Of 150 Escherichia coli strains we cultured from specimens taken from cattle in Europe, 3 had elevated MICs against colistin. We assessed all 3 strains for the presence of the plasmid-mediated mcr-1 gene and identified 1 isolate as mcr-1–positive and co-resistant to β-lactam, florfenicol, and fluoroquinolone antimicrobial compounds.

The main focus of this study was to evaluate the antimicrobial susceptibility profiles of a selected number of human clinical isolates of Enterobacter aerogenes and explore the effects of selected chemosensitisers on the reversal of the resistant phenotype of these isolates.Methodology: This study design was accomplished by: (i) characterising several multidrug resistant (MDR) E. aerogenes clinical isolates; (ii) evaluating the contribution of target gene mutations to the resistance phenotype focusing on fluoroquinolones and chloramphenicol only; (iii) evaluating the contribution of membrane permeability and efflux to the MDR phenotype; (iv) assessing the combined action of selected antimicrobials and chemosensitisers (to identify combinations with synergistic effects and able to reduce the MIC); (v) understand how these combinations can modulate the permeability or efflux on these isolates. Results:Resistance to ciprofloxacin couldn't be totally reversed due to pre-existing mutations in target genes. Chloramphenicol susceptibility was efficiently restored by the addition of the selected chemosensitisers. From the modulation kinetics it was clear that phenothiazines were able to increase the accumulation of the Hoescht dye.Conclusions: Modulations of permeability and efflux in the presence of chemosensitisers help us to propose more appropriate chemotherapeutic combinations that can set the model to be used in the treatment of these and other MDR-infections.

BACKGROUND The emergence of monoclonal antibodies (mAbs) as new biopharmaceutical products requires the development of new purification methods that are not only effective but are able to reduce production costs. To address the problematic recovery of mAbs, gum arabic (GA) coated magnetic particles (MPs) were used for the purification of human antibodies from animal cells supernatants. RESULTS MPs were synthesized via co‐precipitation and exhibited a spherical‐like physical aspect, with an average hydrodynamic diameter of 473 nm and a zeta potential of –26 mV. The adsorption and elution of IgG on these adsorbents was thoroughly studied. Adsorption of human IgG was enhanced at pH 6, for which a qmax of 244 mg IgG g−1 MPs and Kd of 25 mg L−1 were obtained. Increasing salt concentrations at a basic pH (1 mol L−1 NaCl at pH 11) were found to improve the elution of bound IgG. The MPs were challenged with an artificial protein mixture containing human IgG, albumin, insulin and apo‐transferrin. An overall yield of 84% was achieved, retrieving 92% of bound IgG. CONCLUSIONS MPs were successfully used for the capture of monoclonal antibodies from two distinct mammalian cell cultures, a Chinese hamster ovary (CHO) and a hybridoma cell culture supernatants. The elution yields were high, ranging between 84% and 94%, with overall yields ranging from 72% to 88%. Final purities of 85% were reached for hybridoma cell supernatants. © 2014 Society of Chemical Industry

No abstract