Video-based learning to enhance teaching of practical microbiology.

Video-based learning is an increasingly important methodology in higher education and has particular value in practical teaching. In order to enhance learning and promote student engagement in our undergraduate microbiology programme, we designed and produced a suite of teaching videos which demonstrate laboratory techniques core to the syllabus. The methods were demonstrated by Ph.D. students and the professionally-produced videos were made widely available via the free YouTube channel Microbiology teaching videos at NUI Galway (https://www.youtube.com/channel/UCsP4xz5aq7sWfR9eXSCd_QQ/), which accumulated over 40 000 views across 47 countries in its first 15 months online. A survey of students who used the videos in their teaching and learning identified a greatly increased understanding of experimental principles and ability to carry out techniques; greater engagement with practical teaching sessions; particular benefits for visual learners; and increased confidence in teaching and in communicating science amongst undergraduate teaching assistants. The videos will be central to microbiology teaching at NUI Galway over the coming decade and will benefit many third-level institutions exploring online and blended learning approaches in the coming years.

Overview of invasive fungal infections.

The incidence of invasive fungal infections (IFIs) has seen a marked increase in the last two decades. This is especially evident among transplant recipients, patients suffering from AIDS, in addition to those in receipt of immunosuppressive therapy. Worryingly, this increased incidence includes infections caused by opportunistic fungi and emerging fungal infections which are resistant to or certainly less susceptible than others to standard antifungal agents. As a direct response to this phenomenon, there has been a resolute effort over the past several decades to improve early and accurate diagnosis and provide reliable screening protocols thereby promoting the administration of appropriate antifungal therapy for fungal infections. Early diagnosis and treatment with antifungal therapy are vital if a patient is to survive an IFI. Substantial advancements have been made with regard to both the diagnosis and subsequent treatment of an IFI. In parallel, stark changes in the epidemiological profile of these IFIs have similarly occurred, often in direct response the type of antifungal agent being administered. The effects of an IFI can be far reaching, ranging from increased morbidity and mortality to increased length hospital stays and economic burden.

High sensitivity DNA detection using gold nanoparticle functionalised polyaniline nanofibres.

Polyaniline (PANI) nanofibres (PANI-NF) have been modified with chemically grown gold nanoparticles to give a nanocomposite material (PANI-NF-AuNP) and deposited on gold electrodes. Single stranded capture DNA was then bound to the gold nanoparticles and the underlying gold electrode and allowed to hybridise with a complementary target strand that is uniquely associated with the pathogen, Staphylococcus aureus (S. aureus), that causes mastitis. Significantly, cyclic voltammetry demonstrates that deposition of the gold nanoparticles increases the area available for DNA immobilisation by a factor of approximately 4. EPR reveals that the addition of the Au nanoparticles efficiently decreases the interactions between adjacent PANI chains and/or motional broadening. Finally, a second horseradish peroxidase (HRP) labelled DNA strand hybridises with the target allowing the concentration of the target DNA to be detected by monitoring the reduction of a hydroquinone mediator in solution. The sensors have a wide dynamic range, excellent ability to discriminate DNA mismatches and a high sensitivity. Semi-log plots of the pathogen DNA concentration vs. faradaic current were linear from 150×10(-12) to 1×10(-6) mol L(-1) and pM concentrations could be detected without the need for molecular, e.g., PCR or NASBA, amplification.

tmRNA--a novel high-copy-number RNA diagnostic target--its application for Staphylococcus aureus detection using real-time NASBA.

A real-time nucleic acid sequence-based amplification assay, targeting tmRNA, was designed for the rapid identification of Staphylococcus aureus. The selectivity of the assay was confirmed against a panel of 76 Staphylococcus strains and species and 22 other bacterial species. A detection limit of 1 cell equivalent was determined for the assay. A chimeric in vitro transcribed internal amplification control was developed and included in the assay. Application of the assay in natural and artificially contaminated unpasteurized (raw) milk enabled detection of 1-10 CFUS. aureus mL(-1) in 3-4 h, without the need for culture enrichment. Staphylococcus aureus was detected in all artificially contaminated milk samples (n=20) and none of the natural milk samples (n=20). Microbiological analysis of the natural milk samples was performed in parallel according to ISO 6888-3 and confirmed the absence of S. aureus. The method developed in this study has the potential to enable the specific detection of S. aureus in raw milk in a significantly shorter time frame than current standard methods. The assay further demonstrates the usefulness of tmRNA/ssrA as a nucleic acid diagnostic target.