Eslam M. Omar

Dr. Eslam M. Omar

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Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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6 September 2022 in Journal of Apicultural Research
Verified
Journal Article
Open access
Alison GrayAlison Gray
Alison Gray
NANoureddine Adjlane
Noureddine Adjlane
AAAlireza Arab
Alireza Arab
ABAlexis Ballis
Alexis Ballis
VBValters Brusbardis
Valters Brusbardis
RBRobert Brodschneider
Robert Brodschneider
This article presents managed honey bee colony loss rates over winter 2019/20 resulting from using the standardised COLOSS questionnaire in 37 countries. Six countries were from outside Europe, including, for the first time in this series of articles, New Zealand. The 30,491 beekeepers outside New Zealand reported 4.5% of colonies with unsolvable queen problems, 11.1% of colonies dead after winter and 2.6% lost through natural disaster. This gave an overall colony winter loss rate of 18.1%, higher than in the previous year. The winter loss rates varied greatly between countries, from 7.4% to 36.5%. 3216 beekeepers from New Zealand managing 297,345 colonies reported 10.5% losses for their 2019 winter (six months earlier than for other, Northern Hemisphere, countries). We modelled the risk of loss as a dead/empty colony or from unresolvable queen problems, for all countries except New Zealand. Overall, larger beekeeping operations with more than 50 colonies experienced significantly lower losses (p < 0.001). Migration was also highly significant (p < 0.001), with lower loss rates for operations migrating their colonies in the previous season. A higher proportion of new queens reduced the risk of colony winter loss (p < 0.001), suggesting that more queen replacement is better. All three factors, operation size, migration and proportion of young queens, were also included in a multivariable main effects quasi-binomial GLM and all three remained highly significant (p < 0.001). Detailed results for each country and overall are given in a table, and a map shows relative risks of winter loss at the regional level.

12 July 2022 in Nutrients
Verified
Journal Article
Open access
PDF file
Jari Saeed AlgethamiJari Saeed Algethami
Jari Saeed Algethami
AEAida A. Abd El-Wahed
Aida A. Abd El-Wahed
Mohamed Hamdi ElashalMohamed Hamdi Elashal
Mohamed Hamdi Elashal
HAHanan R. Ahmed
Hanan R. Ahmed
EEEsraa Elshafey
Esraa Elshafey
Hesham El-SeediHesham El-Seedi
Hesham El-Seedi
Bee pollen is a natural cocktail of floral nectar, flower pollen, enzymes, and salivary secretions produced by honeybees. Bee pollen is one of the bee products most enriched in proteins, polysaccharides, polyphenols, lipids, minerals, and vitamins. It has a significant health and medicinal impact and provides protection against many diseases, including diabetes, cancer, infectious, and cardiovascular. Bee pollen is commonly promoted as a cost-effective functional food. In particular, bee pollen has been applied in clinical trials for allergies and prostate illnesses, with a few investigations on cancer and skin problems. However, it is involved in several patents and health recipes to combat chronic health problems. This review aimed to highlight the clinical trials and patents involving bee pollen for different cases and to present the role of bee pollen as a supplementary food and a potential product in cosmetic applications.

4 July 2018 in Insects
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Journal Article
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JDJiří Danihlík
Jiří Danihlík
MŠMária Škrabišová
Mária Škrabišová
RLRené Lenobel
René Lenobel
MSMarek Sebela
Marek Sebela
EOEslam M. Omar
Eslam M. Omar
RBRobert Brodschneider
Robert Brodschneider
We investigated the importance of protein nutrition for honey bee immunity. Different protein diets (monofloral pollen of Helianthus spp., Sinapis spp., Asparagus spp., Castanea spp., a mixture of the four different pollen and the pollen substitute FeedbeeTM) were fed to honey bees in cages ad libitum. After 18 days of feeding, apidaecin 1 isoforms concentration in the thorax were measured using nanoflow liquid chromatography coupled with mass spectrometry. Expression levels of genes, coding for apidaecins and abaecin in the abdomen were determined using quantitative PCR. The results indicate that protein-containing nutrition in adult worker honey bees can trigger certain metabolic responses. Bees without dietary protein showed lower apidaecin 1 isoforms concentrations. The significantly lowest concentration of apidaecin 1 isoforms was found in the group that was fed no pollen diet when compared to Asparagus, Castanea, Helianthus, and Sinapis pollen or the pollen supplement FeedBeeTM. Expression levels of the respective genes were also affected by the protein diets and different expression levels of these two antimicrobial peptides were found. Positive correlation between concentration and gene expression of apidaecins was found. The significance of feeding bees with different protein diets, as well as the importance of pollen nutrition for honey bee immunity is demonstrated.

17 October 2024 in Apidologie
Verified
Journal Article
Open access
PDF file
MAMostafa Abdella
Mostafa Abdella
SRSalah H. Rateb
Salah H. Rateb
MKMohammed. M. Khodairy
Mohammed. M. Khodairy
EOEslam M. Omar
Eslam M. Omar
In bee diets, nectar is the primary source of carbohydrates. During scarcity of bee flora, such as in winter, beekeepers typically provide supplemental sugar syrup as a nectar substitute. We examined four types of sugars (sucrose, fructose, glucose, and a mixture of fructose and glucose) on bee longevity, bee appetitive, and their impact on pollen digestion. The results showed that sucrose and glucose had extended the longevity in cages. Bees preferred sucrose at a 50% concentration since they consumed more than the other sugar types in cages and in the multiple-choice test experiment in apiary. Bees given sucrose solution consumed the most pollen. In contrast, the cages provided the fructose solution consumed the least amount of pollen, increasing body fat percentage, which can be considered evidence of a digestive disorder. Generally, the type of sugar affects bee’s benefits from nutrition. Finally, sucrose is the best type of sugar and is considered the ideal substitute for nectar.


17 October 2022 in Research Square
Verified
Preprint
Open access
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EOEslam M. Omar
Eslam M. Omar
GAGamal Abdu_Allah
Gamal Abdu_Allah
ATAamer Tawfik
Aamer Tawfik
Recent studies have shown negative sublethal effects of the microbial bioinsecticides, spinosad (Spd) and spinetoram (Spm) on honeybees concern behavioral effects; only a few concern physiological effects. Therefore, under laboratory conditions we investigated sublethal effects of Spd and Spm on food consumption, the hypopharyngeal glands (HPG) development and activity in nursing honeybee workers. We introduced newly emerged worker honeybees into cages and provided sugar solution and pollen dough ad libitum. Insecticides (Spd and Spm) were administered in sugar solution. The present results showed that continuous exposure to Spd during the first 10 days of adult life in honeybees negatively affects the rate of pollen consumption, HPG development and activity. On the other hand, Spm treatment displayed only negative effect on HPG activity. Therefore, special attention needs to be paid to sublethal effects of some microbial bioinsecticides on honeybee. Overall, data indicate that the microbial bioinsecticides (Spd and Spm) should not be exempted from risk assessment analysis due to their lethal and sublethal components.