Characterization of Lophomonas spp. Infection in a Population of Critical Care Patients

Abstract

Lophomonas are flagellated protozoa that have been increasingly associated with upper and lower airway infection in humans. The prevalence and characterization of this disease in the critically ill remains poorly understood. We present a series of eleven ICU patients with confirmed Lophomonas spp. identification in respiratory samples.

Keywords: critical care; immunosuppression; parasitology; pneumonia; respiratory failure.

Figure A1

Comparison of morphology between bronchial epithelial ciliated cells (A) and Lophomonas spp. (B). Bronchial epithelial ciliated cells ((A), Giemsa stain, amplification ×1000, bar 5 µm) are column-shaped with a nucleus positioned at the basal portion of the cell. Their cilia are short and are positioned above a well-defined terminal band on the apical portion of the cell. Lophomonas protozoa ((B), Giemsa stain, amplification ×1000, bar 5 µm) may be pyriform (B1), ovoid (B2), or round in shape. Their flagella originate from a tuft located at the apical end and are long and irregular in length. Cytoplasmic granules and vacuoles are frequently visible, and the nucleus may be located near the apical end.