Ragab Fereig - Academia.edu (original) (raw)

Papers by Ragab Fereig

Frontiers in Veterinary Science, Jun 30, 2023

Frontiers in Public Health, Dec 7, 2022

High relatedness of bioinformatic data and realistic experimental works on the potentials of Fasc... more High relatedness of bioinformatic data and realistic experimental works on the potentials of Fasciola hepatica and F. gigantica cathepsin L as a diagnostic and vaccine antigen.

Pathogens, Dec 2, 2022

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

PLOS ONE, Aug 12, 2019

Subacute and chronic infections with the intracellular protozoan parasite Toxoplasma gondii are a... more Subacute and chronic infections with the intracellular protozoan parasite Toxoplasma gondii are associated with an increased risk of psychiatric diseases like schizophrenia. However, little is known about the mechanisms involved in T. gondii-induced neuronal disorders. Recently, we reported that Toll-like receptor 2 (TLR2) was required to initiate the innate immune response in cultured mouse brain cells. However, how TLR2 contributes to latent infection with T. gondii remains unclear. Therefore, we examined the role of TLR2 in brain pathology and behavior using wild-type (TLR2 +/+) and TLR2-deficient (TLR2-/-) mice. The behavioral analyses showed that TLR2 deficiency increased the anxiety state of the uninfected and infected animals alike, and TLR2 deficiency showed no relationship with the infection. In the contextual and cued fear-conditioning tests, T. gondii infection decreased the mouse freezing reaction while TLR2 deficiency increased it, but there was no interaction between the two factors. Our histopathological analysis showed that the TLR2 +/+ and TLR2-/mice had similar brain lesions at 30 days post infection (dpi) with T. gondii. Higher numbers of parasites were detected in the brains of the TLR2-/mice than in those from the TLR2 +/+ mice at 30 dpi, but not at 7 and 14 dpi. No significant differences were observed in the proinflammatory gene expression levels in the TLR2 +/+ and TLR2-/mice. Therefore, it appears that TLR2 signaling in the brain might contribute to the control of parasite growth, but not to brain pathology or the impaired fear memory response induced by infection with T. gondii.

Experimental Parasitology, Sep 1, 2020

The intracellular protozoan parasite Neospora caninum is incriminated to induce drastic economic ... more The intracellular protozoan parasite Neospora caninum is incriminated to induce drastic economic losses in both livestock and pet animal industries. Neosporosis is primarily characterized by abortion in cattle and paralytic symptoms in dogs. Because there are no effective treatments or vaccines, diagnosis is critical for Neospora control. Thus, diversification of laboratory tests and specimens used for diagnosis of N. caninum is an essential scientific endeavor to judge and select the most appropriate diagnostic tool. Herein, we provide the first evidence for the utility of urine samples for demonstration of specific antibodies against N. caninum employing an experimentally infected murine model. Specific antibodies to recombinant N. caninum dense granule 7, surface antigen 1, and lysate antigen were assayed using different antibodies-based ELISAs. Urine based IgG ELISA efficiently discriminated between infected mice (acute or chronic infection), and those of non-infected mice. This effect was also noticed for IgG1 and IgG2a suggesting the utility of urine for assessment of T-helper 2-and Thelper 1-mediated immunities, respectively. In addition, reactivity of specific antibody in urine was also confirmed against parasites when indirect fluorescent antibody test was employed. Usefulness of urine as an additional clinical sample for Neospora diagnosis was confirmed via comparison with the relevant control noninfected and infected mouse sera as reference samples. Because of minimum invasiveness and ease of urine collection, this approach might offer new diagnostic opportunities for N. caninum either for the field or research purposes. However, further studies are required to extrapolate this preliminary study and results in the animal species of interest particularly in dogs.

Agricultural research & technology, Sep 21, 2018

The phenomenon of warm welcome of the uterus to conceptus but not allograft implantation is still... more The phenomenon of warm welcome of the uterus to conceptus but not allograft implantation is still ambiguous. In cattle, pregnancy is a highly important physiological process that has a significant economical consideration due to relevance to meat and milk production. Immune system is highly incorporated in development of fetus and fetal membranes. Interferon tau (IFNT) is a type I interferon is reported as crucial molecule for adequate conceptus implantation. Early programmed immune response via numerous pathways is essential for completion of pregnancy. Toll-like receptors (TLRs) are the pivotal innate immune receptors that recognize pathogen specific molecular patterns (PAMPs) in an adequate, potent pathway and enhance specific immune signaling that culminates in triggering antigen-specific adaptive responses. Numerous reports revealed the expression of different TLRs in both male and female germ cells. In this review, we attempt to discuss briefly the role of essential signaling pathways in the stages of conception, implantation, and early pregnancy peculiarly TLR2 and IFNT. The recognition of key molecules in such anaforementioned stage would contribute in increasing the conception rate, and subsequently enhancing the animal reproduction and production.

Veterinary Parasitology: Regional Studies and Reports, Dec 1, 2018

Toxoplasma gondii and Neospora caninum are protozoan parasites that cause huge economic losses in... more Toxoplasma gondii and Neospora caninum are protozoan parasites that cause huge economic losses in animal industries worldwide. N. caninum can cause abortion storms and high culling rates in cattle, whereas T. gondii infection is a significant concern in both human and animals because it can induce abortion and clinical symptoms in immunocompromised hosts. The aim of this study was to determine the seroprevalence of T. gondii and N. caninum in cattle in Mongolia. Specific antibodies to T. gondii and N. caninum were detected by using an indirect enzyme-linked immunosorbent assay (iELISA) based on recombinant antigens of dense granule protein 7 of Toxoplasma gondii and surface antigen 1 of Neospora caninum, respectively. A total of 1438 cattle sera from 20 of 21 provinces of Mongolia and the capital city of Ulaanbaatar were tested. Overall, 18.7% and 26.2% of cattle were positive for specific antibodies to T. gondii and N. caninum, respectively. Prevalence rates were higher (T. gondii infection: P < .0001, N. caninum infection: P = .002) in the central region of Mongolia (T. gondii infection: 27.1%, N. caninum infection: 30.8%) compared with western region, suggesting that prevalence rates might be influenced by geographical condition, particularly warmer temperatures around this area in Mongolia. The lowest prevalence rates were observed in the western region of Mongolia (T. gondii: 9%, N. caninum: 20.8%). In addition, the seroprevalence of N. caninum in female animals (27.5%) was significantly higher than that in male animals (20.4%) (P = .018), suggesting an important risk factor of abortion and stillbirth in cattle. The present results showed that T. gondii and N. caninum infections might be a risk for public health and economy of the livestock industry in Mongolia. In conclusion, this study demonstrates high seroprevalences of T. gondii and N. caninum in Mongolia and provides valuable new data for development of control measures against these infections in Mongolia.

Microorganisms, Nov 12, 2021

Vaccines, Dec 6, 2022

Pathogens, Nov 7, 2022

Parasitology International, Dec 1, 2018

Dense granule protein 7 (NcGRA7) is a potent diagnostic antigen of Neospora caninum. Some studies... more Dense granule protein 7 (NcGRA7) is a potent diagnostic antigen of Neospora caninum. Some studies have reported on the difficult expression, low yield, and variable degree of solubility of recombinant NcGRA7. We aimed to unravel the possible causes for these issues and tested NcGRA7 antigenicity in enzyme linked immunosorbent assays (ELISAs). The NcGRA7 coding sequence (217 amino acids) was split into five amino acid regions: NcGRA7m (27-217), NcGRA7m3 (27-160), NcGRA7m4 (27-135), NcGRA7m5 (161-190), and NcGRA7m6 (188-217). Three fragments, NcGRA7m, NcGRA7m3 and NcGRA7m4, exhibited high antigenic properties when tested against experimentally-infected mice and dog sera by ELISA. High levels of IgG2 antibodies against NcGRA7m were observed in field dog sera. In experimentally and naturally-infected cattle, the N. caninum-specific sera only reacted with NcGRA7m, indicating that this antigenic region differs among the three animal species. This study presents valuable information about the antigenic properties and topology of NcGRA7, and highlights its suitability for diagnostic purposes.

Frontiers in Public Health

IntroductionFascioliasis is a parasitic foodborne disease caused by the liver flukes, Fasciola he... more IntroductionFascioliasis is a parasitic foodborne disease caused by the liver flukes, Fasciola hepatica and F. gigantica. Such parasites cause serious illness in numerous domestic animals and also in humans. Following infection, the parasite secretes a variety of molecules that immediately interact with the host immunity to establish successful infection. These molecules include cathepsin L peptidase 1 (CatL1); the highly investigated diagnostic and vaccine antigens using various animal models. However, a few studies have analyzed the potentials of FhCatL1 as a diagnostic or vaccine antigen using bioinformatic tools and much less for FgCatL1. The present study provides inclusive and exclusive information on the physico-chemical, antigenic and immunogenic properties of F. hepatica cathepsin L1 (FhCatL1) protein using multiple bioinformatic analysis tools and several online web servers. Also, the validation of our employed available online servers was conducted against a huge collecti...

Animals

Toxoplasmosis, neosporosis, and brucellosis are devastating diseases causing infectious abortion ... more Toxoplasmosis, neosporosis, and brucellosis are devastating diseases causing infectious abortion and, therefore, substantial economic losses in farm animals. Toxoplasmosis and neosporosis are caused by the intracellular protozoan parasites Toxoplasma gondii (T. gondii) and Neospora caninum (N. caninum), respectively. Brucellosis is a bacterial disease caused by numerous Brucella species in multiple hosts. Toxoplasmosis and brucellosis are also considered foodborne zoonotic diseases. In the current study, specific antibodies to T. gondii and N. caninum, in addition to those to Brucella spp., were detected to gain a better understanding of the epidemiological situation for these three pathogens. Sheep and goat sera from Egypt (n = 360) of animals with and without a history of abortion were tested using commercial ELISAs. Seropositivity rates of 46.1%, 11.9%, and 8.6% for T. gondii, N. caninum, and Brucella spp., respectively, were revealed. Mixed infections with T. gondii and Brucella...

Frontiers in Cellular and Infection Microbiology

IntroductionToxoplasma gondii and Neospora caninum are closely related intracellular protozoan pa... more IntroductionToxoplasma gondii and Neospora caninum are closely related intracellular protozoan parasites of medical and veterinary concern by causing abortions and systemic illness. Limited or ambiguous data on the prevalence of T. gondii and N. caninum in camels triggered us to conduct this study.MethodsCamels (n = 460) recently imported from Sudan and destined mainly for human consumption, were tested for specific antibodies against these protozoans using commercially available ELISAs. From the two only quarantine stations for camels from Sudan, 368 camels were sampled between November 2015 and March 2016 in Shalateen, Red Sea governorate, and 92 samples were collected between September 2018 and March 2021 from Abu Simbel, Aswan governorate.Results & DiscussionOverall, seropositive rates in camels were 25.7%, 3.9% and 0.8% for T. gondii, N. caninum and mixed infection, respectively. However, marked differences were found between the two study sites and/or the two sampling periods:...

Experimental Parasitology

Pathogens, 2021

Toxoplasma gondii is the causative agent of toxoplasmosis in humans and various animal species wo... more Toxoplasma gondii is the causative agent of toxoplasmosis in humans and various animal species worldwide. In Thailand, seroprevalence studies on T. gondii have focused on domestic animals, and information on infections in Asian elephants (Elephas maximus indicus) is scarce. This study was conducted to determine the seroprevalence of T. gondii infection in archival sera collected from 268 elephants living in Thailand. The serum samples were analyzed for anti-T. gondii immunoglobulin G antibodies using the latex agglutination test (LAT) and indirect enzyme-linked immunosorbent assay (iELISA) based on T. gondii lysate antigen (TLA-iELISA) and recombinant T. gondii dense granular antigen 8 protein (TgGRA8-iELISA). The prevalence of antibodies against T. gondii was 45.1% (121/268), 40.7% (109/268), and 44.4% (119/268) using LAT, TLA-iELISA, and TgGRA8-iELISA, respectively. Young elephants had a higher seropositivity rate than elephants aged >40 years (odds ratio = 6.6; p < 0.001; 9...

The lungworm infection is considered one of the main causes of respiratory tract infections among... more The lungworm infection is considered one of the main causes of respiratory tract infections among goats in various regions of the globe. Herein, we provided the first evidence of occurrence of Dictyocaulus filaria among goats in Qena governorate, southern Egypt. Migratory larvae in fecal samples of tested goats (n=67) were detected using modified Baermann method; the standard method for diagnosis of lungworm infection. Among goats exhibiting chronic respiratory distress, high incidence of D. filaria was recorded (22/67: 32.84%). Higher infection rate was observed during the seasons of winter and autumn (50% and 44%, respectively) than the summer and spring (0%, 18.8%, respectively), assuming to the favorable environmental conditions for survival of the infective 3 rd stage larvae. Concerning the age, the infection rate was apparently lower in group of mid-aged (25-48 month; 25%) than young (6-24 month; 37.5%), and old aged (49-84 month; 34.8%) animals. The infected goats revealed anemia-related findings such as marked decrease in red blood cells count, hemoglobin concentration and packed cell volume percentage. Immunopathology was evidenced in increase in the number of total leucocytes, and percentages of eosinophils, and neutrophils, associated with decrease in lymphocytes. Additionally, the infected goats revealed significant increase in serum total proteins and globulins, and significant decrease in albumin/globulins ratio. This study declares the lungworm D. filaria as an important cause of respiratory problems among goats in Egypt. In regard to its impact on production, emphasis should be given for the prevention and control of lungworm infection in Egypt.

Development of potent and safe vaccines is the utmost goal for all vaccinologists worldwide. Toxo... more Development of potent and safe vaccines is the utmost goal for all vaccinologists worldwide. Toxoplasmosis is a zoo notic disease affecting almost all the warm-blooded animals and caused by the intracellular protozoan parasite Toxoplasma gondii. Up to date, neither potent nor broad spectral vaccine against vulnerable hosts to T. gondii is available. The complexity of life cycle and various parasitic stages render the vaccine development against such parasite is far from straight forward. In the last decade, tremendous advances were achieved in the field of vaccine development against T. gondii. Vaccine studies against T. gondii were focused initially on the live, attenuated live and killed tachyzoite parasites. Although such kinds of vaccine achieved a variable degree of success, their use was restricted because of worries about the induced pathogenicity and expected high cost of manufacturing. As a result, vaccinologists shift their interest to the recombinant DNA and protein antig...