This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Havlir, D Articles by Deresinski, S C Search for Related Content PubMed PubMed Citation Articles by Havlir, D Articles by Deresinski, S C

Reproducibility of lysis-centrifugation cultures for quantification of Mycobacterium avium complex bacteremia.

Department of Medicine, UCSD Medical Center 92103.

ABSTRACT

While quantitative mycobacterial blood cultures have been accepted as the standard for evaluating response to various Mycobacterium avium complex (MAC) treatment regimens, variability in this methodology has not been evaluated in a rigorous fashion. We thus studied the reproducibility of quantitative MAC cultures by a lysis-centrifugation culture system within and among five institutions. To measure the intralaboratory variation in mycobacterial colony counts, colony counts from duplicate blood specimens collected from 52 AIDS patients with MAC bacteremia were determined. Colony counts ranged from 0 to 50,000 CFU/ml. Nonparametric analyses revealed there was no significant difference in colony counts between the 52 duplicate specimens. The agreement between the intralaboratory paired specimens, as measured by the intraclass correlation coefficient, was 0.997. To measure the interlaboratory variation, multiple 10-ml aliquots from 12 patients were distributed to five institutions and processed within 24 to 32 h by lysis-centrifugation. For the 12 specimens distributed to the five laboratories, two-way analysis of variance for repeated measures revealed no significant difference in an individual patient's colony counts between laboratories (P > 0.2). We conclude that quantitation of mycobacterial colony counts by the lysis-centrifugation system is reproducible within and between institutions. Clinical trials evaluating response to therapeutic interventions for MAC can use multiple laboratories for quantitation of mycobacteremia. Furthermore, a 24- to 32-h delay in processing appeared to have no impact on reproducibility.

This article has been cited by other articles:

• Ferrario, G., Gori, A., Rossi, A., Catozzi, L., Molteni, C., Marchetti, G., Bandera, A., Rossi, M. C., Esposti, A. D., Franzetti, F. (2001). PCR-Hybridization Assay for Mycobacterium avium Complex: Optimization of Detection in Peripheral Blood from Humans. J. Clin. Microbiol. 39: 1638-1643 [Abstract] [Full Text]  
• MacGregor, R. R., Dreyer, K., Herman, S., Hocknell, P. K., Nghiem, L., Tevere, V. J., Williams, A. L. (1999). Use of PCR in Detection of Mycobacterium avium Complex (MAC) Bacteremia: Sensitivity of the Assay and Effect of Treatment for MAC Infection on Concentrations of Human Immunodeficiency Virus in Plasma. J. Clin. Microbiol. 37: 90-94 [Abstract] [Full Text]  
• Havlir, D. V., Dube, M. P., Sattler, F. R., Forthal, D. N., Kemper, C. A., Dunne, M. W., Parenti, D. M., Lavelle, J. P., White, A. C., Witt, M. D., Bozzette, S. A., McCutchan, J. A., The California Collaborative Treatment Group, (1996). Prophylaxis against Disseminated Mycobacterium avium Complex with Weekly Azithromycin, Daily Rifabutin, or Both. NEJM 335: 392-398 [Abstract] [Full Text]  
• Masur, H., The Public Health Service Task Force on Prophylaxi, (1993). Recommendations on Prophylaxis and Therapy for Disseminated Mycobacterium avium Complex Disease in Patients Infected with the Human Immunodeficiency Virus. NEJM 329: 898-904 [Full Text]