New frontiers in CRISPR: Addressing antimicrobial resistance with Cas9, Cas12, Cas13, and Cas14

[Frontier progress in complex wound repair: from microenvironment regulation to precision medical practice]

Complex wounds, with high incidence rate, high disability rate, and high medical costs, have brought huge burdens to patients and medical systems. Traditional treatment methods of complex wounds have limitations, therefore it is necessary to further improve and develop innovative strategies of diagnosis and treatment to address this clinical challenge. This article reviews and discusses important advances in the field of complex wound repair, as well as new concepts in the construction of modern wound management systems. The aim is to provide a reference for clinical medical staff, researchers, and related industry personnel, promote the sustainable development of complex wound repair field, and ultimately achieve comprehensive recovery of function and aesthetics of patients with complex wounds.

Staphylococcus aureus: A Review of the Pathogenesis and Virulence Mechanisms

Staphylococcus aureus is a formidable human pathogen responsible for infections ranging from superficial skin lesions to life-threatening systemic diseases. This review synthesizes current knowledge on its pathogenesis, emphasizing colonization dynamics, virulence mechanisms, biofilm formation, and antibiotic resistance. By analyzing studies from PubMed, Scopus, and Web of Science, we highlight the pathogen's adaptability, driven by surface adhesins (e.g., ClfB, SasG), secreted toxins (e.g., PVL, TSST-1), and metabolic flexibility in iron acquisition and amino acid utilization. Nasal, skin, and oropharyngeal colonization are reservoirs for invasive infections, with biofilm persistence and horizontal gene transfer exacerbating antimicrobial resistance, particularly in methicillin-resistant S. aureus (MRSA). The review underscores the clinical challenges of multidrug-resistant strains, including vancomycin resistance and decolonization strategies' failure to target single anatomical sites. Key discussions address host-microbiome interactions, immune evasion tactics, and the limitations of current therapies. Future directions advocate for novel anti-virulence therapies, multi-epitope vaccines, and AI-driven diagnostics to combat evolving resistance. Strengthening global surveillance and interdisciplinary collaboration is critical to mitigating the public health burden of S. aureus.

Advances in CRISPR/Cas9-Based Gene Editing in Filamentous Fungi

As an important class of microorganisms, filamentous fungi have crucial roles in protein secretion, secondary metabolite production and environmental pollution control. However, characteristics such as apical growth, heterokaryon, low homologous recombination (HR) efficiency and the scarcity of genetic markers mean that the application of traditional gene editing technology in filamentous fungi faces great challenges. The introduction of the RNA-mediated CRISPR/Cas (clustered regularly interspaced short palindromic repeat/CRlSPR-associated protein) system in filamentous fungi in recent years has revolutionized gene editing in filamentous fungi. In addition, the continuously expressed CRISPR system has significantly improved the editing efficiency, while the optimized sgRNA design and reduced cas9 concentration have effectively reduced the off-target effect, further enhancing the safety and reliability of the technology. In this review, we systematically analyze the molecular mechanism and regulatory factors of CRISPR/Cas9, focus on the optimization of its expression system and the improvement of the transformation efficiency in filamentous fungi, and reveal the core regulatory roles of HR and non-homologous end-joining (NHEJ) pathways in gene editing. Based on the analysis of various filamentous fungi applications, this review reveals the outstanding advantages of CRISPR/Cas9 in the enhancement of protein secretion, addresses the reconstruction of secondary metabolic pathways and pollutant degradation in the past decade, and provides a theoretical basis and practical guidance for the optimization of the technology and engineering applications.

Reinvigorating AMR resilience: leveraging CRISPR-Cas technology potentials to combat the 2024 WHO bacterial priority pathogens for enhanced global health security-a systematic review

BACKGROUND

Antimicrobial resistance (AMR) poses a global health threat, particularly in low- and middle-income countries (LMICs). Clustered regularly interspaced short palindromic repeats (CRISPR)-Cas system technology offers a promising tool to combat AMR by targeting and disabling resistance genes in WHO bacterial priority pathogens. Thus, we systematically reviewed the potential of CRISPR-Cas technology to address AMR.

METHODS

This systematic review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A comprehensive literature search was conducted using the Scopus and PubMed databases, focusing on publications from 2014 to June 2024. Keywords included "CRISPR/Cas," "antimicrobial resistance," and "pathogen." The eligibility criteria required original studies involving CRISPR/Cas systems that targeted AMR. Data were extracted from eligible studies, qualitatively synthesized, and assessed for bias using the Joanna Briggs Institute (JBI)-standardized tool.

RESULTS

Data from 48 eligible studies revealed diverse CRISPR-Cas systems, including CRISPR-Cas9, CRISPR-Cas12a, and CRISPR-Cas3, targeting various AMR genes, such as blaOXA-232, blaNDM, blaCTX-M, ermB, vanA, mecA, fosA3, blaKPC, and mcr-1, which are responsible for carbapenem, cephalosporin, methicillin, macrolide, vancomycin, colistin, and fosfomycin resistance. Some studies have explored the role of CRISPR in virulence gene suppression, including enterotoxin genes, tsst1, and iutA in Staphylococcus aureus and Klebsiella pneumoniae. Delivery mechanisms include bacteriophages, nanoparticles, electro-transformation, and conjugative plasmids, which demonstrate high efficiency in vitro and in vivo. CRISPR-based diagnostic applications have demonstrated high sensitivity and specificity, with detection limits as low as 2.7 × 102 CFU/mL, significantly outperforming conventional methods. Experimental studies have reported significant reductions in resistant bacterial populations and complete suppression of the targeted strains. Engineered phagemid particles and plasmid-curing systems have been shown to eliminate IncF plasmids, cured plasmids carrying vanA, mcr-1, and blaNDM with 94% efficiency, and restore antibiotic susceptibility. Gene re-sensitization strategies have been used to restore fosfomycin susceptibility in E. coli and eliminate blaKPC-2-mediated carbapenem resistance in MDR bacteria. Whole-genome sequencing and bioinformatics tools have provided deeper insights into CRISPR-mediated defense mechanisms. Optimization strategies have significantly enhanced gene-editing efficiencies, offering a promising approach for tackling AMR in high-priority WHO pathogens.

CONCLUSIONS

CRISPR-Cas technology has the potential to address AMR across priority WHO pathogens. While promising, challenges in optimizing in vivo delivery, mitigating potential resistance, and navigating ethical-regulatory barriers must be addressed to facilitate clinical translation.

Engineering Useful Microbial Species for Pharmaceutical Applications

Microbial engineering has made a significant breakthrough in pharmaceutical biotechnology, greatly expanding the production of biologically active compounds, therapeutic proteins, and novel drug candidates. Recent advancements in genetic engineering, synthetic biology, and adaptive evolution have contributed to the optimization of microbial strains for pharmaceutical applications, playing a crucial role in enhancing their productivity and stability. The CRISPR-Cas system is widely utilized as a precise genome modification tool, enabling the enhancement of metabolite biosynthesis and the activation of synthetic biological pathways. Additionally, synthetic biology approaches allow for the targeted design of microorganisms with improved metabolic efficiency and therapeutic potential, thereby accelerating the development of new pharmaceutical products. The integration of artificial intelligence (AI) and machine learning (ML) plays a vital role in further advancing microbial engineering by predicting metabolic network interactions, optimizing bioprocesses, and accelerating the drug discovery process. However, challenges such as the efficient optimization of metabolic pathways, ensuring sustainable industrial-scale production, and meeting international regulatory requirements remain critical barriers in the field. Furthermore, to mitigate potential risks, it is essential to develop stringent biocontainment strategies and implement appropriate regulatory oversight. This review comprehensively examines recent innovations in microbial engineering, analyzing key technological advancements, regulatory challenges, and future development perspectives.