Cross-contamination of feed with low concentrations of antimicrobials can occur at production, transport and/or farm level. Concerns are rising about possible effects of this contaminated feed on ...resistance selection in the intestinal microbiota. Therefore, an experiment with pigs was set up, in which intestinal and fecal concentrations of chlortetracycline (CTC), doxycycline (DOX) and sulfadiazine-trimethoprim (SDZ-TRIM) were determined after administration of feed containing a 3 % carry-over level of these antimicrobials.
The poor oral bioavailability of tetracyclines resulted in rather high concentrations in cecal and colonic content and feces at steady-state conditions. A mean concentration of 10 mg/kg CTC and 4 mg/kg DOX in the feces was reached, which is higher than concentrations that were shown to cause resistance selection. On the other hand, lower mean levels of SDZ (0.7 mg/kg) and TRIM (< limit of detection of 0.016 mg/kg) were found in the feces, corresponding with the high oral bioavailability of SDZ and TRIM in pigs.
The relation between the oral bioavailability and intestinal concentrations of the tested antimicrobials, may be of help in assessing the risks of cross-contaminated feed. However, future research is needed to confirm our results and to evaluate the effects of these detected concentrations on resistance selection in the intestinal microbiota of pigs.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Extracts of 31 leek cultivars were analyzed using liquid chromatography–tandem mass spectrometry (HPLC-MS/MS) to determine the distribution of the two most abundant S-alk(en)yl-l-cysteine sulfoxides ...(ACSOs) in leek, that is, isoalliin and methiin. The isoalliin concentration of the white shaft and green leaves of the 31 leek cultivars varied from 15 to 53 mg/g dry weight (dw) and from 9 to 45 mg/g dw, respectively, whereas the methiin concentration varied from 3 to 16 mg/g dw and from 1 to 10 mg/g dw, respectively. Leek cultivar and tissue had an effect on the ACSO amounts. Cultivars Artico and Apollo F1 rated highest for the mean isoalliin and methiin concentration, respectively. In general, the whole leek plant of the winter leek cultivars contained a significantly higher ACSO amount than the summer and autumn cultivars. To determine whether this difference was attributed to the cultivar background or time of harvest, ACSOs were also quantitated in nine leek hybrids at four different stages during the next growth season. The amounts of ACSO changed significantly during the growth season, indicating the importance of harvest at specific time moments, although there was still an effect of cultivar on the ACSO amounts.
A liquid chromatographic tandem mass spectrometric method for the determination of sulfa drugs in beeswax was developed. When performing residue control on beeswax intended for the fabrication of wax ...foundations, residues of sulfonamides were found. A migration test was set up to study whether sulfonamide-containing beeswax could lead to the contamination of honey. The higher the concentration of sulfamethazine doped in the wax, the higher was the concentration of sulfamethazine found in the honey. The maximum transfer was 15.6, 56.9, and 29.5% of the initial amount spiked in the wax foundation. In a second experiment, the percentage of sulfamethazine migrating from medicated winter feed to beeswax in relation to the concentration in the syrup and the contact time was studied. The maximum transfer of sulfamethazine from medicated sucrose syrup to beeswax was 3.1%.
A relatively fast, simple and very selective liquid chromatography–tandem mass spectrometry (LC–MS–MS) method for the detection of diclazuril, dimetridazole, halofuginone, nicarbazin and robenidine ...in eggs has been developed and validated. After a simple extraction with acetonitrile and evaporation of the organic phase, the extract was filtered and directly injected into the LC–MS–MS system on a C
18 column. The parent ions were selected for further fragmentation with argon. The developed method was validated according to Revision of Commission Decision 93/256/EC EC, Final version of Commission Decision laying down analytical methods to be used for detecting substances and residues thereof in live animals and animal products according to Council Directive 96/23/EC (Revision of Commission Decision 93/256/EC). The validation parameters linearity, precision, recovery, specificity, decision limit (CCα) and detection capability (CCβ) were determined. CCα varied from 0.75
μg
kg
−1 for dimetridazole to 6
μg
kg
−1 for diclazuril and CCβ varied from 0.9
μg
kg
−1 for dimetridazole up to 8.3
μg
kg
−1 for diclazuril.
A previous multidisciplinary study indicated that gliotoxin‐producing
Aspergillus fumigatus
Fresen. isolates from silage commodities mostly belonged to its variant
A. fumigatus var. ellipticus
Raper ...& Fennell. Sequence analysis revealed the presence of a single nucleotide polymorphism at five positions in a fragment of the
rodA
gene (coding for a hydrophobin
rodletA
protein) between
Aspergillus fumigatus var. fumigatus and
Aspergillus fumigatus var. ellipticus. A method was developed to distinguish these two types of isolates based on restriction analysis of this
rodA
gene fragment using the HinfI restriction enzyme. In addition, in silico analysis of 113
rodA
gene fragments retrieved from GenBank was performed and confirmed the suitability of this method. In conclusion, the method developed in this study allows easy distinction between
A. fumigatus var. fumigatus and its variant ellipticus. In combination with the earlier developed PCR‐restriction fragment length polymorphism method of Staab et al. (2009, J Clin Microbiol
47: 2079), this method is part of a sequencing‐independent identification scheme that allows for rapid distinction between similar species/variants within
Aspergillus section
Fumigati, specifically
A. fumigatus, A. fumigatus var. ellipticus, Aspergillus lentulus
Balajee & K.A. Marr,
Neosartorya pseudofischeri
S.W. Peterson and
Neosartorya udagawae
Y. Horie, Miyaji & Nishim.
Abstract
A previous multidisciplinary study indicated that gliotoxin-producing Aspergillus fumigatus Fresen. isolates from silage commodities mostly belonged to its variant A. fumigatus var. ...ellipticus Raper & Fennell. Sequence analysis revealed the presence of a single nucleotide polymorphism at five positions in a fragment of the rodA gene (coding for a hydrophobin rodletA protein) between Aspergillus fumigatus var. fumigatus and Aspergillus fumigatus var. ellipticus. A method was developed to distinguish these two types of isolates based on restriction analysis of this rodA gene fragment using the HinfI restriction enzyme. In addition, in silico analysis of 113 rodA gene fragments retrieved from GenBank was performed and confirmed the suitability of this method. In conclusion, the method developed in this study allows easy distinction between A. fumigatus var. fumigatus and its variant ellipticus. In combination with the earlier developed PCR-restriction fragment length polymorphism method of Staab et al. (2009, J Clin Microbiol47: 2079), this method is part of a sequencing-independent identification scheme that allows for rapid distinction between similar species/variants within Aspergillus section Fumigati, specifically A. fumigatus, A. fumigatus var. ellipticus, Aspergillus lentulus Balajee & K.A. Marr, Neosartorya pseudofischeri S.W. Peterson and Neosartorya udagawae Y. Horie, Miyaji & Nishim.
Regarding anti-infectious agents, no maximum residue limits are fixed for honey in the European legislation. Discussions are being conducted in order to set working limits at the European level; for ...example, for tetracyclines, 20 µg/kg was proposed. The Tetrasensor Honey test kit is a receptor-based assay using dipsticks for a rapid screening (30 min) of honey on the presence of tetracyclines. The test was validated according to Commission Decision 2002/657/EC. The test detects tetracycline, oxytetracycline, chlortetracycline, and doxycycline in honey in a specific and sensitive way. Depending on the type of tetracycline, detection capabilities (CCβ) between 6 and 12 µg/kg were obtained (4–7 µg/kg for dried dipsticks). The test is rugged and participation with the test in an international ring trial gave compliant results. It can be concluded that the Tetrasensor Honey test kit is a simple and reliable test that can even be used at the production site.
Abstract
The biochemicals utilized in the Charm MRL -Lactam test (8 min test) were applied to faster flowing lateral components to create a new 3 min, one-step -lactam test called Charm MRL-3 (Charm ...Sciences Inc., Lawrence, MA). This new test was validated at T&V-ILVO according to Commission Decision 2002/657/EC. The following analytical parameters were checked: test specificity, detection capability, and test robustness (impact of deviation of the test protocol, and impact of the milk composition, batch differences of reagents). Further, the suitability of the Charm MRL-3 to screen heat-treated milk or milk from animal species other than the cow was also tested. Finally, the test was integrated in the monitoring of dairy samples to check the occurrence of false-negative or false-positive results, and the test was also included in a national ring trial and an international proficiency study. The results proved that the Charm MRL-3 is a fast, simple, and reliable cows' milk test that can be used at the farm level in order to prevent tanker milk contamination, or at the entrance of the dairy plant to screen tanker milk for the presence of -lactam antibiotics.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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