DNA metabarcoding analysis of the bare-nosed wombat (Vombatus ursinus) diet.

Wombats are native herbivorous grazers that have adapted to Australia's low-quality forage. Studies on diet selection by bare-nosed wombats (Vombatus ursinus) are limited and are either observational or based on microhistological studies. The current study determined the diet of wombats through DNA metabarcoding across five study sites in New South Wales over a one-year period. Metabarcoding was chosen as it is non-invasive, less time consuming and more specific than traditional techniques. The list of 209 plant species identified as eaten by wombats in this study is much higher than previously reported, with grasses being the most common plant group identified in all samples. Most dietary items identified were introduced plant species. Seasonal differences in plants eaten occurred at four of the five study sites and may reflect dietary abundance and floristic composition at different times of year. Further studies are required to determine if the dietary items differ markedly across the entire range of wombats, and if nutrition influences dietary preferences.

Assessment of the diet of the critically endangered northern hairy-nosed wombat (Lasiorhinus krefftii) using DNA metabarcoding.

Invasive buffel grass (Cenchrus ciliaris) is considered a threat to the critically endangered northern hairy-nosed wombat (Lasiorhinus krefftii; NHW). Buffel grass outcompetes native grasses, reducing availability of native food items for NHW, and causes more intense fires due to the large volumes of dead matter it produces. Previous studies suggested buffel grass was increasing in the diet; however, the diet of the NHW has not been reassessed for over two decades and was limited to Epping Forest National Park, with the population at Richard Underwood Nature Refuge having never been assessed. The recently released 2022 Recovery Action Plan for the species outlined objectives to assist its conservation and recommended the impact of buffel grass on the species' diet be investigated. This study aimed to determine: (1) which plant species are being consumed by the NHW; (2) the differences in the diet between sites; (3) differences between seasons; and (4) the abundance of buffel grass in the diet. The diet was assessed using DNA metabarcoding of scat samples collected from both sites from winter 2020 to spring 2021. Site and season significantly affected the diet of the NHW. Buffel grass dominated the diet and has increased in the diet since past assessments. The findings of this study will support population and habitat management of the critically endangered NHW. Enhanced knowledge of dietary items consumed at both sites will also assist efforts to locate additional sites suitable for translocation.

Quantification of ALS1 gene expression in Candida albicans biofilms by RT-PCR using hybridisation probes on the LightCycler.

The fungal pathogen Candida albicans has the ability to grow as a biofilm on synthetic materials. This presents a significant problem in the clinical situation when the organism grows as a biofilm on medical devices resulting in infections which are resistant to antifungal agents. Determining the extent to which certain genes are involved in biofilm formation is an important aspect for the development of strategies to control pathogenic biofilms. ALS1 is a member of the ALS (agglutinin-like sequence) family, the protein products of which are implicated in attachment to endothelial cells and biofilm formation. The expression of ALS1 in biofilms grown on silicone elastomer, a material used in the manufacture of medical devices, and planktonically grown cells was investigated using a novel real-time quantitative reverse transcriptase PCR (q-RT PCR) on the LightCycler. This study demonstrates quantitatively that ALS1 is clearly up-regulated during biofilm growth. The real-time q-RT PCR assay described here has the potential to be used as an indicator of biofilm formation on medical devices.