Critical Reviews in Microbiology最新文献

Listeria monocytogenes (L. monocytogenes) is an opportunistic intracellular pathogen that causes listeriosis in human and leads to high mortality rate. L. monocytogenes is resistant to various antibiotics due to its ability to form biofilm. Designing a new generation of antibiotics is a very expensive and time-consuming process. Moreover, the protection of antibiotics via drug delivery system can promote their effectiveness and bioavailability. Nanomedicine can be a promising tool for treating intracellular bacteria and preventing the recurrence of infections. Nanocarriers can be employed as antibacterial agents or as a carrier for antibacterial agents. In the present review, the application of nanotechnology has been discussed for the prevention and treatment of Listeria infection. According to the studies, the application of nanomaterials can be a potential strategy to eradicate infections caused by L. monocytogenes.

There is growing evidence that microbial dysbiosis is intimately related to carcinogenesis across several types of human cancer. Neisseria gonorrhoeae is best known for causing acute exudative genitourinary infection in males. N. gonorrhoeae can also cause chronic, asymptomatic infection of the female genitourinary tract along with the oropharynx and rectum of both sexes. Epidemiological studies suggest that N. gonorrhoeae is an independent risk factor for cancer of the anus, bladder, cervix, prostate, and oropharynx. It is not clear however if this association is causal. The purpose of this review is to appraise epidemiological, experimental, and clinical data in order to understand the possible carcinogenic potential of this sexually transmitted bacterium.

Dental biofilm is a highly complicated and dynamic structure comprising not only microbial communities but also the surrounding matrix of extracellular polymeric substances (EPS), including polysaccharides, proteins, extracellular DNA (eDNA) and other biopolymers. In recent years, the important role of bacterial eDNA in dental biofilms has gradually attracted attention. In this review, we present recent studies on the presence, dynamic conformation and release of oral bacterial eDNA. Moreover, updated information on functions associated with oral bacterial eDNA in biofilm formation, antibiotic resistance, activation of the immune system and immune evasion is highlighted. Finally, we summarize the role of oral bacterial eDNA as a promising target for the treatment of oral diseases. Increasing insight into the versatile roles of bacterial eDNA in dental biofilms will facilitate the prevention and treatment of biofilm-induced oral infections.

Nucleos(t)ide analogs constitute a diverse group of compounds derived from nucleosides and nucleotides, playing a crucial role in various biological processes. These analogs exhibit a wide range of applications, including their use as additives, antiviral, and anticancer agents, which makes them valuable in food and medical research. In this review, we will explore the applications of nucleos(t)ide analogs across different fields and discuss the latest advances in engineering and optimization strategies aimed at improving their production efficiency and tailoring their properties for specific purposes. The article focuses on the design of microbial cell factories and their critical role in the production of nucleos(t)ide analogs. By leveraging microbial biosynthesis pathways and employing strategies such as metabolic engineering, researchers are optimizing the synthesis pathways of nucleos(t)ide analogs. This optimization enhances both the yield and diversity of nucleos(t)ide analogs, leading to the creation of novel compounds with enhanced bioactivity and therapeutic potential. Consequently, these efforts are driving significant advancements in drug discovery and biotechnology.

Extracellular vesicles (EVs) are cell membrane-derived structures between 20-400 nm in size. In bacteria, EVs play a crucial role in molecule secretion, cell wall biogenesis, cell-cell communication, biofilm development, and host-pathogen interactions. Despite these increasing reports of bacterial-derived vesicles, there remains a limited number of studies that summarize oral bacterial EVs, their cargo, and their main biological functions. Therefore, the aim of this review is to present the latest research on oral bacteria-derived EVs and how they can modulate various physiological and pathological processes in the oral cavity, including the pathogenesis of highly relevant diseases such as dental caries and periodontitis and their systemic complications. Overall, caries-associated bacteria (such as Streptococcus mutans) as well as periodontal pathogens (including the red complex pathogens Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola) have all been shown to produce EVs that carry an array of virulent factors and molecules involved in biofilm and immune modulation, bacterial adhesion, and extracellular matrix degradation. As bacterial EV production is strongly impacted by genotypic and environmental variations, the inhibition of EV genesis and secretion remains a key potential future approach against oral diseases.

Antibiotic resistance has expanded as a result of the careless use of antibiotics in the medical field, the food industry, agriculture, and other industries. By means of genetic recombination between commensal and pathogenic bacteria, the microbes obtain antibiotic resistance genes (ARGs). In bacteria, horizontal gene transfer (HGT) is the main mechanism for acquiring ARGs. With the development of high-throughput sequencing, ARG sequence analysis is now feasible and widely available. Preventing the spread of AMR in the environment requires the implementation of ARGs mapping. The metagenomic technique, in particular, has helped in identifying antibiotic resistance within microbial communities. Due to the exponential growth of experimental and clinical data, significant investments in computer capacity, and advancements in algorithmic techniques, the application of machine learning (ML) algorithms to the problem of AMR has attracted increasing attention over the past five years. The review article sheds a light on the application of bioinformatics for the antibiotic resistance monitoring. The most advanced tool currently being employed to catalog the resistome of various habitats are metagenomics and metatranscriptomics. The future lies in the hands of artificial intelligence (AI) and machine learning (ML) methods, to predict and optimize the interaction of antibiotic-resistant compounds with target proteins.

Pseudomonas aeruginosa, able to survive on the surfaces of medical devices, is a life-threatening pathogen that mainly leads to nosocomial infection especially in immunodeficient and cystic fibrosis (CF) patients. The antibiotic resistance in P. aeruginosa has become a world-concerning problem, which results in reduced and ineffective therapy efficacy. Besides intrinsic properties to decrease the intracellular content and activity of antibiotics, P. aeruginosa develops acquired resistance by gene mutation and acquisition, as well as adaptive resistance under specific situations. With in-depth research on drug resistance mechanisms and the development of biotechnology, innovative strategies have emerged and yielded benefits such as screening for new antibiotics based on artificial intelligence technology, utilizing drugs synergistically, optimizing administration, and developing biological therapy. This review summarizes the recent advances in the mechanisms of antibiotic resistance and emerging treatments for combating resistance, aiming to provide a reference for the development of therapy against drug-resistant P. aeruginosa.

The burgeoning proliferation of infections attributed to multidrug-resistant (MDR) bacterial pathogens is profoundly undermining conventional chemotherapeutic modalities, portending a grave menace to global public health. The propagation of drug resistance among bacteria is fundamentally facilitated by bacterial interactions, with extracellular vesicles (EVs) assuming a critical role in interbacterial communication. Here, we briefly delineate the methodologies for isolation, extraction, and characterization of EVs from both Gram-negative and Gram-positive bacterial origins. We further investigate assorted methodologies to augment EV production, embracing physical stimulation, chemical elicitation, and genetic engineering. Moreover, we expound on the pivotal involvement of EVs in the facilitation of bacterial drug resistance proliferation and anticipate future trajectories of research and application potential. This overview of EV-mediated novel mechanisms of horizontal gene transfer implicated in antibiotic resistance among bacteria aims to obstruct the transmission conduits of bacterial drug resistance and thus fortify public health integrity.

The formation of bacterial biofilms in the human body and on medical devices is a serious human health concern. Infections related to bacterial biofilms are often chronic and difficult to treat. Detailed information on biofilm formation and composition over time is essential for a fundamental understanding of the underlying mechanisms of biofilm formation and its response to anti-biofilm therapy. However, information on the chemical composition, structural components of biofilms, and molecular interactions regarding metabolism- and communication pathways within the biofilm, such as uptake of administered drugs or inter-bacteria communication, remains elusive. Imaging these molecules and their distribution in the biofilm increases insight into biofilm development, growth, and response to environmental factors or drugs. This systematic review provides an overview of molecular imaging techniques used for bacterial biofilm imaging. The techniques included mass spectrometry-based techniques, fluorescence-labelling techniques, spectroscopic techniques, nuclear magnetic resonance spectroscopy (NMR), micro-computed tomography (µCT), and several multimodal approaches. Many molecules were imaged, such as proteins, lipids, metabolites, and quorum-sensing (QS) molecules, which are crucial in intercellular communication pathways. Advantages and disadvantages of each technique, including multimodal approaches, to study molecular processes in bacterial biofilms are discussed, and recommendations on which technique best suits specific research aims are provided.