First light microscopy and ultrastructural description of Mesocoelium sociale (Luhe, 1901) Odhner, 1910 (Trematoda: Mesocoeliidae) in Bufo regularis from Egypt

Abstract

Abstract Background Mesocoeliidae is a common parasite of the small intestine of amphibians and reptiles. From Egypt, only Mesocoelium monas (Rudolphi C., Berolini 811 (1819)) (Freitas JF, Revista Brasiliera de Biologia 18:171-174, (1958)) was reported and described by (Saad AI et. al., J Egypt Ger Soc Zool 33: 219-234, (2000)) from the small intestine of the Egyptian toads Bufo regularis from Aswan Governorate, Upper Egypt, and the molecular characterization of the same parasite was reported by (Mansour MFA et. al., Egypt. J. Biol. (Zool.),10:(1)1-8, (2014)) without any morphological description from the same final host. The present study aimed to detect the prevalence and the characteristic morphological features of mesocoeliid parasites of the Egyptian toads Bufo regularis. Methods Toads were collected from Assiut and Giza Governorates during the autumn of 2018. They were dissected and examined by a dissecting microscope for intestinal parasites. The collected trematodes were fixed, stained, dehydrated, cleared, and mounted. Photomicrographs were taken and parasite measurements were determined. Some of the identified worms were prepared for scanning electron microscope for studying their ultrastructure. Results Mesocoelium sociale was detected from the small intestine of 14 out of 51 toads Bufo regularis (27.5%) with worm burden (10–30 worms per host). Detailed morphometric characteristic features of the parasite were described by a light microscope. Scanning electron microscopy showed many fine ultrastructure details in the present study and confirmed the light microscopic description. Conclusion Mesocoelium sociale (Luhe M, Centralblatt für Bakteriologie Parasitenkunde und Infektionsk-rankheiten, 30, 166-177, (1901)) (Odhner T., Res. Swedish Zool Exped Egypt iv, (23a), 1–166, (1910)) is recorded for the first time from Egypt as a trematode parasite of the Egyptian toads’ Bufo regularis and described by a light microscope. In addition, it is described for the first time worldwide by scanning electron microscopy.