Granulomatous inflammations in the intestine of Pelophylax ridibundus (Anura: Ranidae) caused by Brandesia turgida (Plathelminthes: Digenea)

Abstract

The report provides data on granulomatous inflammation in the small intestine of Pelophylax ridibundus, observed in exophytic outgrowths (diverticulums) of duodenum and caused by Brandesia turgida. Amphibians were collected from Protected Areas (Privolzhskaya Lesostep' State Nature Reserve, Penza region, and Sosnovaya Roscha Forest Park near the town Yoshkar-Ola) during the field seasons of 2011–2018. An histological examination was made according to standard histological procedures; we used hematoxylin and eosin stain. The trematode Brandesia turgida was found not only in the Lieberkühn glands, but also in the serosa. Non-caseating epithelioid granulomas were localised in the serosa. Macrophages and single multinuclear Pirogov-Langhans giant cells were also detected in the serosa. Granular decay, puckering of nuclei and nuclear detritus were detected. Marked leukocyte infiltration with a significant predominance of eosinophils was observed. The periphery of such granulomas can be characterised by a lymphohistiocytic profile. Mycobacterial infection was not detected. The obtained data describe a new case of granulomatous inflammation in amphibians.

Keywords

• 28s rrna
• histopathology
• host-parasite interactions
• morphology
• trematode invasion