Caution at choosing a particular colony-forming unit from faecal Escherichia coli: it may not represent the sample profile.

Data about phylogenetic classification of Escherichia coli colonizing calves, lambs and foals are routinely neglected and restricted to outdated methodologies, even in the context of antimicrobial susceptibility (AS) testing. Thus, the aim of this study was to determine the phylogenetic diversity and the AS profile of E. coli colony-forming units (CFUs) from faecal samples of healthy animals. Five CFUs of E. coli were randomly selected from each faecal culture of calves (n = 13), foals (n = 13) and lambs (n = 13), totalizing 195 CFUs phylo-typed by quadruplex PCR. The AS profile of five CFUs from 15 samples (five from each animal species; n = 75 isolates) against nine drugs was determined by agar diffusion test. We found E. coli belonging to all phylo-groups already described, except D group, with the predominance of B1 (65% CFUs; 126/195) in the three-animal species sampled. Most faecal samples of calves (77%; 10/13) and foals (69%; 9/13) harboured both pathogenic and nonpathogenic E. coli. All faecal samples showed CFUs with diverse AS profile, highlighting the ineffectiveness of tetracycline, sulphonamide and ampicillin. As a key point, our data reinforce the importance to select at least four E. coli CFUs for AS testing. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides relevant data about the high phylogenetic and antimicrobial susceptibility diversity observed in Escherichia coli colony-forming units (CFUs) from a bacteriological culture of faeces from healthy calves, foals and lambs. The selection pressure exerted by the herd treatment may directly impact the intestinal microflora of animals that have never been treated. Finally, we emphasize the importance of Clinical Laboratory Standards Institute guidelines and we recommended to analyse at least four E. coli CFUs to determine, in particular, the antimicrobial susceptibility profile of faecal isolates, independent of the animal's health status.

Phase 3 trial of three thalidomide-containing regimens in patients with newly diagnosed multiple myeloma not transplant-eligible.

The introduction of agents such as thalidomide, lenalidomide, and bortezomib has changed the management of patients with multiple myeloma who are not eligible for autologous transplantation, many of whom are elderly. We sought to compare three thalidomide-based oral regimens among such patients in Latin America. We randomized patients with newly diagnosed multiple myeloma with measurable disease to one of the following regimens: melphalan, prednisone, and thalidomide (MPT); cyclophosphamide, thalidomide, and dexamethasone (CTD); and thalidomide and dexamethasone (TD). The TD arm was closed prematurely and was analyzed only descriptively. The primary endpoint was the overall response rate (ORR), whereas progression-free survival (PFS) and overall survival (OS) were secondary endpoints. The accrual rate was slower than expected, and the study was terminated after 82 patients had been randomized. The ORRs were 67.9 % with MPT, 89.7 % with CTD, and 68.7 % with TD (p = 0.056 for the comparison between MPT and CTD). The median PFS was 24.1 months for MPT, 25.9 months for CTD, and 21.5 months for TD. There were no statistically significant differences in PFS or OS between MPT and CTD. In an unplanned logistic regression analysis, ORR was significantly associated with treatment with CTD (p = 0.046) and with performance status of 0 or 1 (p = 0.035). Based on the current results, no definitive recommendations can be made regarding the comparative merit of the regimens tested. Nevertheless and until the results of further studies become available, we recommend either CTD or MPT as suitable frontline regimens for patients with multiple myeloma who are not candidates to transplantation in settings where lenalidomide and bortezomib are not available.