Pulmonary nontuberculous mycobacterial disease: prospective study of a distinct preexisting syndrome.

Rationale: Pulmonary nontuberculous mycobacterial (PNTM) disease is increasing, but predisposing features have been elusive.

Objectives: To prospectively determine the morphotype, immunophenotype, and cystic fibrosis transmembrane conductance regulator genotype in a large cohort with PNTM.

Methods: We prospectively enrolled 63 patients with PNTM infection, each of whom had computerized tomography, echocardiogram, pulmonary function, and flow cytometry of peripheral blood.

Identification and characterization of a novel heme-associated cell surface protein made by Streptococcus pyogenes.

Analysis of the genome sequence of a serotype M1 group A Streptococcus (GAS) strain identified a gene encoding a previously undescribed putative cell surface protein. The gene was cloned from a serotype M1 strain, and the recombinant protein was overexpressed in Escherichia coli and purified to homogeneity. The purified protein was associated with heme in a 1:1 stoichiometry.