Detection of ESBLs and carbapenemases among Enterobacteriaceae isolated from diabetic foot infections in Ouargla, Algeria.

INTRODUCTION: The emergence and rapid spread of Enterobacteriaceae carrying extended spectrum beta-lactamases (ESBLs) and carbapenemases represent a great threat to clinical treatment due to their multi-drug resistance. This study investigated ESBLs and carbapenemases encoding genes in Enterobacteriaceae collected from diabetic foot infections (DFIs) in Ouargla, southern Algeria. METHODOLOGY: A total of 70 Enterobacteriaceae strains were recovered from 76 patients with DFI between February 2017 and April 2018. Antimicrobial susceptibility testing was performed using the disc diffusion method, and the presence of bla genes was detected using polymerase chain reaction (PCR) and DNA sequencing. The genetic transfer of the plasmids was carried out by conjugation using the broth mating method. RESULTS: The most common isolate was Proteus mirabilis, followed by Escherichia coli, Morganella morganii and Klebsiella pneumoniae. The prevalence of ESBL and carbapenemase-producing Enterobacteriaceae was 11.42% and 2.85 % respectively. Plasmid-mediated AmpC was detected in 5.71% isolates. Conjugation experiments showed the transferability of blaCTX-M-2. CONCLUSIONS: Our findings support the view that various pathogens found in DFIs differ from one part of the country to another. This study reports the first description of metallo-ß-lactamase NDM-5 producing Klebsiella pneumoniae clinical isolate in Algeria.

Impact of the terahertz and optical pump penetration depths on generated strain waves temporal profiles in a V2O3 thin film.

Triggering new stable macroscopic orders in materials by ultrafast optical or terahertz pump pulses is a difficult challenge, complicated by the interplay between multiscale microscopic mechanisms, and macroscopic excitation profiles in samples. In particular, the differences between the two types of excitations are still unclear. In this article, we compare the optical response on acoustic timescale of a V2O3 Paramagnetic Metallic (PM) thin film excited by a terahertz (THz) pump or an optical pump, at room temperature. We show that the penetration depth of the deposited energy has a strong influence on the shape of the optical transmission signal, consistent with the modulation of permittivity by the superposition of depth-dependent static strain, and dynamical strain waves travelling back and forth in the sample layer. In particular, the temporal modulation of the optical transmission directly reflects the excitation profile as a function of depth, as well as the sign of the acoustic reflection coefficient between the film and the substrate. The acoustic mismatch between the V2O3 layer and the substrate was also measured. The raw data were interpreted with a one-dimensional analytical model, using three fitting parameters only. These results are discussed in the context of triggering phase transitions by ultrafast pump pulses. To the best of our knowledge, this is the first report of the modulation of the optical transmission of V2O3 with a THz pump within the acoustic timescale.