Date Published: July 4, 2017
Publisher: Springer Berlin Heidelberg
Author(s): Larissa J. M. Jansen, Yvette J. C. Bolck, Janneau Rademaker, Tina Zuidema, Bjorn J. A. Berendsen.
In The Netherlands, all antibiotic treatments should be registered at the farm and in a central database. To enforce correct antibiotic use and registration, and to enforce prudent use of antibiotics, there is a need for methods that are able to detect antibiotic treatments. Ideally, such a method is able to detect antibiotic applications during the entire lifespan of an animal, including treatments administered during the first days of the animals’ lives. Monitoring tissue, as is common practice, only provides a limited window of opportunity, as residue levels in tissue soon drop below measurable quantities. The analysis of feathers proves to be a promising tool in this respect. Furthermore, a qualitative confirmatory method was developed for the analyses of six major groups of antibiotics in ground chicken feathers, aiming for a detection limit as low as reasonably possible. The method was validated according to Commission Decision 2002/657/EC. All compounds comply with the criteria and, as a matter of fact, 58% of the compounds could also be quantified according to regulations. Additionally, we demonstrated that a less laborious method, in which whole feathers were analyzed, proved successful in the detection of applied antibiotics. Most compounds could be detected at levels of 2 μg kg−1 or below with the exception of sulfachloropyridazine, tylosin, and tylvalosin. This demonstrates the effectiveness of feather analysis to detect antibiotic use to allow effective enforcement of antibiotic use and prevent the illegal, off-label, and nonregistered use of antibiotics.
The use of antibiotics is common practice to treat bacterial infections in the poultry sector. Antibiotic treatments, mostly orally administered through drinking water, should be carried out according to registration in order to prevent excessive antibiotic residues in food products meant for human consumption. Through Commission Regulation 96/23/EC , the European Union (EU) strictly monitors the presence of antibiotics in food of animal origin on the basis of EU/37/2010 , which establishes maximum residue limits (MRL) for matrices such as muscle, liver, and eggs.
The following antibiotics are referred to when different antibiotic classes are mentioned. Tetracyclines: chlortetracycline, oxytetracycline, tetracycline, and doxycycline. (Fluoro)quinolones: ciprofloxacin, danofloxacin, difloxacin, enrofloxacin, flumequin, marbofloxacin, nalidixic acid, norfloxacin, oxolic acid, and sarafloxacin. Macrolides: erythromycin, gamithromycin, josamycin, natamycin, neospiramycin, spiramycin, tildipirosin, tilmicosin, tulathromycin, tylosin, and tylvalosin. Lincosamides: lincomycin and pirlimycin. Pleuromutilins: tiamulin and valnemulin. Sulfonamides: dapsone, sulfacetamide, sulfachloropyridazine, sulfadiazine, sulfadimethoxine, sulfadimidine, sulfadoxine, sulfamerazine, sulfamethizole, sulfamethoxazole, sulfamethoxypyridazine, sulfamoxole, sulfaphenazole, sulfapyridine, sulfauqinoxaline, sulfathiazole, sulfisoxazole, and sulfamonomethoxine.
A qualitative confirmatory method was validated for the analysis of tetracyclines, sulfonamides, quinolones, macrolides, lincosamides, and pleuromutilines in chicken feathers. The method is applicable for qualitative confirmatory analysis for all compounds included and, additionally, 58% of the compounds can also be analyzed quantitatively showing trueness, repeatability, and within-laboratory reproducibility within the criteria established in CD 2002/657/EC. Additionally to analyzing the total residue concentration in feathers, we propose a more cost-efficient method for analysis of freely extractable residues only. With this approach, antibiotic use in the poultry sector can effectively be monitored; in many cases even if the animals were treated in the first week of their lives and samples were taken at slaughter.