Direct Detection of Histoplasma DNA from Tissues

Histoplasma capsulatum in Gram stain of BAL specimen
Figure 1. Histoplasma capsulatum in Gram stain of BAL specimen

Histoplasma capsulatum (or Ajellomyces capsulatum) causes Histoplasmosis which mainly affects lungs. Infected individuals generally exhibit no clinical manifestations or ill effects. Acute phase is manifested by non-specific respiratory symptoms that are cough or flu like. Chronic Histoplasmosis can manifest tuberculosis like symptoms and can also lead to disseminated disease that can be fatal if not treated. Diagnosis by detection of antigen (EIA) and detection of antibody are widely used. Culture based confirmatory diagnosis is time consuming due to slow growth and manifestation of specific phenotype. PCR methods have been recently used to confirm presence of Histoplasma capsulatum in biopsy materials.

Histoplasma PCR detects Histoplasma capsulatum (or Ajellomyces capsulatum) with higher specificity and sensitivity than the broad-range fungal PCR. The analytical sensitivity is 1 genome per PCR reaction.

Taxonomic identifications are reported based on sequencing of the amplification product.

Kauffman et al. (2007) Histoplasmosis: Clinical and Laboratory Update in Clinical Microbiology Reviews p. 115-132