Treatment of pigs with enrofloxacin via different oral dosage forms – environmental contaminations and resistance development of Escherichia coli

BackgroundAntibacterial agents play important roles in the treatment of bacterial infections. However, the development of antimicrobial resistance (AMR) and carry-over of substances into the environment are several problems arising during oral treatment of bacterial infections. We assessed AMR development in commensal Escherichia coli (E. coli) in enrofloxacin treated and untreated animals. In addition, we examined fluoroquinolone in the plasma and urine of treated and untreated animals, and in sedimentation dust and aerosol.MethodsIn each trial, six pigs were treated with enrofloxacin via powder, granulate or pellet forms in two time periods (days 1–5 and 22–26). Four pigs served as untreated controls. The minimum inhibitory concentration (MIC) was determined to evaluate AMR development. Analysis of enro- and ciprofloxacin was performed with high performance liquid chromatography.ResultsNon-wildtype E. coli (MIC > 0.125 µg/mL) was detected in the pellet treated group after the first treatment period, whereas in the other groups, non-wildtype isolates were found after the second treatment period. E. coli with MIC > 4 µg/mL was found in only the pellet trial. Untreated animals showed similar susceptibility shifts several days later. Bioavailability differed among the treatment forms (granulate > pellet > powder). Enro- and ciprofloxacin were detected in aerosols and sedimentation dust (granulate, powder > pellet).ConclusionsThis study indicates that the kind of the oral dosage form of antibiotics affects environmental contamination and AMR development in commensal E. coli in treated and untreated pigs.     

<Emphasis Type="Italic">Amaranthus leaf mottle virus</Emphasis>: 3′-end RNA sequence proves classification as distinct virus and reveals affinities within the genus <Emphasis Type="Italic">Potyvirus</Emphasis>

Amaranthus leaf mottle virus (AmLMV) was classified as a member of the genus Potyvirus on the basis of its particle morphology, serology, and biological properties (Casetta et al., 1986). Based on these properties, an Amaranthus viridis-infecting virus isolated in Spain, causing mottle and leaf blistering as well as reduced growth has been identified as AmLMV. The 3′ terminal genomic region of this and a reference isolate from Italy has been sequenced and reveals a 95% nucleotide identity between the two isolates. The sequenced part comprises the coat protein with 281 amino acids and 315 nucleotides of the 3′ untranslated region (UTR) preceding a polyadenylated tail. Pairwise comparisons and phylogenetic analysis of the nucleotide and deduced amino acid sequences of the CP and 3′ UTR of the cloned cDNAs with those of other potyviruses shows that AmLMV is a distinct potyvirus closely related to Potato virus Y.     

Directional dynamics in the photodissociation of oriented molecules

We observed directional dynamics in the photodissociation of an oriented molecule. When a laser dissociated hexapole-oriented carbonyl sulfide molecules, the three-dimensional recoil of carbon monoxide fragments, which we measured with ion imaging, was strongly asymmetric. We obtained a microscopic view of molecular bond breaking that revealed both the sign and the magnitude of the deflection angle of the fragment in the molecular frame. This experimental approach can be applied to study and control the three-dimensional dynamics of photoinitiated reactions of fixed molecules or molecules oriented by emerging techniques.     

Effect of Al hydroxide polymers on cation exchange of montmorillonite

Al hydroxide polymers (AlHO) can significantly influence the cation exchange behaviour of clays. We have determined the effect of synthesized AlHO on Ca–Na, Zn–Na and Pb–Na exchange for a series of exchanger compositions and two Al loadings at pH 6.0 and an ionic strength of 0.01  m . The preference for Ca on the siloxane surface of the clay–AlHO system (CAlHO) was greater than for the pure clay, and the average K _V (Vanselow selectivity coefficient) was determined to be 2.16 and 1.24, respectively. The selectivity coefficients for the exchange reactions Zn–Na and Pb–Na were not directly determined in CAlHO systems, because heavy-metal ions bind as well to the clay surface as to the AlHO over a wide range of pH. We have estimated the effect of the presence of AlHO on the selectivity coefficients of Zn–Na and Pb–Na exchange by extrapolation of the experimental results of Ca–Na, Zn–Na and Pb–Na exchange for pure clay and Ca–Na exchange for CAlHO. The average K _V was increased by the presence of the AlHO from 1.23 to 2.16 for Zn–Na exchange and from 1.59 to 2.77 for Pb–Na exchange. The increase in the preference for the divalent cations is probably caused by parallel alignment of clay platelets by sorption of AlHO. Increasing the amount of AlHO did not change the selectivity for Ca–Na exchange, and probably the structure of the system or the arrangement of the clay platelets and AlHO particles was not substantially changed. This was supported by the linear reduction of the cation exchange capacity with amount of AlHO present at pH 6.6. It seems likely that the selectivity coefficients for Ca–Na, Zn–Na and Pb–Na exchange that we found apply in naturally occurring montmorillonite–AlHO systems.     

The significance of elbow dysplasia (ED) for breeding in Bernese Mountain Dogs in Germany

Results from the elbow dysplasia screening program in Bernese Mountain Dogs of Germany were analysed in respect to its relevance for genetic evaluation and breeding. In total 2677 gradings were used. The grading was performed radiographically according to the recommendations of the International Elbow Working Group (IEWG). 75.8% of the dogs were free from visible dysplastic signs, 10.8%, 6.8% and 5.5% were classified to be of Grade 1, 2 and 3, respectively. 1.1% were classified as a borderline case between ED-free and Grade 1. A slight reduction of ED could be observed over years. Males had a 3.1 higher rate of dysplasia than females. Treating ED as a numerical trait, coded proportional to the severity of clinical relevant signs, gave a heritability estimation of 0.188 and a maternal effect of 0.07. From different mating combinations it was found, that ED average was higher in the progeny if one mate was affected but there was no increase in the prevalence with increasing grade of ED in the affected mates. About 10% more affected dogs could be observed, if one mate is affected. Heritability for dichotomic coding the trait was found to be 0.20. From these results can be suggested, that the differentiation in various grades of ED to describe the clinical relevance for the specific dog is helpfull, however, from a breeders point of view, dogs with ED should be treated equally for genetic evaluation.     

Co‐infection with Cucumber vein yellowing virus and Cucurbit yellow stunting disorder virus leading to synergism in cucumber

Symptom expression and levels of the ipomovirus Cucumber vein yellowing virus (CVYV) and the crinivirus Cucurbit yellow stunting disorder virus (CYSDV) were compared in greenhouse cucumbers in single and mixed infections. Results were contrasted with those obtained for plants infected with the potyvirus Zucchini yellow mosaic virus (ZYMV) in single and in mixed infections with either CVYV or CYSDV. Cucumber showed leaf symptoms of each co‐infecting virus, except for the combination of CYSDV with ZYMV, where the typical CYSDV‐like symptoms of interveinal leaf yellowing were inconspicuous or absent. The progression of CVYV as quantified by real‐time RT‐PCR was similar in plants with single infections and in mixed infection with CYSDV between 15 and 60 days post‐inoculation (dpi). However, CYSDV was detected at significantly enhanced levels in plants when co‐infected with CVYV but not when co‐infected with ZYMV. In the latter case, ZYMV levels were reduced when compared with single infections. During mixed infections of ZYMV and CVYV, the titre levels of the ipomovirus were significantly lower when compared with single infections. Cucumber had reduced plant height, internode length, dry weight and fruit yield, positively correlated with the titre levels of CVYV and not of CYSDV during mixed infections. It is concluded that co‐infections with CVYV enhance the titre of CYSDV, which could have epidemiological significance.     

Invloed der bemesting op de gezondheid van de aardappel

Met een inleiding door Prof. Dr. H. M. Quanjer.