Morphological and molecular identification of Sarcocystis sp. from the little grebe, Tachybaptus ruficollis (Aves: Podicipediformes), for the first time in Egypt

Khaled Mohamed El-Dakhly,Nermean M Hussein,Waleed M Arafa

doi:10.1186/s43088-022-00205-3

Khaled Mohamed El-Dakhly, Nermean M Hussein + Show 1 more

Open Access

https://doi.org/10.1186/s43088-022-00205-3

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Abstract

BackgroundIn Egypt, studies of sarcocystosis in migratory and wading birds specially Podicipediformes are scarce. Therefore, the occurrence of Sarcocystis spp. in the little grebe, Tachybaptus ruficollis (Podicipediformes: Podicipdidae) was investigated in Qena province, Upper Egypt. During the period from September 2017 to March 2018, muscle specimens of esophagus from 25 little grebes were examined for the occurrence of Sarcocystis spp. using light microscopy, transmission electron microscopy (TEM) and molecular tools including conventional PCR and phylogenetic analysis with both 18S rRNA and 28S rRNA genetic loci.ResultsSarcocystis spp. were identified in 84.0% (21/25) of the T. ruficollis esophageal muscle samples by morphological analysis; each was long, ribbonlike and extended along the muscle fibers. TEM revealed a characteristic thin and wavy cyst wall and an undulating vacuolar membrane with villar protrusions of slightly variant sulci and gyri, as well as several septated compartments filled with bradyzoites. The applied 18S rRNA and 28S rRNA were not enough variable for the identification of Sarcocystis species.ConclusionThis study is the first to report the occurrence of Sarcocystis sp. in little grebes in Egypt. Further studies are required to identify Sarcocystis spp. in various wild birds by ITS1 region in Egypt.Graphical abstract

Highlights

In Egypt, studies of sarcocystosis in migratory and wading birds specially Podicipediformes are scarce
The intermediate host becomes infected through the ingestion of oocysts/sporocysts in water or food contaminated with feces and the definitive host is infected via ingestion of muscles containing sarcocysts [3]
Kutkiene et al [35] detected very long ribbon-shaped sarcocysts with a thin cyst wall and irregular villar protrusions that differed in size and shape; Prakas et al [18] identified wavy wall sarcocysts in the jackdaw, Corvus monedula, and named the species S. corvusi; and El-Morsey et al [24] reported that the wall of sarcocysts in G. chloropus contained fingerlike projections with a broader base and narrower tips

Summary

Introduction

In Egypt, studies of sarcocystosis in migratory and wading birds specially Podicipediformes are scarce. During the period from September 2017 to March 2018, muscle specimens of esophagus from 25 little grebes were examined for the occurrence of Sarcocystis spp. using light micros‐ copy, transmission electron microscopy (TEM) and molecular tools including conventional PCR and phylogenetic analysis with both 18S rRNA and 28S rRNA genetic loci. Sarcocystis (Eucoccidiorida: Sarcocystidae) species are protozoan parasites of mammals, birds and reptiles that are distributed worldwide [1] They are characterized by an obligatory two-host life cycle, consisting of prey as an intermediate host and a carnivore/omnivore as a definitive host [2]. Sarcocystis species have been described based on morphological analysis of sarcocysts by light microscopy (LM) and transmission electron microscopy (TEM), and through the detection of their definitive hosts. In recent decades, the majority of Sarcocystis species have been characterized with a combination of morphological and molecular analysis [9,10,11,12,13,14,15,16,17,18,19,20,21]

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