. Mycobacterium growth was noted in 70/138 blood specimens from 30 (60%) patients. These cultures yielded Mycobacterium tuberculosis in 19 (63%) and Mycobacterium avium complex organisms in 11 (37%) patients. Cultures using the lysis-centrifugation method were positive in 54% of the patients while cultures using biphasic medium were positive in 44% (P > 0.05). The positivity for M. avium complex was higher with lysis-centrifugation (91%) than with biphasic medium (45.4%) (P < 0.05). However, the positivities for M. tuberculosis with the lysis-centrifugation method (89.5%) and direct inoculation in biphasic medium (100%) were similar (P > 0.05). The use of a non-commercial lysis-centrifugation technique is inexpensive, reliable, and can be an alternative method for the diagnosis of mycobacteraemia in developing countries.
Fandinho
F C
FC
Microbiology Institute, Federal University of Rio de Janeiro, Brazil.
Grinsztejn
B
B
Veloso
V G
VG
Lourenço
M C
MC
Werneck-Barroso
E
E
João
E
E
Nogueira
S A
SA
Fonseca
L de S
Lde S
D017088:AIDS-Related Opportunistic Infections / Q000175:diagnosis* / Q000382:microbiology; D016470:Bacteremia / Q000175:diagnosis* / Q000382:microbiology; D001431:Bacteriological Techniques; D001769:Blood / Q000382:microbiology; D003906:Developing Countries; D006801:Humans; D009164:Mycobacterium Infections / Q000175:diagnosis* / Q000382:microbiology; D015269:Mycobacterium avium Complex / Q000302:isolation & purification; D015270:Mycobacterium avium-intracellulare Infection / Q000175:diagnosis / Q000382:microbiology; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification; D014376:Tuberculosis / Q000175:diagnosis / Q000382:microbiology