High Prevalence of blaNDM Among Carbapenem Non‑Susceptible Klebsiella pneumoniae in a Tunisian Hospital First Report of blaNDM‑9, blaKPC‑20, and blaKPC‑26 Genes

peer reviewedFifty-four carbapenem non-susceptible Klebsiella pneumoniae (CNSKP) isolates were collected from a Tunisian hospital over a period of 13 consecutive months. Carbapenemase production and the prevalence of carbapenemase-encoding genes were investigated using combined-disk test (CDT), modified Carba NP (mCarba NP) test, and UV-spectrophotometry method complemented by PCR experiments and sequencing. Carbapenemase production was detected by the mCarba NP test and CDT in 92.59% and 96.29% of the 54 CNSKP isolates, respectively; while imipenem hydrolysis was detected using UV-spectrophotometry in the crude extracts of 44 isolates. blaNDM, blaOXA-48-like , and blaKPC carbapenemase-encoding genes were found in 48, 31, and 22 isolates, respectively. Remarkably, blaNDM-9, blaKPC-20 , and blaKPC-26 genes were reported. The co-occurrence of carbapenemase-encoding genes in a single isolate was detected in 62.96% of the isolates. The analysis of clonal relationships between the isolates by pulsed field gel electrophoresis revealed that the majority of them were geneti-cally unrelated. Our investigation provides molecular data on enzymatic mechanism of carbapenem non-susceptibility among 54 CNSKP showing the dominance of blaNDM, and comprises the first identification of blaNDM-9, blaKPC-20 , and blaKPC-26 genes in a Tunisia hospital

Étude cinétique et thermodynamique de l’adsorption d’un metal lourd (Fer (III)) sur un déchet de clou de girofle en milieu aqueux

L’utilisation d’adsorbants respectueux de l’environnement a été étudiée comme une source alternative de charbon actif pour l’élimination des métaux lourds dans les eaux usées. Cette étude examine l’utilisation de biosorbants préparés à partir de clou de girofle après extraction de l’eugénol pour l’élimination de Fe (III) dans une solution aqueuse. L’effet de divers paramètres expérimentaux tels que le temps de contact, la température, la concentration initiale de Fer (III) et la dose d’adsorbant ont été étudiés. Les résultats ont montré qu’au fur et à mesure que la quantité d’adsorbant augmente, l’adsorption de Fe (III) diminue alors qu’elle augmente avec l’augmentation de la concentration initiale du métal. La cinétique d’adsorption suit le modèle de pseudo-second ordre, (R2 > 0,99). Les paramètres thermodynamiques ont été calculés. Ils ont prouvé que le processus d’adsorption est spontané et exothermique

Etude Cinétique et thermodynamique de l’adsorption de méthyle orange sur deux biomasses aquatiques : Crabes et Coquilles.

Kinetic and thermodynamic study of adsorption of methyl orange on two aquatic biomass: Crabs and Shells. Description of the subject. This article examines the use of biosorbents prepared from two aquatic animal biomass for purifying water contaminated with methyl orange. Objectives. Contaminated water with methyl orange is taken as a sample for studying the effect of various experimental parameters such as contact time, temperature, the initial concentration of dye and the dose of adsorbent.Results. The results show that as the amount of adsorbent increases, the adsorption of methyl orange decreases while it increases with increasing the concentration of the initial dye. The adsorption kinetics follows the pseudo-second-order model (R2> 0.99). The thermodynamic parameters were calculated. They proved that the adsorption process is spontaneous and endothermic. Conclusions.Biomass made from two aquatic animal biomass can be used as adsorbents for the removal of methyl orange and opens prospects for their recovery with other pollutants

Corrosion inhibition of carbon steel A 283 C using the acetylsalicylic acid

The corrosion inhibition characteristics of acetylsalicylic acid on carbon steel has been studied using electrochemical measurements. Results showed that: The inhibition efficiency values give maximum inhibition at the concentration of 300 ppm and decrease back. They decreased with increasing temperature. Polarization studies showed that this compound is an anodic inhibitor for carbon steel in decanted water from a tank bottom hydrocarbon storage (East Region Transport: Skikda Algeria ). The inhibition occurs through adsorption of the inhibitor molecule on the metal surface. The adsorption of the inhibitor on the metal surface is found to obey Langmuir’s adsorption isotherm. The values of thermodynamic parameters, such as Kads, G°ads, H°ads and S°ads are calculated

Synthesis of copper-based catalyst supported on bentonite for the removal of water pollutants

Objectives. The objective is to characterize the catalytic efficiency in the oxidation reaction of two BM and MO dyes using H2O2 alone and / Sun. Methodes. In this work, supported catalysts (Cu / bentonite) to different metal content (1%, 2.5%, 5%) were prepared in order to study their catalytic behavior in the photodegradation reaction of organic pollutants by the diffusional impregnation method and characterized by IR spectroscopy by Fourier transform. Solutions loaded by orange and methylen methyl blue were taken as samples to investigate the effect of the contents in the degradation kinetics. Results. The results show that the degradation of BM is considerably effective. The effect of sunlight on the mineralization of the MO is very efficient compared to that in the presence of H2O2 alone Conclusions. Biomass made from two aquatic animal biomass can be used as adsorbents for the removal of methyl orange and opens prospects for their recovery with other pollutant