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.
The present study is undertaken to evaluate the effects of hypothyroidism induced by carbimazol in male rat reproductive system. Rats were treated with carbimazol (80 and 160 mg/kg body weight) daily for two, four, six, and eight weeks, while control rats were given distilled water orally. The results of these experiments are: 1-Treatment with carbimazol produced increase in body weight of treated animals. This increase was not statistically significant even at high concentrations. 2-Decrease in testicular weight was observed during all administration points. This decrease was aggravated proportional to duration and dose (p≤0.001). 3-Results of most intervals showed significant decrease in epididymal-head weight, while no sig
... Show MoreKamel, S.H., R.F. Al-Jassani and H.A. Al-Shammari. 2022. Effects of Pseudomonas fluorescens, Bacillus thuringiensis tenebrionis Isolates and Biologically Synthesized Silver Nanoparticles on Cellulase Enzyme Activity in Workers' Digestive System of the Termite Microcerotermes diversus Silv. Arab Journal of Plant Protection, 40(4): 315-324. https://doi.org/10.22268/AJPP-40.4.315324 The purpose of this study was to investigate the effect of different bacterial isolates of P. fluorescens and B. t. tenebrionis and silver nanoparticles on the activity of the cellulase enzyme in termites' middle digestive system and its role in glucose release by treating cellulose media with bacterial strains and nanoparticles. Ultraviolet spectroscopy re
... Show MoreLaryngoscopy and tracheal intubation are considered the most invasive stimuli in anesthesia. They provoked cardiovascular responses that include hypertension, tachycardia and dysrhythmias. Various pharmacological approaches have been used to blunt or attenuate such pressor responses. The present study was designed to evaluate the effect of medazolom, lignocaine and propranolol as a valuable adjuvant to fentanyl in attenuating hemodynamic responses to endotracheal intubation in normotensive patients. Thirty two patient with physical status I or II according to the score of American Society of Anesthesiologist (ASA), scheduled for elective surgery under standard general anesthesia, were randomly allocated into four groups (8 patients in ea
... Show MoreBackground: Polymorphisms in the TNF-α gene affect the development and progression of rheumatoid arthritis. Objective: To investigate the associations between (-806 T/C) and (-857 T/C) SNPs with rheumatoid arthritis severity and susceptibility in a sample of Iraqi patients. Methods: A case-control study was conducted in Baghdad, Iraq. Twenty healthy controls and 63 patients confirmed to be newly diagnosed with rheumatoid arthritis were included. Those are divided into two groups (patients and controls), and the patients were further subdivided into severe and mild-moderate groups. Samples from those participants were analyzed for clinical and inflammatory parameter measurements. Genotyping by the Sanger method was performed to stu
... Show MoreAn experiment was carried out in the vegetables field of Horticulture Department / College of Agriculture / Baghdad University , for the three seasons : spring and Autumn of 2005 , and spring of 2007 , to study the type of gene action in some traits of vegetative and flowery growth in summer squash crosses (4 x 3 = cross 1 , 3 x 7 = cross 2 , 3 x 4 = cross 3 , 3 x 5 = cross 4 , 5 x 1 = cross 5 , 5 x 2 = cross 6). The study followed generation mean analysis method which included to each cross (P1 , P2 , F1 , F2 , Bc1P1 , Bc1P2) , and those populations obtained by hybridization during the first and second seasons. Experimental comparison was performed in the second (Two crosses only) and third seasons , (four crosses) by using RCBD with three
... Show MoreDiabetic mellitus is one of the main risk factors of fungal infections because poor glycemic control is associated with a high level of glucose in blood and saliva which could be treated as nutrient to fungi. This study aimed to isolate and identification of pathogenic fungi from diabetic patient. 140 samples were taken from different places of human body from the national center of diabetic patients that related to Mustansiriyah University / college of medicine and Al-yarmuk Hospital in Baghdad. 84 sample (60%) tested positive to fungi and 56 sample (40%) tested negative to fungi. The most frequented fungi isolated have been chosen for molecular identification by PCR (Millerozyma farinosa and Candida orthopsilosis) using specific pri
... Show MoreBackground: Previous studies about the correlation of genetic polymorphisms in the multigene family of cyto- chrome P450 (CYPs), the effect of tobacco smoking, and the risk of developing cancer have been well in- vestigated in different populations, but not in Iraq. Furthermore, the studies of malignance occurrence re- lationship with cigarette tobacco smoking revealed the presence of strong association, however, little is known about the risk of Waterpipe (WP) tobacco smoking. Thus, determination two important genetic polymorphisms in CYP1A1, a main member of CYPs, among Iraqi men was our first aim. This is the first study that highlights the correlation of CYP1A1 polymorphisms with the risk of lung cancer in Iraq. The second aim was to ev
... Show MoreCumulative lifetime lead (Pb) exposure has been associated with accelerated declines in cognition through the free radical generation and epigenetic effects. Several pieces of literature have identified a correlation between exposure to lead and neurodegenerative disorders. Harwich strain Drosophila melanogaster was exposed to lead acetate for two weeks, and changes in pulse transmission by acetylcholinesterase and systemic redox were evaluated. Besides, molecular docking studies of acetylcholinesterase against Quercetin and its most common derivatives contained in food have been performed. Pharmacokinetic studies on Quercetin and its derivatives have also been performed in silico toxicity. The data obtained showed alterations in antioxi
... Show MoreFisetin is a plant flavonoid found in strawberries and other fruits and vegetables such as apples, persimmons, and onions. It has many pharmacological effects like anti-inflammatory, antioxidant, cardioprotective, neuroprotective, and anti-carcinogenicity which are attributed to its ability to reduce oxidative stress which considers the main reason for different disease conditions. Genotoxicity refers to the genetic material destruction within the cell which can be caused by different chemicals as well as radiation. The present study evaluates the effect of orally-administered fisetin daily for seven constitutive days on genotoxicity induced by cyclophosphamide in rats’ bone marrow and spleen cells. Results showed that fisetin exh
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