Introduction: The stringent response is a bacterial adaptation mechanism triggered by stress conditions, including nutrient limitation. This response helps bacteria survive under harsh conditions, such as those encountered during infection. A key feature of the stringent response is the synthesis of the alarmone (p)ppGpp, which influences various bacterial phenotypes. In several bacterial species, stringent response activation significantly affects biofilm formation and maintenance. Methods: Clinical specimens were collected from multiple hospitals in Baghdad, Iraq. Staphylococcus aureus was identified using conventional biochemical tests. The PCR technique was applied to detect mecA, icaA, and icaD genes, while the Vitek 2 compact system confirmed Methicillin sensitivity in mecA-negative isolates. Biofilm intensity of all S. aureus isolates was assessed under normal and starved conditions. Additionally, the gene expression levels of icaA and icaD were measured in five MRSA and five MSSA strains under both conditions. Results: The mecA, icaA, and icaD genes were detected in 94%, 96.3%, and 100% of S. aureus isolates, respectively. Biofilm production analysis showed that 24% of isolates were strong producers, 49% were moderate producers, and 9% were weak producers. Statistical analysis indicated that biofilm intensity significantly decreased under nutrient limitation (p < 0.0001) compared to normal conditions across all isolates. Furthermore, icaA and icaD genes were upregulated under stringent response conditions, regardless of Methicillin resistance status. Conclusion: The stringent response influences S. aureus biofilm formation, with biofilm intensity decreasing under nutrient-limited conditions. However, the upregulation of icaA and icaD genes suggests a regulatory role of the stringent response in biofilm-related gene expression. These findings highlight the potential impact of stress adaptation mechanisms on bacterial persistence and pathogenicity.
Polyaniline (PANI) and Ag/PANI nanocomposite thin films have prepared by microwave induced plasma. The Ag powder of average particle size of 50 nm, were used to prepare Ag/PANI nanocomposite thin films. The Ag/PANI nanocomposite thin films prepared by polymerization in plasma and characterized by UV-VIS, FTIR, AFM and SEM to study the effect of silver nanoparticles on the optical properties, morphology and structure of the thin films. The optical properties studies showed that the energy band gap of the Ag/PANI (5%wt silver) decreased from 3.6 to 3.2 eV, where the substrate location varied from 4.4 to 3.4 cm from the axis of the cylindrical plasma chamber. Also the optical energy gap decreased systematically from 3.3 to 3 eV with increas
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There are many animal models for polycystic ovary (PCO); using exogenous testosterone enanthate is one of the methods of induction of these models. However, induction of insulin resistance should also be studied in the modeling technics. Therefore, the present study aims to investigate the expression of insulin receptor substrate (Irs)-2 mRNA in the liver tissue of rat PCO model. Nineteen Wistar rats were divided into three groups; (1) PCO modeling group (N =7) received daily 1.0 mg/100g testosterone enanthate solved in olive oil along with free access dextrose water 5%, (2) vehicle group (N =6), which handled like the PCO group, but did not receive testosterone enanthate, (3) control group (N =6) with standard care. Al
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المستودع الرقمي العراقي. مركز المعلومات الرقمية التابع لمكتبة العتبة العباسية المقدسة
Back ground : The transforming growth factor beta (TGFB) signaling pathway is involved in many cellular processes in both the adult organism and the developing embryo including cell growth, cell differentiation, apoptosis. The interaction between implant material and surrounding tissues is believed to play a fundamental role in implant success and illustrates different expression of growth factors by different cells that involved in the formation of peri-implant tissue. The aim of this study was to localize expression of TGF B by newly formed bone tissue around surface-conditioned implants with placental collagen at different time intervals: 3 ,7,14,28, and 56 days . Materials and Methods: Commercially pure Titanium (CPTi) implants coated w
... Show MoreObjectives: With the advent of ongoing novel modalities toward the treatment of human epidermal growth factor receptor 2 (HER2)/NEU - positive malignancies, the serious side effects of chemoradiotherapy have been minimized. Hence, this study was conducted to identify the patterns of immunohistochemical expression of the promising therapeutic target (HER2/NEU) among Iraqi patients with medulloblastoma in an attempt to provide basic histological information’s that would help in future clinical researches.Materials and Methods: In this retrospective study, 42 formalin - fixed paraffin - embedded tissue blocks represent cases of surgically removed medulloblastomas were retrieved from the archived materials in a specialized surgical ho
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Background: Rituximab is a chimeric IgG1 kappa immunoglobulin that has been genetically modified to incorporate human constant region sequences together with murine light- and heavy-chain variable region sequences. People use it to treat rheumatoid arthritis and certain malignancies. Objective: The study aimed to assess the potential association between the serum levels of Factor I, CD59, interleukins (IL)-6, and interferon-gamma (IFN)-γ and the response to Rituximab treatment in Iraqi rheumatoid arthritis patients. Methods: A cross-sectional study was conducted at the rheumatology center at Baghdad Teaching Hospital. Ninety adult patients who have been diagnosed with rheumatoid arthritis and are receiving Rituximab intravenous i
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Item Difficulty and Item Discrimination Coefficient for School and College Ability Tests (SCAT) Advanced Form in Classical Test Theory (CTT) and Item Response Theory (IRT) and the Correlation among Them Mohammad moqasqas Haifa T. Albokai Assistant Professor of Measurement and Evaluation Associate Professor of Measurement and Evaluation College of Education, Taibah University The aim of this study was to study the item difficulty and item discrimination of the SCAT (advance form) with CTT, and IRT, and to study the correlation among them. To do this, the researchers used the data of their previous study, which conducted in (2011). It consisted of (3943) subject. Then, they used two-statistical programs (TAP, Bilog-MG-3) to obtain the item
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