1. Investigación

The widespread irrational use of antibiotics in recent years has resulted in an increase in the detection of multi-resistant bacterial strains, particularly methicillin-resistant Staphylococcus aureus (MRSA). The use of natural derivatives such as flavonoids is postulated as one of the most promising avenues to solve this emerging public health problem. The objective of the present study is to characterize the antimicrobial activity of icariin, a flavonoid compound isolated from a variety of plants of the Epimedium genus, against human and animal clinical MRSA isolates. Our study found that icariin alone did not have any antimicrobial effect on S. aureus or MRSA clinical isolates. However, icariin enhanced the effect of amoxycillin-clavulanate or ampicillin, whereas no effect was seen when used in combination with vancomycin. Specifically, co-incubation of S. aureus with amoxycillin-clavulanate plus icariin resulted in an increased proportion of dead cells, suggesting that this flavonoid potentially increases antimicrobial activity when used in combination with the beta-lactam antibiotic amoxycillin-clavulanate. Furthermore, we demonstrate that co-incubation of S. aureus with AmoxyClav plus icariin resulted in increased membrane disruption and growth inhibition. This study demonstrates the potential utility of icariin in permitting lower antibiotic therapeutic doses in alignment with strategies to reduce the spread of antibiotic resistance. Further research is required to determine the optimum concentration of icariin and to define clinically relevant combinations of flavonoid and antibiotic.

Background: Resistance to antimicrobial agents has become a problem in modern society. Antibiotic resistant bacteria undermine the prevention and treatment of infections. Undergraduate dental students in Europe are required to receive information in aspects of microbiology relevant for dental practice, including oral microbial pathogens and resistance mechanisms against antimicrobial compounds. The objective of this study was to implement a research-based strategy to aid the understanding of the increase in antimicrobial resistance in undergraduate dental student training. The primary outcome of this project is the efficacious delivery of the learning objectives. Methods: Ten volunteer undergraduate student “ambassadors” were recruited to manage the project with assistance from lead academics. Student ambassadors were a source of peer learning for their colleagues. The project consisted of three phases: Pre-project preparation (in which the ambassadors received special instruction and training); Practical experience (in which the ambassadors worked with volunteer student colleagues to carry out the project); Public presentation of results (in which ambassadors presented study results at a scientific conference of their choosing). Results: A total of 1164 students volunteered for the project, corresponding to an average participation rate of 76.4% students per year of the course. Following final debriefing, student participants and ambassadors were strongly positive in their evaluation of the achievement of 8 key student learning objectives. The results demonstrate that most volunteers improved their knowledge related to antimicrobial resistance mechanisms in microbiology. Additional benefits of participation in this project included an improvement in dental knowledge and ethics in biomedical research for the student volunteers, whilst the student ambassadors reported improved knowledge about critical thinking and study design, as well as a deeper understanding about microbiological analysis methods. Conclusions: To the best of our knowledge, this the first instance of the application of project-based methodologies to the teaching of a traditionally non-laboratory component of a subject taught in the dentistry curriculum. Results from both students and ambassadors highlighted the increase in dental knowledge and an increased awareness of antimicrobial resistance as the key outcomes of this project.