Paracoccus yeei – An emerging pathogen or incidental finding?

Abstract

Paracoccus yeei is an aerobic Gram-negative coccobacilli that is found in soil. There are increasing reports of infection in the literature. The organism can appear under-decolourised on Gram-stain and thus be inadvertently reported or dismissed as a Gram-positive cocci. We report two cases of identification of the organism in our laboratory and the associated clinical findings. The first case is of a 5-month-old girl with unilateral ulcerating groin crease lesions who cultured P. yeei in blood culture, identified on MALDI-TOF-MS. Treatment in this case was directed at a Pseudomonas aeruginosa cultured from the wound, although Gram-positive cocci seen on the Gram-stain of the wound were never cultured. The second case is a 49-year-old woman with P. yeei cultured from a left knee joint aspirate with a polymorph count of 16,500×106/L, again identified on MALDI-TOF-MS. In this case, no directed treatment was administered. Identification of P. yeei may be increasing due to inclusion in the database of rapid microbiological identification systems such as the MALDI-TOF-MS and automated biochemical systems such as the VITEK-2 GN cards. Ongoing case publication is required to elucidate the prevalence and pathogenicity of this organism.