DAO 34:39-44 (1998)  -  doi:10.3354/dao034039

Changes of intestinal epithelial structure and cell turnover in carp Cyprinus carpio infected with Goussia carpelli (Protozoa: Apicomplexa)

Nicole Hemmer1, Dieter Steinhagen1,*, Wolfgang Drommer2, Wolfgang Körting1

1Fish Disease Research Unit, School of Veterinary Medicine, Bünteweg 17, D-30559 Hannover, Germany
2Pathology Department, School of Veterinary Medicine, Bünteweg 17, D-30559 Hannover, Germany
*Addressee for correspondence. E-mail:

ABSTRACT: Epithelial cell turnover in the intestine of common carp Cyprinus carpio infected with the coccidian parasite Goussia carpelli (Leger & Stankovitch, 1921) was investigated during laboratory infection using histological and electron microscopical techniques. During the development of the parasite an increased number of mitotic enterocytes, identified by bromodeoxyuridine (BRDU) uptake, were observed at the base of infected mucosal folds. During the merogonic and gamogonic development of the parasite, severe damage to infected epithelium occurred, and concomitantly BRDU-positive cells spread along the mucosal folds. These cells exhibited immature characteristics, including a squamous to cuboidal shape, nuclear apolarity, a high number of ribosomes, and short or reduced microvilli. Contact with adjoining cells was formed by tight junctions and desmosomes, indicating the epithelial origin of these cells. These cells covered gut segments with damaged epithelium within a few days, suggesting a high regenerative capacity of the carp intestine, and this could explain the mild clinical symptoms in fish affected by G. carpelli-coccidiosis. Our study for the first time describes epithelial cell responses to injuries caused by enteric protozoa in piscine hosts.


KEY WORDS: Carp coccidiosis · Epithelial cell turnover · Enteric infection · Tissue repair · Goussia carpelli · Cyprinus carpio


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