Molecular and Morphologic Identification of Spirometra ranarum Found in the Stool of African Lion, Panthera leo in the Serengeti Plain of Tanzania

Abstract

The present study was performed with morphological and molecular analysis (cox1 and nad1 mitochondrial genes) to identify the proglottids of spirometrid tapeworm found in the stool of an African lion, Panthera leo, in the Serengeti plain of Tanzania. A strand of tapeworm strobila, about 75 cm in length, was obtained in the stool of a male African lion in the Serengeti National Park (34˚ 50' E, 02˚ 30' S), Tanzania, in February 2012. The morphological features of the adult worm examined exhibited 3 uterine coils with a bow tie appearance and adopted a diagonal direction in the second turn. The posterior uterine coils are larger than terminal uterine ball and the feature of uteri are swirling rather than spirally coiling. The sequence difference between the Spirometra species (Tanzania origin) and S. erinaceieuropaei (GenBank no. KJ599680) was 9.4% while those of S. decipiens (GenBank no. KJ599679) differed by 2.1% in the cox1 and nad1 genes. Phylogenetic tree topologies generated using the 2 analytic methods were identical and presented high level of confidence values for the 3 major branches of the 3 Spirometra species in the cox1 gene. The morphological and molecular findings obtained in this study were nearly coincided with those of S. ranarum. Therefore, we can know for the first time that the African lion, Panthera leo, is to the definitive host of this tapeworm.

Keywords: Spirometra ranarum; Tanzania; cox1; lion; nad1.

Fig. 1

Gravid proglottids of Spirometra ranarum (Tanzania origin) collected from an African male lion. Whole mounted specimens of proglottids showing the cirrus (C), uterus (U), genital pore (GP), vaginal pore (VP), uterine pore (UP), and ovary (OV) (acetocarmine stain). (A)×12, (B)×40.

Fig. 2

Phylogenetic tree of Spirometra species based on complete mitochondria cox1 sequences. Numbers above the branches represent bootstrap value for Bayesian inference (BI) and maximum likelihood (ML). *GenBank No. AB369249-AB369251, AB374543 are currently registered as S. erinaceieuropaei by complete mitochondrial cox1 sequences. GenBank No. LC328893-LC328901 are registered as S. decipiens by complete mitochondrial cox1 sequences.