Escherichia coli is one of the foodborne pathogens associated with several cases of human sickness. Duck meat is an excellent source of animal-derived high quality proteins. This study was undertaken to investigate the possible transmission of diarrheagenic E. coli from consumption of duck meat and giblets. Additionally, expression of some virulence-associated genes in the isolated E. coli serotypes was examined using polymerase chain reaction. Finally, antibiogram of the identified E. coli serotypes was also investigated.E. coli could be isolated from the examined duck meat and giblets. Five serogroups could be identified, including E. coli O86, O127, O114, O26 and O78. Liver harbored the highest incidence of E. coli followed by gizzard, heart, spleen and muscle. Isolated E. coli serogroups harbored different virulent factors responsible for diarrhea and hemorrhage. Additionally, isolated E. coli serogroups showed marked low sensitivity or even resistance to the most common used antibiotics in Egypt. PRACTICAL APPLICATIONSThe results of this study declare that duck meat and giblets may be a possible source for transmission of enteropathogenic Escherichia coli to human. The isolated E. coli serotypes harbored various virulence-associated genes, in particular those responsible for hemorrhage and toxin production. Additionally, the isolated serotypes showed variable degrees of antibiotic resistance. Accordingly, adoption of strict hygienic measures should be followed during preparation of ducks for human consumption. Additionally, efficient cooking of ducks and duck giblets must be considered before serving to human.

ABSTRACT. The aim of this study was to estimate total carotenoids, β-carotene and retinol concentrations in the livers and muscles of some ungulates (cattle, buffalo, sheep, goats and horses) in comparison with the Wistar rats as a control. Cattle and horses had the highest contents of total carotenoids and β-carotene. Unexpectedly, sheep was the highest accumulator of retinol with a mean concentration of 203 ± 23.34 µg/g, while the least accumulator was buffalo, having a mean value of 58.28 ± 13.77 µg/g. Livers had higher contents of the examined phytochemicals than muscles. Consumption of these tissues may provide human with some needs from these important phytochemicals, though ingestion of livers, especially that of the sheep, is not advisable for the pregnant women. Carotenoids are a family of phytochemical compounds that are synthesized naturally by higher plants. Carotenoid metabolism mainly takes place at the liver of animals and human. Meat-producing animals reared on high forage rations pass a portion of the ingested carotenoids into the milk, muscle and body fat [5].Carotenes (mainly β-carotene) are precursors of retinol (Vitamin A), a critical fat-soluble vitamin, which is important for cell division and cell differentiation, normal vision, bone growth and reproduction [17]. Specifically, it is responsible for maintaining the surface lining of the eyes and the lining of the respiratory, urinary and intestinal tracts. The integrity of the skin and mucous membranes is maintained by retinol, creating a biodefense barrier to bacteria and viruses [13,18]. In addition, retinol is involved in the regulation of immune function by supporting the production and function of white blood cells [2,15].Retinol is an essential dietary substance, which is required for rhodopsin formation and vision [3,4]. It is estimated that 250 million persons are marginally deficient in vitamin A [22]. The exact number of persons who consume vitamin A well in excess of physiological needs is unknown, especially in developing countries. This number is clearly high, especially in economically developed countries, in which fortified foods and nutritional supplements containing preformed vitamin A are widely available [22]. At the same time, higher oral doses of vitamin A have been shown to be teratogenic, and accordingly, the World Health Organization has recommended that the daily intake for pregnant women should not exceed 3.3 mg/day [12,22]. Thus, not surprisingly, both a deficiency and excess of retinol adversely affect human and animal health.The contents of carotenoids in the fat and milk had been extensively studied in cattle. However, there is little information available about the content of these naturally occurring phytochemicals in livers and muscles of other meat-producing animals like buffalo, sheep, goat and horses. Additionally, the contribution of the relevant concentrations of these phytochemicals in the meat (muscle and liver) to human health is poorly studied. Thus, this investigation was undertaken to estimate th...