Pharyngodon mamillatus (Nematoda: Pharyngodonidae) in the ocellated skink Chalcides ocellatus (Squamata: Scincidae) from Egypt: Light and scanning electron microscopic studies.

Twenty-one Pharyngodon mamillatus were recovered from the large intestine of 4 out of 12 ocellated skink Chalcides ocellatus collected from the South Sinai desert, Egypt. The prevalence of infection was 33.33% (intensity 2-4). The recovered pharyngodonid was re-described based on light and scanning electron microscopy. According to the morphology, it was characterized by regular transverse annulations extending from the posterior margin of the lips to the level of the anus, triangular mouth opening was surrounded by three large bilobed lips possessing three papillae, oval-shaped excretory pore, slit-like vulva opening, and slit-like anal ventral opening at the posterior end which terminates with a tail filament. Here, the morphometric measurements of adult female P. mamillatus were given in this study. It has no intraspecific morphological variations from the previously described P. mamillatus, but it appeared with small range on biometric features. These variations may be accounted by host/environment attributes since they exhibit wide host and geographical spectra. The present study was applied for detailed morphological knowledge of the recovered P. mamillatus for strengthening their taxonomic validity. HIGHLIGHTS: The Pharyngodon mamillatus naturally parasite of the intestinal region of Chalcides ocellatus. The present study clarifies the morphological key for the description of P. mamillatus.

Prevalence and Molecular Epidemiology of Cryptosporidium Infection in Clarias gariepinus Fish in Egypt.

PURPOSE: This study investigated the prevalence and molecular detection of Cryptosporidium spp. in catfish (Clarias gariepinus). METHODS: A total of 300 Carias gariepinus fish were collected from two freshwater sources: the Nile River (180) and drainage canals (120). The stomach and intestine epithelium of each individual fish sample were screened by modified Ziehl-Neelsen (mZN) staining technique for the detection of Cryptosporidium oocysts followed by the serological survey for detection of Cryptosporidium antibodies using Enzyme-Linked Immunosorbent Assay (ELISA) and molecular characterization using complemented DNA polymerase chain reaction (cPCR). RESULTS: ELISA showed higher prevalence of 69.3% than that prevalence obtained by mZN, 64% for the total examined Clarias gariepinus fish. Also, higher prevalence of Cryptosporidium infection 65.5% and 75.8% obtained by ELISA than 61.1% and 68.3% by mZN, in both fish groups from Nile River and Drainage canal, respectively. PCR analysis revealed the expected positive bands at 1056 bp. DNA sequencing and phylogenetic analysis proved that the positive-PCR Cryptosporidium isolate identified in the present study was Cryptosporidium molnari. CONCLUSION: Freshwater fishes (Clarias gariepinus) are subjected to a high infection rate with Cryptosporidium spp.; the drainage canals obtained fishes showed higher prevalence than that collected from Nile River which indicates an important public health problem and a potential risk of drainage canals in Egypt. ELISA showed higher prevalence of cryptosporidiosis than mZN, for the total examined Clarias gariepinus fish and phylogenetic analyses confirmed this protozoal organism to be a novel species of Cryptosporidium molnari.

Morphological description and phylogenetic assessment of 28S rRNA for Thelandros chalcidiae sp. nov. from Chalcides ocellatus.

Thelandros is a genus of oxyurid nematodes which parasitize both omnivorous and herbivorous hosts. Thelandros chalcidiae sp. nov. is a new taxa described from the large intestine of the ocellated skink, Chalcides ocellatus, from the South Sinai Desert in Egypt. The recovered parasite species was examined at both morphological and molecular levels in order to determine the exact taxonomic position within Pharyngodonidae family. The current pharyngodonid species is characterized by a mouth opening bounded by three bilobed lips; male worms are characterized by the presence of two pairs of cloacal papillae (pre- and adcloacal) and one single caudal papillae (postcloacal) and caudal alae in an auricular form and females with post-equatorial vulva, amphidelphic ovary in which anterior ovary extended to level of excretory pore and posterior ovary extended posteriorly up anal opening. The recovered nematodes were compared with other known species from different hosts and it was found to be morphologically different from them. Molecular characterization based on the partial 28S rRNA nuclear ribosomal gene sequence showed sequence identities ≥ 83.15% with taxa under family Pharyngodonidae, 74.84-87.37% with Oxyuridae, 80.54% with Heteroxynematidae, and 75.98-77.72% with Thelastomatidea. Phylogenetic analysis showed that parasite sequence in conjunction with existing data facilitate placement of this species within Oxyurida. The present species is deeply embedded in genus Thelandros with close relationships to previously described Thelandros sp. and T. galloti in same taxon. This study highlighted importance of combining morphological and genetic data with taxonomy in pharyngodonid species.

An ultrastructural study on Desportesius invaginatus (Nematoda, Acuariidae) from Ardeola ibis ibis in Egypt.

The present study is undertaken to describe the ultrastructure of Desportesius invaginatus (Nematoda, Acuariidae) for the first time in Egypt showing details that were not clearly defined before. This nematode is found in the proventriculus of Ardeola ibis ibis. The latter is known in Egypt as "Abu Erdan" and it is a very common and useful bird to Egyptian farmers. The pathogenecity of this nematode within their host was observed. The presence of such high number of worms raised the curiosity of the present author to see if they had the potential to cause any harm to such economically important birds to Egyptian farmers.