Assessment of antibacterial drug residues in milk for consumption in Kosovo.

The objective of this study was to assess the occurrence of drug residues in the raw milk collected from individual farms and milk collection points during 2009-2010 in six different major regions of Kosovo (Prishtinë, Gjilan, Mitrovicë, Pejë, Gjakovë, Prizren). In the present study, a total of 1734 raw milk samples were collected, and qualitatively screened with two different tests, the Delvotest SP assay and an enzyme-linked receptor-binding assay (SNAP). Overall, 106 (6.11%) out of 1734 samples examined with Delvotest SP contained possible drug residues (5.12% and 7.51% of samples from 2009 and 2010, respectively). All suspect samples were further analyzed by three distinct enzyme-linked receptor-binding assays specific for ß-lactams (new ß-lactam test), tetracyclines (SNAP tetracycline test), and sulfonamides (SNAP sulfamethazine test). Only the new SNAP ß-lactam test detected residues in 40 out of 52 samples in 2009 and 54 out of 54 suspect samples in 2010. A confirmatory method based on liquid chromatography-tandem mass spectrometry was used to confirm the presence of ß-lactam drug residues in samples detected by the enzyme-linked receptor-binding assay. Amoxicillin, penicillin G, and cloxacillin were the most frequently detected residues and were in a concentration range between 2.1 µg/kg and 1973 µg/kg. Seventeen of the positive samples exceeded the maximum residue levels for one or more ß-lactam drug. The highest number of positive milk samples came from the Pejë Region (58.8%) and Gjakovë Region (23.5%), and the lowest number of positive samples originated from Gjilan (5.88%), with no positive samples detected in two regions, Mitrovicë and Prizren.

In vivo studies to highlight possible illegal treatments of rabbits with carbadox and olaquindox.

For the treatment of rabbit dysentery and bacterial enteritis, veterinary practitioners often adopt veterinary medicinal products authorised for other food-producing species, but in some cases non-authorised drugs frequently used in the past, such as carbadox and olaquindox, might be illegally adopted. To verify the carbadox and olaquindox distribution and persistence in rabbit tissues, two independent in vivo studies were carried out. In the first study, 24 healthy rabbits received water medicated with carbadox at 100 mg l(-1) over a period 28 days, whereas in the second one, 24 healthy rabbits were administered water containing olaquindox at 100 mg l(-1). In each study rabbits were randomly assigned to four groups to be sacrificed respectively at 0, 5, 10 and 20 days from treatment withdrawal, for depletion studies. A control group of six animals was adopted for control and as a reservoir of blank tissues. Muscle and liver samples collected from each treated animal were stored at -20°C pending the analysis. Sensitive and robust liquid chromatography-tandem mass spectrometry analytical methods were set up for the parent compounds and their main metabolites quinoxaline-2-carboxylic acid, desoxycarbadox and 3-methylquinoxaline-2-carboxylic acid to verify their residual. Data collected demonstrate that the combination of liver as target matrix, quinoxaline-2-carboxylic acid and 3-methylquinoxaline-2-carboxylic acid as marker residue and enzymatic digestion is strategic to evidence carbadox and/or olaquindox illegal treatments in rabbits, even 20 days after treatment withdrawal at concentration levels higher than 0.5 µg kg(-1). This findings suggests that liver should be proposed as target matrix for official control in national monitoring plan.

Multi-residue determination of eleven anticoagulant rodenticides by high-performance liquid chromatography with diode array/fluorimetric detection: investigation of suspected animal poisoning in the period 2012-2013 in north-eastern Italy.

Misuse or deliberate abuse of anticoagulant rodenticides (AR) may often result in incidental or malicious non-target animal poisoning. This study presents preliminary results of the analysis of 561 real suspected samples, ranging from baits to livers and stomach contents, collected at the Istituto Zooprofilattico Sperimentale delle Venezie (official referral laboratory for the regions of north-eastern Italy), in the period 2012-2013. Samples were analyzed by a method based on a combination of liquid chromatography with diode array/fluorescence detection (HPLC-DAD/F) able to identify 11 different AR (brodifacoum, bromadiolone, chloropahacinone, coumachlor, coumafuryl, coumatetralyl, difenacoum, diphacinone, flocoumafen, pindone, warfarin).