Objective: The present work was undertaken to investigate the impact of sub inhibitory concentration of gentamicin on hla gene expression in methicillin resistant Staphylococcus aureus isolates. Methods: The bacterial isolates used in this study represent 33 MRSA strains, previously isolated form patients visiting several hospitals in Baghdad. Gentamicin, vancomycin, and oxacillin MIC were determined using broth dilution method. Microtiter plate method was adopted to investigate the biofilm forming capacity. Alpha hemolysin was detected by culturing MRSA isolates on rabbit blood agar. Furthermore, hla gene was detected in MRSA isolates using conventional PCR technique; while, qRT-PCR method was performed to assay the hla expression in planktonic and biofilm cells in presence and absence of gentamicin. Results: the present results demonstrated that 12 (36.36%) isolates were gentamicin-resistant; whereas, all isolates were resistant to oxacillin and sensitive to vancomycin. Out of 33 MRSA, 3, 23, and 7 isolates formed a weak, moderate, and strong biofilm, respectively. Phenotypically, 30 isolates produced alpha hemolysin on rabbit blood agar plates; nevertheless, hla gene was located in 29 isolates. Of considerable interest, the addition of gentamicin significantly (P < 0.05) reduced the hemolysis activity; while, insignificant fold change (less than two) of hla gene was observed in all tested isolates in the presence of sub MIC of gentamicin (16 µg/ml). Conclusion: gentamicin upregulated the hla gene expression in biofilm cells; hitherto, this increment was isolate specific.
Summary The aim of this study is the evaluation the resistance of S. marcescence obtained from soil and water to metals chlorides (Zn+2, Hg+2, Fe+2, Al+3, and Pb+2). Four isolates, identified as Serratia marcescence and S. marcescena (S4) were selected for this study according to their resistance to five heavy metals. The ability of S. marcescena (S4) to grow in different concentrations of metals chloride (200-1200 µg/ml) was tested, the highest concentration that S. marcescence (S4) tolerate was 1000 µg/ml for Zn+2, Hg+2, Fe+2, AL+3, pb+2 and 300 µg/ml for Hg+2 through 24 hrs incubation at 37 Co. The effects of temperature and pH on bacteria growth during 72 hrs were also studied. S. marcescence (S4) was affected by ZnCl2, PbCl2, FeC12
... Show MoreIn this study, six square reinforced concrete flat plates with dimensions of (1500×1500×100) mm were tested under a concentrated load applied on a column located at the center of the slabs. One of these slabs was the control specimen, whereas, in the others, steel angles (steel collars) were used, fixed at the connection region between the slab and the column to investigate the effect of the presence of these collars on punching shear strength. Five thicknesses were used (4, 5, 6, 8, 10mm) with constant legs of angles (75×75) mm of the steel collars to investigate the effects on the punching shear resistance with respect to the control slab. The results of the experimental study show that the punching shear resistance increased b
... Show MorePseudomonas aeruginosa is a Gram-negative opportunistic pathogen and a model bacterium for studying virulence and bacterial social traits. While it can be isolated in low numbers from a wide variety of environments including soil and water, it can readily be found in almost any human/animal-impacted environment. It is a major cause of illness and death in humans with immunosuppressive and chronic conditions, and infections in these patients are difficult to treat due to a number of antibiotic resistance mechanisms and the organism’s propensity to form multicellular biofilms. One hundred twenty clinical samples and forty hospital environmental samples (various sources) were collected from hospitals in Baghdad city during the period from Oc
... Show MoreOne of the most important virulence factors in Pseudomonas aeruginosa is biofilm formation, as it works as a barrier for entering antibiotics into the bacterial cell. Different environmental and nutritional conditions were used to optimize biofilm formation using microtitre plate assay by P. aeruginosa. The low nutrient level of the medium represented by tryptic soy broth (TSB) was better in biofilm formation than the high nutrient level of the medium with Luria Broth (LB). The optimized condition for biofilm production at room temperature (25 °C) is better than at host temperature (37 °C). Moreover, the staining with 0.1% crystal violet and reading the biofilm with wavelength 360 are considered essential factors in
... Show MoreThirty one samples of gum swabs were collected from patients with tooth caries (5-30 years old) from the College of Science (Biology department )- University of Baghdad- Iraq for the period from October 2018 to December 2018. , The samples were transported, after inoculation in a transport media (nutrient broth), to the laboratory of the College of Science and then cultured on mannitol salt agar and blood agar). The isolates belonging to Staphylococcus spp. were identified by biochemical tests and Vitek 2 compact system, while the more antibiotic resistant isolates were identified by using Polymerase Chain Reaction(ï´¾PCR) and sequencing of 16SrRNA . The results showed sharp UV absorption peaks at 330 - 340nm and AFM at 5
... Show MoreA field study was conducted in Al-Khalis district, Diyala Governorate in 2019 to test the sensitivity of three varieties of pepper to the population density of the whitefly B. tabaci, Anaheim pepper, Aleppo and local variety, and the results showed that the Anaheim variety was the most infested with the whitefly density 4.08 whitefly/ leaf and then the local variety 2.7 whitefly/ leaf. The lowest population density was 1.25 whitefly/ leaf of Aleppo variety. Variety Aleppo also recorded the lowest percentage of whitefly infection B. tabaci of 39.22%, but not have significant differences in the percentage of whitefly infestation, as it reached 53.64% and 54.85% for the Anaheim and local varieties, respectively. The resistance of variety Alepp
... Show MoreColonialism radically transformed the cultures of colonized peoples, often rupturing Indigenous traditions and folklore. Whether creating colonial discourse, promoting orientalist literature, advocating western educational institutions, or through biased media representations, imperial powers systematically oppressed Indigenous and Native peoples. Subjugated communities, however, created, and still form postcolonial discourse from their knowledge systems. This discourse insists on Indigenous and Native culture as central to Indigenous and Native peoples identity. This study examines the postcolonial literature of three groups: Kānaka Maoli, African Americans, and Iraqis. The scope of this dissertation scrutinizes how folklore is employed
... Show MoreIn the present work, the feasibility of formation near-ideal ohmic behavior of In/n-Si contact efficiently by 300 s duration Nd:YAG pulsed laser processing has been recognized. Several laser pulses energy densities have been used, and the optimal energy density that gives best results is obtained. Topography of the irradiated region was extensively discussed and supported with micrographic illustrations to determine the surface condition that can play the important role in the ohmic contact quality. I-V characteristics in the forward and reverse bias and barrier height measurements have been studied for different irradiated samples to determine the laser energy density that gives best ohmic behavior. Comparing the current results with
... Show MoreAeromonas salmonicida is a fish pathogen and recognized to cause a variety of diseases in humans. There are a few information about A.salmonicida in Iraq and there is no any previous molecular study on it. During the period of December 2017 to May 2018; Sixteen isolates of the A. salmonicida were isolated and identified from 300 common carp (Cyprinus carpio) fishes stomach in aquarium of Erbil city/ Iraq by using manual, automated Vitek 2 compact system, and confirmed by PCR using gene TonB-dependent siderophore (364bp). Antimicrobial susceptibility was determined by disk diffusion method and the results found that all isolates 100% susceptible to imipenem, 100% resistant to nalidixic acid and variable resistan
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