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.
Bacterial toxins are considered to be virulence factors due to the fact that they interfere with the normal processes of the host cell in which they are found. The interplay between the infectious processes of bacteria and the immune system is what causes this impact. In this discussion, we are going to focus on bacterial toxins that act in the extracellular environment, especially on those that impair the activity of macrophages and neutrophils. These toxins are of particular interest since they may be found in a wide variety of bacteria. We will be concentrating our efforts, in particular, on the toxins that are generated by Gram-positive and Gram-negative bacteria. These toxins are able to interact with and have an effect on the many dif
... Show MoreThe cheif aim of the present investigation is to develop Leslie Gower type three species food chain model with prey refuge. The intra-specific competition among the predators is considered in the proposed model. Besides the logistic growth rate for the prey species, Sokol Howell functional response for predation is chosen for our model formulation. The behaviour of the model system thoroughly analyses near the biologically significant equilibria. The linear stability analysis of the equilibria is carried out in order to examine the response of the system. The present model system experiences Hopf bifurcation depending on the choice of suitable model parameters. Extensive numerical simulation reveals the validity of the proposed model.
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Abortion is categorized as the termination of conception caused by the failure or removal of the embryo from the uterus before the conclusion of pregnancy. Microorganisms and genetic factors are two of the many factors associated with abortion. Cytomegalovirus is a widespread congenital virus infection pathogen that affects a wide variety of people. The prothrombin gene is one of the essential causes that trigger blood clotting and the function of abortion women, therefore the aim of the study is to detect and associate Cytomegalovirus and prothrombin gene mutation (Gene ID: 14061 in NCBI) with abortion through genetic and immunological methods. Five ml of whole blood was collected from an intravenous puncture and divided into two tubes,
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The design of this paper is to find the possible correlation of Epstein Barr virus infection ina group of Iraqi women with cervical carcinoma though detection of Latent Membrane Protein 1 (LMP1) in these cervical tissues. Paraffinized blocks of two groups were included. The first sample of 30 cervical carcinomatous tissues and 15 biopsies from an apparently normal cervical tissues. All the samples were sectioned on a positive charged slides with 4 mm – thickness then submitted for immunohistochemical (IHC) staining to detect viral LMP1 expression. Sixty three percentage (19 out of 30) of the studies group showed positive overexpression as shown in with a significant association of the expression with cervical cancer with a significant ass
... Show MoreBoth normally developed insects and insects developed after cessation of eggs growth were
used in this work. Cessation of eggs growth occurred following abnormal conditions, which
lasted for 3.5 months before developing into adults, due to the war led by the U.S. and her
alliances against Iraq. These insects showed low rates of water contents and an active response
to water loss. Therefore their tolerance of desiccation was weak. In addition, they had an active
ability to restore their water loss quickly, after return them to a culture, this indicates that some
changes occurred in their integumentary properties were not permanent and took their turn
within one population only, but may or may not serve this population
The present study was directed to determine the effect of silver nanoparticles (Ag NPs) on the weights of the testes and epididymides and the characteristics of sperm in male albino mice. Animals were orally dosed with 200 mg/kg of Ag NPs for 5,10,15 days and then during the day following the end of dosage period all animals were sacrificed, then the testes and epididymes (head and tail) were isolated and after their weights measured. Then we studied the percentage of vitality and sperm abnormalities and calculate the concentration of sperm in the testes and epididymides. The results of this study after comparing it with the control showed a statistical decrease (P<0.05) in the weights of testes and tunica albuginea for the three peri
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