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United States Department of Agriculture

Agricultural Research Service

Title: The Application of Repetitive DNA Probes in Assessing the Potential for Hybridization Between Trichinella Nativa and T Spiralis

item Zarlenga, Dante

Submitted to: Trichinellosis International Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: April 20, 1995
Publication Date: N/A

Interpretive Summary: At present, problems with morphological differentiation of putative species of Trichinella make parasite cross-hybridization studies virtually impossible. Herein, we developed species specific DNA probes that could easily differentiate T. spiralis from the freeze resistant T. nativa. These probes were used to demonstrate that, contrary to current beliefs in this field of research, it is biologically possible to obtain non-synchronous multiple infections of two different species of Trichinella within the same host; consequently, the potential for hybridization between the pig species and the freeze resistant species of Trichinella remains plausible.

Technical Abstract: A repetitive DNA probe, designated pPB 1.21, which hybridizes to DNA from Trichinella nativa and does not hybridize with genomic DNA from Trichinella spiralis along with the T. spiralis specific DNA probe, pBP 2, were used to evaluate the potential for 2 distinct, non-synchronically inoculated species of Trichinella to infect the same host. Mice (Swiss webster) were infected with varying numbers of T. nativa then reinoculated 45 days later with T. spiralis. In a second group of animals, the order of infection was reversed using T. spiralis as the primary inoculum. Forty days following the second infection, the muscle larvae were collected and genomic DNA extracted. DNA dot blots performed in duplicate, demonstrated that a primary infection of T. spiralis significantly reduced the potential for reinfection of the same host with T. nativa; however, mice first infected with T. nativa clearly exhibited reinfection by T. spiralis which was propagated through at least 5 passages in mice including the initial infection. These results suggest that sylvatic hosts infected with sylvatic genotypes of Trichinella can become reinfected with the more common T. spiralis and thus provide an opportunity for gene flow between Trichinella genotypes in nature.

Last Modified: 5/5/2015
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