A wireless sensor based on bioresponsive DNA hydrogel provides smartphone-based detection of wound infection.

Cancer therapies developed using bacteria and their components have been around since the 19th century. Compared to traditional cancer treatments, the use of bacteria-derived compounds as cancer therapeutics could offer a higher degree of specificity, with minimal off-target effects. Here, we explored the use of soluble bacteria-derived toxins as a potential squamous cell carcinoma (SCC) therapeutic. We optimized a protocol to generate Staphylococcus aureus biofilm-conditioned media (BCM), where soluble bacterial products enriched in the development of biofilms were isolated from a bacterial culture and applied to SCC cell lines. Bioactive components of S. aureus ATCC 29213 (SA29213) BCM display selective toxicity towards cancerous human skin SCC-12 at low doses, while non-cancerous human keratinocyte HaCaT and fibroblast BJ-5ta are minimally affected. SA29213 BCM treatment causes DNA damage to SCC-12 and initiates Caspase 3-dependent-regulated cell death. The use of the novel SA29213 bursa aurealis transposon mutant library led to the identification of S. aureus alpha hemolysin as the main bioactive compound responsible for the observed SCC-12-specific toxicity. The antibody neutralisation of Hla eradicates the cytotoxicity of SA29213 BCM towards SCC-12. Hla displays high SCC-12-specific toxicity, which is exerted primarily through Hla-ADAM10 interaction, Hla oligomerisation, and pore formation. The high target specificity and potential to cause cell death in a controlled manner highlight SA29213 Hla as a good candidate as an alternative SCC therapeutic.

The opportunistic pathogen Staphylococcus aureus has an extremely complex relationship with humans. While the bacteria can exist as a commensal in many, it can cause a wide range of diseases and infections when turned pathogenic. Its presence is a determinant of chronicity and poor prognosis in numerous diseases, and its genomic plasticity causes S. aureus antimicrobial resistance to be one of the most dire contemporary medical problems to solve. Genetic manipulation of S. aureus has led to numerous findings that are vital in the fight against its pathogenesis. The utilisation of transposon mutant libraries for the systematic inspection of the S. aureus genome led to many landmark discoveries pertaining to the bacteria’s pathogenicity, antimicrobial resistance acquisition, and virulence regulation. In this review, we describe mutant libraries, and their significant contributions, from various S. aureus strains created with commonly used transposons. The general workflow for the construction of libraries will be presented, along with a discussion of the challenges of undertaking the task of large-scale library construction. As the accessibility of transposon mutant library construction, screening, and analysis increases, this genetic tool could be further exploited in the study of the S. aureus genome.