This study investigated the prevalence of oqxA and oqxB genes and their effective roles in the development of multidrug resistant (MDR) phenotype among clinical isolates of Klebsiella pneumoniae. Out of 150 clinical samples, 50 (33%) isolates were recognized as K. pneumoniae according to the morphological and biochemical properties. The minimum inhibitory concentrations (MICs) assay revealed that the resistance values of the isolates were 43 (86%) against ceftriaxone (4- ≥64 µg/ml), 42 (84%) against ceftazidime (16- ≥64 µg/ml), 41 (82%) against cefepime (≥16 µg/ml), 21 (42%) against ertapenem (≥8 µg/ml), 18 (36%) against imipenem (4- ≥16 µg/ml), 15 (30%) against ciprofloxacin (≥4 µg/ml), 11 (22%) against levofloxacin (≥8 µg/ml), 45 (90%) against nitrofurantoin (128- ≥512 µg/ml), 36 (72%) against trimethoprime-sulfamethoxazole (≥320 µg/ml), and 4 (8%) against tigecycline (≥8 µg/ml). Genotype detection revealed that oqxA was found in 48 (96%) of K. pneumoniae isolates, whereas oqxB was found in 6 (12%) isolates. The MDR phenotype was observed in 40 (80%) isolates, of which 38 (95%) were harbored oqxA and/or oqxB genes. DNA sequencing of oqxA revealed the presence of three silent mutations. The phylogenetic tree of oqxA variants showed a significant deviation of these variants from K. pneumoniae species. The high prevalence of oqxA among K. pneumoniae isolates may contribute to the reduction of their susceptibility to multiple antimicrobial agents.
The adsorption ability of Iraqi initiated calcined granulated montmorillonite to adsorb Symmetrical Schiff Base Ligand 4,4’-[hydrazine-1, 2-diylidenebis (methan-1-yl-1-ylidene)) bis (2-methoxyphenol)] derived from condensation reaction of hydrazine hydrate and 4-hydroxy-3-methoxybenzaldehyde, from aqueous solutions has been investigated through columnar method.The ligand (H2L) adsorption found to be dependent on adsorbent dosage, initial concentration and contact time.All columnar experiments were carried out at three different pH values (5.5, 7and 8) using buffer solutions at flow rate of (3 drops/ min.),at room temperature (25±2)°C. The experimental isotherm data were analyzed using Langmuir, Freundlich and Temkin equations. The monol
... Show MoreTwo well-known fluorescent molecules: fluorescein sodium salt (FSS) and 2,7-dichloro fluorescein (DCF) were tried to prove the efficiency, trustability and repeatability of ISNAG fluorimeter by using discrete and continuous flow injection analysis modes.A linear range of 0.002-1 mmol/L for FSS and 0.003-0.7 mmol/L was for DCF, with LOD 0.0018 mmol/L and 0.002 mmol/L for FSS and DCF respectively, were obtained for discrete mode of analysis. While the continuous mode gave a linear range of 0.002-0.7 mmol/L and 0.003-0.5 mmol/L for FSS and DCF respectively, the LOD were 0.0016mmol/L and 0.0018 mmol/L for FSS and DCF respectively. The results were compared with classical method at variable λex for both fluorescent molecules at 95
... Show MoreIn this paper we will investigate some Heuristic methods to solve travelling salesman problem. The discussed methods are Minimizing Distance Method (MDM), Branch and Bound Method (BABM), Tree Type Heuristic Method (TTHM) and Greedy Method (GRM).
The weak points of MDM are manipulated in this paper. The Improved MDM (IMDM) gives better results than classical MDM, and other discussed methods, while the GRM gives best time for 5≤ n ≤500, where n is the number of visited cities.
The effect of thickness variation on some physical properties of hematite α-Fe2O3 thin films was investigated. An Fe2O3 bulk in the form of pellet was prepared by cold pressing of Fe2O3 powder with subsequent sintering at 800 . Thin films with various thicknesses were obtained on glass substrates by pulsed laser deposition technique. The films properties were characterized by XRD, and FT-IR. The deposited iron oxide thin films showed a single hematite phase with polycrystalline rhombohedral crystal structure .The thickness of films were estimated by using spectrometer to be (185-232) nm. Using Debye Scherrerś formula, the average grain size for the samples was found to be (18-32) nm. Atomic force microscopy indicated that the films had
... Show MoreThe reaction oisolated and characterized by elemental analysis (C,H,N) , 1H-NMR, mass spectra and Fourier transform (Ft-IR). The reaction of the (L-AZD) with: [VO(II), Cr(III), Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II)], has been investigated and was isolated as tri nuclear cluster and characterized by: Ft-IR, U. v- Visible, electrical conductivity, magnetic susceptibilities at 25 Co, atomic absorption and molar ratio. Spectroscopic evidence showed that the binding of metal ions were through azide and carbonyl moieties resulting in a six- coordinating metal ions in [Cr (III), Mn (II), Co (II) and Ni (II)]. The Vo (II), Cu (II), Zn (II), Cd (II) and Hg (II) were coordinated through azide group only forming square pyramidal
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