Critical Reviews in Microbiology最新文献

The gut microbiota produces a variety of metabolites that are crucial for regulating host health and physiological homeostasis. Indole-3-acetic acid (IAA), a microbial metabolite of tryptophan, exhibits diverse biological activities including anti-inflammatory, anti-tumor, anti-obesity, hepatoprotective, enteroprotective, and neuromodulatory effects. Accumulating evidence has demonstrated its therapeutic potential against metabolic, inflammatory, and neurological disorders. Emerging evidence suggests that IAA exerts beneficial effects on mammalian health through multiple mechanisms, including modulation of gut microbiota composition, enhancement of intestinal barrier integrity, immune regulation, attenuation of bone loss, and improvement of glucose and lipid homeostasis. This review systematically summarizes current knowledge regarding IAA sources, elucidates recent advances in understanding its biological functions, and integrates existing evidence on its mechanisms of action in mammalian systems. Collectively, this synthesis provides a framework for future investigations and translational applications of IAA.

Fungal infections pose a significant global health threat, particularly among immunocompromised individuals facing life-threatening complications. The severity of secondary fungal infections is driven by the expression of virulence factors in immunocompromised individuals. The COVID-19 pandemic has highlighted the susceptibility of immunocompromised patients to secondary fungal infections, prompting a closer examination of the underlying mechanisms. This review provides a comprehensive overview of the virulence mechanisms of major fungal pathogens (Aspergillus, Candida, and Mucorales) in COVID-19-associated secondary infections. The review systematically categorizes key virulence factors, including thermotolerance, adhesins, hydrolytic enzymes, mycotoxins, and biofilm formation, and explores their interplay with the host's immune status, particularly under corticosteroid therapy. Focusing on the intersection of fungal pathogenesis and COVID-19, the article examines molecular mechanisms underlying Aspergillus, Mucorales, and Candida pathogenicity, including iron metabolism, spore coat proteins, and immune evasion strategies. Followed by linking the molecular mechanisms to therapeutic strategies and clinical outcomes.

Physiological hemostasis is a balance between pro- and anticoagulant pathways, with multiple factors, regulators, and cellular components. Hemostasis is also closely associated with inflammation and immune response. In leptospirosis, a zoonotic disease caused by pathogenic spirochetal bacteria of the genus Leptospira, the hemostatic equilibrium is disturbed, resulting in coagulopathies that ultimately result in hemorrhages. Thrombocytopenia is a common complication in the affected patients and is often associated with poor clinical outcomes and high mortality. To date, the reports unraveling the origin of the molecular pathogenesis of leptospirosis hemostatic disturbances are scarce. In this review article, we summarize and analyze the complex pathophysiology of hemostatic impairment in the illness with a focus on the role of endotheliopathy, induction of pro-coagulant and pro-inflammatory states, and platelet dysfunction. We believe this can guide future studies aiming to unravel the molecular mechanisms underlying coagulopathy in leptospirosis to improve our understanding based on evidence, which will give insight into novel interventions to tackle the disease.

Thermophile research has been transformed over the past decade by advances in genome sequencing. Once centered on culture collections and physiological studies of terrestrial hot springs and deep-sea hydrothermal vents, the field now employs amplicon sequencing, shotgun metagenomics, and long-read platforms to reveal the diversity, ecology, and genomic potential of thermophiles. Metagenome-assembled genomes (MAGs), metatranscriptomes, and metaproteomes have become crucial for linking taxonomy with function, uncovering previously hidden microbial dark matter in heated ecosystems. Bioinformatics, increasingly integrated with machine learning, has expanded insights into microbial biology, biomolecules, and ecological interactions. These advances highlight the broader environmental significance of thermophiles, spanning fundamental roles in ecosystem processes to practical applications. In 2015, we published Thermophiles in the Genomic Era: Biodiversity, Science, and Application to capture early next-generation sequencing milestones. A decade later, with tremendous progress achieved, this review revisits the field by synthesizing recent advances across viruses, planktonic thermophiles, and biofilm communities, emphasizing the power of genome-resolved approaches. We also highlight overlooked areas, opportunities for ecological integration and predictive modeling, and the importance of translating discoveries into biotechnological innovation. Our aim is to provide young researchers with a roadmap of emerging questions and strategies likely to shape the next decade of thermophile research.

Crohn's disease (CD) is a chronic inflammatory bowel disease becoming a major issue for healthcare systems in most parts of the world. While the causes of the disease are still not fully understood, the role of the microbiota has been widely demonstrated including the colonization by a particular pathovar of Escherichia coli, defined as adherent and invasive E. coli (AIEC), able to adhere to, and invade the intestinal epithelium, as well as to survive within macrophages. As the involvement of AIEC within CD pathophysiology is highly suspected, developing new strategies to limit AIEC colonization is a promising area of research. In this context, chitin and its derivatives, such as chitosan and chito-oligosaccharides (COS), possessing immunomodulatory and antimicrobial properties, could be promising candidates. This review provides a structural overview of chitin and its derivatives and summarizes the existing literature in the context of the potential beneficial effects of chitinous elements in CD and CD-like models, their capability to restrict AIEC colonization via multiple mechanisms, such as of reducing AIEC growth, countering biofilm formation, blocking bacterial adhesion, or stimulating the innate immune response. Lastly, we will explore strategies based on chitin-supplemented diet as therapeutic strategy in patients with CD.

Influenza viruses are highly contagious respiratory pathogens that cause seasonal outbreaks, leading to millions of infections and a significant number of deaths worldwide. To support rapid replication and transmission, influenza viruses hijack the host's metabolic pathways, including those involved in carbohydrate, amino acid, and lipid metabolism. Through this metabolic reprogramming, the virus leverages the host's metabolic resources to produce viral components and create specialized compartments necessary for replication and dissemination. In response, host cells activate a range of metabolic defense mechanisms to detect and counteract the virus-induced metabolic changes, resulting in a dynamic interplay that profoundly impacts the outcome of the infection. Advances in metabolomics have provided valuable insights into these complex host-virus interactions, identifying key metabolic biomarkers with potential for early diagnosis, real-time disease monitoring, and therapeutic response evaluation, especially in the early detection and management of severe influenza infections. In the future, these metabolic biomarkers could drive the development of new strategies for influenza prevention and treatment, providing a scientific foundation for precision medicine.

The incidence and prevalence of nontuberculous mycobacterial (NTM) lung disease (LD) cases are rising, with diagnosis and treatment proving difficult. With the preponderance of viable NTM in both natural and engineered environments, the understood route of human infection is through environmental exposures. In an effort to decrease the occurrence of NTM LD, methods to reduce environmental NTM exposures are of great interest to people with infection and the clinical community. In 2013, coauthor Falkinham summarized methods known at the time to reduce exposure to LD-causing Mycobacterium avium. The objective of this current review was to perform an updated PubMed, Web of Science, and Google Scholar literature search spanning 2014-2025 for newly reported methods and newer studies that expand on known mitigation strategies. In total, 31 articles were found. Among these new reports that posed new or improved methods to reduce environmental NTM exposure, risk assessment remains limited underscoring the need for more research in this area. We propose a feasible solution may be to revisit the "healthy home" concept and to consider the engineered environmental microbiome interactions when designing future homes.

The human gut microbiome is increasingly recognized as a key modulator of health and disease, with growing evidence supporting its influence on responses to cancer therapy. An important aspect of this relationship is gut microbial resilience, defined as the ability of the microbiome to recover its ecological equilibrium following disruption. Individual variations in microbial composition significantly influence resilience and, consequently, personalized responses to cancer treatments. However, the underlying functional characteristics of a resilient microbiome remain incompletely understood. Identifying specific microbial profiles with greater resilience to cancer therapies could improve the ability to predict treatment responses and mitigate adverse events. However, despite growing interest, a lack of longitudinal and mechanistic studies currently limits their clinical translation. This review examines current literature on gut microbiome compositions and individual treatment response to cancer therapy, with a focus on microbial features linked to resilience which could enable prediction of adverse response. While the use of microbial metabolites as predictive biomarkers (e.g. short-chain fatty acids and bile acids) is promising, further longitudinal and interventional studies are essential to support clinical application. Establishing specific microbial and metabolite profiles that promote resilience is essential to advance this emerging field of personalized gut-microbiome therapy.

Although biofilms pose significant challenges in healthcare and in different industries, main antibiofilm agents currently used for surface disinfection and clinical applications often exhibit harmful side effects and contribute to the development of antimicrobial resistance. To tackle this challenge many biomolecules have been studied as alternatives, including bioemulsifiers, amphiphilic polymers that exhibit low toxicity and high biodegradability yet remain largely unexplored to date. By covering publications from 1983 to early 2025, this review aims to compile the current knowledge on bioemulsifiers from different microbial sources with a focus on their relevant properties as promising antibiofilm agents. Research on probiotics, often involving producer strains isolated from dairy products and animal microbiomes, focusing on marine-derived microorganisms were the most prominent fields benefiting from these molecules. Among different molecules, polysaccharides stood out, especially those from cultivable bacteria. This review focuses on key physico-chemical properties, such as their ability to alter surface hydrophobicity and to inhibit quorum sensing, while providing a comprehensive overview of their putative antibiofilm mechanisms. Finally, we highlight several identified bottlenecks and discuss key strategies and recent advances in metabolic and molecular engineering to instigate the research appetite on unlocking the full potential of microbial bioemulsifiers for biofilm control and prevention.

Pore-forming toxins (PFTs) are essential virulence factors produced by many bacterial pathogens, enabling tissue invasion, nutrient acquisition, and immune evasion. Neutralizing these toxins offers a promising therapeutic avenue to mitigate infection symptoms and slow disease progression. Recent research highlights the potential of host-inspired strategies targeting toxin-membrane interactions. Statins and oxysterols disrupt intracellular cholesterol synthesis and trafficking to reduce its abundance in cell membranes, mimicking natural cellular defenses against PFTs. Aminosterols alter membrane properties to hinder toxin binding and pore formation. Nanoparticle-based decoys, such as artificial liposomes composed of the lipids cholesterol and sphingomyelin or recycled cell membranes, act as toxin traps, sequestering PFTs to protect host tissues. These nanoparticles demonstrate broad-spectrum efficacy across many bacterial species and offer additional functions, such as scavenging inflammatory cytokines. This review evaluates the clinical potential of these emerging treatment strategies and discusses the advantages of leveraging host factors to mitigate bacterial virulence rather than directly targeting toxins. Such host-inspired approaches represent a novel and complementary addition to the arsenal against antibiotic-resistant bacterial pathogens.