Critical Reviews in Microbiology最新文献

Pseudomonas aeruginosa (PA), an opportunistic human pathogen that is frequently linked with chronic infections in immunocompromised individuals, is also metabolically versatile, and thrives in diverse environments. Additionally, studies report that PA can interact with other microorganisms, such as bacteria, and fungi, producing unique metabolites that can modulate the host immune response, and contribute to disease pathogenesis. This review summarizes the current knowledge related to the metabolic interactions of PA with other microorganisms (Staphylococcus, Acinetobacter, Klebsiella, Enterococcus, and Candida) and human hosts, and the importance of these interactions in a polymicrobial context. Further, we highlight the potential applications of studying these metabolic interactions toward designing better diagnostic tools, and therapeutic strategies to prevent, and treat infections caused by this pathogen.

Lipids play essential roles in the cell as components of cellular membranes, signaling molecules, and energy storage sources. Lipid droplets are cellular organelles composed of neutral lipids, such as triglycerides and cholesterol esters, and are also considered as cellular energy reserves, yet new functions have been recently associated with these structures, such as regulators of oxidative stress and cellular lipotoxicity, as well as modulators of pathogen infection through immune regulation. Lipid metabolism and lipid droplets participate in the infection process of many RNA viruses and control their replication and assembly, among others. Here, we review and discuss the contribution of lipid metabolism and lipid droplets over the replication cycle of RNA viruses, altogether pointing out potentially new pharmacological antiviral targets associated with lipid metabolism.

Helicobacter pylori is a gram-negative, spiral-shaped, flagellated bacterium that colonizes the stomach of half the world's population. Helicobacter pylori infection causes pathologies of varying severity. Standard oral therapy fails in 15-20% since the barriers of the oral route decrease the bioavailability of antibiotics and the intrinsic factors of bacteria increase the rates of resistance. Nanoparticles and microparticles are promising strategies for drug delivery into the gastric mucosa and targeting H. pylori. The variety of building blocks creates systems with distinct colloidal, surface, and biological properties. These features improve drug-pathogen interactions, eliminate drug depletion and overuse, and enable the association of multiple actives combating H. pylori on several fronts. Nanoparticles and microparticles are successfully used to overcome the barriers of the oral route, physicochemical inconveniences, and lack of selectivity of current therapy. They have proven efficient in employing promising anti-H. pylori compounds whose limitation is oral route instability, such as some antibiotics and natural products. However, the current challenge is the applicability of these strategies in clinical practice. For this reason, strategies employing a rational design are necessary, including in the development of nano- and microsystems for the oral route.

The classical microbiology techniques have inherent limitations in unraveling the complexity of microbial communities, necessitating the pivotal role of sequencing in studying the diversity of microbial communities. Whole genome sequencing (WGS) enables researchers to uncover the metabolic capabilities of the microbial community, providing valuable insights into the microbiome. Herein, we present an overview of the rapid advancements achieved thus far in the use of WGS in microbiome research. There was an upsurge in publications, particularly in 2021 and 2022 with the United States, China, and India leading the metagenomics research landscape. The Illumina platform has emerged as the widely adopted sequencing technology, whereas a significant focus of metagenomics has been on understanding the relationship between the gut microbiome and human health where distinct bacterial species have been linked to various diseases. Additionally, studies have explored the impact of human activities on microbial communities, including the potential spread of pathogenic bacteria and antimicrobial resistance genes in different ecosystems. Furthermore, WGS is used in investigating the microbiome of various animal species and plant tissues such as the rhizosphere microbiome. Overall, this review reflects the importance of WGS in metagenomics studies and underscores its remarkable power in illuminating the variety and intricacy of the microbiome in different environments.

The oral cavity contains a site-specific microbiota that interacts with host cells to regulate many physiological processes in the human body. Emerging evidence has suggested that changes in the oral microbiota can increase the risk of lung cancer (LC), and the oral microbiota is also altered in patients with LC. Human and animal studies have shown that oral microecological disorders and/or specific oral bacteria may play an active role in the occurrence and development of LC through direct and/or indirect mechanisms. These studies support the potential of oral microbiota in the clinical treatment of LC. Oral microbiota may therefore be used in the prevention and treatment of LC and to improve the side effects of anticancer therapy by regulating the balance of the oral microbiome. Specific oral microbiota in LC may also be used as screening or predictive biomarkers. This review summarizes the main findings in research on oral microbiome-related LC and discusses current challenges and future research directions.

Type 2 diabetes (T2D) is a metabolic disease characterized by chronic hyperglycemia because of insulin resistance (IR) andor pancreatic β-cell dysfunction. Last century research showed that gut microbiota has a direct effect on metabolism and metabolic diseases. New studies into the human microbiome and its connection with the host is making it possible to develop new therapies for a wide variety of diseases. Inflammation is a well-known precursor to metabolic syndrome, which increases the risk of hypertension, visceral obesity, and dyslipidemia, which can lead to T2D through the damage of pancreatic β-cell and reduce insulin secretion. Current understanding for beneficial effects of probiotics in T2D strictly rely on both animal and clinical data, which mostly focused on their impact on IR, anthropometric parameters, glycemic control and markers of chronic systemic inflammation. From the other hand, there is a lack of evidence-based probiotic efficacy on pancreatic β-cell function in terms of T2D and related metabolic disorders. Therefore, current review will focus on the efficacy of probiotics for the protection of β-cells damage and it`s mechanism in patients with T2D.

Bile acids (BAs) are an important metabolite produced by cholesterol catabolism. It serves important roles in glucose and lipid metabolism and host-microbe interaction. Recent research has shown that different gut-microbiota can secrete different metabolic-enzymes to mediate the deconjugation, dehydroxylation and epimerization of BAs. In addition, microbes mediate BAs transformation and exert physiological functions in metabolic diseases may have a potentially close relationship with diet. Therefore, elaborating the pathways by which gut microbes mediate the transformation of BAs through enzymatic reactions involved are principal to understand the mechanism of effects between dietary patterns, gut microbes and BAs, and to provide theoretical knowledge for the development of functional foods to regulate metabolic diseases. In the present review, we summarized works on the physiological function of BAs, as well as the classification and composition of BAs in different animal models and its organs. In addition, we mainly focus on the bidirectional interactions of gut microbes with BAs transformation, and discuss the effects of diet on microbial transformation of BAs. Finally, we raised the question of further in-depth investigation of the food-gut microbial-BAs relationship, which might contribute to the improvement of metabolic diseases through dietary interventions in the future.

Pseudomonas aeruginosa can efficiently adapt to changing environmental conditions due to its ubiquitous nature, intrinsic/acquired/adaptive resistance mechanisms, high metabolic versatility, and the production of numerous virulence factors. As a result, P. aeruginosa becomes an opportunistic pathogen, causing chronic infection in the lungs and several organs of patients suffering from cystic fibrosis. Biofilm established by P. aeruginosa in host tissues and medical device surfaces has been identified as a major obstruction to antimicrobial therapy. P. aeruginosa is very likely to be closely associated with the various microorganisms in the host tissues or organs in a pathogenic or nonpathogenic behavior. Aside from host-derived molecules, other beneficial and pathogenic microorganisms produce a diverse range of secondary metabolites that either directly or indirectly favor the persistence of P. aeruginosa. Thus, it is critical to understand how P. aeruginosa interacts with different molecules and ions in the host and abiotic environment to produce extracellular polymeric substances and virulence factors. Thus, the current review discusses how various natural and synthetic molecules in the environment induce biofilm formation and the production of multiple virulence factors.

Anaerobic fungi are known to migrate and establish a 3D network of biofilms (microbiomes) and live invisible in the rumen and terrestrial subsurface, deep-sea - marine, and anoxic environment. They deserve our attention to understand anoxic fungal ecology and functions and develop new products and solutions. Such fungi activate unique genes to produce various polysaccharidases deemed essential for degrading plants' lignocellulosic materials. Nutrient release, recycling, and physical support by anaerobic fungi are crucial for microbiome formation. Multiple reports point to the ability of strictly anaerobic and facultative fungi to adapt and live in anoxic subsurface. Deep-sea sediments and natural anoxic methane-emitting salty waters of sulfidic springs offer suitable habitats for developing prokaryotic-fungal microbiomes. Researchers found a billion-year-old fossil of the fungus-prokaryotic sulfate-reducing consortium buried in deep-sea biospheres. Fungal spores' ability to migrate, even after germination, through sandy layers demonstrates their potential to move up and down porous geological layers or rock fissures. Selective fungal affinity to specific wood in wood chip arrays might help differentiate viable anaerobic fungi from an anoxic environment for their rapid collection and investigation. New collection methods, cultivation, gene expression, and drug and enzyme activity analyses can boost anaerobic fungal research.