Bacteria have evolved the ability to form multicellular, surface-adherent communities called biofilms that allow survival in hostile environments. In clinical settings, bacteria are exposed to various sources of stress, including antibiotics, nutrient limitation, anaerobiosis, heat shock, etc., which in turn trigger adaptive responses in bacterial cells. The combination of this and other defens...

Pathogens offer many of the most fascinating and well-studied examples of evolution because their speed of adaptation allows observation of evolutionary change within human lifetimes. The rapid evolution observed in pathogenic viruses, bacteria, and fungi affect human, animal, and plant health globally. For example, influenza viruses regularly recombine genes affecting host range, infection pat...

Systemic acquired resistance is a pathogen-inducible defense mechanism in plants. The resistant state is dependent on endogenous accumulation of salicylic acid (SA) and is characterized by the activation of genes encoding pathogenesis-related (PR) proteins. Recently, selected nonpathogenic, root-colonizing biocontrol bacteria have been shown to trigger a systemic resistance response as well. To...

AtWRKY70, encoding a WRKY transcription factor, is co-expressed with a set of Arabidopsis genes that share a pattern of RPP4- and RPP7-dependent late upregulation in response to Hyaloperonospora parasitica infection (LURP) genes. We show that AtWRKY70 is required for both full RPP4-mediated resistance and basal defense against H. parasitica. These two defense pathways are related to each other,...

Resistance to human skin innate defenses is crucial for survival and carriage of Staphylococcus aureus, a common cutaneous pathogen and nasal colonizer. Free fatty acids extracted from human skin sebum possess potent antimicrobial activity against S. aureus. The mechanisms by which S. aureus overcomes this host defense during colonization remain unknown. Here, we show that S. aureus IsdA, a sur...

there are evidences in both animal and human studies which show that exercise has beneficial effects on the central nervous system and cognition. so, the aim of this study was to investigate the effect of resistance exercise on memory and probable mechanisms of this effect (i.e. neurotrophic factors) in sedentary students. 30 sedentary students (mean age, 23.8±1.6 yr) were randomly divided into...

Broad use of fluoroquinolones has been followed by emergence of resistance, which has been due mainly to chromosomal mutations in genes encoding the subunits of the drugs' target enzymes, DNA gyrase and topoisomerase IV, and in genes that affect the expression of diffusion channels in the outer membrane and multidrug-resistance efflux systems. Resistance emerged first in species in which single...

used in conjunction with or as a replacement for traditional methods, it is expected that specific laser technologies will become an essential component of contemporary dental practice over the next decade. the current review is designed to focus on the acid resistance of laser application and tries to introduce laser settings capable to achieve this feature for clinical application. applicatio...

onion thrips, thrips tabaci, is the most important pest of onion in isfahan. onion growers often rely on the pesticide spraying. imidacloprid is frequently used against this pest. to investigate the thrips resistance to this insecticide, 10 onion-growing regions of isfahan were selected. after their laboratory rearing, certain concentrations of imidacloprid were applied to these populations, us...