Within‐Host Evolution for the Invasiveness of Commensal Bacteria: an Experimental Study of Bacteremias Resulting from<i>Haemophilus influenzae</i>Nasal Carriage

Abstract

Our results provide support for within-host evolution as one but not the sole explanation for the invasiveness of these bacteria. We discuss the implications of these results for both the rare invasiveness of commensal bacteria and the general observation that bacteria isolated from the sites of human invasive disease are almost invariably monoclonal.