Biochemical resolution of European and African isolates of Trichinella nelsoni Britov and Boev, 1972.

Isoenzyme analysis was used to characterize 47 isolates of Trichinella nelsoni from Europe (EUR) and two from Kenya and Tanzania (AFR). In all, 27 isoenzymes showed polymorphism within the species. The EUR parasites, isolated from domestic, synanthropic, sylvatic animals and man, showed isoenzymatic profiles different from those exhibited by AFR parasites isolated from sylvatic animals. The EUR parasites showed polymorphism due to three isoenzymes, i.e. ME, MPI and PGM. Euclidean distance and a dendrogram were used to evaluate the relationships among isolates. The Euclidean values showed that EUR and AFR genotypes are distant from each other and from the reference strains T. spiralis s.str. and T. pseudospiralis. The genetic data indicate the absence of gene flow between AFR and EUR isolates. The biochemical results suggest the presence of genetic heterogeneity in T. nelsoni and support the existence of a zoogeographical segregation of the two gene pools. The authors propose that as operational labels, code T3 be assigned to EUR isolates and code T7, to AFR isolates.