Temperatures above 37°C increase virulence of a convergent Klebsiella pneumoniae sequence type 307 strain

Frontiers in Cellular and Infection Microbiology, Год журнала: 2024, Номер 14

Опубликована: Июнь 7, 2024

Background Convergence of Klebsiella pneumoniae (KP) pathotypes has been increasingly reported in recent years. These pathogens combine features both multidrug-resistant and hypervirulent KP. However, clinically used indicators for KP identification, such as hypermucoviscosity, appear to be differentially expressed convergent KP, potential outbreak clones are difficult identify. We aimed fill knowledge gaps by investigating the temperature dependence hypermucoviscosity virulence a strain isolated during clonal belonging high-risk sequence type (ST)307. Methods Hypermucoviscosity, biofilm formation, mortality rates Galleria mellonella larvae were examined at different temperatures (room temperature, 28°C, 37°C, 40°C 42°C) with various phenotypic experiments including electron microscopy. The underlying mechanisms changes explored via qPCR analysis evaluate plasmid copy numbers, transcriptomics. Results Our results show temperature-dependent switch above 37°C towards hypermucoviscous phenotype, consistent increased formation vivo mortality, possibly reflecting bacterial response fever-like conditions. Furthermore, we observed an increase number hybrid harboring carbapenemase rmpA genes. transcriptomic revealed no expression higher temperatures, suggesting alternative regulatory pathways. Conclusion This study not only elucidates impact elevated on but also sheds light previously unrecognized aspects its adaptive behavior, underscoring resilience changing environments.

Язык: Английский

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Comparative Analysis of In Vivo and In Vitro Virulence Among Foodborne and Clinical Listeria monocytogenes Strains

Microorganisms, Год журнала: 2025, Номер 13(1), С. 191 - 191

Опубликована: Янв. 17, 2025

Listeria monocytogenes is one of the most important foodborne pathogens that can cause invasive listeriosis. In this study, virulence levels 26 strains L. isolated from food and clinical samples in Shanghai, China, between 2020 2022 were analyzed. There significant differences among isolates terms their mortality rate Galleria mellonella, cytotoxicity to JEG-3 cells, hemolytic activity, expression genes. Compared with other STs, both ST121 (food source) ST1930 (clinic exhibited higher G. mellonella mortality. The 48 h lineage II was significantly than I. ST1930, ST3, ST5, ST1032 cells. Based on classification sources strains) serogroups (II a, b, c), there no observed mortality, cytotoxicity, activity. addition, hly, inlA, inlB, prfA, plcA, plcB gene compared STs. A gray relation analysis showed a high correlation toxicity hly inlB genes; may have consistent mechanism involving hemolysis activity cytotoxicity. Through integration vivo vitro infection models information factor genes, or subtypes be better understood.

Язык: Английский

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New Antimicrobial Cyclodepsipeptides from a Freshwater Fungus from the Sierra Madre Oriental in Mexico

ACS Omega, Год журнала: 2025, Номер 10(5), С. 5087 - 5096

Опубликована: Янв. 29, 2025

The Sierra Madre Oriental (SMO) in Mexico is a complex, unexplored geological area with multiple habitats and unique physical, chemical, biological features. A bioactive-guided study of the organic extract from solid-state fermentation culture taxonomically unidentified fungus isolated submerged wood waterfall "El Caracol", Nuevo Leon, at SMO, led to identification three new cyclodepsipeptides (1–3) known Sch 217048 (4) 378161 (5). Structures all compounds were elucidated by spectroscopic spectrometric methods. 4 5 showed antimicrobial activity against Gram-positive strains Gram-negative Acinetobacter baumannii ATCC 17978, including multidrug-resistant clinical strain A564. In addition, no toxic Galleria mellonella larvae model. Finally, molecular networking analysis allowed us annotate network. This first systematic chemical SMO Mexico.

Язык: Английский

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Low and high-density polyethylene and expanded polystyrene biodegradation by the greater wax moth Galleria mellonella L reveals a key role of the gut microbiome.

Ecotoxicology and Environmental Safety, Год журнала: 2025, Номер 294, С. 118074 - 118074

Опубликована: Март 20, 2025

Язык: Английский

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The activation of caspases in immunocompetent cells is an important infection factor of the pathogenic fungus Conidiobolus coronatus (Entomophthorales: Ancylistaceae)

Journal of Invertebrate Pathology, Год журнала: 2025, Номер unknown, С. 108328 - 108328

Опубликована: Апрель 1, 2025

Язык: Английский

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