Molecular identification of Trichodina compacta Van As and Basson, 1989 (Ciliophora: Peritrichia) from cultured Oreochromis niloticus in Egypt and its impact on immune responses and tissue pathology

Abstract

Trichodinids are peritrichous ciliated protozoa that affect both wild and cultured fishes. Several Trichodina species have low host specificity and are morphologically distinct, facilitating their identification based primarily on the presence of adhesive discs and the number of attached denticles. A trichodinid species named Trichodina compacta was first reported by Van As and Basson (1989) (Protozoa: Ciliophora: Peritrichia). However, in trichodinid infestations, morphological characteristics are insufficient for identifying the infesting species. Therefore, molecular and phylogenetic analyses are considered to be promising and useful tools for identifying the infesting species. This study aimed to achieve the molecular identification of a trichodinid infestation in Nile tilapia and to construct the phylogenetic relationships between the identified species and other peritrichous parasites. Moreover, we also aimed to study the pathological and immunological impacts of trichodinids on fry tissue to improve our understanding of the immune responses of teleost fish to trichodinae parasitic infestations and develop a better control method. Here, we used molecular techniques to identify the isolated trichodina species as T. compacta and demonstrated that Trichodina infestation in Nile tilapia is associated with remarkable immunogenic and inflammatory responses (increased il-1β expression and decreased il-8 and tgf-β expression). These findings improve our understanding of the responses of teleost fish to trichodinid parasite infestation and will be helpful for the development of novel control strategies that reverse the inflammatory and immunogenic alterations that occur in infested fish.

Morphomolecular identification of two trichodinid coinfections ( Ciliophora : Trichodinidae ) and their immunological impacts on farmed Nile Tilapia

“…It is worth mentioning that mobilids peritrichous initially evolved from sessilids peritrichous (Gong et al, 2010), and in our phylogenetic tree, mobilia branch of Nassulidae family was grouped with Sessilidae branch, while Trichodinidae was grouped separately from other peritrichous. These results coincided with that of Abdelkhalek et al (2018). Homologs trichodinid coinfections might occur when fish get concomitantly infected by two different species of trichodinids.…”

“…T. centrostrigeata , T. compacta and T. heterodentata are the most important trichodinid pathogens because they cause severe injuries to fish and economic losses to fish farmers. In Egypt, most previous studies were employed morphological and histopathological assays for characterizing T. centrostrigeata , T. compacta and T. heterodentata infections in Nile tilapia, and there are no records for their molecular characterization or their immunological impacts on infected fish except in T. compacta (Abdelkhalek et al, 2018).…”

First diagnosis of ectoparasitic ciliates (TrichodinaandChilodonella) on farmed juvenile yellow catfish,Tachysurus fulvidracoin China

“…T. acuta is distinguished mainly by its acute sickle-shaped blade with well-developed sharp apophysis, robust rays and the distance between ray tips and the central circle (Abdelkhalek et al, 2018;Irwin, Sabetrasekh, & Lynn, 2017). The present T. acuta population falls well within the range of morphometry presented by previous studies and shows intraspecific variations in the shape of the ray tip and its posterior projection, which confirms the high morphological variation that exists in T. acuta.…”

“…Trichodina acuta , originally described by Lom in 1961, is mainly found parasitizing the skin of various freshwater fish (Basson, ; Lom, ; Mitra et al, ; Tao & Zhao, ; Wang, Zhou, & Gu, ). Compared with other Trichodina having a central circle, T. acuta is distinguished mainly by its acute sickle‐shaped blade with well‐developed sharp apophysis, robust rays and the distance between ray tips and the central circle (Abdelkhalek et al, ; Irwin, Sabetrasekh, & Lynn, ). The present T. acuta population falls well within the range of morphometry presented by previous studies and shows intraspecific variations in the shape of the ray tip and its posterior projection, which confirms the high morphological variation that exists in T. acuta .…”

Immunological and antioxidant role of curcumin in ameliorating fipronil toxicity in Nile tilapia ( Oreochromis niloticus )

“…An equivalent of 2 µg of RNA was transferred to cDNA with HiSenScript cDNA synthesis kit (Intronbio). In a 20 µl PCR, 2 µl of cDNA template was mixed with 1 µl of forward and reverse template of the primer pairs interleukin‐8 (IL‐8), transform growth factor‐beta 1 (TGF‐β1) and interleukin 1 beta (IL‐1β) and β‐actin that was designed according to Abdelkhalek et al (2018). The PCR was mixed with 10 µl of RealMOD™ Green SF 2X qPCR mix (Intronbio) and finally 7 µl of nuclease‐free water was added.…”