Parasitic Enteritis Associated with the Camallanid Nematode Serpinema microcephalus in Wild Invasive Turtles (Trachemys, Pseudemys, Graptemys, and Ocadia) in Spain
This cross-sectional study characterized the prevalence of enteritis associated with Serpinema microcephalus infections in the intestinal tracts of red-eared slider turtles (Trachemys scripta elegans), river cooters (Pseudemys concinna), false map turtles (Graptemys pseudogeographica), and Chinese stripe-necked turtles (Ocadia sinensis) in Spain. All four species (three American, one Asiatic) were introduced into Spain through the pet trade. S. microcephalus is an Old World nematode that has been found to parasitize both invasive and native turtles. This parasite causes a significant inflammatory reaction in the intestines of exotic turtles that is not usually seen in native species. Parasites were detected in 27/70 turtles examined (38.6%; 95% confidence interval: 27.2–51%). Total worm counts ranged from 5 to 21. The nematodes were always found in the enteric mucosa of the duodenum and jejunum. The lesions in the turtles varied but included catarrhal to ulcerative enteritis and secondary hemorrhage surrounding the parasitized areas.Abstract
Serpinema microcephalus anchored to the duodenal mucosa of a river cooter (Pseudemys concinna). Bar = 1 cm.
Cephalic extremity showing ridges in buccal valves (lateral view); specimen of Serpinema microcephalus (present study) is on the right, and a specimen of S. trispinosum is on the left (from the small intestine of an imported Chrysemys picta belli).
Intestinal mucosa from a river cooter (Pseudemys concinna). Note the presence of cross sections of parasite stages (black arrows) in the mucosa and a lymphoplasmacytic infiltrate (white arrow). Hematoxylin and eosin stain.
Parasite uterus with first-stage larvae of Serpinema trispinosum from a Trachemys scripta elegans (histology; hematoxylin and eosin stain; longitudinal section; 200×).
