Eman Khalifa
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The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
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Research Interests
Eman Khalifa has a total of 208 co-authors. Here are the top co-authors by number of shared publications:
- Doaa Ibrahim
Department of Nutrition and Clinical Nutrition, Faculty of Veterinary Medicine, Zagazig University, Zagazig 44519, Egypt
4 shared publications - Ahmed M. S. Menshawy
Department of Veterinary Medicine, Faculty of Veterinary Medicine, Beni-Suef University, Beni-Suef 62511, Egypt
3 shared publications - Marwa Ibrahim Abd El-Hamid
Department of Microbiology, Faculty of Veterinary Medicine, Zagazig University, Zagazig, 44511, Egypt
3 shared publications - Mohsen Abdel-Tawwab
Department of Fish Biology and Ecology, Central Laboratory for Aquaculture Research, Agricultural Research Center, Abbassa, Abo-Hammad 44662, Egypt
3 shared publications - Tamer Ahmed Ismail
Department of Clinical Laboratory Sciences, Turabah University College, Taif University, P.O. Box 11099, Taif, 21944, Saudi Arabia
3 shared publications - Ahmed H. Abed
Mycology and Immunology Department, Faculty of Veterinary Medicine, Beni-Suef University, Beni-Suef 62511, Egypt
2 shared publications
Latest Publications
- 24 June 2026
- Published by Taylor & Francis in Avian Pathology
- Vol. 55 (4) , 1-18
Early challenge with LPAI-H9N2 followed by vNDV-VII.1.1 in vaccinated and unvaccinated broilers: a comprehensive study
Vaccinated broilers were protected against mortality from early H9N2-vNDV-VII.1.1 co-infections.Vaccination of broilers significantly decreased but did not stop shedding of either virus.H9N2 infection prior to vNDV infection in nonvaccinated broilers induced faster mortality.
- 24 June 2026
- Published by Taylor & Francis in Avian Pathology
- Vol. 55 (4) , 1-18
Early challenge with LPAI-H9N2 followed by vNDV-VII.1.1 in vaccinated and unvaccinated broilers: a comprehensive study
Vaccinated broilers were protected against mortality from early H9N2-vNDV-VII.1.1 co-infections.Vaccination of broilers significantly decreased but did not stop shedding of either virus.H9N2 infection prior to vNDV infection in nonvaccinated broilers induced faster mortality.
- 29 December 2025
- Published by Pleiades Publishing Ltd in Russian Journal of Marine Biology
- Vol. 51 (6) , 406-422
Comprehensive Genomic and Metabolic Profiling of ι-Carrageenase A2 from Seonamhaeicola marinus: In Silico Modeling and Molecular Dynamics for Biotechnological Applications
Seonamhaeicola marinus, a marine bacterium from the family Flavobacteriaceae, was genomically analyzed. Approximately 23% of its predicted CDSs were linked to subsystems, with amino acid and protein metabolism being the most abundant. Four biosynthetic gene clusters (BGCs) were identified, including those for flexirubin and carotenoid. CAZyme analysis via dbCAN3 revealed 178 CAZymes, representing 3.87% of the genome, with glycosyl hydrolases, particularly GH2, being the most prevalent group. Polysaccharide-producing organisms, such as those yielding carrageenan from red algae, find applications in food, cosmetics, and pharmacology. ι-Carrageenan, characterized by its double sulfate groups, holds significant potential in pharmaceutical systems. ι-Carrageenase A2 from S. marinus has desirable properties for carrageenan processing, supporting the investigation of such novel enzymes for biotechnological uses. This study aimed to comprehensively analyze S. marinus ι-carrageenase A2 through various computational modeling methods. A comparative analysis of the enzyme’s physicochemical properties, binding site locations, and structural features was conducted with other enzymes from the same family. Multiple computer modeling software programs were employed for three-dimensional structure prediction and modeling. Molecular docking identified potential ligands, with neo-ι-carratetraose demonstrating strong binding affinity. Molecular dynamics simulations assessed the stability and flexibility of the ligand-enzyme complex, offering insights into key residues involved in substrate interactions.
- 29 December 2025
- Published by Pleiades Publishing Ltd in Russian Journal of Marine Biology
- Vol. 51 (6) , 406-422
Comprehensive Genomic and Metabolic Profiling of ι-Carrageenase A2 from Seonamhaeicola marinus: In Silico Modeling and Molecular Dynamics for Biotechnological Applications
Seonamhaeicola marinus, a marine bacterium from the family Flavobacteriaceae, was genomically analyzed. Approximately 23% of its predicted CDSs were linked to subsystems, with amino acid and protein metabolism being the most abundant. Four biosynthetic gene clusters (BGCs) were identified, including those for flexirubin and carotenoid. CAZyme analysis via dbCAN3 revealed 178 CAZymes, representing 3.87% of the genome, with glycosyl hydrolases, particularly GH2, being the most prevalent group. Polysaccharide-producing organisms, such as those yielding carrageenan from red algae, find applications in food, cosmetics, and pharmacology. ι-Carrageenan, characterized by its double sulfate groups, holds significant potential in pharmaceutical systems. ι-Carrageenase A2 from S. marinus has desirable properties for carrageenan processing, supporting the investigation of such novel enzymes for biotechnological uses. This study aimed to comprehensively analyze S. marinus ι-carrageenase A2 through various computational modeling methods. A comparative analysis of the enzyme’s physicochemical properties, binding site locations, and structural features was conducted with other enzymes from the same family. Multiple computer modeling software programs were employed for three-dimensional structure prediction and modeling. Molecular docking identified potential ligands, with neo-ι-carratetraose demonstrating strong binding affinity. Molecular dynamics simulations assessed the stability and flexibility of the ligand-enzyme complex, offering insights into key residues involved in substrate interactions.
- Open Access
- 13 April 2025
- Published by Egyptian Knowledge Bank in Assiut Veterinary Medical Journal
- Vol. 71 (185) , 240-258
Molecular Identification and Sequencing of Uterine Bacterial Infection Associated with Subfertility problems and Suggested Treatment Protocol in Arabian Mares
Reproduction failure in Arabian mares is mainly attributed to endometritis. To achieve successful solutions to endometritis, several diagnostic methods must be combined. 36 mares were diagnosed with endometritis, and 69.4% of mares scanned showed abnormal echogenicity and echotexture of endometrium by ultrasonography. This was confirmed by endometrial cytology via low-volume uterine flush, whereas 63.9% of smears contained more than 2–3 PMNs per HPF X100. Additionally, 86.1% of mares were positive for microbial culture. Sequencing of different isolates revealed that Staphylococcus was 44.4% more prevalent than Brevundimonas 27.8%, and Alcaligenes 27.8%. The mares were allocated to four groups; G1 (n= 6) mares left without treatment as control. G2 (KAN, n= 10) mares received three IM doses of kanamycin 10%. G3 (DHS, n= 10) mares were given 3 intramuscular injections of dihydrostreptomycin. G4 (PRF, n= 10) 30 mL autologous platelets rich fibrin (PRF), freshly prepared 6 to 10 minutes at 20-25°C, which was infused intrauterine within 6 hours after natural mating via one-way catheter to obtain its optimum therapeutic benefits. Twice mating was performed within 24-48 hours after ovulation induction of 30 mm follicles using 2500 IU of HCG, IV. A single fertile stallion per group was used. A noteworthy decrease in the endometrial thickness (p<0.05) between groups with an average of 8.35±0.32 mm, besides subsiding of the retained black anechoic intrauterine discharges. Moreover, a significant (p<0.05) enhancement in pregnancy percentage was noticed between the treated groups comparison versus the control. It could be concluded that bacterial infection can be involved in endometritis in Arabian mares, and also autologous PRF can be applied as an inexpensive substitute treatment.
- 13 April 2025
- Published by Egyptian Knowledge Bank in Assiut Veterinary Medical Journal
- Vol. 71 (185) , 240-258
Open AccessMolecular Identification and Sequencing of Uterine Bacterial Infection Associated with Subfertility problems and Suggested Treatment Protocol in Arabian Mares
Reproduction failure in Arabian mares is mainly attributed to endometritis. To achieve successful solutions to endometritis, several diagnostic methods must be combined. 36 mares were diagnosed with endometritis, and 69.4% of mares scanned showed abnormal echogenicity and echotexture of endometrium by ultrasonography. This was confirmed by endometrial cytology via low-volume uterine flush, whereas 63.9% of smears contained more than 2–3 PMNs per HPF X100. Additionally, 86.1% of mares were positive for microbial culture. Sequencing of different isolates revealed that Staphylococcus was 44.4% more prevalent than Brevundimonas 27.8%, and Alcaligenes 27.8%. The mares were allocated to four groups; G1 (n= 6) mares left without treatment as control. G2 (KAN, n= 10) mares received three IM doses of kanamycin 10%. G3 (DHS, n= 10) mares were given 3 intramuscular injections of dihydrostreptomycin. G4 (PRF, n= 10) 30 mL autologous platelets rich fibrin (PRF), freshly prepared 6 to 10 minutes at 20-25°C, which was infused intrauterine within 6 hours after natural mating via one-way catheter to obtain its optimum therapeutic benefits. Twice mating was performed within 24-48 hours after ovulation induction of 30 mm follicles using 2500 IU of HCG, IV. A single fertile stallion per group was used. A noteworthy decrease in the endometrial thickness (p<0.05) between groups with an average of 8.35±0.32 mm, besides subsiding of the retained black anechoic intrauterine discharges. Moreover, a significant (p<0.05) enhancement in pregnancy percentage was noticed between the treated groups comparison versus the control. It could be concluded that bacterial infection can be involved in endometritis in Arabian mares, and also autologous PRF can be applied as an inexpensive substitute treatment.
- Open Access
- 29 June 2024
- Published by Springer Nature in BMC Oral Health
- Vol. 24 (1) , 1-7
A critical influence of HIF-1 on MMP-9 and Galectin-3 in oral lichen planus
Objective: Oral lichen planus carries a risk for malignancy. The pathogenesis of the disease is mediated by various inflammatory mediators. Several mediators could be responsible for the oncogenic behavior in certain cases. Hypoxia-inducible factor-1a (HIF-1), and its possible correlation to Galactin-3 (Gal-3) and matrix metalloproteinase-9 (MMP-9) over expression represents an important indicator for malignant transformation. The investigation of these factors may present evidence-based information on malignant transformation of the disease. Subjects and methods: The study investigated the expression of HIF-1, Gla-3 and MMP-9 in tissue samples of OLP compared to control subjects of un-inflamed gingival overgrowth. 20 biospecimen were allocated in each group. Results: Immunohistochemical findings of OLP showed immunoreactivity for Galectin 3, HIF1a and MMP-9 by most of the epithelial cells. There was a positive correlation between HIF1α and MMP-9, r = 0.9301 (P-value < 0.00001). A positive correlation was detected between Galectin 3 and MMP-9, r = 0.7292 (P-value = 0.000264) between Galectin 3 and HIF1α, r = 0.5893 (P-value = 0.006252). Conclusion: These findings confirm the hypothesis that the adaptive pathways to hypoxia as Gal 3 and MMP-9 expressions and their HIF-1 may play a crucial role in carcinogenesis of OLP.
- 29 June 2024
- Published by Springer Nature in BMC Oral Health
- Vol. 24 (1) , 1-7
Open AccessA critical influence of HIF-1 on MMP-9 and Galectin-3 in oral lichen planus
Objective: Oral lichen planus carries a risk for malignancy. The pathogenesis of the disease is mediated by various inflammatory mediators. Several mediators could be responsible for the oncogenic behavior in certain cases. Hypoxia-inducible factor-1a (HIF-1), and its possible correlation to Galactin-3 (Gal-3) and matrix metalloproteinase-9 (MMP-9) over expression represents an important indicator for malignant transformation. The investigation of these factors may present evidence-based information on malignant transformation of the disease. Subjects and methods: The study investigated the expression of HIF-1, Gla-3 and MMP-9 in tissue samples of OLP compared to control subjects of un-inflamed gingival overgrowth. 20 biospecimen were allocated in each group. Results: Immunohistochemical findings of OLP showed immunoreactivity for Galectin 3, HIF1a and MMP-9 by most of the epithelial cells. There was a positive correlation between HIF1α and MMP-9, r = 0.9301 (P-value < 0.00001). A positive correlation was detected between Galectin 3 and MMP-9, r = 0.7292 (P-value = 0.000264) between Galectin 3 and HIF1α, r = 0.5893 (P-value = 0.006252). Conclusion: These findings confirm the hypothesis that the adaptive pathways to hypoxia as Gal 3 and MMP-9 expressions and their HIF-1 may play a crucial role in carcinogenesis of OLP.
- Open Access
- 7 December 2023
- Published by Springer Nature in AMB Express
- Vol. 13 (1) , 1-10
Silver nanoparticles synthesized by probiotic bacteria and antibacterial role in resistant bacteria
Many dangerous bacteria have become highly resistant to traditional antibiotics, which is a huge public health concern. This study investigated the use of silver nanoparticles biosynthesized in a culture filtrate of Lactobacillus acidophilus as antimicrobials. UV–visual spectrophotometry, Fourier-transform-infrared spectroscopy, X-ray power diffraction, and scanning electron microscopy have all validated the findings. The biosynthesized nanoparticles ranged in size from 33 to 90 nm. The cytotoxicity of the nanosilver generated was then investigated using nine 200 g BW rats separated into three groups. When compared to the control group, the treated rats showed little signs of toxicity; parameters of physiological function, including alanine transaminase, aspartate aminotransferase, albumin, creatinine, and urea were significantly different in treated and non-treated animals. Moreover, the antibacterial role of the generated silver nanoparticles was examined in multi-drug resistant (MDR) pathogenic bacteria, Proteus vulgaris, Escherichia coli, Staphylococcus aureus, and Klebsiella pneumoniae, revealing high antibacterial activity against the examined bacteria. For more demonstration of the effect of the nanosilver on transcription and gene regulation of treated and non-treated bacteria differential display droplet digital-PCR was used, and the results revealed that several genes were up- and down-regulated. Some genes were selected for DNA sequencing and according to the sequence analysis, these genes were mecA, beta-lactam, and unidentified protein genes, and these have been deposited in the GenBank Database with the following accession numbers: Staphylococcus MZ748472 and Klebsiella MZ748473. We conclude that silver nanoparticles biosynthesized by L. acidophilus are environmentally friendly and have antibacterial activities against MDR pathogenic bacteria.
- 7 December 2023
- Published by Springer Nature in AMB Express
- Vol. 13 (1) , 1-10
Open AccessSilver nanoparticles synthesized by probiotic bacteria and antibacterial role in resistant bacteria
Many dangerous bacteria have become highly resistant to traditional antibiotics, which is a huge public health concern. This study investigated the use of silver nanoparticles biosynthesized in a culture filtrate of Lactobacillus acidophilus as antimicrobials. UV–visual spectrophotometry, Fourier-transform-infrared spectroscopy, X-ray power diffraction, and scanning electron microscopy have all validated the findings. The biosynthesized nanoparticles ranged in size from 33 to 90 nm. The cytotoxicity of the nanosilver generated was then investigated using nine 200 g BW rats separated into three groups. When compared to the control group, the treated rats showed little signs of toxicity; parameters of physiological function, including alanine transaminase, aspartate aminotransferase, albumin, creatinine, and urea were significantly different in treated and non-treated animals. Moreover, the antibacterial role of the generated silver nanoparticles was examined in multi-drug resistant (MDR) pathogenic bacteria, Proteus vulgaris, Escherichia coli, Staphylococcus aureus, and Klebsiella pneumoniae, revealing high antibacterial activity against the examined bacteria. For more demonstration of the effect of the nanosilver on transcription and gene regulation of treated and non-treated bacteria differential display droplet digital-PCR was used, and the results revealed that several genes were up- and down-regulated. Some genes were selected for DNA sequencing and according to the sequence analysis, these genes were mecA, beta-lactam, and unidentified protein genes, and these have been deposited in the GenBank Database with the following accession numbers: Staphylococcus MZ748472 and Klebsiella MZ748473. We conclude that silver nanoparticles biosynthesized by L. acidophilus are environmentally friendly and have antibacterial activities against MDR pathogenic bacteria.
- Open Access
Utilization of Algae Extracts as Natural Antibacterial and Antioxidants for Controlling Foodborne Bacteria in Meat Products
Padina pavonica, Hormophysa cuneiformis, and Corallina officinalis are three types of algae that are assumed to be used as antibacterial agents. Our study’s goal was to look into algal extracts’ potential to be used as food preservative agents and to evaluate their ability to inhibit pathogenic bacteria in several meat products (pastirma, beef burger, luncheon, minced meat, and kofta) from the local markets in Alexandria, Egypt. By testing their antibacterial activity, results demonstrated that Padina pavonica showed the highest antibacterial activity towards Bacillus cereus, Staphylococcus aureus, Escherichia coli, Streptococcus pyogenes, Salmonella spp., and Klebsiella pneumoniae. Padina pavonica extract also possesses most phenolic and flavonoid content overall. It has 24 mg gallic acid equivalent/g and 7.04 mg catechol equivalent/g, respectively. Moreover, the algae extracts were tested for their antioxidant activity, and the findings were measured using ascorbic acid as a benchmark. The IC50 of ascorbic acid was found to be 25.09 μg/mL, while Padina pavonica exhibited an IC50 value of 267.49 μg/mL, Corallina officinalis 305.01 μg/mL, and Hormophysa cuneiformis 325.23 μg/mL. In this study, Padina pavonica extract was utilized in three different concentrations (Treatment 1 g/100 g, Treatment 2 g/100 g, and Treatment 3 g/100 g) on beef burger as a model. The results showed that as the concentration of the extract increased, the bacterial inhibition increased over time. Bacillus cereus was found to be the most susceptible to the extract, while Streptococcus pyogenes was the least. In addition, Padina pavonica was confirmed to be a safe compound through cytotoxicity testing. After conducting a sensory evaluation test, it was confirmed that Padina pavonica in meat products proved to be a satisfactory product.
Open AccessUtilization of Algae Extracts as Natural Antibacterial and Antioxidants for Controlling Foodborne Bacteria in Meat Products
Padina pavonica, Hormophysa cuneiformis, and Corallina officinalis are three types of algae that are assumed to be used as antibacterial agents. Our study’s goal was to look into algal extracts’ potential to be used as food preservative agents and to evaluate their ability to inhibit pathogenic bacteria in several meat products (pastirma, beef burger, luncheon, minced meat, and kofta) from the local markets in Alexandria, Egypt. By testing their antibacterial activity, results demonstrated that Padina pavonica showed the highest antibacterial activity towards Bacillus cereus, Staphylococcus aureus, Escherichia coli, Streptococcus pyogenes, Salmonella spp., and Klebsiella pneumoniae. Padina pavonica extract also possesses most phenolic and flavonoid content overall. It has 24 mg gallic acid equivalent/g and 7.04 mg catechol equivalent/g, respectively. Moreover, the algae extracts were tested for their antioxidant activity, and the findings were measured using ascorbic acid as a benchmark. The IC50 of ascorbic acid was found to be 25.09 μg/mL, while Padina pavonica exhibited an IC50 value of 267.49 μg/mL, Corallina officinalis 305.01 μg/mL, and Hormophysa cuneiformis 325.23 μg/mL. In this study, Padina pavonica extract was utilized in three different concentrations (Treatment 1 g/100 g, Treatment 2 g/100 g, and Treatment 3 g/100 g) on beef burger as a model. The results showed that as the concentration of the extract increased, the bacterial inhibition increased over time. Bacillus cereus was found to be the most susceptible to the extract, while Streptococcus pyogenes was the least. In addition, Padina pavonica was confirmed to be a safe compound through cytotoxicity testing. After conducting a sensory evaluation test, it was confirmed that Padina pavonica in meat products proved to be a satisfactory product.
- Open Access
Evaluation of the Effectiveness of Charcoal, Lactobacillus rhamnosus, and Saccharomyces cerevisiae as Aflatoxin Adsorbents in Chocolate
The high incidence of aflatoxins (AFs) in chocolates suggests the necessity to create a practical and cost-effective processing strategy for eliminating mycotoxins. The present study aimed to assess the adsorption abilities of activated charcoal (A. charcoal), yeast (Saccharomyces cerevisiae), and the probiotic Lactobacillus rhamnosus as AFs adsorbents in three forms—sole, di- and tri-mix—in phosphate-buffered saline (PBS) through an in vitro approach, simulated to mimic the conditions present in the gastrointestinal tract (GIT) based on pH, time and AFs concentration. In addition, the novel fortification of chocolate with A. charcoal, probiotic, and yeast (tri-mix adsorbents) was evaluated for its effects on the sensory properties. Using HPLC, 60 samples of dark, milk, bitter, couverture, powder, and wafer chocolates were examined for the presence of AFs. Results showed that all the examined samples contained AFs, with maximum concentrations of 2.32, 1.81, and 1.66 µg/kg for powder, milk, and dark chocolates, respectively. The combined treatment demonstrated the highest adsorption efficiency (96.8%) among all tested compounds. Scanning electron microscope (SEM) analysis revealed the tested adsorbents to be effective AF-binding agents. Moreover, the novel combination of tri-mix fortified chocolate had a minor cytotoxicity impact on the adsorptive abilities, with the highest binding at pH 6.8 for 4 h, in addition to inducing an insignificant effect on the sensory attributes of dark chocolate. Tri-mix is thus recommended in the manufacturing of dark chocolate in order to enhance the safety of the newly developed product.
Open AccessEvaluation of the Effectiveness of Charcoal, Lactobacillus rhamnosus, and Saccharomyces cerevisiae as Aflatoxin Adsorbents in Chocolate
The high incidence of aflatoxins (AFs) in chocolates suggests the necessity to create a practical and cost-effective processing strategy for eliminating mycotoxins. The present study aimed to assess the adsorption abilities of activated charcoal (A. charcoal), yeast (Saccharomyces cerevisiae), and the probiotic Lactobacillus rhamnosus as AFs adsorbents in three forms—sole, di- and tri-mix—in phosphate-buffered saline (PBS) through an in vitro approach, simulated to mimic the conditions present in the gastrointestinal tract (GIT) based on pH, time and AFs concentration. In addition, the novel fortification of chocolate with A. charcoal, probiotic, and yeast (tri-mix adsorbents) was evaluated for its effects on the sensory properties. Using HPLC, 60 samples of dark, milk, bitter, couverture, powder, and wafer chocolates were examined for the presence of AFs. Results showed that all the examined samples contained AFs, with maximum concentrations of 2.32, 1.81, and 1.66 µg/kg for powder, milk, and dark chocolates, respectively. The combined treatment demonstrated the highest adsorption efficiency (96.8%) among all tested compounds. Scanning electron microscope (SEM) analysis revealed the tested adsorbents to be effective AF-binding agents. Moreover, the novel combination of tri-mix fortified chocolate had a minor cytotoxicity impact on the adsorptive abilities, with the highest binding at pH 6.8 for 4 h, in addition to inducing an insignificant effect on the sensory attributes of dark chocolate. Tri-mix is thus recommended in the manufacturing of dark chocolate in order to enhance the safety of the newly developed product.
- Open Access
Modulatory Impacts of Multi-Strain Probiotics on Rabbits’ Growth, Nutrient Transporters, Tight Junctions and Immune System to Fight against Listeria monocytogenes Infection
Multi-strain probiotics (MSP) are considered innovative antibiotics’ substitutes supporting superior gut health and immunity of farmed rabbits. The promising roles of MSP on performance, intestinal immunity, integrity and transporters, and resistance against Listeria monocytogenes (L. monocytogenes) were evaluated. In the feeding trial, 220 rabbits were fed a control diet or diet supplemented with three MSP graded levels. At 60 days of age, rabbits were experimentally infected with L. monocytogenes and the positive control, enrofloxacin, prophylactic MSP (MSPP), and prophylactic and therapeutic MSP (MSPTT) groups were included. During the growing period, MSP at the level of 1 × 108 CFU/kg diet (MSPIII) promoted the rabbits’ growth, upregulated the nutrient transporters and tight-junction-related genes, and modified cytokines expression. Supplementing MSPTT for L. monocytogenes experimentally-infected rabbits restored the impaired growth and intestinal barriers, reduced clinical signs of severity and mortalities, and attenuated the excessive inflammatory reactions. Notably, enrofloxacin decreased L. monocytogenes and beneficial microbial loads; unlike MSPTT, which decreased pathogenic bacterial loads and sustained the beneficial ones. Histopathological changes were greatly reduced in MSPTT, confirming its promising role in restricting L. monocytogenes translocation to different organs. Therefore, our results suggest the use of MSPTT as an alternative to antibiotics, thereby conferring protection for rabbits against L. monocytogenes infection.
Open AccessModulatory Impacts of Multi-Strain Probiotics on Rabbits’ Growth, Nutrient Transporters, Tight Junctions and Immune System to Fight against Listeria monocytogenes Infection
Multi-strain probiotics (MSP) are considered innovative antibiotics’ substitutes supporting superior gut health and immunity of farmed rabbits. The promising roles of MSP on performance, intestinal immunity, integrity and transporters, and resistance against Listeria monocytogenes (L. monocytogenes) were evaluated. In the feeding trial, 220 rabbits were fed a control diet or diet supplemented with three MSP graded levels. At 60 days of age, rabbits were experimentally infected with L. monocytogenes and the positive control, enrofloxacin, prophylactic MSP (MSPP), and prophylactic and therapeutic MSP (MSPTT) groups were included. During the growing period, MSP at the level of 1 × 108 CFU/kg diet (MSPIII) promoted the rabbits’ growth, upregulated the nutrient transporters and tight-junction-related genes, and modified cytokines expression. Supplementing MSPTT for L. monocytogenes experimentally-infected rabbits restored the impaired growth and intestinal barriers, reduced clinical signs of severity and mortalities, and attenuated the excessive inflammatory reactions. Notably, enrofloxacin decreased L. monocytogenes and beneficial microbial loads; unlike MSPTT, which decreased pathogenic bacterial loads and sustained the beneficial ones. Histopathological changes were greatly reduced in MSPTT, confirming its promising role in restricting L. monocytogenes translocation to different organs. Therefore, our results suggest the use of MSPTT as an alternative to antibiotics, thereby conferring protection for rabbits against L. monocytogenes infection.
- Open Access
- 28 June 2022
- Published by Frontiers Media SA in Frontiers in Veterinary Science
- Vol. 9, 918440
Effect of Co-infection of Low Pathogenic Avian Influenza H9N2 Virus and Avian Pathogenic E. coli on H9N2-Vaccinated Commercial Broiler Chickens
In the last 40 years, low pathogenic avian influenza virus (LPAIV) subtype H9N2 has been endemic in most Middle Eastern countries and of course Egypt which is one of the biggest poultry producers in the middle east region. The major losses with the H9N2 virus infections come from complicated infections in commercial broiler chickens, especially E. coli infection. In this work, 2,36,345 Arbor acres broiler chickens from the same breeder flock were placed equally in four pens, where two pens were vaccinated against LPAIV of subtype H9N2 virus, and the other two pens served as non-vaccinated controls. All were placed on the same farm under the same management conditions. A total of twenty birds from each pen were moved to biosafety level−3 chicken isolators (BSL-3) on days 21 and 28 of life and challenged with LPAIV-H9N2 or E. coli. Seroconversion for H9N2 was evaluated before and after the challenge. The recorded results revealed a significant decrease in clinical manifestations and virus shedding in terms of titers of shedding virus and number of shedders in vaccinated compared to non-vaccinated chickens. In groups early infected with LPAIV-H9N2 virus either vaccinated or not vaccinated, there was no significant difference in clinical sickness or mortalities in both groups, but in late infection groups with H9N2 alone, non-vaccinated infected group showed significantly higher clinical sickness in comparison with infected vaccinated group but also without mortality. In groups co-infected with E. coli (I/M) and H9N2, it showed 100% mortalities either in vaccinated or non-vaccinated H9N2 groups and thus reflect the high pathogenicity of used E. coli isolates, whereas in groups co-infected with E. coli (per os to mimic the natural route of infection) and LPAIV-H9N2, mortality rates were significantly higher in non-vaccinated groups than those vaccinated with H9N2 vaccine (15 vs. 5%). In conclusion, the use of the LPAIV H9N2 vaccine has significantly impacted the health status, amount of virus shed, and mortality of challenged commercial broilers, as it can minimize the losses and risks after co-infection with E. coli (orally) and LPAIV-H9N2 virus under similar natural route of infection in commercial broilers.
- 28 June 2022
- Published by Frontiers Media SA in Frontiers in Veterinary Science
- Vol. 9, 918440
Open AccessEffect of Co-infection of Low Pathogenic Avian Influenza H9N2 Virus and Avian Pathogenic E. coli on H9N2-Vaccinated Commercial Broiler Chickens
In the last 40 years, low pathogenic avian influenza virus (LPAIV) subtype H9N2 has been endemic in most Middle Eastern countries and of course Egypt which is one of the biggest poultry producers in the middle east region. The major losses with the H9N2 virus infections come from complicated infections in commercial broiler chickens, especially E. coli infection. In this work, 2,36,345 Arbor acres broiler chickens from the same breeder flock were placed equally in four pens, where two pens were vaccinated against LPAIV of subtype H9N2 virus, and the other two pens served as non-vaccinated controls. All were placed on the same farm under the same management conditions. A total of twenty birds from each pen were moved to biosafety level−3 chicken isolators (BSL-3) on days 21 and 28 of life and challenged with LPAIV-H9N2 or E. coli. Seroconversion for H9N2 was evaluated before and after the challenge. The recorded results revealed a significant decrease in clinical manifestations and virus shedding in terms of titers of shedding virus and number of shedders in vaccinated compared to non-vaccinated chickens. In groups early infected with LPAIV-H9N2 virus either vaccinated or not vaccinated, there was no significant difference in clinical sickness or mortalities in both groups, but in late infection groups with H9N2 alone, non-vaccinated infected group showed significantly higher clinical sickness in comparison with infected vaccinated group but also without mortality. In groups co-infected with E. coli (I/M) and H9N2, it showed 100% mortalities either in vaccinated or non-vaccinated H9N2 groups and thus reflect the high pathogenicity of used E. coli isolates, whereas in groups co-infected with E. coli (per os to mimic the natural route of infection) and LPAIV-H9N2, mortality rates were significantly higher in non-vaccinated groups than those vaccinated with H9N2 vaccine (15 vs. 5%). In conclusion, the use of the LPAIV H9N2 vaccine has significantly impacted the health status, amount of virus shed, and mortality of challenged commercial broilers, as it can minimize the losses and risks after co-infection with E. coli (orally) and LPAIV-H9N2 virus under similar natural route of infection in commercial broilers.
- Open Access
- 13 June 2022
- Published by MDPI AG in International Journal of Environmental Research and Public Health
- Vol. 19 (12) , 7250
Diversity of Toxigenic Fungi in Livestock and Poultry Feedstuffs
The purpose of this study was to discover how abundant toxigenic fungi and mycotoxins are in animal feedstuff samples. A total of ninety samples representing various types of animal feedstuff samples were collected from ninety sites in Egypt. Isolation, identification, and determination of mycotoxins (aflatoxins B1, B2, G1, G2, and ochratoxin A) were performed. The results revealed that 79 (87.77%) of the samples were contaminated with fungi, and 1.1 × 105 CFU/g were recovered, including 41 fungal species belonging to 18 genera, such as Zygomycota, which was represented by three species (7.31% of the total species number), teleomorphic Ascomycota (10 species, 24.39%), and anamorphic Ascomycota (28 species, 69.29%). When taxonomically investigated, these species were categorized into 2 phyla, 4 classes, 6 orders, and 12 families (one of them with an uncertain position). Moreover, the genus Aspergillus exhibited 16 species (39.02%). Notably, site no. 6 showed the highest Margalef species richness index at 10.87 followed by site no. 4, while the Shannon diversity index (H) of the recovered taxa was 2.20. Based on the frequency of occurrence, Aspergillus flavus recorded the highest percentage (65.56%) followed by A. niger (50%) and Penicillium chrysogenum (40%). Genus Aspergillus was recorded in 75 samples (88.33%), while Penicillium appeared only in 43 samples, accounting for 47.77% out of 90 samples. The High-performance liquid chromatography (HPLC) analysis showed that aflatoxin B1 (AFB1) was recorded in two animal feedstuff samples at a ratio of 0.851 and 1.363 µg/kg, While AFB2 was discovered in only one animal feedstuff sample at a ratio of 0.479 g/kg. The aflatoxins levels in the positive samples (AFB1 and AFB2) Beef cattle sample components were below the permissible limit for animal feedstuff which is (20 g/kg). Although aflatoxins were found in certain samples, the amounts were much below the maximum residue limits (MRLs) defined by the international authorities or Egyptian guidelines. toxigenic fungi found in contaminated animal feed samples pose a major threat to animal and poultry health, productivity, and even human health. Therefore, periodic monitoring is an excellent way to keep track of their existence and mitigate their hazards.
- 13 June 2022
- Published by MDPI AG in International Journal of Environmental Research and Public Health
- Vol. 19 (12) , 7250
Open AccessDiversity of Toxigenic Fungi in Livestock and Poultry Feedstuffs
The purpose of this study was to discover how abundant toxigenic fungi and mycotoxins are in animal feedstuff samples. A total of ninety samples representing various types of animal feedstuff samples were collected from ninety sites in Egypt. Isolation, identification, and determination of mycotoxins (aflatoxins B1, B2, G1, G2, and ochratoxin A) were performed. The results revealed that 79 (87.77%) of the samples were contaminated with fungi, and 1.1 × 105 CFU/g were recovered, including 41 fungal species belonging to 18 genera, such as Zygomycota, which was represented by three species (7.31% of the total species number), teleomorphic Ascomycota (10 species, 24.39%), and anamorphic Ascomycota (28 species, 69.29%). When taxonomically investigated, these species were categorized into 2 phyla, 4 classes, 6 orders, and 12 families (one of them with an uncertain position). Moreover, the genus Aspergillus exhibited 16 species (39.02%). Notably, site no. 6 showed the highest Margalef species richness index at 10.87 followed by site no. 4, while the Shannon diversity index (H) of the recovered taxa was 2.20. Based on the frequency of occurrence, Aspergillus flavus recorded the highest percentage (65.56%) followed by A. niger (50%) and Penicillium chrysogenum (40%). Genus Aspergillus was recorded in 75 samples (88.33%), while Penicillium appeared only in 43 samples, accounting for 47.77% out of 90 samples. The High-performance liquid chromatography (HPLC) analysis showed that aflatoxin B1 (AFB1) was recorded in two animal feedstuff samples at a ratio of 0.851 and 1.363 µg/kg, While AFB2 was discovered in only one animal feedstuff sample at a ratio of 0.479 g/kg. The aflatoxins levels in the positive samples (AFB1 and AFB2) Beef cattle sample components were below the permissible limit for animal feedstuff which is (20 g/kg). Although aflatoxins were found in certain samples, the amounts were much below the maximum residue limits (MRLs) defined by the international authorities or Egyptian guidelines. toxigenic fungi found in contaminated animal feed samples pose a major threat to animal and poultry health, productivity, and even human health. Therefore, periodic monitoring is an excellent way to keep track of their existence and mitigate their hazards.