Assessment of Oxytetracycline Residue in Table Eggs from Khartoum State’s Markets

Background: Antibiotics residue in food from animal origin represents a public health issue concerns the authorities worldwide. Method: 100 egg samples were collected from Khartoum state’s markets to evaluate the current situation of oxy tetracycline residue. briefly, Samples were homogenized, weighed (2 g); and processed by adding citric acid (100 mg), 30% nitric acid (1 ml), methanol (4 ml) followed by adding 1 ml of deionized water; then centrifuged at 5300 for 10 mints followed by filtration throughout 0.22 µm syringe filter and 20 µl of the sample was injected into HPLC equipped with UV-VIS detector and ODS (C-18) column and read at 360 nm. Result: 49 % of total samples were positive. 48% of those positive samples (24 out of 49); were equal or exceeded the MRL of Oxytetracycline in egg (200 ppb). The mean values obtained from the three different state’s cities were not significantly different between different localities, never theless between each city and the MRL the variance was vastly significant.


Introduction
Fowls are tended for meat and egg production as a vital protein sources. Drugs are crucial section of chicken production and used to preclude and manage diseases, reduce stress due to environmental alterations, vaccination and other administration practices.
Antibiotics are described as the antimicrobial substances that are produced both naturally by residing organisms or synthetically by way of laboratory processes with the potential to inhibit the boom of microorganisms or kill the microorganisms [1]. Antibiotics are industrially produced for the cause of the prevention and therapy of animal ailments such as mastitis, brucellosis, gastrointestinal diseases, respiratory diseases and many other bacterial infectious ailments [2].
In intensified farming antibiotics are also used to advance animal production like amplify of growth level and increasing weight gain [3]. When these antibiotics are administered to an animal, they dissolve and distribute rapidly in animal tissues and fluids. Over 90% of these antibiotics bind to plasma proteins and attain a high concentration between the 3rd and sixth hour of administration [4], they are then metabolized in the liver and are expelled through glomerular filtration. If the right technique is no longer used in administration and use of these pills, they are left in large amounts i.e., residues, in animal products like milk and egg [5]. The occurrence of antibacterial drug residues in eggs can carriage a health hazard to consumers such as hypersensitivity reaction, development of resistant organisms to these antibacterial agents and damage of gastrointestinal natural microbiota [6].
Depending on the type of antimicrobial administrated to the animal, variable periods of time is needed to avoid the tremendous harmful effect of the parent administrated drug or it's metabolites residue on the consumer's health, [7]. Direct impact on customers may be witnessed, such as allergy in hypersensitive persons [8].
Residue may also be the underlying reason behind the initiation of resistant strains of bacteria. Thus, assurance on presence of regulations govern the exist of antimicrobial residue in food; has become a necessity. Oxytetracycline (OTC) is currently accredited for use in feed to amplify egg manufacturing and feed competence and for the prevention of ailment for breeder hens and meat-type chicken [9]. Oxytetracycline is now not authorized for use in laying hens producing eggs for human consumption. However, eggs may incorporate OTC residues after: i.
Illegal or extra-label use of drugs

Chemicals and Standard
Nitric acid 69%, Methanol HPLC grade, Acetonitrile HPLC grade, Citric acid and Sulfuric acid were purchased from Sigma Aldrich and HPLC pure water.
Oxytetracycline hydrated reference standard was attained from Sigma Aldrich.

Sample Preparation
Following the method described by [10], samples were extracted (LLE). Tow grams of well homogenized egg sample were taken into falcon tube, 100 mg of citric acid, 1 ml of (30%) nitric acid, 4 ml of methanol and 1ml of deionized water were added to the samples in order. Samples were vortexed and placed in ultrasonic water bath for 15 min, followed by centrifugation at 5300 rpm for 10 mints.

Method validation:
The HPLC assay linearity was determined by analysis of series standard solution on three different days in concentrations ranged between 100-500 µg/ml. the Calibration curve plotted using the linear least squares regression procedure of the peak area ratios against concentrations.
Extraction recovery: Spiked samples were prepared by adding 100 µl of (300,400 and 500 ppb), standard solutions to blank sample. Spiked samples were fortified on 3 different days.
The average of recovery values was used to evaluate the residue concentration and the precision of data.      (7); symbolize antibacterial, the analysis was done using Delvotest kit. Algamidi [15], documented the existence of OCT in egg samples assembled from different regions of Saudi Arabia using HPLC method.
A study performed by, Sirdar [16], to evaluate the residue of antibiotics residue in commercial egg from Khartoum state farms; in period between 2007-2008, he stated there is a strong association between reported poultry diseases and the presence antibiotics residue in egg samples collected from commercial farms when samples screened using antimicrobial inhibition test. Hind [17], conducted study to monitor the residue of OCT in egg samples gathered from Khartoum State-Sudan. HPLC analysis of collect samples resulted in 35% samples above the allowed limit.

Conclusion
The present and previous studies result in Khartoum state, ensures the need for firm law applied by specialized structure to govern the use of antimicrobial in poultry sector. This structure follows up the usage of antimicrobial and commitment of farms owners with withdrawal period of every drug. Following vaccination program and restricted hygiene system may lower the need to use antimicrobial drugs consequently avoid the risk of residual parent drug or it's metabolites in poultry products. The current comprehensive concern of antimicrobial resistant issue, which raised from the random use of antimicrobial requires official and civilian collaboration to guarantee safe poultry products free of residue served for the consumers.