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Science (New York, N.Y.) Dec 2023The human gut microbiome plays an important role in resisting colonization of the host by pathogens, but we lack the ability to predict which communities will be...
The human gut microbiome plays an important role in resisting colonization of the host by pathogens, but we lack the ability to predict which communities will be protective. We studied how human gut bacteria influence colonization of two major bacterial pathogens, both in vitro and in gnotobiotic mice. Whereas single species alone had negligible effects, colonization resistance greatly increased with community diversity. Moreover, this community-level resistance rested critically upon certain species being present. We explained these ecological patterns through the collective ability of resistant communities to consume nutrients that overlap with those used by the pathogen. Furthermore, we applied our findings to successfully predict communities that resist a novel target strain. Our work provides a reason why microbiome diversity is beneficial and suggests a route for the rational design of pathogen-resistant communities.
Topics: Animals; Humans; Mice; Gastrointestinal Microbiome; Nutrients; Host-Pathogen Interactions; Klebsiella pneumoniae; Salmonella typhimurium; Symbiosis; Germ-Free Life; Klebsiella Infections; Salmonella Infections; Escherichia coli
PubMed: 38096285
DOI: 10.1126/science.adj3502 -
Trends in Microbiology Oct 2023
Topics: Enterobacteriaceae; Dickeya; Plant Diseases
PubMed: 36958995
DOI: 10.1016/j.tim.2023.03.003 -
Journal of Neuro-ophthalmology : the... Dec 2023
Topics: Humans; Bartonella; Retinitis; Bartonella henselae; Cat-Scratch Disease
PubMed: 37651205
DOI: 10.1097/WNO.0000000000002000 -
Trends in Microbiology Jan 2024is a Gram negative, facultative intracellular bacterium that resides in the rhizosphere of tropical soils. causes melioidosis, which is transmitted by cutaneous entry,...
is a Gram negative, facultative intracellular bacterium that resides in the rhizosphere of tropical soils. causes melioidosis, which is transmitted by cutaneous entry, ingestion, or inhalation of contaminated soil or water. Infection with can cause a wide array of clinical symptoms such as pneumonia, bone, joint, skin, genitourinary, and central nervous system infections, as well as parotid abscesses in children. Mammalian virulence is linked to the intracellular life cycle, which begins with attachment and internalization by host cells. can infect a wide range of eukaryotic cells, including macrophages, monocytes, and neutrophils, as well as nonphagocytic cells. Once internalized, a type 3 secretion system (T3SS) facilitates escape from the phagosome, and the bacteria replicate in the cytoplasm. Autotransporter protein BimA mediates actin polymerization, enabling to spread, cell to cell, using actin-based motility. This process, coupled with the activity of a type 6 secretion system (T6SS-5), results in host membrane fusion and the formation of multinucleated giant cells. Capsule polysaccharides also contribute to virulence and evasion of host innate immunity. Treatment of infections is complicated by the organism’s intrinsic resistance to multiple classes of antimicrobials, largely due to an abundance of efflux pumps and reduced outer membrane permeability. While is commonly associated with endemic ‘hotspots’ in southeast Asia and northern Australia, there is increasing evidence that it is likely endemic in a large range of tropical and subtropical areas, including regions in Africa, South America, the Middle East, Central America, and the Caribbean. Soil and climate conditions favorable for survival are also found in additional areas worldwide. Consequently, it is important for clinical and public health laboratories located outside of high-endemicity areas to be aware of , as well as for improved diagnostic and reporting methods.
Topics: Burkholderia pseudomallei; Burkholderia
PubMed: 37634974
DOI: 10.1016/j.tim.2023.07.008 -
Journal of Clinical Microbiology Aug 2023Bacteria of the genus Brucella are facultative intracellular parasites that cause brucellosis, a severe animal and human disease. Recently, a group of taxonomists merged...
Bacteria of the genus Brucella are facultative intracellular parasites that cause brucellosis, a severe animal and human disease. Recently, a group of taxonomists merged the brucellae with the primarily free-living, phylogenetically related spp. in the genus Brucella. This change, founded only on global genomic analysis and the fortuitous isolation of some opportunistic spp. from medically compromised patients, has been automatically included in culture collections and databases. We argue that clinical and environmental microbiologists should not accept this nomenclature, and we advise against its use because (i) it was presented without in-depth phylogenetic analyses and did not consider alternative taxonomic solutions; (ii) it was launched without the input of experts in brucellosis or ; (iii) it applies a non-consensus genus concept that disregards taxonomically relevant differences in structure, physiology, population structure, core-pangenome assemblies, genome structure, genomic traits, clinical features, treatment, prevention, diagnosis, genus description rules, and, above all, pathogenicity; and (iv) placing these two bacterial groups in the same genus creates risks for veterinarians, medical doctors, clinical laboratories, health authorities, and legislators who deal with brucellosis, a disease that is particularly relevant in low- and middle-income countries. Based on all this information, we urge microbiologists, bacterial collections, genomic databases, journals, and public health boards to keep the Brucella and genera separate to avoid further bewilderment and harm.
Topics: Ochrobactrum; Brucella; Terminology as Topic; Phylogeny; Brucellosis; Humans; Opportunistic Infections
PubMed: 37395662
DOI: 10.1128/jcm.00438-23 -
Research in Microbiology 2023Myxobacteria are Gram-negative eubacteria and they thrive in a variety of habitats including soil rich in organic matter, rotting wood, animal dung and marine... (Review)
Review
Myxobacteria are Gram-negative eubacteria and they thrive in a variety of habitats including soil rich in organic matter, rotting wood, animal dung and marine environment. Myxobacteria are a promising source of new compounds associated with diverse bioactive spectrum and unique mode of action. The genome information of myxobacteria has revealed many orphan biosynthetic pathways indicating that these bacteria can be the source of several novel natural products. In this review, we highlight the biology of myxobacteria with emphasis on their habitat, life cycle, isolation methods and enlist all the bioactive secondary metabolites purified till date and their mode of action.
Topics: Animals; Myxococcales; Bacteria; Biology; Biological Products
PubMed: 37169232
DOI: 10.1016/j.resmic.2023.104079 -
Cell Host & Microbe Oct 2023Salmonella employs an arsenal of different tools to obtain iron. In this issue of Cell Host & Microbe, Spiga et al. add to these mechanisms, revealing that commensal...
Salmonella employs an arsenal of different tools to obtain iron. In this issue of Cell Host & Microbe, Spiga et al. add to these mechanisms, revealing that commensal Bacteroides species use a specialized lipoprotein to acquire catecholate siderophores from Enterobacteriaceae, only to have them reacquired by Salmonella.
Topics: Siderophores; Iron; Enterobacteriaceae; Salmonella
PubMed: 37827119
DOI: 10.1016/j.chom.2023.09.009 -
Seminars in Cell & Developmental Biology 2023Plant diseases caused by soilborne pathogens are a major limiting factor in crop production. Bacterial wilt disease, caused by soilborne bacteria in the Ralstonia... (Review)
Review
Plant diseases caused by soilborne pathogens are a major limiting factor in crop production. Bacterial wilt disease, caused by soilborne bacteria in the Ralstonia solanacearum Species Complex (Ralstonia), results in significant crop loss throughout the world. Ralstonia invades root systems and colonizes plant xylem, changing plant physiology and ultimately causing plant wilting in susceptible varieties. Elucidating how Ralstonia invades and colonizes plants is central to developing strategies for crop protection. Here we review Ralstonia pathogenesis from root detection and attachment, early root colonization, xylem invasion and subsequent wilting. We focus primarily on studies in tomato from the last 5-10 years. Recent work has identified elegant mechanisms Ralstonia uses to adapt to the plant xylem, and has discovered new genes that function in Ralstonia fitness in planta. A picture is emerging of an amazingly versatile pathogen that uses multiple strategies to make its surrounding environment more hospitable and can adapt to new environments.
Topics: Ralstonia; Virulence; Ralstonia solanacearum; Plants; Plant Diseases
PubMed: 36526528
DOI: 10.1016/j.semcdb.2022.12.002 -
Ugeskrift For Laeger Jan 2024We present a case report detailing therapeutic application of two lytic antipseudomonal bacteriophages to treat a chronic relapsing Pseudomonas aeruginosa infection of a...
We present a case report detailing therapeutic application of two lytic antipseudomonal bacteriophages to treat a chronic relapsing Pseudomonas aeruginosa infection of a prosthetic aortic graft. As there are currently no Danish laboratories offering phages for clinical therapy, and this case, to our knowledge represents the first applied phage therapy in Denmark, the practical and regulatory aspects of offering this treatment option in Denmark is briefly reviewed along with the clinical case.
Topics: Humans; Bacteriophages; Pseudomonas; Pseudomonas Phages; Blood Vessel Prosthesis; Pseudomonas aeruginosa
PubMed: 38305316
DOI: 10.61409/V09230617 -
Clinical Infectious Diseases : An... Nov 2023Bacteriophages (phages) have shown great potential as natural antimicrobials against extracellular pathogens (eg, Escherichia coli or Klebsiella pneumoniae), but little... (Review)
Review
Bacteriophages (phages) have shown great potential as natural antimicrobials against extracellular pathogens (eg, Escherichia coli or Klebsiella pneumoniae), but little is known about how they interact with intracellular targets (eg, Shigella spp., Salmonella spp., Mycobacterium spp.) in the mammalian host. Recent research has demonstrated that phages can enter human cells. However, for the design of successful clinical applications, further investigation is required to define their subcellular behavior and to understand the complex biological processes that underlie the interaction with their bacterial targets. In this review, we summarize the molecular evidence of phage internalization in eucaryotic cells, with specific focus on proof of phage activity against their bacterial targets within the eucaryotic host, and the current proposed strategies to overcome poor penetrance issues that may impact therapeutic use against the most clinically relevant intracellular pathogens.
Topics: Animals; Humans; Bacteriophages; Bacteria; Klebsiella pneumoniae; Escherichia coli; Mammals
PubMed: 37932114
DOI: 10.1093/cid/ciad515