A new approach for the identification and the diagnosis of Eimeria media parasite of the rabbit

Morphological and molecular characterization of Eimeria magna infecting local rabbit (Oryctolagus cuniculus) in Alkarg City, Saudi Arabia

Coccidiosis is one of the most prevalent diseases found in local rabbits (Oryctolagus cuniculus), which is caused by the Eimeria. The study aimed to more reliably identify Eimeria species (Eimeria magna) infecting Local Rabbits in Alkarg City, Saudi Arabia, based the method on the molecular properties and morphological and molecular biological techniques. Sub-spheroidal oocysts measuring 21-27 × 12-16 (24 × 14.4) μm (20 n) and with a length/width (L/W) ratio of 0.9-1.1 (1.0) were identified by microscopic analysis of a fecal sample. Oocysts feature a bi-layered wall that is 1.0-1.2 (1.1) μm thick. About two-thirds of the wall's thickness is made up of a smooth outer layer. A polar granule is present, but neither a micropyle nor an oocyst residuum is present. The ovoidal sporozoites measure 15-18 × 8-11 (16.5 × 9.5) μm, have an L/W ratio of 1.6-1.8 (1.7), and take up around 21% of the oocyst's total surface. The mean size of the sub-Stieda body is 1.4 × 2.3 μm, while the average size of the Stieda body is 0.9 × 1.8 μm. The para-Stieda body is lacking. Sporocyst residuum appears membrane-bound and has an uneven form made up of several granules. With two refractile bodies below the striations and pronounced striations at the more pointed end, sporozoites are vermiform, measuring an average of 11.6 × 4.0 μm. The results of the sequencing for the 18S rDNA gene confirmed the species of Eimeria parasites found in the host (rabbits). The current parasite species is closely related to the previously described and deposited E. magna and deeply embedded in the genus Eimeria (family Eimeriidae). According to the findings, single oocyst molecular identification of Eimeria may be accomplished through consistent use of the morphological and molecular results. It is possible to draw the conclusion that the current research supplies relevant facts that help assess the potential infection and future control measures against rabbit coccidiosis to reduce the financial losses that can be incurred by the rabbit industry in Saudi Arabia.

Expression Analysis and Serodiagnostic Potential of Microneme Proteins 1 and 3 in Eimeria stiedai

Eimeria stiedai is an apicomplexan protozoan parasite that invades the liver and bile duct epithelial cells in rabbits and causes severe hepatic coccidiosis, resulting in significant economic losses in the domestic rabbit industry. Hepatic coccidiosis lacks the typical clinical symptoms and there is a lack of effective premortem tools to timely diagnose this disease. Therefore, in the present study we cloned and expressed the two microneme proteins i.e., microneme protein 1 (EsMIC1) and microneme protein 3 (EsMIC3) from E. stiedai and used them as recombinant antigens to develop a serodiagnostic method for an effective diagnosis of hepatic coccidiosis. The cDNAs encoding EsMIC1 and EsMIC3 were cloned and the mRNA expression levels of these two genes at different developmental stages of E. stiedai were determined by quantitative real-time PCR analysis (qRT-PCR). The immunoreactivity of recombinant EsMIC1 (rEsMIC1) and EsMIC3 (rEsMIC3) proteins were detected by Western blotting, and indirect enzyme-linked immunosorbent assays (ELISAs) based on these two recombinant antigens were established to evaluate their serodiagnostic potential. Our results showed that the proteins encoded by the ORFs of EsMIC1 (711 bp) and EsMIC3 (891 bp) were approximately 25.89 and 32.39 kDa in predicted molecular weight, respectively. Both EsMIC1 and EsMIC3 showed the highest mRNA expression levels in the merozoites stage of E. stiedai. Western blotting analysis revealed that both recombinant proteins were recognized by E. stiedai positive sera, and the indirect ELISAs using rEsMIC1 and rEsMIC3 were developed based on their good immunoreactivity, with 100% (48/48) sensitivity and 97.9% (47/48) specificity for rEsMIC1 with 100% (48/48) sensitivity and 100% (48/48) specificity for rEsMIC3, respectively. Moreover, rEsMIC1- and rEsMIC3-based indirect ELISA were able to detect corresponding antibodies in sera at days 6, 8, and 10 post E. stiedai infection, with the highest positive diagnostic rate (62.5% (30/48) for rEsMIC1 and 66.7% (32/48) for rEsMIC3) observed at day 10 post infection. Therefore, both EsMIC1 and EsMIC3 can be used as potential serodiagnostic candidate antigens for hepatic coccidiosis caused by E. stiedai.

Exogenous and endogenous stages of Eimeria perforans naturally infected domestic rabbit (Oryctolagus cuniculus) in Saudi Arabia: Light microscopic study

Exogenous and endogenous stages of Eimeria perforans naturally infected rabbits in Saudi Arabia were described. The prevalence of infection was 75%. Oocysts were ovoid to elliptical and measured 16 × 10 μm. The four dizoic sporocysts were ovoid and measured 7 × 5 μm. Endogenous stages were restricted to the duodenum. Meronts, microgamonts, macrogamonts and young oocysts were recorded and described.

Coccidiosis of domestic rabbit (Oryctolagus cuniculus) in Egypt: light microscopic study

In the present study, the incidence and prevalence of coccidian infection among domestic rabbits in Egypt were investigated. Severe overall prevalence reaching 70% (70/100) was recorded. Eight species of Eimeria were detected. Mixed infection with three different species occurred most frequently. Eimeria intestinalis and Eimeria coecicola were generally the most predominant species. The complete life cycle of E. intestinalis was investigated. This study is the first to report coccidia in domestic rabbits in Egypt. Six species of Eimeria were reported for the first time.

Coccidia of rabbit: a review

This article summarises the current knowledge of the rabbit coccidia and the disease they cause. Various aspects, such as life cycles, localisation in the host, pathology and pathogenicity, immunity and control, are discussed.

Effect of chromium compounds on sporulation of Eimeria piriformis oocysts

Freshly defecated unsporulated oocysts of Eimeria piriformis from rabbit were treated with various concentrations (1%, 2.5%, 5%, and 10%) of chromium compounds, potassium dichromate, potassium chromate, chromium oxide and chromium nitrate, to examine their effect on sporulation. The sporulation time of oocysts treated with 1 to 10% K(2)Cr(2)O(7) was 28 h. However, much longer sporulation times of about 60 h were required for oocysts treated with 2.5% CrO(3) and Cr(NO(3))(3). Moreover, for oocysts treated with distilled water, 1% K(2)CrO(4) and 10% K(2)CrO(4), the sporulation times required were 216, 156 and 96 h, respectively. Thus, potassium dichromate was found to have higher catalytic activity for the sporulation of E. piriformis oocysts than other chromium compounds.

Phylogenetic relationships among Eimeria spp. (Apicomplexa, Eimeriidae) infecting rabbits: evolutionary significance of biological and morphological features

Monophyly of all 11 valid Eimeria species from rabbits (Oryctolagus cuniculus Linnaeus, 1758) was revealed based on nuclear 18S rDNA sequence data. This finding implies that these species, which vary considerably in terms of their morphology and biology, diversified on a single host or several closely related species. Phylogenetic analysis divided rabbit Eimeria species into 2 sister lineages, corresponding to the presence/absence of the oocyst residuum. Other morphological or biological traits (oocyst shape and size, presence/absence of oocyst inner structures, pathogenicity, infection site, pre-patent and patent periods, sporulation time, and number of asexual generations) do not explicitly correlate with the phylogeny of rabbit coccidia.

Molecular epidemiology: A multidisciplinary approach to understanding parasitic zoonoses

Sound application of molecular epidemiological principles requires working knowledge of both molecular biological and epidemiological methods. Molecular tools have become an increasingly important part of studying the epidemiology of infectious agents. Molecular tools have allowed the aetiological agent within a population to be diagnosed with a greater degree of efficiency and accuracy than conventional diagnostic tools. They have increased the understanding of the pathogenicity, virulence, and host-parasite relationships of the aetiological agent, provided information on the genetic structure and taxonomy of the parasite and allowed the zoonotic potential of previously unidentified agents to be determined. This review describes the concept of epidemiology and proper study design, describes the array of currently available molecular biological tools and provides examples of studies that have integrated both disciplines to successfully unravel zoonotic relationships that would otherwise be impossible utilising conventional diagnostic tools. The current limitations of applying these tools, including cautions that need to be addressed during their application are also discussed.

Detection of Hammondia heydorni-like organisms and their differentiation from Neospora caninum using random-amplified polymorphic DNA-polymerase chain reaction

Neospora caninum and Hammondia heydorni are morphologically and phylogenetically related coccidians that are found in dogs. New diagnostic genetic loci, based on random-amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR), were developed to aid in the detection of H. heydorni-like parasites and to discriminate them from N. caninum and other related coccidians of dogs. On the basis of the data obtained from 5 random decamers, H. heydorni (Manhattan-1) and N. caninum (NC1) were characterized by distinct banding patterns (similarity index = 0.068). High-stringency PCR assays were developed from the sequences of 2 cloned bands (GenBank BZ592549 and BZ592593), uniquely amplified from H. heydorni. Interestingly, using these primers, PCR amplification was achieved only from 2 of the 5 isolates presumed to represent H. heydorni. The same result was obtained from these 5 isolates using a recently described PCR assay directed to the H. heydorni internal transcribed spacer-1. It is concluded that H. heydorni and N. caninum are genetically distinct and that such tools may be useful for more detailed characterization of the diversity of related parasites occurring in dogs.

A multiplex PCR assay for the simultaneous detection and discrimination of the sevenEimeriaspecies that infect domestic fowl

This study reports the development of a novel multiplex PCR assay based on SCAR (Sequence-Characterised Amplified Region) markers for the simultaneous diagnosis of the 7Eimeriaspecies that infect domestic fowl. Primer pairs specific for each species were designed in order to generate a ladder of amplification products ranging from 200 to 811 bp. Sensitivity tests for each species were carried out, showing a detection threshold of 1–5 pg, which corresponds approximately to 2–8 sporulated oocysts. Distinct isolates of the 7Eimeriaspecies from different geographical sources were tested and successfully detected by the assay. All the species were amplified homogeneously, whether or not one of them was present in a high quantity, indicating that there was no cross-interference. The assay was also tested with different sources ofTaqDNA polymerase and thermocycler models, confirming the high reproducibility of the reaction. The economy of consumables and labour represented by a single-tube reaction greatly facilitates the molecular diagnosis of a large number of samples, making it appropriate for field epizootiological surveys. We propose the use of this multiplex PCR assay as a rapid and cost-effective diagnostic method for the detection and discrimination of the 7Eimeriaspecies that infect domestic fowl.