Document 0146
 DOCN  M9470146
 TI    [Inter- and intra-cephalic variations in pathogenicity in Toxoplasma
       gondii. Clinical and epidemiologic consequences]
 DT    9409
 AU    Ambroise-Thomas P; Okay T; Departement de Parasitologie-Mycologie
       Medicale et; Moleculaire, Faculte de Medecine, Universite Joseph
       Fourier,; Grenoble.
 SO    Bull Acad Natl Med. 1993 Nov;177(8):1411-9; discussion 1419-21. Unique
       Identifier : AIDSLINE MED/94251636
 AB    Clinical and epidemiological studies, especially the ones conducted in
       HIV+ patients indicate that the pathogenicity of Toxoplasma gondii
       varies according to the strain considered. The differences observed
       among strains are represented by distinct genomic DNA patterns which
       could be experimentally evaluated by means of the RFLP (Restriction
       Fragment Length Polymorphism) and the RAPD (Random Amplified Polymorphic
       DNA). If on the one hand virulent strains present very similar genomic
       DNA patterns, on the other hand chronic strains are highly polymorphic.
       These differences may be, at least in part, due to the asexual (clonal)
       multiplication of virulent strains. The existence of an intraspecific
       pathogenicity variation and genetic heterogeneity was observed within a
       single strain either after attenuation (infection in Fischer or Wistar
       rats), or during reactivation (in immunodepressed animals). In a
       congenital model of toxoplasmosis, the differences are detected from one
       animal to another and sometimes, even from one organ to another in the
       same host. This finding do not seem to be related to the occurrence of
       mutations but rather to selective pressures, notably of immunological
       origin, exerted by the infected organism. A better understanding of
       these phenomena could result in significant therapeutic and prophylactic
       advances. Our first effort will be directed to the establishment of more
       precise diagnostic and predictive elements. The accomplishment of this
       step relies on the use of primers deriving from DNA sequences
       characteristic of virulence and which will be tested by PCR.
 DE    Animal  English Abstract  Human  Rats  Rats, Inbred F344  Rats, Wistar
       Toxoplasma/*PATHOGENICITY  Toxoplasmosis/*EPIDEMIOLOGY/THERAPY
       Toxoplasmosis, Animal/*CONGENITAL  JOURNAL ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).