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Expert Review of Anti-infective Therapy Jun 2020: The emergence of multi- and pan-drug-resistant bacteria represents a global crisis that calls for the development of alternative anti-infective strategies. These... (Review)
Review
: The emergence of multi- and pan-drug-resistant bacteria represents a global crisis that calls for the development of alternative anti-infective strategies. These comprise anti-virulence approaches, which target pathogenicity without exerting a bacteriostatic or bactericidal effect and are claimed to reduce the development of resistance. Because in many pathogens, quorum-sensing (QS) systems control the expression of virulence factors, interference with QS, or quorum-quenching, is often proposed as a strategy with a broad anti-virulence effect.: We discuss the role and regulatory targets of QS control in selected Gram-positive and Gram-negative bacteria, focusing on those with clinical importance and QS control of virulence. We present the components of QS systems that form possible targets for the development of anti-virulence drugs and discuss recent research on quorum-quenching approaches to control bacterial infection.: While there has been extensive research on QS systems and quorum-quenching approaches, there is a paucity of in-vivo research using adequate animal models to substantiate applicability. In-vivo research on QS blockers needs to be intensified and optimized to use clinically relevant setups, in order to underscore that such drugs can be used effectively to overcome problems associated with the treatment of severe infections by antibiotic-resistant pathogens.
Topics: Animals; Anti-Bacterial Agents; Drug Development; Drug Resistance, Multiple, Bacterial; Gram-Negative Bacteria; Gram-Negative Bacterial Infections; Gram-Positive Bacteria; Gram-Positive Bacterial Infections; Humans; Quorum Sensing
PubMed: 32243194
DOI: 10.1080/14787210.2020.1750951 -
Trends in Microbiology Aug 2022Invasive bacteria colonise their host tissues by establishing niches inside eukaryotic cells, where they grow either in the cytosol or inside a specialised vacuole.... (Review)
Review
Invasive bacteria colonise their host tissues by establishing niches inside eukaryotic cells, where they grow either in the cytosol or inside a specialised vacuole. These two distinct intracellular lifestyles both present benefits but also impose various constraints on pathogenic microorganisms, in terms of nutrient acquisition, space requirements, exposure to immune responses, and ability to disseminate. Here we review the major characteristics of cytosolic and vacuolar lifestyles and the strategies used by bacteria to overcome challenges specific to each compartment. Recent research providing evidence that these scenarios are not mutually exclusive is presented, with the dual lifestyles of two foodborne pathogens, Listeria monocytogenes and Salmonella Typhimurium, discussed in detail. Finally, we elaborate on the conceptual implications of polyvalence from the perspective of host-pathogen interactions.
Topics: Cytosol; Host-Pathogen Interactions; Listeria monocytogenes; Salmonella typhimurium; Vacuoles
PubMed: 35168833
DOI: 10.1016/j.tim.2022.01.015 -
IUBMB Life Jul 2019Propelled by the overuse and inappropriate use of antibiotics, antimicrobial resistance is now widespread in the environment, leaving us with limited drugs for treating... (Review)
Review
Propelled by the overuse and inappropriate use of antibiotics, antimicrobial resistance is now widespread in the environment, leaving us with limited drugs for treating a large number of resistant pathogens. The use of bacteriophages that kill bacteria has come up as a viable alternative to circumvent the antimicrobial resistance crisis, and phage therapy-based approaches are fast advancing in recent times. In this minireview, we try to describe the advantages associated with phage therapy and update the latest developments in the field including the clinical trials that are underway. Particularly, we highlight the synergistic bactericidal effect of phages in the presence of sub-lethal dose of antibiotics and the potency of lytic phages, and their hydrolytic enzymes in expunging pathogens from drug-tolerant biofilms and animal farm produce. We also discuss how major challenges, including human immune response to phage components, development of bacterial resistance and elimination of intracellular pathogens, presented as potential setbacks to the implementation of phage therapy is being removed using engineered phages and novel formulations. © 2019 IUBMB Life, 2019.
Topics: Animals; Anti-Bacterial Agents; Bacteria; Bacterial Infections; Bacteriophages; Biofilms; Drug Resistance, Bacterial; Humans; Phage Therapy
PubMed: 30674079
DOI: 10.1002/iub.2010 -
Frontiers in Cellular and Infection... 2023Obligate intracellular pathogens occupy one of two niches - free in the host cell cytoplasm or confined in a membrane-bound vacuole. Pathogens occupying membrane-bound... (Review)
Review
Obligate intracellular pathogens occupy one of two niches - free in the host cell cytoplasm or confined in a membrane-bound vacuole. Pathogens occupying membrane-bound vacuoles are sequestered from the innate immune system and have an extra layer of protection from antimicrobial drugs. However, this lifestyle presents several challenges. First, the bacteria must obtain membrane or membrane components to support vacuole expansion and provide space for the increasing bacteria numbers during the log phase of replication. Second, the vacuole microenvironment must be suitable for the unique metabolic needs of the pathogen. Third, as most obligate intracellular bacterial pathogens have undergone genomic reduction and are not capable of full metabolic independence, the bacteria must have mechanisms to obtain essential nutrients and resources from the host cell. Finally, because they are separated from the host cell by the vacuole membrane, the bacteria must possess mechanisms to manipulate the host cell, typically through a specialized secretion system which crosses the vacuole membrane. While there are common themes, each bacterial pathogen utilizes unique approach to establishing and maintaining their intracellular niches. In this review, we focus on the vacuole-bound intracellular niches of , and .
Topics: Vacuoles; Coxiella burnetii; Anaplasma phagocytophilum; Chlamydia trachomatis; Ehrlichia chaffeensis
PubMed: 37645379
DOI: 10.3389/fcimb.2023.1206037 -
Journal of Bacteriology Jul 2019The 25th annual Midwest Microbial Pathogenesis Conference (MMPC) was held at the University of Iowa from 28 to 30 September 2018. The conference has a long-standing... (Review)
Review
The 25th annual Midwest Microbial Pathogenesis Conference (MMPC) was held at the University of Iowa from 28 to 30 September 2018. The conference has a long-standing tradition of providing scientists from the Midwest with a forum to present and discuss cutting-edge advances in microbial pathogenesis with particular focus on bacterial interactions with the environment, host, and other microbes. This review summarizes the genesis of the MMPC, topics presented at the conference, and articles found in the special MMPC sections of this issue of the .
Topics: Bacteria; Congresses as Topic; Host-Pathogen Interactions; Humans; Iowa; Microbial Interactions; Microbiology; Universities; Virulence
PubMed: 30988032
DOI: 10.1128/JB.00239-19 -
International Journal of Molecular... Mar 2020Plants are associated with hundreds of thousands of microbes that are present outside on the surfaces or colonizing inside plant organs, such as leaves and roots.... (Review)
Review
Plants are associated with hundreds of thousands of microbes that are present outside on the surfaces or colonizing inside plant organs, such as leaves and roots. Plant-associated microbiota plays a vital role in regulating various biological processes and affects a wide range of traits involved in plant growth and development, as well as plant responses to adverse environmental conditions. An increasing number of studies have illustrated the important role of microbiota in crop plant growth and environmental stress resistance, which overall assists agricultural sustainability. Beneficial bacteria and fungi have been isolated and applied, which show potential applications in the improvement of agricultural technologies, as well as plant growth promotion and stress resistance, which all lead to enhanced crop yields. The symbioses of arbuscular mycorrhizal fungi, rhizobia and species with their host plants have been intensively studied to provide mechanistic insights into the mutual beneficial relationship of plant-microbe interactions. With the advances in second generation sequencing and omic technologies, a number of important mechanisms underlying plant-microbe interactions have been unraveled. However, the associations of microbes with their host plants are more complicated than expected, and many questions remain without proper answers. These include the influence of microbiota on the allelochemical effect caused by one plant upon another via the production of chemical compounds, or how the monoculture of crops influences their rhizosphere microbial community and diversity, which in turn affects the crop growth and responses to environmental stresses. In this review, first, we systematically illustrate the impacts of beneficial microbiota, particularly beneficial bacteria and fungi on crop plant growth and development and, then, discuss the correlations between the beneficial microbiota and their host plants. Finally, we provide some perspectives for future studies on plant-microbe interactions.
Topics: Bacteria; Crops, Agricultural; Microbiota; Plant Development; Signal Transduction; Symbiosis
PubMed: 32150945
DOI: 10.3390/ijms21051792 -
Microbial Genomics Jul 2020Groundbreaking studies conducted in the mid-1980s demonstrated the possibility of sequencing ancient DNA (aDNA), which has allowed us to answer fundamental questions... (Review)
Review
Groundbreaking studies conducted in the mid-1980s demonstrated the possibility of sequencing ancient DNA (aDNA), which has allowed us to answer fundamental questions about the human past. Microbiologists were thus given a powerful tool to glimpse directly into inscrutable bacterial history, hitherto inaccessible due to a poor fossil record. Initially plagued by concerns regarding contamination, the field has grown alongside technical progress, with the advent of high-throughput sequencing being a breakthrough in sequence output and authentication. Albeit burdened with challenges unique to the analysis of bacteria, a growing number of viable sources for aDNA has opened multiple avenues of microbial research. Ancient pathogens have been extracted from bones, dental pulp, mummies and historical medical specimens and have answered focal historical questions such as identifying the aetiological agent of the black death as . Furthermore, ancient human microbiomes from fossilized faeces, mummies and dental plaque have shown shifts in human commensals through the Neolithic demographic transition and industrial revolution, whereas environmental isolates stemming from permafrost samples have revealed signs of ancient antimicrobial resistance. Culminating in an ever-growing repertoire of ancient genomes, the quickly expanding body of bacterial aDNA studies has also enabled comparisons of ancient genomes to their extant counterparts, illuminating the evolutionary history of bacteria. In this review we summarize the present avenues of research and contextualize them in the past of the field whilst also pointing towards questions still to be answered.
Topics: Animals; Bacteria; Bone and Bones; DNA, Ancient; Dental Pulp; Feces; Genome, Bacterial; High-Throughput Nucleotide Sequencing; Humans; Mummies; Sequence Analysis, DNA
PubMed: 32598277
DOI: 10.1099/mgen.0.000384 -
Archives of Microbiology Aug 2021A homeostatic balance exists between the resident microbiota in the oral cavity and the host. Perturbations of the oral microbiota under particular conditions can... (Review)
Review
A homeostatic balance exists between the resident microbiota in the oral cavity and the host. Perturbations of the oral microbiota under particular conditions can contribute to the growth of non-oral pathogens that are hard to kill because of their higher resistance to antimicrobials, raising the probability of treatment failure and reinfection. The presence of these bacteria in the oral cavity has been proven to be associated with several oral diseases such as periodontitis, caries, and gingivitis, and systemic diseases of importance in clinical medicine such as cystic fibrosis, HIV, and rheumatoid arthritis. However, it is still controversial whether these species are merely transient members or unique to the oral cavity. Mutualistic and antagonistic interactions between the oral microbiota and non-oral pathogens can also occur, though the mechanisms used by these bacteria are not clear. Therefore, this review presents an overview of the current knowledge about the presence of non-oral bacteria in the oral cavity, their relationship with systemic and oral diseases, and their interactions with oral bacteria.
Topics: Bacteria; Gastrointestinal Microbiome; Humans; Mouth
PubMed: 33791834
DOI: 10.1007/s00203-021-02300-y -
International Journal of Molecular... Jan 2020The Ton complex is a molecular motor that uses the proton gradient at the inner membrane of Gram-negative bacteria to generate force and movement, which are transmitted... (Review)
Review
The Ton complex is a molecular motor that uses the proton gradient at the inner membrane of Gram-negative bacteria to generate force and movement, which are transmitted to transporters at the outer membrane, allowing the entry of nutrients into the periplasmic space. Despite decades of investigation and the recent flurry of structures being reported by X-ray crystallography and cryoEM, the mode of action of the Ton molecular motor has remained elusive, and the precise stoichiometry of its subunits is still a matter of debate. This review summarizes the latest findings on the Ton system by presenting the recently reported structures and related reports on the stoichiometry of the fully assembled complex.
Topics: Bacterial Proteins; Escherichia coli; Escherichia coli Proteins; Gram-Negative Bacteria; Gram-Negative Bacterial Infections; Humans; Membrane Proteins; Models, Molecular; Protein Multimerization; Proton-Motive Force
PubMed: 31936081
DOI: 10.3390/ijms21020375 -
International Journal of Molecular... Dec 2021has a strong carbohydrate utilization ability. This characteristic plays an important role in its gastrointestinal tract colonization and probiotic effects. LP-F1...
has a strong carbohydrate utilization ability. This characteristic plays an important role in its gastrointestinal tract colonization and probiotic effects. LP-F1 presents a high carbohydrate utilization capacity. The genome analysis of 165 strains indicated the species has a plenty of carbohydrate metabolism genes, presenting a strain specificity. Furthermore, two-component systems (TCSs) analysis revealed that the species has more TCSs than other lactic acid bacteria, and the distribution of TCS also shows the strain specificity. In order to clarify the sugar metabolism mechanism under different carbohydrate fermentation conditions, the expressions of 27 carbohydrate metabolism genes, catabolite control protein A (CcpA) gene and TCSs genes were analyzed by quantitative real-time PCR technology. The correlation analysis between the expressions of regulatory genes and sugar metabolism genes showed that some regulatory genes were correlated with most of the sugar metabolism genes, suggesting that some TCSs might be involved in the regulation of sugar metabolism.
Topics: Carbohydrate Metabolism; Fermentation; Lactobacillaceae; Lactobacillus; Lactobacillus plantarum; Probiotics
PubMed: 34948249
DOI: 10.3390/ijms222413452