scholarly journals The Phagosome–Lysosome Fusion Is the Target of a Purified Quillaja saponin Extract (PQSE) in Reducing Infection of Fish Macrophages by the Bacterial Pathogen Piscirickettsia salmonis

Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 847
Author(s):  
Hernán D. Cortés ◽  
Fernando A. Gómez ◽  
Sergio H. Marshall
Keyword(s):  
Immune Response ◽  
Antimicrobial Activity ◽  
Pathogenic Bacteria ◽  
Bacterial Pathogen ◽  
Control Measures ◽  
Quillaja Saponaria ◽  
Pathogen Virulence ◽  
Piscirickettsia Salmonis ◽  
Vitro Model

Piscirickettsia salmonis, the etiological agent of Piscirickettsiosis, is a Gram-negative and facultative intracellular pathogen that has affected the Chilean salmon industry since 1989. The bacterium is highly aggressive and can survive and replicate within fish macrophages using the Dot/Icm secretion system to evade the host’s immune response and spread systemically. To date, no efficient control measures have been developed for this disease; therefore, the producers use large amounts of antibiotics to control this pathogen. In this frame, this work has focused on evaluating the use of saponins from Quillaja saponaria as a new alternative to control the Piscirickettsiosis. It has been previously reported that purified extract of Q. saponaria (PQSE) displays both antimicrobial activity against pathogenic bacteria and viruses and adjuvant properties. Our results show that PQSE does not present antimicrobial activity against P. salmonis, although it reduces P. salmonis infection in an in vitro model, promoting the phagosome–lysosome fusion. Additionally, we demonstrate that PQSE modulates the expression of IL-12 and IL-10 in infected cells, promoting the immune response against the pathogen and reducing the expression of pathogen virulence genes. These results together strongly argue for specific anti-invasion and anti-intracellular replication effects induced by the PQSE in macrophages.

scholarly journals Characterization and In Vitro Efficacy against Listeria monocytogenes of a Newly Isolated Bacteriophage, ΦIZSAM-1

2021 ◽  
Vol 9 (4) ◽  
pp. 731
Author(s):  
Silvia Scattolini ◽  
Daniela D’Angelantonio ◽  
Arianna Boni ◽  
Iolanda Mangone ◽  
Maurilia Marcacci ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Pathogenic Bacteria ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Bacterial Pathogen ◽  
Control Measures ◽  
New Approach ◽  
Blue Cheese ◽  
A Genome

Listeria monocytogenes is a bacterial pathogen responsible of listeriosis, a disease that in humans is often related to the contamination of ready-to-eat foods. Phages are candidate biodecontaminants of pathogenic bacteria thanks to their ability to lyse prokaryotes while being safe for eukaryotic cells. In this study, ΦIZSAM-1 was isolated from the drain-waters of an Italian blue cheese plant and showed lytic activity against antimicrobial resistant Listeria monocytogenes strains. This phage was subjected to purification and in vitro efficacy tests. The results showed that at multiplicities of infection (MOIs) ≤ 1, phages were able to keep Listeria monocytogenes at low optical density values up to 8 h, with bacterial counts ranging from 1.02 to 3.96 log10 units lower than the control. Besides, ΦIZSAM-1 was further characterized, showing 25 principal proteins (sodium dodecyl sulfate polyacrylamide gel electrophoresis profile) and a genome of approximately 50 kilo base pairs. Moreover, this study describes a new approach to phage isolation for applications in Listeriamonocytogenes biocontrol in food production. In particular, the authors believe that the selection of phages from the same environments where pathogens live could represent a new approach to successfully integrating the control measures in an innovative, cost effective, safe and environmentally friendly way.

Phytochemical composition and in vitro screening of the antimicrobial activity of essential oils on oral pathogenic bacteria

2017 ◽  
Vol 32 (5) ◽  
pp. 544-551 ◽  
Author(s):  
Roberta Tardugno ◽  
Federica Pellati ◽  
Ramona Iseppi ◽  
Moreno Bondi ◽  
Giacomo Bruzzesi ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Essential Oils ◽  
Pathogenic Bacteria ◽  
In Vitro Screening ◽  
Phytochemical Composition

Biosynthesis of Silver Nanoparticles by Punica Granatum Peel Extract and their Biological Activity on different Pathogenic Bacteria

2021 ◽  
Vol 19 (9) ◽  
pp. 38-45
Author(s):  
Hussein H. Al-Turnachy ◽  
Fadhilk. alibraheemi ◽  
Ahmed Abd Alreda Madhloom ◽  
Zahraa Yosif Motaweq ◽  
Nibras Yahya Abdulla
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Biological Activity ◽  
Pathogenic Bacteria ◽  
Punica Granatum ◽  
Gram Positive ◽  
Gram Negative ◽  
Inhibition Zones ◽  
Peel Extract

The present study was included the assessment of the antimicrobial activity of AgNPs synthesized by Punica granatum peel extract against pathogenic bacteria by testing warm aqueous P. granatum peel extract and silver nanoparticles. Punica granatum indicated potency for AgNP extracellular nanobiosynthesis after addition of silver nitrate (AgNO3) 4mM to the extract supernatant, in both concentrations (100mg and 50mg). The biogenic AgNPs showed potency to inhibit both gram-negative and gram-positive bacterial growth. Zons of inhibition in (mm) was lesser in gram-positive than gram-negative bacteria. The resulted phytogenic AgNPs gave higher biological activity than warm aqueous Punica granatum peel extract. The inhibition zone of the phytogenic AgNPs on E. coli reached 17.53, 22.35, and 26.06 mm at (0.1, 0.5, and 1) mg/ml respectively. While inhibition zones of Punica warm aqueous extract reached 5.33, 10.63, and 16.08 mm at the same concentrations. phytogenic AgNPs gave smaller inhibition zones in gram-positive than gram- negative. Cytotoxic activity of the phytogenic AgNPs was assayed in vitro agaist human blood erythrocytes (RBCs), spectroscopic results showed absorbance at 540 nm hemolysis was observed. In general, AgNPs showed least RBCs hemolysis percentage, at 1 mg/ml concentration, hemolysis percentage was (4.50%). This study, concluded that the Punica granatum peel extract has the power of synthses of AgNPs characterized by broad spectrum antimicrobial activity with cyto-toxicity proportional to AgNPs concentration.

scholarly journals A Trifecta of New Insights into Ovine Footrot for Infection Drivers, Immune Response and Host Pathogen Interactions.

2021 ◽  
Author(s):  
Adam M. Blanchard ◽  
Ceri E. Staley ◽  
Laurence Shaw ◽  
Sean R Wattegedera ◽  
Christina-Marie Baumbach ◽  
...  
Keyword(s):  
Immune Response ◽  
Type I Collagen ◽  
Global Analysis ◽  
Bacterial Species ◽  
Skin Barrier ◽  
Control Measures ◽  
Skin Barrier Function ◽  
Type I ◽  
Bacterial Populations

Footrot is a polymicrobial infectious disease in sheep causing severe lameness, leading to one of the industry’s biggest welfare problems. The complex aetiology of footrot makes in-situ or in-vitro investigations difficult. Computational methods offer a solution to understanding the bacteria involved, how they may interact with the host and ultimately providing a way to identify targets for future hypotheses driven investigative work. Here we present the first combined global analysis of the bacterial community transcripts together with the host immune response in healthy and diseased ovine feet during a natural polymicrobial infection state using metatranscriptomics. The intra tissue and surface bacterial populations and the most abundant bacterial transcriptome were analysed, demonstrating footrot affected skin has a reduced diversity and increased abundances of, not only the causative bacteria Dichelobacter nodosus , but other species such as Mycoplasma fermentans and Porphyromonas asaccharolytica . Host transcriptomics reveals a suppression of biological processes relating to skin barrier function, vascular functions, and immunosurveillance in unhealthy interdigital skin, supported by histological findings that type I collagen (associated with scar tissue formation) is significantly increased in footrot affected interdigital skin comparted to outwardly healthy skin. Finally, we provide some interesting indications of host and pathogen interactions associated with virulence genes and the host spliceosome which could lead to the identification of future therapeutic targets. Impact Statement Lameness in sheep is a global welfare and economic concern and footrot is the leading cause of lameness, affecting up to 70% of flocks in the U.K. Current methods for control of this disease are labour intensive and account for approximately 65% of antibiotic use in sheep farming, whilst preventative vaccines suffer from poor efficacy due to antigen competition. Our limited understanding of cofounders, such as strain variation and polymicrobial nature of infection mean new efficacious, affordable and scalable control measures are not receiving much attention. Here we examine the surface and intracellular bacterial populations and propose potential interactions with the host. Identification of these key bacterial species involved in the initiation and progression of disease and the host immune mechanisms could help form the basis of new therapies.

scholarly journals Apis andreniformis associated Actinomycetes show antimicrobial activity against black rot pathogen (Xanthomonas campestris pv. campestris)

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12097
Author(s):  
Yaowanoot Promnuan ◽  
Saran Promsai ◽  
Wasu Pathom-aree ◽  
Sujinan Meelai
Keyword(s):  
Antimicrobial Activity ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Honey Bee ◽  
Pseudomonas Syringae ◽  
Xanthomonas Campestris ◽  
Pathogenic Bacteria ◽  
Rrna Gene ◽  
Apis Andreniformis

This study aimed to investigate cultivable actinomycetes associated with rare honey bee species in Thailand and their antagonistic activity against plant pathogenic bacteria. Actinomycetes were selectively isolated from the black dwarf honey bee (Apis andreniformis). A total of 64 actinomycete isolates were obtained with Streptomyces as the predominant genus (84.4%) followed by Micromonospora (7.8%), Nonomuraea (4.7%) and Actinomadura (3.1%). All isolates were screened for antimicrobial activity against Xanthomonas campestris pv. campestris, Pectobacterium carotovorum and Pseudomonas syringae pv. sesame. Three isolates inhibited the growth of X. campestris pv. campestris during in vitro screening. The crude extracts of two isolates (ASC3-2 and ASC5-7P) had a minimum inhibitory concentration (MIC) of 128 mg L−1against X. campestris pv. campestris. For isolate ACZ2-27, its crude extract showed stronger inhibitory effect with a lower MIC value of 64 mg L−1 against X. campestris pv. campestris. These three active isolates were identified as members of the genus Streptomyces based on their 16S rRNA gene sequences. Phylogenetic analysis based on the maximum likelihood algorithm showed that isolate ACZ2-27, ASC3-2 and ASC5-7P were closely related to Streptomyces misionensis NBRC 13063T (99.71%), Streptomyces cacaoi subsp. cacaoi NBRC 12748T (100%) and Streptomyces puniceus NBRC 12811T (100%), respectively. In addition, representative isolates from non-Streptomyces groups were identified by 16S rRNA gene sequence analysis. High similarities were found with members of the genera Actinomadura, Micromonospora and Nonomuraea. Our study provides evidence of actinomycetes associated with the black dwarf honey bee including members of rare genera. Antimicrobial potential of these insect associated Streptomyces was also demonstrated especially the antibacterial activity against phytopathogenic bacteria.

scholarly journals Chemical characterization and in vitro antimicrobial activity of honeybee propolis and Scaptotrigona jujuyensis geopropolis against tomato pathogenic bacteria

2020 ◽  
Vol 42 (5) ◽  
pp. 1799-1808
Author(s):  
Irene Laura Cibanal ◽  
◽  
Leticia Andrea Fernández ◽  
Giovanni Galietta Positano ◽  
Lucía Bóffano Chebataroff ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Pathogenic Bacteria ◽  
Chemical Characterization ◽  
In Vitro Antimicrobial Activity

scholarly journals Approximation of immune response abilities in salmonid gills using the RTgill-W1 cell line as an in vitro model

2016 ◽  
Vol 53 ◽  
pp. 74
Author(s):  
Claudio Alvarez ◽  
Paula Santana ◽  
Francisco Donoso ◽  
Felipe Ramírez ◽  
Jimena Cortés ◽  
...  
Keyword(s):  
Immune Response ◽  
Cell Line ◽  
In Vitro Model ◽  
Vitro Model

scholarly journals Genome-Wide Sensitivity Analysis of the MicrosymbiontSinorhizobium melilotito Symbiotically Important, Defensin-Like Host Peptides

mBio ◽  
2017 ◽  
Vol 8 (4) ◽  
Author(s):  
Markus F. F. Arnold ◽  
Mohammed Shabab ◽  
Jon Penterman ◽  
Kevin L. Boehme ◽  
Joel S. Griffitts ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Associated Factors ◽  
Pathogenic Bacteria ◽  
High Throughput Sequencing ◽  
Bacterial Resistance ◽  
Outer Membrane Proteins ◽  
Effector Proteins ◽  
Symbiotic Interaction ◽  
Model Legume

ABSTRACTThe model legume speciesMedicago truncatulaexpresses more than 700 nodule-specific cysteine-rich (NCR) signaling peptides that mediate the differentiation ofSinorhizobium melilotibacteria into nitrogen-fixing bacteroids. NCR peptides are essential for a successful symbiosis in legume plants of the inverted-repeat-lacking clade (IRLC) and show similarity to mammalian defensins. In addition to signaling functions, many NCR peptides exhibit antimicrobial activityin vitroandin vivo. Bacterial resistance to these antimicrobial activities is likely to be important for symbiosis. However, the mechanisms used byS. melilotito resist antimicrobial activity of plant peptides are poorly understood. To address this, we applied a global genetic approach using transposon mutagenesis followed by high-throughput sequencing (Tn-seq) to identifyS. melilotigenes and pathways that increase or decrease bacterial competitiveness during exposure to the well-studied cationic NCR247 peptide and also to the unrelated model antimicrobial peptide polymyxin B. We identified 78 genes and several diverse pathways whose interruption altersS. melilotiresistance to NCR247. These genes encode the following: (i) cell envelope polysaccharide biosynthesis and modification proteins, (ii) inner and outer membrane proteins, (iii) peptidoglycan (PG) effector proteins, and (iv) non-membrane-associated factors such as transcriptional regulators and ribosome-associated factors. We describe a previously uncharacterized yet highly conserved peptidase, which protectsS. melilotifrom NCR247 and increases competitiveness during symbiosis. Additionally, we highlight a considerable number of uncharacterized genes that provide the basis for future studies to investigate the molecular basis of symbiotic development as well as chronic pathogenic interactions.IMPORTANCESoil rhizobial bacteria enter into an ecologically and economically important symbiotic interaction with legumes, in which they differentiate into physiologically distinct bacteroids that provide essential ammonia to the plant in return for carbon sources. Plant signal peptides are essential and specific to achieve these physiological changes. These peptides show similarity to mammalian defensin peptides which are part of the first line of defense to control invading bacterial populations. A number of these legume peptides are indeed known to possess antimicrobial activity, and so far, only the bacterial BacA protein is known to protect rhizobial bacteria against their antimicrobial action. This study identified numerous additional bacterial factors that mediate protection and belong to diverse biological pathways. Our results significantly contribute to our understanding of the molecular roles of bacterial factors during legume symbioses and, second, provide insights into the mechanisms that pathogenic bacteria may use to resist the antimicrobial effects of defensins during infections.

scholarly journals Microglial Immune Response to Low Concentrations of Combustion-Generated Nanoparticles: An In Vitro Model of Brain Health

Nanomaterials ◽  
2018 ◽  
Vol 8 (3) ◽  
pp. 155 ◽  
Author(s):  
Cayla Duffy ◽  
Jacob Swanson ◽  
William Northrop ◽  
Joshua Nixon ◽  
Tammy Butterick
Keyword(s):  
Immune Response ◽  
In Vitro Model ◽  
Brain Health ◽  
Low Concentrations ◽  
Vitro Model

scholarly journals In-vitro Antioxidant Activity and Antimicrobial Activity of Hydroalcoholic Extracts of Vernonia cinerea

2019 ◽  
Vol 9 (1) ◽  
pp. 225-228
Author(s):  
Jaswinder Mehta ◽  
Peenu Mahendra Joshi ◽  
Priyanka Kushwaha ◽  
Geeta Parkhe
Keyword(s):  
Antimicrobial Activity ◽  
Antioxidant Activity ◽  
Free Radicals ◽  
Pathogenic Bacteria ◽  
Radical Scavenging ◽  
Diffusion Method ◽  
Dependent Manner ◽  
Hydroalcoholic Extract ◽  
Vernonia Cinerea

The aim of present study was to estimate the in vitro antioxidant potential and antimicrobial activity of hydroalcoholic extract of Vernonia cinerea. Antioxidant activity was assessed by using 2, 2- diphenyl-1-picryl-hydrazyl (DPPH) assay using ascorbic acid as standard antioxidant. The extract was found to scavenge effectively the free radicals. The total flavonoid contents were determined by established methods and were found to be 0.547 mg/100mg in quercitin equivalents. Antimicrobial activity was performed against 2 stains of human pathogenic bacteria by well diffusion method. Hydroalcoholic extract of Vernonia cinerea showed good antimicrobial activity against gram positive bacteria. The antioxidant activities may be attributed to the presence of significant amounts of flavonoid compounds. Results indicated that hydroalcoholic extract of Vernonia cinerea possess significant antioxidant effect in dose dependent manner, followed by the hydroalcoholic extract of Vernonia cinerea possessed good antimicrobial activity. Keywords: Antioxidant activity, Radical scavenging activity, Free radicals, Antimicrobial activity.

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