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Analysis of residual levels of tetracyclines (TCs) in chicken meat was performed using a validated liquid chromatography coupled with a tandem mass spectrometry (LC-MS/MS) technique. Overall, the recoveries for TCs ranged from 56.9% to 101.2%, with standard deviations of 4.5-13.2%. Detection limits ranged from 7.9 to 14.6 µg kg⁻¹. In four of 60 samples, doxycycline (DXC) was determined in a range from 19.9 to 35.6 µg kg⁻¹; and in one sample tetracycline was detected at 17.2 µg kg⁻¹. Chlortetracycline (CTC) and oxytetracycline (OTC) were not detected in any of the tested samples. This study indicates that chicken meat sold in Bursa, Turkey, contained some residues of TCs. Therefore, stricter regulations for the use of antibiotics in the poultry industry and the monitoring of drug residues in chicken meat prior to marketing are needed. Finally, this method has been applied successfully for the confirmation of TCs in chicken meat.

The aim of this work is to identify the parameters influencing the flame behavior. Three different species (Pinus pinaster, Pinus halepensis and Erica arborea) involved in forest fire were crushed to decrease the geometric effects on their combustion. The flaming behavior is studied experimentally from unsteady, axisymmetric, non-premixed laminar flames. The distribution of temperature, the flame geometry, the mass loss as well as the gases released by the fuels are measured. This study confirms the role of the mass burning rate of fuels on the flame dynamics. However, this work highlights a second influence for laminar flames: the composition of degradation gases. It affects the flame geometry and changes the combustion kinetics in the reaction zone.

In this study, the presence of genes responsible for the pathogenicity and antibiotic resistance profile of enterococci isolated from various foodstuffs of animal origin was investigated. The percentage prevalence of enterococci was 54.1% (203/375) and the average count was found to be 3.81 log cfu/ml-g. Species-specific primers revealed Enterococcus faecalis as the predominant species carrying one or more virulence-associated traits of efa, gelE, ace, esp and agg genetic markers. Only one E. faecium isolate (from milk) was positive for the esp gene. Regarding antibiotic resistance, the highest frequency of resistance was observed for tetracycline (21.7%), followed by quinupristin/dalfopristin (13.3%), ciprofloxacin (2.0%), penicillin (2.0%), linezolid (1.0%), ampicillin (1.0%), streptomycin (1.0%), and gentamicin (0.5%). Enterococcus faecalis showed a higher prevalence of antibiotic resistance than other enterococci. The percentage of multidrug resistance among the isolates was 3.4%. Twenty-nine E. faecalis isolates (26.6%) carrying one of the virulence-associated traits were at the same time resistant to at least one antibiotic. Our results show that foods of animal origin, including ready-to-eat products, may be reservoirs of antibiotic-resistant and potentially virulent enterococci.

In the period December 2008 to August 2009, 180 chicken meat samples, including 90 thigh and 90 breast meats in Bursa province, Turkey, were collected. The determination of chloramphenicol (CAP) residues in the samples was screened by ELISA, and a confirmatory method based on liquid chromatography coupled with tandem mass spectrometry was described and validated. The ELISA screening of the samples was performed after extraction with ethyl acetate and defatting with n-hexane. The results showed that 15 (8.3%) of the chicken meat samples were positive for CAP residues from 12.64 to 226.22 ng/kg, with a mean of 45.32 ng/kg. Confirmatory analysis of the results from ELISA was practiced after an extraction with ethyl acetate. Chromatographic seperation was carried out by using a Synergy MAX-RP 80A column and the mixture of acetic acid-water as a mobile phase. The mass spectral acquisition was done in the negative-ion mode applying selective reaction monitoring with the following ions (mass-to-charge ratio, m/z): m/z 321 → 152 and m/z 321 → 194 for CAP. By liquid chromatography-tandem mass spectrometry, CAP was confirmed in 2 of 15 ELISA positive samples and 1 of 45 negative samples, with concentration levels that varied between 150 and 361 ng/kg. The method was validated according to Commission Decision 2002/657/EC. The calibration curves were linear with a typical r(2) value of 0.9966. The recovery values ranged from 97.3 to 104.0% and within-laboratory repeatability was lower than 5%. The decision limit was 0.10 µg/kg and detection capability was 0.11 µg/kg. To evaluate the presence of CAP residues, this method was successfully implemented in chicken meat samples.