Abstract Reduced vancomycin susceptibility phenotypes in Staphylococcus aureus contribute to treatment failure, yet the genetic determinants of survival under inhibitory vancomycin exposure remain incompletely defined. We performed transposon directed insertion-site sequencing (TraDIS) on a methicillin resistant S. aureus (MRSA) ST398 mutant library following exposure to vancomycin at its minimum inhibitory concentration, identifying 52 genes whose disruption was associated with loss of population survival at inhibitory drug concentrations. Prophage associated loci were the largest functional group, spanning predicted structural and regulatory genes as well as multiple conserved hypothetical proteins. Targeted testing of defined transposon mutants in a USA300 background confirmed that disruption of selected loci impaired growth under vancomycin exposure. Our results highlight the contribution of diverse physiological processes, including metabolism, stress responses, and a prominent role for prophage-associated functions, rather than discrete resistance pathways. Together, these findings indicate that vancomycin tolerance is shaped by the general physiological state of the bacterial cell, including metabolic capacity and stress adaptation. Importance Treatment failure in Staphylococcus aureus infections often occurs in the absence of known antibiotic resistance determinants, suggesting that additional survival mechanisms influence therapeutic outcomes. In this study, we identify genetic determinants required for survival during inhibitory vancomycin exposure, revealing a broad role for metabolic functions, stress adaptation, and prophage-associated loci. The prominence of these diverse processes highlights that survival reflects global physiological adaptation rather than discrete resistance pathways. This insight underscores the need to consider cellular physiology and stress responses when developing strategies to prevent antibiotic tolerance and improve treatment efficacy.

Discovered in the late 19th century as a heat-sensitive plasma factor called "alexin", complement was first identified for its ability to work with antibodies to destroy microorganisms. Over the past two centuries, research advances have firmly established the complement system as a fundamental component of the immune system, with broader roles in immune surveillance, inflammation, and clearing immune complexes and apoptotic debris, while also bridging innate and adaptive immunity. Due to complement playing a central role in modulating biological processes on a system-wide scale, dysregulation or excessive activation can drive harmful inflammation and self-tissue damage. Despite some initial safety concerns and biological complexity, therapeutic targeting of the complement system has, over the past decade, emerged as a key strategy for controlling disorders in which its unregulated activation becomes pathogenic. However, inhibition of complement, particularly at the level of C3 or C5, predisposes patients to infections, most notably by encapsulated bacteria. These include a markedly increased risk of invasive infections caused by Neisseria meningitidis, as well as susceptibility to Streptococcus pneumoniae, Haemophilus influenzae, and other opportunistic viral and fungal pathogens. In this review, we aim to describe the infection risks associated with therapeutic complement inhibition and outline emerging approaches to mitigate their complications. These include optimised vaccination protocols, antimicrobial prophylaxis, patient education, and surveillance programs, as well as next-generation approaches such as pathway-selective inhibitors, personalised risk stratification, and adjunctive immune support. Enhancing these protective measures will be vital to optimising the therapeutic benefit of complement inhibition while reducing infectious morbidity and mortality.

Early-stage bacterial contamination and rapid biofilm growth are critical barriers to effective wound healing, highlighting the need for dressing materials that enable prompt, localised antibacterial intervention while maintaining cytocompatibility and sustainability. Here, we report a sustainable electrospun Janus nanofiber membrane based on two bio-derived semi-aromatic furan polyamides, poly(octamethylene furanamide) (PA8F) and poly(decamethylene furanamide) (PA10F), for antibacterial wound dressing applications. Although PA8F and PA10F differ only by two methylene units and show modest wettability differences as dense films, electrospinning into nanofiber networks amplifies this subtle molecular contrast into a pronounced, robust wettability asymmetry that enables a Janus dressing architecture without chemical surface modification. Tetracycline was physically dispersed within the hydrophilic PA8F, prior to electrospinning, to localise antibiotic delivery at the wound-material interface. The Janus membrane exhibits uniform, bead-free nanofibrous morphology and pronounced interfacial wettability asymmetry. Molecular dynamics simulations reveal distinct polymer-water interaction behaviours that underpin the experimentally observed hydration contrast between PA8F and PA10F. Drug release studies demonstrate rapid antibiotic availability, reaching ∼20 μg mL-1 in phosphate-buffered saline within 4 h. The Janus membranes achieve ∼1 log and ∼2 log reductions against Pseudomonas aeruginosa and Staphylococcus aureus colony biofilms, respectively, and produce ∼0.5 log bacterial reduction in an ex vivo porcine burn wound infection model. This study establishes the first use of sustainable furan-based semi-aromatic polyamides as electrospun wound dressings and demonstrates how electrospinning-induced asymmetry can translate subtle molecular differences into efficient, localised antibacterial delivery for advanced wound care.

A 1,3,4 oxadiazole-based compound named 1771 and its derivatives have been reported to exhibit antibacterial activity against Gram-positive bacteria, with activity extended to Gram-negative pathogens when the outer membrane permeability barrier and/or efflux pump systems were disrupted. However, these compounds suffer from low metabolic stability due to the labile ester and amide moieties. Here, we describe a study aimed at improving their metabolic stability and defining the structural features required for antibacterial activity.Replacing the ester with an ether moiety, combined with the introduction of a methyl group at the α-carbon of the amide, yielded the more metabolically stable derivative 10, which mantained good antibacterial activity. The secondary amide and the phenyl group were identified as essential for activity, whereas incorporation of the perfluorinated pentafluorosulfanyl group at the para-position of the phenyl ring further enhanced the antibacterial potency.Overall, these results demonstrate that the oxadiazole-based scaffold can be strategically modified to improve metabolic stability and further highlights its potential as a platform for antibacterial drug development.

Abstract Staphylococcus aureus , a major human and livestock pathogen, is the second biggest cause of antimicrobial resistance-associated mortality. Although S. aureus transcriptional regulation has been extensively characterised, the potential role of DNA methylation in S. aureus transcriptional regulation and stress response remains largely undefined. We tackled this gap by combining genome-wide nanopore sequencing-derived DNA methylation data and transcriptomic data, acquired before and during exposure of methicillin-resistant Staphylococcus aureus strain USA300 to clinically relevant oxidative, antibiotic and nitrosative stresses. Stress-induced significant DNA methylation changes were rare, with <0.1% of cytosines/adenines undergoing ≥20% change in methylation; these changes were enriched within genomic features (protein-coding genes, predicted promoter regions, ncRNAs). Transcription changes reflected metabolic, regulatory and stress-specific pathway adjustments. Many of the stress-induced DNA methylation changes occurred alongside transcription changes, although there was no obvious overarching relationship between the directions of changes in DNA methylation and transcription. Pre-stress treatment methylation entropy tended to be elevated at sites containing a base that underwent stress-induced change in methylation level, identifying focal sites of pre-existing methylome heterogeneity relative to both local and genome-wide backgrounds; the magnitude of the site-specific methylation entropy peak, moreover, correlated with the magnitude of subsequent methylation change. Genome-wide entropy levels were consistent with a finite number of methylation patterns, distinguished by key bases, that could correspond to clinically important S. aureus subpopulations exhibiting persistence, dormancy and immune evasion. These findings support the principle that DNA methylation is an important component of the regulatory machinery underpinning S. aureus adaptability and persistence. Importance Staphylococcus aureus survives antibiotic treatment and host immune attack partly through phenotypic diversity, yet the regulatory processes that support this adaptability remain incompletely understood. Here, we integrate genome-wide DNA methylation and transcriptomic profiling to examine how epidemic methicillin-resistant S. aureus USA300 responds to oxidative, antibiotic, and nitrosative stresses. Stress-induced methylation changes were rare but non-random, concentrated in coding and regulatory regions linked to stress defence, metabolism, persistence, virulence, biofilm formation, and host interaction. Sites that underwent stress-induced methylation changes tended to have unusually high pre-stress methylation pattern diversity relative to local and genome-wide pattern diversity. These findings support a model in which an S. aureus population contains a pre-stress repertoire of epigenetic states that stress selectively redistributes via bases that differentiate stable methylation patterns. By revealing a layer of heterogeneity that may support pathogen resilience, this work provides a framework for investigating whether bacterial methylation dynamics can be exploited clinically.

Bacteria pose a significant threat to human health as they can cause diseases and outbreaks; therefore rapid, easy, and specific detection of bacteria in a short time is crucial. Various methods such as polymerase chain reaction and enzyme-linked immunosorbent assay have been developed for bacteria detection. However, most of these methods require sample preparation, trained personnel, and 2-4 days for identification. In this study, an electrochemical sensor has been developed in which a molecularly imprinted polymer (MIP) and aptamer were used together as a bioreceptor for the multiplexed detection of Staphylococcus aureus and Escherichia coli. Non-Faradaic electrochemical impedance spectroscopy (EIS) was employed to assess bacterial detection. Sensor performance was assessed in buffer solution, deionized water and spiked tap water. Aptamer-molecularly imprinted polymer (Apta-MIP) based electrochemical sensors demonstrate high sensitivity and selectivity for the detection of S. aureus and E. coli, with limits of detection of 4 CFU/mL and 2 CFU/mL, respectively. Additionally, these sensors exhibited a broad dynamic range from 1 CFU/mL to 108 CFU/mL. The Apta-MIPs performance surpasses those obtained for Aptasensors alone and MIPs alone, demonstrating the high efficiency of the double recognition effect that originates from the affinity between aptamer and bacteria and target-specific cavities on the polymer. This is the first study in which aptamers and imprinted polymers were used as a hybrid bioreceptors for multiplexed detection of bacteria. The Apta-MIP sensors produced in this study can be used as a point-of-care diagnostic tool for bacteria-related diseases and test of water quality.

We report the fabrication and analysis of a vanillin cross-linked chitosan film containing gallic acid as the active component. The active packaging material was found to successfully block 100% of UV light and had good water vapour barrier properties. Cross-linking via Schiff base formation reduced the water solubility and moisture content of the chitosan films and improved tensile properties, with a force at break measured as 29.4 +/- 0.5 N. The material performed well in thermal testing, and we evaluated a glass transition temperature of 274.0 degrees C. We determined the successful controlled release of gallic acid from the composite film using UV-visible spectroscopy over 2 weeks. The material had strong antioxidant and antimicrobial capacities, reducing >98% of 2,2-diphenyl-1-picrylhydrazyl radicals and inhibiting the growth of both E. coli and S. aureus. We investigated the degradation of this biopolymer film in different environments including soil, compost, seawater, UV-light and water. The material reached over 90% degradation in soil within 12 weeks, rising to complete degradation after 24 weeks. We also investigated the potential mechanism for the degradation of the chitosan films, showing the effect of moisture and microbial availability in soil, and the related cleavage of the chitosan backbone via fragmentation. We determined improved degradation when the active components were released into solution before testing. Overall, the film has good physiochemical properties, strong antioxidant and antimicrobial activity and excellent degradation properties. Thus, the presented material is a strong candidate for future development of sustainable active packaging materials.

Biofilms are structured communities of bacterial cells enclosed in a self-produced extracellular matrix. In the pathogen Staphylococcus aureus, this can enhance resistance to antibiotics and immune responses, contributing significantly to chronic infections associated with medical devices. The underlying mechanisms include the production of polysaccharide intercellular adhesin (PIA), encoded by the icaADBC operon, and surface proteins that mediate adhesion. However, it has been challenging to translate in vitro understanding to explain the molecular mechanisms governing biofilm formation in vivo. Here we combined functional and comparative genomics approaches to investigate genetic factors influencing biofilm formation in isolates belonging to the clinically important ST-8 clonal complex (CC8). Phenotypic and genomic screening of a closely related strain cohort (MRSA USA300 isolates) revealed considerable variability in biofilm formation. Genome-wide association studies (GWAS) identified several genes and polymorphisms linked to biofilm development. These included known biofilm genes and compensatory mutations that restored wild-type biofilm levels in hyper-biofilm forming mucoid isolates. Finally, contextualizing CC8 genomes within diverse S. aureus populations revealed the natural occurrence of biofilm-associated genomic variation as well as evidence for the conservation of the ica loci in CC8. This offers insight into the mechanisms and microevolutionary events that give rise to clinically relevant staphylococcal infections.

We report the successful fabrication and application of a vanillin cross-linked chitosan film for use as an active packaging material using Agaricus bisporus (white button mushroom) as an alternative feedstock for chitosan. Utilizing an alkali extraction method, chitosan was obtained with a degree of deacetylation (DDA) of 85%. The mushroom-derived chitosan was combined with vanillin and gallic acid to form composite films by casting. The thin films were analyzed using a suite of analytical techniques including Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), Scanning Electron Microscopy (SEM), UV-visible spectroscopy (UV-vis), and water vapor permeability testing. The chitosan films displayed 100% UV-blocking and mechanical and thermal properties similar to crustacean-derivatives with values of 10.4 +/- 0.8 MPa for tensile strength and a glass transition temperature of 224.8 degrees C. The controlled release of gallic acid into a lipophilic food simulant was achieved and tested over 336 h. Antioxidant and antimicrobial testing confirmed the potent effects of gallic acid on the prevention of bacterial growth and the quenching of free radicals. Chitosan films were effective against Escherichia coli and Staphylococcus aureus and quenched 95.5 +/- 0.1% of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals. The results presented provide a promising starting point for the development of a degradable active packaging material from mushroom feedstocks.

Novel strategies to counter multidrug-resistant pathogens such as methicillin-resistant Staphylococcus aureus are urgently required. The antimicrobial properties of fatty acids (FAs) have long been recognized and offer significant promise as viable alternatives to, or potentiators of, conventional antibiotics. In this review, we examine the interplay between FAs and S. aureus, specifically detailing the underlying molecular mechanisms responsible for FA-mediated inhibition and the counteracting staphylococcal systems evolved to withstand FA onslaught. Finally, we present an update on the recent therapeutic FA applications to combat S. aureus infection, either as a monotherapy or in combination with antibiotics or host-derived antimicrobial peptides. Given the frequency of interaction between FAs and S. aureus during host colonization and infection, understanding FA mode of action and deciphering S. aureus FA resistance strategies are central in rationally designing future anti-staphylococcal FAs and FA-combination therapies.

Dual- or multi-template molecularly imprinted polymers have been an attractive research field for many years as they allow simultaneous detection of more than one target with high selectivity and sensitivity by creating template-specific recognition sites for multiple targets on the same functional monomer. Dual/multi-template molecular imprinting techniques have been applied to identify, extract, and detect many targets, from heavy metal ions to viruses, by different methods, such as high-performance liquid chromatography (HPLC), liquid chromatography–mass spectrometry (LC-MS), and piezoelectric, optical, and electrochemical methods. This article focuses on electrochemical sensors based on dual/multi-template molecularly imprinted polymers detecting a wide range of targets by electrochemical methods. Furthermore, this work highlights the use of these sensors for point-of-care applications, their commercialization and their integration with microfluidic systems.

Extracellular proteases are a class of Staphylococcus aureus virulence factors that thwart the immune system, promote nutrient acquisition, and shape the activity of virulence determinants. S. aureus displays considerable phenotypic and genotypic variation within clinically important lineages, giving rise to diverse infection types. Therefore, understanding how protease expression influences pathogenicity requires consideration of the underlying genes and their regulation in natural populations. In this study we determined the protease activity of 134 USA300 S. aureus isolates from clinical infections and asymptomatic carriage. In high-throughput casein hydrolysis assays, bloodstream infection isolates had significantly lower protease activity than carriage isolates. To identify the genetic variation underlying this variation in protease expression, we employed a k-mer-based genome wide association study, identifying 68 genes with polymorphisms significantly associated with proteolytic activity. Population-scale genomic variation was compared with strains from a sequenced-defined transposon library, validating the function of 27 loci that were significantly associated with decreased protease expression. Associated genes included known protease-regulating genes, including agrA, but most were novel. These included genes linked to central metabolism, permeases, transporters and membrane proteins. Characterizing the complexity of protease regulation and expression will enhance our fundamental understanding of S. aureus virulence which may result in improved treatment options for problematic clinical S. aureus infections.

The emergence of multidrug-resistant Staphylococcus aureus underscores the urgent need for novel therapeutic agents targeting essential bacterial pathways. The lipoteichoic acid synthase (LtaS) is crucial for the synthesis of lipoteichoic acid in the cell wall of Gram-positive bacteria and represents a promising and vulnerable target for antimicrobial drug development. This study employed a comprehensive computational pipeline to identify potent inhibitors of the LtaS enzyme. A library of natural compounds was retrieved from the COCONUT database and screened against the crystal structure of the extracellular domain of LtaS (eLtaS) (PDB ID: 2W5R, obtained from the Protein Data Bank) through a multi-stage molecular docking strategy. This process started with High-Throughput Virtual Screening (HTVS), followed by Standard Precision (SP) docking, and culminated in Extra Precision (XP) docking to refine the selection of hits. The top-ranking compounds from XP docking were subsequently subjected to MM-GBSA binding free energy calculations for further filtration. The stability and dynamic behavior of the resulting candidate complexes were then evaluated using 100 ns molecular dynamics (MD) simulations, which confirmed the structural integrity and binding stability of the ligands. Density Functional Theory calculations revealed that screened ligands exhibit improved electronic stabilization and charge-transfer characteristics compared to a reference compound, suggesting enhanced reactivity and stability relevant for hit identification. Finally, ADMET (Absorption, Distribution, Metabolism, Excretion, and Toxicity) profiling was conducted to assess the drug-likeness and pharmacokinetic safety of the lead compounds. These findings support them as promising orally active leads for further optimization. Our integrated approach shortlisted eight initial hits (A-H) that showed interesting scaffold diversity and finally identified two compounds, herein referred to as Compound A and Compound B, which demonstrated stable binding, favorable free energy, and an acceptable Absorption, Distribution, Metabolism, and Excretion, and Toxicity (ADMET) profile. These candidates emerge as promising starting points for developing novel anti-staphylococcal agents targeting the LtaS enzyme that cand be further proved by experimental validation.

INTRODUCTION:Streptococcus pyogenes (group A streptococcus; GAS) is a pathogen causing over half a million deaths annually worldwide. Human immune cells respond to GAS infection by activating the NLRP3 inflammasome leading to the release of pro-inflammatory cytokines that control infection. We investigated the role of C4b-binding protein (C4BP) and factor H (FH) in the inflammasome response to GAS, as they are recruited by GAS to prevent complement deposition and limit phagocytosis. METHODS:The inflammasome response was investigated using primary human cells and the strain GAS-AP1. Cytokine responses were evaluated by ELISA. C4BP internalisation was investigated using confocal microscopy. Activation of the NLRP3 inflammasome components was assessed by Western blotting. RESULTS:Interleukin-1β (IL-1β) release, induced by GAS-AP1, was inhibited by FH which interferes with priming of human cells. In contrast, C4BP restricted the IL-1β response without affecting cell priming. C4BP was engulfed by cells together with bacteria and excluded from low-pH vesicles but localised within the cytosol and near the ASC speck inflammasome complex. C4BP did not inhibit either the inflammasome complex assembly or caspase-1 activation. However, C4BP limited the cleavage of gasdermin D N-terminal fragments by interfering with caspase-1 enzymatic activity. CONCLUSION:Given that the amount of IL-1β modulates the severity of GAS infection, our results provide new insights into the effect of FH and internalised C4BP to control GAS sensing by inflammasomes.

Catheter associated urinary tract infections (CAUTI) caused by urease-positive organisms can lead to catheter blockage: urease metabolizes urea in urine to ammonia causing an increase in pH and hence precipitation of struvite and apatite salts into the catheter lumen and bladder leading to blockage. Acetohydroxamic acid (AHA) is the only urease inhibitor currently approved for patient use, however, it is rarely used owing to its side effects. Here, we report the identification and development of new urease inhibitors discovered using a rational in silico drug design approach. A series of compounds were designed, the compounds were screened and filtered to identify three compounds which were tested in in vitro urease activity assays. N,N '-Bis(3-pyridinylmethyl)thiourea (Bis-TU) outperformed AHA in activity assays and was tested in an in vitro bladder model, where it significantly extended the lifetime of the catheter compared to AHA. Bis-TU was delivered via a diffusible balloon catheter directly to the site of activity, thus demonstrating localized drug delivery. This cost-effective drug design approach allowed the identification of a potent urease inhibitor, which could be improved through iterative repeats of the method, and the process of design could be utilized to target other diseases.

We report a genipin-crosslinked gelatin hydrogel for the detection of the pathogenic strains of Pseudomonas aeruginosa releasing active metalloproteases. Enzymatic degradation of the blue gel gives a clear visual signal that indicates the presence of P. aeruginosa. A total of 36 strains of both Gram-positive and Gram-negative bacteria were tested and only P. aeruginosa strains caused degradation of the gels within 24 h. Gene sequencing revealed that P. aeruginosa strains with mutations in their quorum sensing operon were not able to degrade the hydrogels even though the genes coding for metalloproteases were present. Finally, we created a gel multilayer that can both detect and treat active strains of P. aeruginosa through the release of bacteriophage. Our system provides a simple and reproducible assay for P. aeruginosa metalloproteases and showcases the feasibility of responsive wound dressings able to both detect and treat P. aeruginosa infection.

Electrically conductive hydrogels (ECHs) combine the electrical properties of conductive materials with the unique features of hydrogels. They are attractive for various biomedical applications due to their smart response to electrical fields. Owing to their distinctive properties, such as biocompatibility, thermosensitivity and self-assembling behaviour, Pluronics can be adopted for the generation of hydrogels for biomedical applications. Here, innovative self-assembling ECHs holding antimicrobial properties for biomedical applications are developed, providing a full characterization of their macroscopic and microscopic properties. The rheological, morphological, and structural properties of Pluronic F68 (PF68) in the presence of conductive poly(3,4-ethylenedioxythiophene):poly-(styrenesulfonate) (PEDOT:PSS) are studied to optimize the synthesis of novel biocompatible and electrically conductive hydrogels. The addition of silver (Ag) flakes to the aqueous samples of PF68/PEDOT:PSS is used to further enhance the systems electrical conductivity and antimicrobial potency. Aqueous optimal samples with 45 wt% PF68 and different PEDOT:PSS/silver contents are investigated by means of experimental rheology and small-angle X-ray scattering (SAXS), to unveil the influence of both PEDOT:PSS and silver on the phase diagram, macroscopic flow properties, and morphology of the Pluronic-based systems.The presence of PEDOT:PSS and silver flakes endows Pluronic systems with high conductive properties, while preserving the same self-assembly features of PF68 in water. Moreover, the functionalisation with silver flakes confers antimicrobial properties to the ECHs, as demonstrated by growth inhibition of the multi-drug resistant bacterium Staphylococcus aureus.The use of PF68 in this work provides a novel route for the synthesis of innovative ECHs, whose functionalities such as self-assembling behaviour, biocompatibility, conductivity, and bioactivity may inspire future avenues in the biomedical field.

Streptococcus agalactiae, (Group B Streptococcus (GBS)), is a common colonizer of the female vagina. In women giving birth it can be transmitted to the baby and cause serious illness and even death to the child. We have developed a biosensor comprising of phospholipids and fatty acids vesicles encapsulating high concentration, self-quenched carboxyfluorescein, which is released by the lysis of the vesicle by virulence factors expressed by GBS, becoming diluted and fluorescent. The microbial specificity of the sensor was tested against a number of GBS strains and other microbes including Candida albicans, Enterococcus faecalis and Staphylococcus epidermidis and a statistically significant response to GBS measured over these other microbes. To test the in vivo efficacy of the biosensor, a pilot study using donated lower vaginal swabs from non-pregnant women was conducted, where 58 female adults were recruited. Participants donated two swabs, one which was used for the vesicle test and one for the 'gold standard', enriched culture media (ECM) test. An overall GBS carriage rate of 17.2% was measured using the ECM test. The vesicle biosensor test took 45 min to obtain a result, and showed a sensitivity of 83.3%, specificity of 85.7% and accuracy of 85.3%. The test accuracy is in line with current novel GBS identification tests, with the advantage of being rapid, easy to use, low-cost and able to be conducted by bedside during start of labour.

Antibiotic chemotherapy is widely regarded as one of the most significant medical advancements in history. However, the continued misuse of antibiotics has contributed to the rapid rise of antimicrobial resistance (AMR) globally. Staphylococcus aureus, a major human pathogen, has become synonymous with multidrug resistance and is a leading antimicrobial-resistant pathogen causing significant morbidity and mortality worldwide. This review focuses on (1) the targets of current anti-staphylococcal antibiotics and the specific mechanisms that confirm resistance; (2) an in-depth analysis of recently licensed antibiotics approved for the treatment of S. aureus infections; and (3) an examination of the pre-clinical pipeline of anti-staphylococcal compounds. In addition, we examine the molecular mechanism of action of novel antimicrobials and derivatives of existing classes of antibiotics, collate data on the emergence of resistance to new compounds and provide an overview of key data from clinical trials evaluating anti-staphylococcal compounds. We present several successful cases in the development of alternative forms of existing antibiotics that have activity against multidrug-resistant S. aureus. Pre-clinical antimicrobials show promise, but more focus and funding are required to develop novel classes of compounds that can curtail the spread of and sustainably control antimicrobial-resistant S. aureus infections.