Treatment Of Food-producing Animals Research Articles

Oxytetracycline and beta- lactam residues in raw milk of different species marketed in Alexandria city, Egypt

Antibiotic residues in milk are of great public health concern since milk is being widely consumed by infants, youngster and adults throughout the globe. Therefore, eighty samples of different species including (cow, buffalo, camel and sheep) 20 of each type were collected from different markets and dairy shops located in Alexandria governorate, Egypt for determination antibiotic residues using HPLC. The obtained results were revealed that oxytetracycline, penicillin G and cloxacillin residues were detected at incidence rate (30, 30, 15, & 30%), (25, 20, 10, & 25%), and (10, 10, 0, &15%) with a mean values of (97.9±28.1, 85.5± 25.9, 48.4±28.0 & 122.9±29.2 ppb); (8.86 ± 3.60, 7.583± 4.73, 1.95± 0.95 &10.2 ± 3.40 ppb), and (39.3 ± 7.40, 21.5 ± 9.05, 0 & 37.6 ± 9.91 ppb) in examined cow, buffalo , camel and sheep’s milk samples, respectively. Positive samples for antibiotic residues were compared with the maximum residual limits established by international standards. In addition, calculated daily intake for each antibiotic residues were compared with acceptable daily intake. One sample of camel and sheep milk may contain three antibiotic residues and these may cause public health hazards for consumers. Therefore, Legislations for monitoring and control antibiotics treatment of food producing animals should be adopted.

Antibiotics Residues of Some Famous Antibiotics in Raw Milk of Different Species Sold at Local Markets

Antibiotic residues in milk are of great public health concern since milk is being widely consumed by infants, youngster and adults throughout the globe. Therefore, eighty samples of different species including (cow, buffalo, camel and sheep) 20 of each type were collected from different markets and dairy shops located in Alexandria governorate, Egypt for detection antibiotic residues using HPLC. The obtained results revealed oxytetracycline, penicillin G and cloxacillin residues were detected at incidence rate (30, 30, 15, & 30%), (25, 20, 10, & 25%), and (10, 10, 0, &15%) with a mean values of (97.9±28.1, 85.5± 25.9, 48.4±28.0 & 122.9±29.2 ppb); (8.86 ± 3.60, 7.583± 4.73, 1.95± 0.95 &10.2 ± 3.40 ppb), and (39.3 ± 7.40, 21.5 ± 9.05, 0 & 37.6 ± 9.91 ppb) in examined cow, buffalo , camel and sheep’s milk samples, respectively. Positive samples for antibiotic residues compared with maximum residual limits established by international standards. In addition, calculated daily intake for each antibiotic residues were compared with acceptable daily intake. One milk samples may contain one or more antibiotic residues and these may cause public health hazards for consumers. Therefore, Legislations for monitoring and control antibiotics treatment of food producing animals should be adopted.

Determination of Antimicrobial Residues in Honey by Liquid Chromatography Tandem Mass Spectrometry

Antibiotics are generally used worldwide against bacterial diseases in the treatment of food-producing animals. Since the residues of active agents or their metabolites can appear in these foods, the European Union, for instance, has set maximum residue limit concentrations for authorised veterinary drugs in foodstuffs. However, as yet, regulatory limits have not been established for honey and thus far, only recommendations exist. The aim of this study is to present a multiscreening method for residues in honey for the determination of 36 antimicrobial residues associated with several antibiotics of the B1 group (sulfonamides, trimethoprim, aminoglycosides, tetracyclines, quinolones and lincomycin) as well as the antibiotic griseofulvin. During the screening analysis, samples are hydrolysed in an acidified medium, purified on polymeric solid-phase extraction cartridges and subsequently analysed by reversed phase ion pair liquid chromatography tandem mass spectrometry. The liquid chromatographic separation was optimised by computer simulation with DryLab software. The positive identification of target compounds in suspicious samples was confirmed using earlier developed antibiotic class specific methods of which the aminoglycoside method is herein described in detail. The developed approaches were then applied to samples in the national monitoring program after their successful validation. Moreover, the screening and confirmatory methods were applied to proficiency test samples resulting in satisfactory identification and quantification. However, the analysis of real samples revealed that co-eluting target compounds can have considerable influence on the accuracy of this semi-quantitative multiscreening method.

Effects of intramuscularly administered enrofloxacin on the susceptibility of commensal intestinal Escherichia coli in pigs (sus scrofa domestica)

BackgroundIn the European Union, various fluoroquinolones are authorised for the treatment of food producing animals. Each administration poses an increased risk of development and spread of antimicrobial resistance. The aim of this study was to investigate the impact of parenteral administration of enrofloxacin on the prevalence of enrofloxacin and ciprofloxacin susceptibilities in the commensal intestinal E. coli population.MethodsE. coli isolates from faeces of twelve healthy pigs were included. Six pigs were administered enrofloxacin on day 1 to 3 and after two weeks for further three days. The other pigs formed the control group. MIC values were determined. Virulence and resistance genes were detected by PCR. Phylogenetic grouping was performed by PCR. Enrofloxacin and ciprofloxacin were analysed in sedimentation samples by HPLC.ResultsSusceptibility shifts in commensal E. coli isolates were determined in both groups. Non-wildtype E. coli could be cultivated from two animals of the experimental group for the first time one week after the first administration and from one animal of the control group on day 28. The environmental load with enrofloxacin in sedimentation samples showed the highest amount between days one and five. The repeated parenteral administration of enrofloxacin to pigs resulted in rapidly increased MIC values (day 28: MIC up to 4 mg/L, day 35: MIC ≥ 32mg/L). E. coli populations of the control group in the same stable without direct contact to the experimental group were affected.ConclusionThe parenteral administration of enrofloxacin to piglets considerably reduced the number of the susceptible intestinal E. coli population which was replaced by E. coli strains with increased MIC values against enrofloxacin. Subsequently also pigs of the control were affected suggesting a transferability of strains from the experimental group through the environment to the control group especially as we could isolate the same PFGE strains from both pig groups and the environment.

Multi-residue monitoring for the simultaneous determination of five nitrofurans (furazolidone, furaltadone, nitrofurazone, nitrofurantoine, nifursol) in poultry muscle tissue through the detection of their five major metabolites (AOZ, AMOZ, SEM, AHD, DNSAH) by liquid chromatography coupled to electrospray tandem mass spectrometry—In-house validation in line with Commission Decision 657/2002/EC

Following the ban of four nitrofurans in the mid-90s (furazolidone, furaltadone, nitrofurantoine, nitrofurazone), the nifursol, a veterinary drug from the nitrofuran class of antibacterials which has been used prophylactically as feed additive for treating turkeys against histomoniasis (blackhead disease) was also declared in Annex IV of the European Union Directive no. 90/2377/EC in 2002 according to the Regulation no. 1756/2002/EC. As for the four other nitrofurans, nifursol disappears from tissues within a few days after treatment of food-producing animals. But toxic metabolites are still present for longer periods (several weeks or even months). The major metabolite that can readily be monitored in the tissues following nifursol abuse is the 3,5-dinitro-salicylic acid hydrazine (DNSAH). This article displays some improvements and the revalidation of the analytical method by liquid chromatography coupled to electrospray tandem mass spectrometry (LC-esiMS/MS) already in use in our laboratory for monitoring nitrofuran metabolites but also including the nifursol metabolite at the confirmatory minimum required performance level (MRPL) of 1μgkg−1. The validation is applied both to artificially and to naturally incurred turkey muscle.

Regulation of Residues of Antimicrobial Veterinary Medicinal Products in Food in the European Union

The current regulation of residues of antimicrobial veterinary medicinal products resulting from the treatment of food-producing animals in the European Union (EU) is reviewed and results of the application of the regulation are presented. European legislation concerning the control of residues of veterinary medicinal products requires the evaluation of antimicrobial properties of residues of such products. Three evaluation approaches are accepted: (i) human data, (ii) data to demonstrate no-observed-effect-levels obtained in gnotobiotic human gut flora associated (HFA) animals or (iii) the calculation of a microbiological acceptable daily intake (ADI) from in vitro minimum inhibition concentration (MIC) data. By September 1999, a total of 55 antimicrobial substances of 16 different classes were evaluated in the EU with respect to the safety of their residues to the consumer and for 46 of these the microbiological effects of their residues was assessed. In most instances (41 substances) in vitro MIC data were used for the evaluation and an arbitrary microbiological ADI was calculated. Sufficient human data were present only for tetracyclines (tetra-, chlortetra-, oxytetra- and doxycycline) and adequate data from gnotobiotic animals (human gut flora-associated rats or mice) were available only for tilmicosin. However, only for 39 of the 55 compounds the antimicrobial effects of residues were considered the most relevant for the overall safety assessment, while for 16 compounds of 5 different classes the toxicological effects were most relevant and their overall evaluation was based on a toxicological ADI. Keywords: Influence on human gut flora, microbiological safety of residues, regulation, residues of veterinary medicinal products, review article, safety evaluation.

Conversion of cephapirin to deacetylcephapirin in milk and tissues of treated animals.

Cephapirin is one of six beta-lactam antibiotics approved for use in the treatment of food-producing animals in the United States. When used for treatment of mastitis by intramammary infusion, it is partially converted to a microbiologically active metabolite identified as deacetylcephapirin (DACEP). The degradation was followed in four cows with naturally acquired mastitis which were treated with cephapirin. DACEP persisted longer than the parent compound in the milk. When a calf was treated with cephapirin by intramuscular injection, the compound was almost completely converted to DACEP in tissues. The deacetyl form must be considered in the determination of residues in treated animals.

Quality control and safety of animal products

This paper discusses the new animal drug approval process regulated by the Center for Veterinary Medicine (CVM), Food and Drug Administration (FDA) of the United States. The Center for Veterinary Medicine of FDA considers two criteria in ensuring the human food safety of edible animal products: i) safety of the chemical residues and ii) for antimicrobial products, microbiological safety including changes in bacterial pathogen load and resistance pattern. The hazard associated with animal drug products of non-carcinogenic compounds is assessed by conducting a standard battery of toxicology test, whereas the hazard from the carcinogenic potential of compounds is evaluated based on structure, results of genetic toxicity tests, and toxicology studies. Post approval monitoring is carried out to ensure that the animal drugs are being used properly after their approval. Particular concern is given to those eliciting an "acute" toxic reaction at relatively low levels. The other aspect of food safety regulated by CVM of FDA is microbiological safety, especially to antimicrobial drugs used at subtherapeutic levels in feeds. The studies are designed by FDA to ensure that antibiotic treatment of food-producing animals does not alter pathogen load or resistance pattern of pathogens. Two studies are generally performed: i) the salmonella shedding study, which addresses the effect of drug treatment on the excretion of salmonella in the feces of animals artificially infected with salmonella; and ii) the coliform resistance study, which monitors the effect of the drug on the resistance pattern of E. coli present in the endogenous fecal flora. After a retrospective study of the microbiological safety over past 20 yr, CVM of FDA is planning to revise some microbiological safety studies with focuses on: i) pathogen load, pathogen excretion and microorganism resistance pattern at the time of slaughter; and ii) susceptibility studies on products that have utility in human medicine. Key words: Animal drug, food safety, antibiotic

National Surveillance for Antibiotic Resistance in Zoonotic Enteric Pathogens

Treatment of food-producing animals with antimicrobial agents that are important in human therapy may present a public health risk by the transfer of resistant zoonotic pathogens from animals to humans. Resistant bacteria can diminish the effectiveness of antibiotics and demand the use of more expensive or less safe alternatives. In 1996, the Centers for Disease Control (CDC), United States Department of Agriculture (USDA), and Food and Drug Administration (FDA) established the National Antimicrobial Monitoring System to prospectively monitor changes in antimicrobial susceptibilities of zoonotic pathogens from human and animal clinical specimens, healthy farm animals, and carcasses of food-producing animals at slaughter plants. This article describes the development, implementation, and objectives of the monitoring system and presents initial data generated by the system.

Tissue Clearance of Rofenaid® in Chickens and Turkeys

ROFENAID®, a combination of sulfadimethoxine (4-sulfanilamido-2,6-dimethoxypyrimidine) and ormetoprim (2,4-diamino-5-(4,5-dimethoxy-2-methylbenzyl)- pyrimidine) in a ratio of 5:3, has been shown to be an effective and safe antibacterial and coccidiostat for broilers and turkeys (Mitrovic et al., 1969a, b, 1971a, b; Marusich et al., 1969, 1971). Treatment of food-producing animals with Rofenaid® has created the need for tissue residue studies capable of accurately measuring the disappearance of both components of the drug from the animal body. A review of these studies forms the subject of the present report. Assays for sulfadimethoxine (SDM) and ormetoprim were carried out in our laboratory by previously described tissue residue procedures sensitive to 0.1 p.p.m. (Fellig and Westheimer, 1968; Fellig et al., 1971). Arsenic was determined by an outside contract laboratory (Hazleton Laboratories, Inc., Falls Church, Virginia), using a standard method (Food Chemicals Codex, 1963).STUDY 1It was the purpose of this study to determine Rofenaid® tissue…