scholarly journals Lipidomic Analysis of the Outer Membrane Vesicles from Paired Polymyxin-Susceptible and -Resistant Klebsiella pneumoniae Clinical Isolates

2018 ◽  
Vol 19 (8) ◽  
pp. 2356 ◽  
Author(s):  
Raad Jasim ◽  
Mei-Ling Han ◽  
Yan Zhu ◽  
Xiaohan Hu ◽  
Maytham Hussein ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Outer Membrane ◽  
Membrane Vesicles ◽  
Average Diameter ◽  
Polymyxin B ◽  
Outer Membrane Vesicles ◽  
Resistant Isolate ◽  
Average Particle ◽  
Lipid Species ◽  
The Impact

Gram-negative bacteria produce outer membrane vesicles (OMVs) as delivery vehicles for nefarious bacterial cargo such as virulence factors, which are antibiotic resistance determinants. This study aimed to investigate the impact of polymyxin B treatment on the OMV lipidome from paired polymyxin-susceptible and -resistant Klebsiella pneumoniae isolates. K. pneumoniae ATCC 700721 was employed as a reference strain in addition to two clinical strains, K. pneumoniae FADDI-KP069 and K. pneumoniae BM3. Polymyxin B treatment of the polymyxin-susceptible strains resulted in a marked reduction in the glycerophospholipid, fatty acid, lysoglycerophosphate and sphingolipid content of their OMVs. Conversely, the polymyxin-resistant strains expressed OMVs richer in all of these lipid species, both intrinsically and increasingly under polymyxin treatment. The average diameter of the OMVs derived from the K. pneumoniae ATCC 700721 polymyxin-susceptible isolate, measured by dynamic light scattering measurements, was ~90.6 nm, whereas the average diameter of the OMVs isolated from the paired polymyxin-resistant isolate was ~141 nm. Polymyxin B treatment (2 mg/L) of the K. pneumoniae ATCC 700721 cells resulted in the production of OMVs with a larger average particle size in both the susceptible (average diameter ~124 nm) and resistant (average diameter ~154 nm) strains. In light of the above, we hypothesize that outer membrane remodelling associated with polymyxin resistance in K. pneumoniae may involve fortifying the membrane structure with increased glycerophospholipids, fatty acids, lysoglycerophosphates and sphingolipids. Putatively, these changes serve to make the outer membrane and OMVs more impervious to polymyxin attack.

scholarly journals Antibiotic-Mediated Modulations of Outer Membrane Vesicles in Enterohemorrhagic Escherichia coli O104:H4 and O157:H7

2017 ◽  
Vol 61 (9) ◽  
Author(s):  
Andreas Bauwens ◽  
Lisa Kunsmann ◽  
Helge Karch ◽  
Alexander Mellmann ◽  
Martina Bielaszewska
Keyword(s):  
Escherichia Coli ◽  
Outer Membrane ◽  
Shiga Toxin ◽  
Membrane Vesicles ◽  
Polymyxin B ◽  
Outer Membrane Vesicles ◽  
Enterohemorrhagic Escherichia Coli ◽  
Content Type ◽  
E Coli ◽  
Major Virulence Factor

ABSTRACT Ciprofloxacin, meropenem, fosfomycin, and polymyxin B strongly increase production of outer membrane vesicles (OMVs) in Escherichia coli O104:H4 and O157:H7. Ciprofloxacin also upregulates OMV-associated Shiga toxin 2a, the major virulence factor of these pathogens, whereas the other antibiotics increase OMV production without the toxin. These two effects might worsen the clinical outcome of infections caused by Shiga toxin-producing E. coli. Our data support the existing recommendations to avoid antibiotics for treatment of these infections.

scholarly journals Interspecies Outer Membrane Vesicles (OMVs) Modulate the Sensitivity of Pathogenic Bacteria and Pathogenic Yeasts to Cationic Peptides and Serum Complement

2019 ◽  
Vol 20 (22) ◽  
pp. 5577 ◽  
Author(s):  
Justyna Roszkowiak ◽  
Paweł Jajor ◽  
Grzegorz Guła ◽  
Jerzy Gubernator ◽  
Andrzej Żak ◽  
...  
Keyword(s):  
Outer Membrane ◽  
Pathogenic Bacteria ◽  
Membrane Vesicles ◽  
Polymyxin B ◽  
Outer Membrane Vesicles ◽  
Antifungal Drugs ◽  
Cationic Peptides ◽  
Serum Complement ◽  
Fungicidal Action ◽  
Potential Measurement

The virulence of bacterial outer membrane vesicles (OMVs) contributes to innate microbial defense. Limited data report their role in interspecies reactions. There are no data about the relevance of OMVs in bacterial-yeast communication. We hypothesized that model Moraxella catarrhalis OMVs may orchestrate the susceptibility of pathogenic bacteria and yeasts to cationic peptides (polymyxin B) and serum complement. Using growth kinetic curve and time-kill assay we found that OMVs protect Candida albicans against polymyxin B-dependent fungicidal action in combination with fluconazole. We showed that OMVs preserve the virulent filamentous phenotype of yeasts in the presence of both antifungal drugs. We demonstrated that bacteria including Haemophilus influenza, Acinetobacter baumannii, and Pseudomonas aeruginosa coincubated with OMVs are protected against membrane targeting agents. The high susceptibility of OMV-associated bacteria to polymyxin B excluded the direct way of protection, suggesting rather the fusion mechanisms. High-performance liquid chromatography-ultraviolet spectroscopy (HPLC-UV) and zeta-potential measurement revealed a high sequestration capacity (up to 95%) of OMVs against model cationic peptide accompanied by an increase in surface electrical charge. We presented the first experimental evidence that bacterial OMVs by sequestering of cationic peptides may protect pathogenic yeast against combined action of antifungal drugs. Our findings identify OMVs as important inter-kingdom players.

scholarly journals Study on RNA Regulating Iron Transport in Outer Membrane Vesicles of Hypervirulent Klebsiella Pneumoniae

2020 ◽  
Author(s):  
Mao Zhou ◽  
Siyi Wang ◽  
You Lan ◽  
Xin Li ◽  
Xuan Liu ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Outer Membrane ◽  
Iron Transport ◽  
High Throughput Sequencing ◽  
Iron Acquisition ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Transporter Family ◽  
Iron Deficient ◽  
Deficient Medium

Abstract Background: The iron acquisition ability of hypervirulent Klebsiella pneumoniae (hvKP) is an important part of its super virulence mechanism, increasing studies have proved that outer membrane vesicles (OMVs) are involved in the iron acquisition process of bacteria. Thus, we compared the difference in RNA expression in OMVs of hvKP in iron-rich and iron-deficient medium, and explore the possible mechanism of RNA in OMVs involved in hvKP iron acquisition. Results: The results of high-throughput sequencing showed that in iron-deficient medium, there were 239 up-regulated and 89 down-regulated mRNAs in OMVs of hvKP, of which 20 mRNAs related to iron transport was up-regulated, mainly including siderophore synthesis and receptor genes, ATP binding cassette transporter family and iron sulfur cluster. Only two of the differential ncRNAs that regulate these mRNAs are up-regulated, which are lncRNAs.Conclusion: We demonstrated that mRNA and lncRNA in OMVs were directly or indirectly involved in the iron acquisition mechanism of hvKP under iron deficiency environment, which enhanced the adaptive survival ability of hvKP. It provided a basis for further exploring the iron acquisition mechanism of OMVs involved in hvKP.

scholarly journals Porin Loss Impacts the Host Inflammatory Response to Outer Membrane Vesicles of Klebsiella pneumoniae

2015 ◽  
Vol 60 (3) ◽  
pp. 1360-1369 ◽  
Author(s):  
Kelli L. Turner ◽  
Bethaney K. Cahill ◽  
Sarah K. Dilello ◽  
Dedra Gutel ◽  
Debra N. Brunson ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Klebsiella Pneumoniae ◽  
Outer Membrane ◽  
Proinflammatory Cytokine ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Cytokine Secretion ◽  
Phagocytic Cells ◽  
Altered Expression ◽  
Content Type

Antibiotic-resistant strains ofKlebsiella pneumoniaeoften exhibit porin loss. In this study, we investigated how porin loss impacted the composition of secreted outer membrane vesicles as well as their ability to trigger proinflammatory cytokine secretion by macrophages. We hypothesize that porin loss associated with antibiotic resistance will directly impact both the composition of outer membrane vesicles and their interactions with phagocytic cells. Using clonally related clinical isolates of extended-spectrum beta-lactamase (ESBL)-positiveKlebsiella pneumoniaewith different patterns of porin expression, we demonstrated that altered expression of OmpK35 and OmpK36 results in broad alterations to the protein profile of secreted vesicles. Additionally, the level of OmpA incorporation was elevated in strains lacking a single porin. Porin loss significantly impacted macrophage inflammatory responses to purified vesicles. Outer membrane vesicles lacking both OmpK35 and OmpK36 elicited significantly lower levels of proinflammatory cytokine secretion than vesicles from strains expressing one or both porins. These data demonstrate that antibiotic resistance-associated porin loss has a broad and significant effect on both the composition of outer membrane vesicles and their interactions with phagocytic cells, which may impact bacterial survival and inflammatory reactions in the host.

Isolation, characterization and analysis of pro-inflammatory potential of Klebsiella pneumoniae outer membrane vesicles

2019 ◽  
Vol 136 ◽  
pp. 103719 ◽  
Author(s):  
Francesca Martora ◽  
Federica Pinto ◽  
Veronica Folliero ◽  
Marcella Cammarota ◽  
Federica Dell’Annunziata ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Outer Membrane ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles

scholarly journals OmpA Protein-Deficient Acinetobacter baumannii Outer Membrane Vesicles Trigger Reduced Inflammatory Response

Pathogens ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 407
Author(s):  
Jūratė Skerniškytė ◽  
Emilija Karazijaitė ◽  
Asta Lučiūnaitė ◽  
Edita Sužiedėlienė
Keyword(s):  
Inflammatory Response ◽  
Acinetobacter Baumannii ◽  
Outer Membrane ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Host Cells ◽  
Proinflammatory Response ◽  
Ompa Protein ◽  
The Impact

Multidrug resistant Acinetobacter baumannii shows a growing number of nosocomial infections worldwide during the last decade. The outer membrane vesicles (OMVs) produced by this bacterium draw increasing attention as a possible treatment target. OMVs have been implicated in the reduction of antibiotic level in the surrounding environment, transfer of virulence factors into the host cells, and induction of inflammatory response. Although the evidence on the involvement of OMVs in A. baumannii pathogenesis is currently growing, their role during inflammation is insufficiently explored. It is likely that bacteria, by secreting OMVs, can expand the area of their exposure and prepare surrounding matrix for infection. Here, we investigated the impact of A. baumannii OMVs on activation of macrophages in vitro. We show that OmpA protein present in A. baumannii OMVs substantially contributes to the proinflammatory response in J774 murine macrophages and to the cell death in both lung epithelium cells and macrophages. The loss of OmpA protein in OMVs, obtained from A. baumannii ∆ompA mutant, resulted in the altered expression of genes coding for IL-6, NLRP3 and IL-1β proinflammatory molecules in macrophages in vitro. These results imply that OmpA protein in bacterial OMVs could trigger a more intense proinflammatory response.

scholarly journals Influence of Environmental and Genetic Factors on Proteomic Profiling of Outer Membrane Vesicles from Campylobacter jejuni

2019 ◽  
Vol 68 (2) ◽  
pp. 255-261 ◽  
Author(s):  
RENATA GODLEWSKA ◽  
JOANNA KLIM ◽  
JANUSZ DĘBSKI ◽  
AGNIESZKA WYSZYŃSKA ◽  
ANNA ŁASICA
Keyword(s):  
Outer Membrane ◽  
Flagellar Apparatus ◽  
Membrane Vesicles ◽  
Fold Increase ◽  
Polymyxin B ◽  
Outer Membrane Vesicles ◽  
Proteomic Profiling ◽  
Cell Compartments ◽  
Common Group ◽  
Quantitative Changes

The proteomes of outer membrane vesicles (OMVs) secreted by C. jejuni 81–176 strain, which was exposed to oxygen or antibiotic stress (polymyxin B), were characterized. We also assessed the OMVs production and their content in two mutated strains – ∆dsbI and ∆htrA. OMVs production was significantly increased under the polymyxin B stress and remained unaltered in all other variants. Interestingly, the qualitative load of OMVs was constant regardless of the stress conditions or genetic background. However, certain proteins exhibited notable quantitative changes, ranging from 4-fold decrease to 10-fold increase. Up- or downregulated proteins (e.g. major outer membrane protein porA, iron ABC transporter, serine protease- htrA, 60 kDa chaperonin-groL, enolase) represented various cell compartments (cytoplasm, periplasm, and membrane) and exhibited various functions; nevertheless, one common group was noted that consisted of components of flagellar apparatus, i.e., FlaA/B, FlgC/E, which were mostly upregulated. Some of these proteins are the putative substrates of DsbI protein. Further investigation of the regulation of C. jejuni OMVs composition and their role in virulence will allow a better understanding of the infectious process of C. jejuni.

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