[Identification of Mycobacterium avium-intracellulare complex by PCR of AIDS and disseminated mycobacteriosis]

Rev Med Inst Mex Seguro Soc. 2016 Mar-Apr;54(2):170-5.
[Article in Spanish]

Abstract

Objective: The aim of this study is to differentially identify MAC by PCR in patients with AIDS and disseminated mycobacteriosis.

Methods: A cross sectional study was conducted in Mexico to identify MAC by Molecular Biology. Two sets of primers were synthesized: MAV and MIN, for M. avium and M. intracellulare, respectively. Whole-cell DNAs obtained from 29 clinical isolates and clinical serum specimens from other 24 patients with AIDS and disseminated mycobacterial infection were extracted and amplified by PCR with the MAV and MIN primers. The MAV and MIN primers each amplified one highly specific 1.3-kb segment of the homologous DNA, respectively.

Results: Twenty-nine DNAs from MAC clinical isolates identified by Gen-Probe AccuProbes were amplified with the MAV primers. Of the 24 clinical samples, 3 were positive for M. avium and 6 for M. tuberculosis.

Conclusions: Our results demonstrated that PCR technique could be applied for the differentiation of M. avium and M. intracellulare by specific 16S rRNA primers. In patients with advanced stage AIDS and in whom disseminated mycobacteriosis is suspected, the presence of anemia (even with negative cultures), elevated alkaline phosphatase and a median CD4 count of 15.9/mL, the diagnosis of infection by MAC should be strongly considered; we suggest that in accordance with our findings, a more precise stratification of patients in terms of their CD4 T cell counts is warranted.

Introducción: el objetivo de este artículo es Identificar y diferenciar el complejo MAC por PCR en pacientes con SIDA y micobacteriosis diseminada. Métodos: se llevó a cabo un estudio transversal para identificar MAC por biología molecular. Se sintetizaron dos conjuntos de iniciadores: MAV y MIN, para M. avium y M. intracellulare, respectivamente. El ADN total de células obtenidas de 29 aislados clínicos y muestras de suero de otros 24 pacientes con SIDA e infección micobacteriana diseminada fue extraído y se amplificó por PCR con los iniciadores MAV y MIN. Cada uno de los iniciadores MAV y MIN amplificó un segmento altamente específico de 1.3 kb del ADN homólogo, respectivamente. Resultados: veintinueve ADN de los aislados clínicos de MAC identificadas por Gen-Probe AccuProbes se amplificaron con los iniciadores MAV (M. avium). De las 24 muestras clínicas, 3 fueron positivas para M. avium y 6 para M. tuberculosis. Conclusiones: nuestros resultados demostraron que la técnica de PCR se puede aplicar para la diferenciación de M. avium y M. intracellulare por iniciadores específicos 16S rRNA. En pacientes con estadio avanzado de SIDA y en quienes se sospecha micobacteriosis diseminada, la presencia de anemia (incluso con cultivos negativos) fosfatasa alcalina elevada y una mediana de CD4 de 15.9/ml, se debe considerar seriamente el diagnóstico de infección por MAC; sugerimos que, de acuerdo con nuestros resultados, se justifica una estratificación más precisa de los pacientes en términos de sus recuentos de células T CD4.

Keywords: Acquired immunodeficiency syndrome; Mycobacterium avium complex; Nontuberculous mycobacterium infections; Polymerase chain reaction.

Publication types

  • Clinical Trial

MeSH terms

  • AIDS-Related Opportunistic Infections / diagnosis*
  • AIDS-Related Opportunistic Infections / microbiology
  • Adult
  • Cross-Sectional Studies
  • DNA, Bacterial / analysis*
  • Diagnosis, Differential
  • Female
  • Humans
  • Male
  • Middle Aged
  • Mycobacterium avium Complex / genetics*
  • Mycobacterium avium Complex / isolation & purification
  • Mycobacterium avium-intracellulare Infection / diagnosis*
  • Mycobacterium avium-intracellulare Infection / microbiology
  • Polymerase Chain Reaction*

Substances

  • DNA, Bacterial