Antibiotic resistance and virulence of faecal enterococci isolated from food-producing animals in Tunisia

Antimicrobial agents exert a selection pressure not only on pathogenic, but also on commensal bacteria of the intestinal tract of humans and animals. The aim of this work was to determine the occurrence of different enterococcal species and to analyse the prevalence of antimicrobial resistance and the mechanisms implicated, as well as the genetic diversity in enterococci recovered from faecal samples of food-producing animals (poultry, beef and sheep) in Tunisia. Antimicrobial resistance and the mechanisms implicated were studied in 87 enterococci recovered from 96 faecal samples from animals of Tunisian farms. Enterococcus faecium was the most prevalent species detected (46 %), followed by E. hirae (33.5 %). High percentages of resistance to erythromycin and tetracycline were found among our isolates, and lower percentages to aminoglycosides and ciprofloxacin were identified. Most of the tetracycline-resistant isolates carried the tet(M) and/or tet(L) genes. The erm(B) gene was detected in all erythromycin-resistant isolates. The ant(6)-Ia, aph(3)-Ia and aac(6)-aph(2) genes were detected in nine aminoglycoside-resistant isolates. Of our isolates, 11.5 % carried the gelE gene and exhibited gelatinase acitivity. The esp gene was detected in 10 % of our isolates and the hyl gene was not present in any isolate. The predominant species (E. faecium and E. hirae) showed a high genetic diversity by repetitive extragenic palindromic (REP)-PCR. Food animals might play a role in the spread through the food chain of enterococci with virulence and resistance traits to humans. © 2014 Springer-Verlag Berlin Heidelberg and the University of Milan

Fluid flow phenomena in metals processing operations: numerical description of the fluid flow field by an impinging gas jet on a liquid surface

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Numerical study of sediment transport in turbulent two-phase flows around an obstacle

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Effect of nozzle-to-plate spacing on the development of a plane jet impinging on a heated plate

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Numerical and experimental study of a jet in a crossflow for different velocity ratio

International audienceThis paper deals with a flow generated by the interaction between a circular jet and a crossflow for different velocity ratios (R = v(0)/u(infinity)). This particular side of this study is of extremely high interest as it allows a better understanding of the mixing process of different interacting flows. This work presents experimental results obtained by means of the particle image velocimetry technique to track the evolution of the jet among the environment flow. Results showed the dependence of the emerging jet flow structure on its ratio velocity. A three-dimensional numerical model with a second-order turbulent model (RSM) and a non-uniform grid system is used to examine the behavior of the emerging jet in the crossflow. The comparison of the numerical and experimental results gives satisfactory agreement

Echographic factors of atrial arrhythmia in patients with arrythmogenic right ventricular dysplasia

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The effect of coflows on a turbulent jet impacting on a plate

International audienceThe study examines the dynamic and the turbulent behavior of a plane jet impinging normally on a flat target plate in a flow at rest or in a coflow stream. First, numerical and experimental investigations of the characteristics of a turbulent plane jet impinging on a flat surface in still air are depicted. The measurements are conducted using Particle Image Velocimetry (PIV). A comparison has been carried out between numerical results of three turbulence closure models (k-epsilon standard model, RNG k-epsilon model and a second-order model RSM) and experimental data. It has been found that the second order turbulence model (RSM) reasonably predicts the mean flow properties of the flow field. Next, a numerical study of the flow field of an impinging jet in a coflow stream is conducted. The study of the jet in a no-directed coflow stream shows the presence of a phenomenon of recirculation near the flat plate. In addition, the study focuses on the influence of the coflow velocity ratio on the behavior of an impinging jet and the influence of the directed co-flow on various physical parameters such as the mean and the turbulent quantities. The results clearly show that the coflow stream imposed noticeable restrictions on the spreading of the impinging jet and decreases considerably the entrainment of air jet. (C) 2016 Elsevier Inc. All rights reserved

Parametric analysis of a round jet impingement on a heated plate

International audienceIn this study, the flow and heat transfer characteristics of a round air jet have been experimentally investigated in details using two techniques: Particle Image Velocimetry (PIV) and the Laser Doppler Velocimetry (LDV). The measurement of the mean velocity components are compared, and agree well with the experimental data obtained by Baydar (1999). The distributions of the velocity, turbulence quantities and temperature profiles are analyzed in the main characteristic regions of the jet where the heat transfer occurs. Parametric variations were conducted to produce information about the influences of the Reynolds number (Re = 1000, 2000, 3000), the distance between the pipe exit and the flat impingement plate (hid = 1 and hid = 2) and the temperature of the plane (T-p = 22 degrees C, 54 degrees C, 96 degrees C) on the impinging jet flow field. (C) 2015 Elsevier Inc. All rights reserved

A Tunisian patient with CLCN2‐related leukoencephalopathy

Abstract CLCN2‐related leukoencephalopathy (CC2L OMIM#: 615651) is a recently identified rare disorder. It is caused by autosomal recessive mutations in the CLCN2 gene and leads to the dysfunction of its encoded CLC‐2 chloride channel protein with characteristic brain MRI features of leukoencephalopathy. We report the first Tunisian patient with clinical features of ClCN‐2‐related leukoencephalopathy. A 54‐year‐old female with a family history of leukemia, male infertility, motor disability, and headaches who initially presented with a tension‐type headache and normal physical examination. At the follow‐up, she developed mild gait ataxia and psycho‐cognitive disturbances. A previously reported homozygous NM_004366.6(CLCN2):c.1709G > A (p.Trp570Ter) stop gained mutation was identified. This report expands the knowledge related to CC2L and highlights the clinical features in affected individuals of African descent