Virulence Factors in Hypervirulent Klebsiella pneumoniae

Frontiers in Microbiology, Journal Year: 2021, Volume and Issue: 12

Published: April 8, 2021

Hypervirulent Klebsiella pneumoniae (hvKP) has spread globally since first described in the Asian Pacific Rim. It is an invasive variant that differs from classical K. (cKP), with hypermucoviscosity and hypervirulence, causing community-acquired infections, including pyogenic liver abscess, pneumonia, meningitis, endophthalmitis. utilizes a battery of virulence factors for survival pathogenesis, such as capsule, siderophores, lipopolysaccharide, fimbriae, outer membrane proteins, type 6 secretion system, which former two are dominant. This review summarizes these hvKP-associated order to understand its molecular pathogenesis shed light on new strategies improve prevention, diagnosis, treatment hvKP-causing infection.

Language: Английский

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“Superbugs” with hypervirulence and carbapenem resistance in Klebsiella pneumoniae: the rise of such emerging nosocomial pathogens in China

Science Bulletin, Journal Year: 2023, Volume and Issue: 68(21), P. 2658 - 2670

Published: Sept. 30, 2023

Although hypervirulent Klebsiella pneumoniae (hvKP) can produce community-acquired infections that are fatal in young and adult hosts, such as pyogenic liver abscess, endophthalmitis, meningitis, it has historically been susceptible to antibiotics. Carbapenem-resistant K. (CRKP) is usually associated with urinary tract acquired hospitals, pneumonia, septicemias, soft tissue infections. Outbreaks quick spread of CRKP hospitals have become a major challenge public health due the lack effective antibacterial treatments. In early stages development, HvKP first appear distinct routes. However, lines dividing two pathotypes vanishing currently, advent carbapenem-resistant (CR-hvKP) devastating simultaneously multidrug-resistant, hypervirulent, highly transmissible. Most CR-hvKP cases reported Asian clinical settings, particularly China. Typically, develops when hvKP or acquires plasmids carry either carbapenem-resistance gene virulence gene. Alternatively, classic (cKP) may acquire hybrid plasmid carrying both genes. this review, we provide an overview key antimicrobial resistance mechanisms, factors, presentations, outcomes infection. Additionally, discuss possible evolutionary processes prevalence Given wide occurrence CR-hvKP, continued surveillance control measures organisms should be assigned higher priority.

Language: Английский

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The pathobiology of human fungal infections

Nature Reviews Microbiology, Journal Year: 2024, Volume and Issue: 22(11), P. 687 - 704

Published: June 25, 2024

Language: Английский

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Activity, delivery, and diversity of Type VI secretion effectors

Molecular Microbiology, Journal Year: 2020, Volume and Issue: 115(3), P. 383 - 394

Published: Nov. 21, 2020

The bacterial type VI secretion system (T6SS) is a contractile apparatus that delivers proteins to neighboring or eukaryotic cells. Antibacterial effectors are mostly toxins inhibit the growth of other species and help dominate niche. A broad variety these cause cell lysis prey by disrupting envelope. Other delivered into cytoplasm where they affect DNA integrity, division exhaust energy resources. modular nature T6SS machinery allows different means recruitment toxic secreted inner tube spike components act as carriers. Toxic can be translationally fused interact with them through specialized structural domains. These interactions also assisted dedicated chaperone proteins. Moreover, conserved sequence motifs in effector-associated domains subject genetic rearrangements therefore engage diversification arsenal effectors. This review discusses diversity presents current knowledge about their loading on machinery.

Language: Английский

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An Overview of Anti-Eukaryotic T6SS Effectors

Frontiers in Cellular and Infection Microbiology, Journal Year: 2020, Volume and Issue: 10

Published: Oct. 19, 2020

The type VI secretion system (T6SS) is a transmembrane multiprotein nanomachine employed by many Gram-negative bacterial species to translocate, in contact-dependent manner, effector proteins into adjacent prokaryotic or eukaryotic cells. Typically, the T6SS gene cluster encodes at least 13 conserved core components for apparatus assembly and other less accessory effectors. It functions as contractile tail machine comprising TssB/C sheath an expelled puncturing device consisting of Hcp tube topped spike complex VgrG PAAR proteins. Contraction propels out cell target leads injection toxic Different bacteria use specific roles according niche versatility organism. Effectors are present both cargo (by non-covalent interactions with one components) specialized domains (fused structural components). Although several anti-prokaryotic effectors T6SSs have been studied, recent studies led substantial increase number characterized anti-eukaryotic Against cells, involved modifying manipulating diverse cellular processes that allows colonize, survive disseminate, including adhesion modification, stimulating internalization, cytoskeletal rearrangements evasion host innate immune responses.

Language: Английский

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Killing of Gram-negative and Gram-positive bacteria by a bifunctional cell wall-targeting T6SS effector

Proceedings of the National Academy of Sciences, Journal Year: 2021, Volume and Issue: 118(40)

Published: Sept. 29, 2021

Significance Previous studies have indicated that Gram-positive bacteria are not affected by type VI secretion serum (T6SS) intoxication. However, here we show Acinetobacter baumannii employs its T6SS to kill different bacteria. Furthermore, determined killing was dependent on Tse4, a bifunctional effector possessing lytic transglycosylase and endopeptidase activities. Tse4 represents broad family of modularly organized peptidoglycan-degrading effectors. In addition, D-lysine A. results in pH increase, which greatly enhances activity. These expand the range T6SS-mediated interbacterial interactions may shape composition bacterial communities context human microbiota polymicrobial infections.

Language: Английский

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Klebsiella pneumoniae induces host metabolic stress that promotes tolerance to pulmonary infection

Cell Metabolism, Journal Year: 2022, Volume and Issue: 34(5), P. 761 - 774.e9

Published: April 11, 2022

K. pneumoniae sequence type 258 (Kp ST258) is a major cause of healthcare-associated pneumonia. However, it remains unclear how causes protracted courses infection in spite its expression immunostimulatory lipopolysaccharide, which should activate brisk inflammatory response and bacterial clearance. We predicted that the metabolic stress induced by bacteria host cells shapes an immune tolerates infection. combined situ imaging transcriptional analyses to demonstrate Kp ST258 activates glutaminolysis fatty acid oxidation. This creates oxidant-rich microenvironment conducive accumulation anti-inflammatory myeloid cells. In this setting, metabolically active elicits disease-tolerant response. The bacteria, turn, adapt airway oxidants upregulating VI secretion system, highly conserved across strains worldwide. Thus, much global success hospital settings can be explained activity provoked promotes disease tolerance.

Language: Английский

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The ecological impact of a bacterial weapon: microbial interactions and the Type VI secretion system

FEMS Microbiology Reviews, Journal Year: 2021, Volume and Issue: 45(6)

Published: June 20, 2021

Bacteria inhabit all known ecological niches and establish interactions with organisms from kingdoms of life. These are mediated by a wide variety mechanisms very often involve the secretion diverse molecules bacterial cells. The Type VI system (T6SS) is protein that uses bacteriophage-like machinery to secrete array effectors, usually translocating them directly into neighbouring effectors display toxic activity in recipient cell, making T6SS an effective weapon during inter-bacterial competition eukaryotic Over last two decades, microbiology research has experienced shift towards using systems-based approaches study between their communities context. Here, we focus on this aspect T6SS. We consider how our perspective developed examine what currently about impact bacteria deploying can have environments, including associated plants, insects mammals. T6SS-mediated affect host shaping microbiota, as well be established different microorganisms through deployment versatile system.

Language: Английский

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Human commensal gut Proteobacteria withstand type VI secretion attacks through immunity protein-independent mechanisms

Nature Communications, Journal Year: 2021, Volume and Issue: 12(1)

Published: Oct. 1, 2021

Abstract While the major virulence factors for Vibrio cholerae , cause of devastating diarrheal disease cholera, have been extensively studied, initial intestinal colonization bacterium is not well understood because non-human adult animals are refractory to its colonization. Recent studies suggest involvement an interbacterial killing device known as type VI secretion system (T6SS). Here, we tested T6SS-dependent interaction V. with a selection human gut commensal isolates. We show that pathogen efficiently depleted representative genera Proteobacteria in vitro, while members Enterobacter cloacae complex and several Klebsiella species remained unaffected. demonstrate this resistance against T6SS assaults was mediated by production superior machinery or barrier exerted group I capsules. Collectively, our data provide new insights into immunity protein-independent employed microbiota general.

Language: Английский

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SecReT6 update: a comprehensive resource of bacterial Type VI Secretion Systems

Science China Life Sciences, Journal Year: 2022, Volume and Issue: 66(3), P. 626 - 634

Published: Nov. 4, 2022

Language: Английский

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