​Optimization of Cultural Conditions for Maximum Production of Outer Membrane Vesicles from Salmonella Typhimurium

2021 ◽  
Author(s):  
Menguzotunuo Solo ◽  
Shantanu Tamuly ◽  
Luit Moni Barkalita ◽  
Girin Kumar Saikia ◽  
Dhruba Jyoti Kalita
Keyword(s):  
Oxidative Stress ◽  
Salmonella Typhimurium ◽  
Outer Membrane ◽  
Large Scale ◽  
Multiple Drug Resistance ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Multiple Drug ◽  
Scale Production ◽  
Maximum Production

Background: The non-typhoidal Salmonella causes gastroenteritis in humans that makes its way to the food chain mainly through the animal products. The multiple drug resistance imposes one of the major hurdle in the treatment of the disease. The vaccination appears to be the most important method for prevention of the disease. Unfortunately, there is no liscenced vaccine available against non-typhoidal Salmonellae. The use of outer membrane vesicles (OMVs) of Salmonella as a vaccine candidate has attained significant centre-stage in the recent years given to its protective immunogenicity. However, the large scale production of OMVs is difficult owing to low yield per liter of culture. Methods: In the present study, we have optimized the culture conditions viz. pH, phase of growth and presence of oxidative stress for maximum production of OMVs from Salmonella Typhimurium. The OMVs were characterized based on yield based on protein concentration, lipopolysaccharide concentration and zeta size. Result: In the present study, it was found that incubation of Salmonella Typhimurium up to peak of the growth phase at pH 7 in presence of oxidative stress was found to be the most suitable condition for maximum production of OMVs.

scholarly journals Hydrostatic Filtration Enables Large-Scale Production of Outer Membrane Vesicles That Effectively Protect Chickens against Gallibacterium anatis

Vaccines ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 40
Author(s):  
Fabio Antenucci ◽  
Homa Arak ◽  
Jianyang Gao ◽  
Toloe Allahgadry ◽  
Ida Thøfner ◽  
...  
Keyword(s):  
Outer Membrane ◽  
Egg Production ◽  
Large Scale ◽  
Membrane Vesicles ◽  
Optimal Dose ◽  
Outer Membrane Vesicles ◽  
Poultry Meat ◽  
Scale Production ◽  
Layer Chickens ◽  
N Proteins

Gallibacterium anatis is a Gram-negative opportunistic avian pathogen representing an emerging threat to poultry meat and egg production worldwide. To date, no vaccine able to effectively prevent the morbidity associated with G. anatis infections has been developed yet. Our group previously reported that inoculation of different combinations of G. anatis outer membrane vesicles (OMVs), FlfA and GtxA-N proteins is effective in preventing lesions caused by G. anatis infections in layer chickens. Here we report the testing of the efficacy as vaccine prototypes of G. anatis OMVs isolated by hydrostatic filtration, a simple technique that allows the cost-effective isolation of high yields of OMVs. Layer chickens were immunized with OMVs alone or in combination with FlfA and/or GtxA-N proteins. Subsequent challenge with a heterologous G. anatis strain showed that immunization with OMVs alone could significantly reduce the lesions following a G. anatis infection. A second study was carried out to characterize the dose-response (0.25, 2.5 and 25 µg) relationship of G. anatis OMVs as immunogens, showing that 2.5 μg of OMVs represent the optimal dose to elicit protection in the immunized animals after a similar challenge. Additionally, administration of ≥2.5 μg of G. anatis OMVs induced specific IgY titers and possibly vertical transfer of immunity.

scholarly journals Effect of Borrelia burgdorferi Outer Membrane Vesicles on Host Oxidative Stress Response

Antibiotics ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 275
Author(s):  
Keith Wawrzeniak ◽  
Gauri Gaur ◽  
Eva Sapi ◽  
Alireza G. Senejani
Keyword(s):  
Oxidative Stress ◽  
Borrelia Burgdorferi ◽  
Outer Membrane ◽  
Neuroblastoma Cells ◽  
Membrane Vesicles ◽  
Antioxidant Response ◽  
Outer Membrane Vesicles ◽  
Vitro Model ◽  
Superoxide Dismutase 2

Outer membrane vesicles (OMVs) are spherical bodies containing proteins and nucleic acids that are released by Gram-negative bacteria, including Borrelia burgdorferi, the causative agent of Lyme disease. The functional relationship between B. burgdorferi OMVs and host neuron homeostasis is not well understood. The objective of this study was to examine how B. burgdorferi OMVs impact the host cell environment. First, an in vitro model was established by co-culturing human BE2C neuroblastoma cells with B. burgdorferi B31. B. burgdorferi was able to invade BE2C cells within 24 h. Despite internalization, BE2C cell viability and levels of apoptosis remained unchanged, but resulted in dramatically increased production of MCP-1 and MCP-2 cytokines. Elevated secretion of MCP-1 has previously been associated with changes in oxidative stress. BE2C cell mitochondrial superoxides were reduced as early as 30 min after exposure to B. burgdorferi and OMVs. To rule out whether BE2C cell antioxidant response is the cause of decline in superoxides, superoxide dismutase 2 (SOD2) gene expression was assessed. SOD2 expression was reduced upon exposure to B. burgdorferi, suggesting that B. burgdorferi might be responsible for superoxide reduction. These results suggest that B. burgdorferi modulates cell antioxidant defense and immune system reaction in response to the bacterial infection. In summary, these results show that B. burgdorferi OMVs serve to directly counter superoxide production in BE2C neurons, thereby ‘priming’ the host environment to support B. burgdorferi colonization.

scholarly journals Naturally Derived Outer Membrane Vesicles confer Immunity to Salmonella typhimurium in a Murine Model

2016 ◽  
Vol 3 (suppl_1) ◽  
Author(s):  
Frances Lee ◽  
Christopher Davitt ◽  
Jonathan Kurtz ◽  
James Mclachlan ◽  
Lisa Morici
Keyword(s):  
Salmonella Typhimurium ◽  
Outer Membrane ◽  
Murine Model ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles

Electrophysiological Characterization of Transport Across Outer Membrane Channels from Gram-Negative Bacteria in Their Native Environment

2019 ◽  
Author(s):  
Jiajun Wang ◽  
Rémi Terrasse ◽  
Jayesh Arun Bafna ◽  
Lorraine Benier ◽  
Mathias Winterhalter
Keyword(s):  
Outer Membrane ◽  
Lipid Membrane ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Multi Drug Resistance ◽  
Gram Negative Bacteria ◽  
Membrane Channels ◽  
Gram Negative ◽  
Electrophysiological Characterization

Multi-drug resistance in Gram-negative bacteria is often associated with low permeability of the outer membrane. To investigate the role of membrane channels in the uptake of antibiotics, we extract, purify and reconstitute them into artificial planar membranes. To avoid this time-consuming procedure, here we show a robust approach using fusion of native outer membrane vesicles (OMV) into planar lipid bilayer which moreover allows also to some extend the characterization of membrane protein channels in their native environment. Two major membrane channels from <i>Escherichia coli</i>, OmpF and OmpC, were overexpressed from the host and the corresponding OMVs were collected. Each OMV fusion revealed surprisingly single or only few channel activities. The asymmetry of the OMV´s translates after fusion into the lipid membrane with the LPS dominantly present at the side of OMV addition. Compared to conventional reconstitution methods, the channels fused from OMVs containing LPS have similar conductance but a much broader distribution. The addition of Enrofloxacin on the LPS side yields somewhat higher association (<i>k<sub>on</sub></i>) and lower dissociation (<i>k<sub>off</sub></i>) rates compared to LPS-free reconstitution. We conclude that using outer membrane vesicles is a fast and easy approach for functional and structural studies of membrane channels in the native membrane.

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