Molecular variations based on RAPD among oxyurids in Egypt

ABSTRACT

Pinworms are nuisance parasites of man and animals. In addition to the human pinworm Enterobius vermicularis, Syphacia muris has been reported to infect man. Morphological differences between pinworm species are difficult to determine. Polymerase chain reaction [PCR] based assays including random amplified polymorphic DNA [RAPD] have been used effectively as a complementary approach for fast and simple detection of genomic variability and similarity among parasites. Such information is essential for accurate identification and for finding appropriate experimental models for species under study. The present study seeks to investigate the degree of similarity between the encountered pinworms aiming to find out the closely related species to E. vermicularis to be used as an experimental model. This is evaluated through RAPD-PCR using ten arbitrary primers to differentiate between the encountered pinworm species. The results are statistically evaluated to reveal the significant variations and to specify the degree of similarity and divergence between the encountered species. The pinworms included in this study are Syphacia obvelata from the house mouse Mus musculus, S. muris from the black house rat Rattus rattus, E. vermicularis from infected children and Aspiculuris tetraptera from the white laboratory rats Rattus norvegicus alba. The degree of similarity between the encountered species was evaluated by PCR-RAPD using the following ten arbitrary primers OPB-03 [5-CAT CCC CCT G-3], OPB-06 [5- CAT CCC CCT G-3], OPB-19 [5- ACC CCC GAA G-3], OPC-02 [5- GTG AGG CGT C-3], OPC-05 [5- GAT GAC CGC C-3], OPC-14 [5- TGC GTG CTT G-3], OPD-03 [5- GTC GCC GTC A-3], OPD-13 [5- GGG GTG ACG A-3], OPE-07 [5- AGA TGC AGC C-3], and OPE-12 [5- TTA TCG CCC C-3]. PCR-RAPD technique produced common as well as species specific multiband fingerprints with the ten used arbitrary primers for S. obvelata, S. muris, A. tetraptera and E. vermicularis. These variations proved valid for differentiation between the oxyurid species in Egypt. OPC-02, OPC-14 and OPD-3 revealed higher similarity between E. vermicularis and S. muris than with the other pinworm species. Seven of the ten tested arbitrary primers [OPB-03, OPB-06, OPB-19, OPC-05, OPD-13, OPE-07, and OPE-12] revealed that the similarity between A. tetraptera and E. vermicularis is higher than that between E. vermicularis and both Syphacia species. The present study concluded that the primers used in the present study can be used to differentiate between the encountered species and that A. tetraptera and S. muris can be used as experimental models for studying enterobiasis