xenoparasite

xenoparasite

 [zen″o-par´ah-sīt]
an organism not usually parasitic on a particular species, but which becomes so because of a weakened condition of the host.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

xen·o·par·a·site

(zen'ō-par'ă-sīt),
An ecoparasite that becomes pathogenic as a consequence of its host's weakened resistance.
Farlex Partner Medical Dictionary © Farlex 2012

xen·o·par·a·site

(zen'ō-par'ă-sīt)
An ecoparasite that becomes pathogenic in consequence of weakened resistance on the part of its host.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012