scholarly journals Insights Into the Immune Response of the Black Soldier Fly Larvae to Bacteria

2021 ◽  
Vol 12 ◽  
Author(s):  
Daniele Bruno ◽  
Aurora Montali ◽  
Maristella Mastore ◽  
Maurizio Francesco Brivio ◽  
Amr Mohamed ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune System ◽  
Health Status ◽  
Gram Negative Bacteria ◽  
Organic Substrates ◽  
Gram Positive ◽  
Black Soldier Fly ◽  
Gram Negative ◽  
Wide Range ◽  
Functional Features

In insects, a complex and effective immune system that can be rapidly activated by a plethora of stimuli has evolved. Although the main cellular and humoral mechanisms and their activation pathways are highly conserved across insects, the timing and the efficacy of triggered immune responses can differ among different species. In this scenario, an insect deserving particular attention is the black soldier fly (BSF), Hermetia illucens (Diptera: Stratiomyidae). Indeed, BSF larvae can be reared on a wide range of decaying organic substrates and, thanks to their high protein and lipid content, they represent a valuable source of macromolecules useful for different applications (e.g., production of feedstuff, bioplastics, and biodiesel), thus contributing to the development of circular economy supply chains for waste valorization. However, decaying substrates bring the larvae into contact with different potential pathogens that can challenge their health status and growth. Although these life strategies have presumably contributed to shape the evolution of a sophisticated and efficient immune system in this dipteran, knowledge about its functional features is still fragmentary. In the present study, we investigated the processes underpinning the immune response to bacteria in H. illucens larvae and characterized their reaction times. Our data demonstrate that the cellular and humoral responses in this insect show different kinetics: phagocytosis and encapsulation are rapidly triggered after the immune challenge, while the humoral components intervene later. Moreover, although both Gram-positive and Gram-negative bacteria are completely removed from the insect body within a few hours after injection, Gram-positive bacteria persist in the hemolymph longer than do Gram-negative bacteria. Finally, the activity of two key actors of the humoral response, i.e., lysozyme and phenoloxidase, show unusual dynamics as compared to other insects. This study represents the first detailed characterization of the immune response to bacteria of H. illucens larvae, expanding knowledge on the defense mechanisms of this insect among Diptera. This information is a prerequisite to manipulating the larval immune response by nutritional and environmental factors to increase resistance to pathogens and optimize health status during mass rearing.

Characterization and identification of antimicrobial peptides with different functional activities

2019 ◽  
Vol 21 (3) ◽  
pp. 1098-1114 ◽  
Author(s):  
Chia-Ru Chung ◽  
Ting-Rung Kuo ◽  
Li-Ching Wu ◽  
Tzong-Yi Lee ◽  
Jorng-Tzong Horng
Keyword(s):  
Antimicrobial Peptides ◽  
Hot Spot ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Van Der Waals Volume ◽  
Gram Negative ◽  
Functional Activities ◽  
Wide Range ◽  
Anti Cancer ◽  
Anti Fungal

Abstract In recent years, antimicrobial peptides (AMPs) have become an emerging area of focus when developing therapeutics hot spot residues of proteins are dominant against infections. Importantly, AMPs are produced by virtually all known living organisms and are able to target a wide range of pathogenic microorganisms, including viruses, parasites, bacteria and fungi. Although several studies have proposed different machine learning methods to predict peptides as being AMPs, most do not consider the diversity of AMP activities. On this basis, we specifically investigated the sequence features of AMPs with a range of functional activities, including anti-parasitic, anti-viral, anti-cancer and anti-fungal activities and those that target mammals, Gram-positive and Gram-negative bacteria. A new scheme is proposed to systematically characterize and identify AMPs and their functional activities. The 1st stage of the proposed approach is to identify the AMPs, while the 2nd involves further characterization of their functional activities. Sequential forward selection was employed to extract potentially informative features that are possibly associated with the functional activities of the AMPs. These features include hydrophobicity, the normalized van der Waals volume, polarity, charge and solvent accessibility—all of which are essential attributes in classifying between AMPs and non-AMPs. The results revealed the 1st stage AMP classifier was able to achieve an area under the receiver operating characteristic curve (AUC) value of 0.9894. During the 2nd stage, we found pseudo amino acid composition to be an informative attribute when differentiating between AMPs in terms of their functional activities. The independent testing results demonstrated that the AUCs of the multi-class models were 0.7773, 0.9404, 0.8231, 0.8578, 0.8648, 0.8745 and 0.8672 for anti-parasitic, anti-viral, anti-cancer, anti-fungal AMPs and those that target mammals, Gram-positive and Gram-negative bacteria, respectively. The proposed scheme helps facilitate biological experiments related to the functional analysis of AMPs. Additionally, it was implemented as a user-friendly web server (AMPfun, http://fdblab.csie.ncu.edu.tw/AMPfun/index.html) that allows individuals to explore the antimicrobial functions of peptides of interest.

Blood leukocyte transcriptomes in gram-positive and gram-negative community-acquired pneumonia

2021 ◽  
pp. 2101856
Author(s):  
Liza Pereverzeva ◽  
Fabrice Uhel ◽  
Hessel Peters Sengers ◽  
Joe Butler ◽  
Lonneke A. van Vught ◽  
...  
Keyword(s):  
Immune Response ◽  
Host Response ◽  
Host Immune Response ◽  
Community Acquired Pneumonia ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Icu Admission ◽  
Blood Leukocyte ◽  
Response Biomarkers

BackgroundGram-positive and Gram-negative bacteria are the most common causative pathogens in community-acquired pneumonia (CAP) on the intensive care unit (ICU). The aim of this study was to determine whether the host immune response differs between Gram-positive and Gram-negative CAP upon ICU admission.MethodsSixteen host response biomarkers providing insight in pathophysiological mechanisms implicated in sepsis and blood leukocyte transcriptomes were analysed in patients with CAP upon ICU admission in two tertiary hospitals in the Netherlands.Results309 patients with CAP with a definite or probable likelihood (determined by predefined criteria) were included. A causative pathogen was determined in 74.4% of admissions. Patients admitted with Gram-positive CAP (n=90) were not different from those admitted with Gram-negative CAP (n=75) regarding demographics, chronic comorbidities, severity of disease and mortality. Host response biomarkers reflective of systemic inflammation, coagulation activation and endothelial cell function, as well as blood leukocytes transcriptomes, were largely similar between Gram-positive and Gram-negative CAP. Blood leukocyte transcriptomes were also similar in Gram-positive and Gram-negative CAP in two independent validation cohorts. On a pathogen-specific level, Streptococcus pneumoniae and Escherichia coli induced the most distinct host immune response.ConclusionOutcome and host response are similar in critically ill patients with CAP due to Gram-positive bacteria compared to Gram-negative bacteria.

scholarly journals DETERMINATION OF ANTIBACTERIAL ACTIVITY OF SOME IMPORTANT SPICES

2015 ◽  
Vol 3 (10) ◽  
pp. 57-64
Author(s):  
Ranganathan Kapilan
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Pathogenic Bacteria ◽  
Maximum Activity ◽  
Gram Negative Bacteria ◽  
Alcoholic Extract ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Wide Range

Wide range of plant extracts are used for medicinal purposes as they are very cheap, efficient, harmless and do not cause any side effects. Spices are parts of different plants and they add special aroma and taste to the food preparations. The aim of the study was to determine the antimicrobial activity of some important naturally grown spices against gram positive and gram negative pathogenic bacteria. Antibacterial activity of the spices was tested against gram positive bacteria Bacillus pumilus, Bacillus cereus and Staphylococcus aureus and gram negative bacteria Escherichia coli, Salmonella typhi and Pseudomonas aeruginosa using aqueous, ethanolic, methanolic and liquid nutrient extracts. Among all the extracts tested alcoholic extracts of Cardamom (Elettaria cardamom), clove (Eugenia caryophyllus) and lemongrass (Cymbopogoncitratus) showed maximum antimicrobial activity against gram negative bacteria while alcoholic extract of Cardamom (Elettaria cardamom) and lemongrass (Cymbopogoncitratus) showed maximum activity against gram positive bacteria. All the spices tested in this study proved that they have antibacterial activity and the maximum activity index (1.39) was exhibited by the ethanol extract of cardamom against E.coli.

scholarly journals Lipoproteins of Gram-Positive Bacteria: Key Players in the Immune Response and Virulence

2016 ◽  
Vol 80 (3) ◽  
pp. 891-903 ◽  
Author(s):  
Minh Thu Nguyen ◽  
Friedrich Götz
Keyword(s):  
Immune Response ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Content Type ◽  
Gram Positive Bacteria ◽  
Key Players ◽  
Toll Like Receptor 2 ◽  
Number Of Publications

SUMMARYSince the discovery in 1973 of the first of the bacterial lipoproteins (Lpp) inEscherichia coli, Braun's lipoprotein, the ever-increasing number of publications indicates the importance of these proteins. Bacterial Lpp belong to the class of lipid-anchored proteins that in Gram-negative bacteria are anchored in both the cytoplasmic and outer membranes and in Gram-positive bacteria are anchored only in the cytoplasmic membrane. In contrast to the case for Gram-negative bacteria, in Gram-positive bacteria lipoprotein maturation and processing are not vital. Physiologically, Lpp play an important role in nutrient and ion acquisition, allowing particularly pathogenic species to better survive in the host. Bacterial Lpp are recognized by Toll-like receptor 2 (TLR2) of the innate immune system. The important role of Lpp in Gram-positive bacteria, particularly in the phylumFirmicutes, as key players in the immune response and pathogenicity has emerged only in recent years. In this review, we address the role of Lpp in signaling and modulating the immune response, in inflammation, and in pathogenicity. We also address the potential of Lpp as promising vaccine candidates.

scholarly journals Quaternary Ammonium Leucine-Based Surfactants: The Effect of a Benzyl Group on Physicochemical Properties and Antimicrobial Activity

Pharmaceutics ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 287 ◽  
Author(s):  
Diego Romano Perinelli ◽  
Dezemona Petrelli ◽  
Luca Agostino Vitali ◽  
Giulia Bonacucina ◽  
Marco Cespi ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Quaternary Ammonium ◽  
Cationic Surfactants ◽  
Cytotoxic Effect ◽  
Bacterial Species ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Wide Range ◽  
Surface Active

Quaternary ammonium amphiphiles are a class of compounds with a wide range of commercial and industrial uses. In the pharmaceutical field, the most common quaternary ammonium surfactant is benzalkonium chloride (BAC), which is employed as a preservative in several topical formulations for ocular, skin, or nasal application. Despite the broad antimicrobial activity against Gram-positive and Gram-negative bacteria, as well as fungi and small enveloped viruses, safety concerns regarding its irritant and cytotoxic effect on epithelial cells still remain. In this work, quaternary ammonium derivatives of leucine esters (C10, C12 and C14) were synthesised as BAC analogues. These cationic surfactants were characterised in terms of critical micelle concentration (CMC, by tensiometry), cytotoxicity (MTS and LDH assays on the Caco-2 and Calu-3 cell lines) and antimicrobial activity on the bacterial species Staphylococcus aureus and Enterococcus faecalis among the Gram-positives, Escherichia coli and Pseudomonas aeruginosa among the Gram-negatives and the yeast Candida albicans. They showed satisfactory surface-active properties, and a cytotoxic effect that was dependent on the length of the hydrophobic chain. Lower minimum inhibiting concentration (MIC) values were calculated for C14-derivatives, which were comparable to those calculated for BAC toward Gram-positive bacteria and slightly higher for Gram-negative bacteria and C. albicans. Thus, the synthesised leucine-based quaternary ammonium cationic surfactants can potentially find application as promising surface-active compounds with antimicrobial activity.

scholarly journals The intestinal microbiota of rats under the influence of biotechnological strains of microorganisms from various taxonomic groups

2021 ◽  
Vol 100 (3) ◽  
pp. 234-239
Author(s):  
Natalia I. Sheina ◽  
Elena V. Budanova ◽  
Valentina V. Kolesnikova ◽  
Lyubov I. Mjalina ◽  
Lyubov I. Sazonova
Keyword(s):  
Intestinal Microbiota ◽  
Ambient Air ◽  
Control Group ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
White Rats ◽  
Wide Range ◽  
Taxonomic Groups ◽  
Animal Feces

Introduction. The microbiota of the gastrointestinal tract (GIT) plays an essential role in maintaining human health. Many factors, including industrial pollutions with biotechnological strains of microbes, can affect the normal balance of intestinal microbiota. The biotechnological industry nowadays produces a wide range of products for medical and veterinary use, agriculture, food, chemical industries, etc. To develop hygienic standards that regulate the possible adverse effect of biotechnological strains of microorganisms on workers’ health, the intestinal microflora of rats in the experiment can be studied. The data obtained were used as the basic concept in elaborating state sanitary standards for limitations of the concentrations of biotechnological strains of microorganisms in the ambient air of the working area and settlements’ atmosphere. Materials and methods. We have tested 52 strains of microorganisms applied in biotechnology as producers of a variety of biological substances. They included members of different taxonomic groups: gram-positive and gram-negative bacteria, actinomycetes, molds, and yeasts. The experiments were carried out on conventional male and female white rats (290-320 g, body weight). Each test and control group of animals included eight animals. The strains of microorganisms mentioned above were given to animals by inhalation of minimal effective doses of microbes in the concentrations of 103-108 CFU/m3 during one month. To demonstrate possible adverse effects to gut microflora, the routine bacteriological examination of animal feces was performed. To do this, after the priming, the 10-fold dilutions of animal feces in sterile saline were inoculated onto a set of general-purpose and selective culture media for Enterobacteriaceae members, staphylococci, enterococci, clostridia, bifidobacteria, lactobacilli, and fungi, with subsequent identification of the genus of the isolated microorganism. After that, the concentrations of microorganisms were calculated and measured in lg of CFU/g of feces. The Institutional Ethical Committee of Animal Care and Use of the Pirogov Russian National Research Medical University approved all procedures involving animals. The results of experiments were analyzed with a simple t-test using Statistica (v.6.0, Stat Soft, USA) and Microsoft Office Excel 2007. Results were considered statistically significant when p < 0.05. Results. The most notable changes in the composition of the intestinal microbiota were observed after inhaling of yeasts of genus Candida at the level of 103-104 CFU/m3 and in cases of exposure to molds (Aspergillus awamori, Penicillium funiculosum, and Tolypocladium cylindrosporum) in the concentration of 2•104 CFU/m3, and gram-negative bacteria of the genus Alcaligenes and genus Pseudomonas at 5•105 CFU/m3. We observed a dramatic decrease of Escherichia coli and the increase of gram-positive bacteria (staphylococci, enterococci). For some genera of biotechnological strains, a significant decline in the content of lactobacilli was also shown. On the other hand, Rhodococcus did not cause any disturbances even at high concentrations in the ambient air. Conclusion. The obtained data can be used to develop biosafety and hygienic standards for industrial microbes to help decrease or minimize the occupational risk of infection or undesirable allergic effect when working with biotechnological strains of microbes in the ambient air of residential areas.

scholarly journals Broad Spectrum Anti-Quorum Sensing Activity of Tannin-Rich Crude Extracts of Indian Medicinal Plants

Scientifica ◽  
2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Varsha Shukla ◽  
Zarine Bhathena
Keyword(s):  
Quorum Sensing ◽  
Medicinal Plants ◽  
Broad Spectrum ◽  
Gram Negative Bacteria ◽  
High Concentration ◽  
Gram Positive ◽  
Gram Negative ◽  
Medicinal Plant Extracts ◽  
Wide Range ◽  
Autoinducing Peptides

Quorum sensing (QS) mechanisms have been demonstrated to have significance in expression of pathogenicity in infectious bacteria. In Gram negative bacteria the autoinducer molecules that mediate QS are acyl homoserine lactones (AHL) and in Gram positive bacteria they are peptides called autoinducing peptides (AIP). A screening of tannin-rich medicinal plants was attempted to identify extracts that could interrupt the QS mechanisms in both Gram positive and Gram negative bacteria over a wide range of concentrations and therefore potentially be potent agents that could act as broad spectrum QS inhibitors. Six out of the twelve Indian medicinal plant extracts that were analyzed exhibited anti-QS activity inChromobacterium violaceum12472 and inS.aureusstrain withagr:blaZfusion over a broad range of subinhibitory concentrations, indicating that the extracts contain high concentration of molecules that can interfere with the QS mechanisms mediated by AHL as well as AIP.

The interaction of macrophage receptors with bacterial ligands

2006 ◽  
Vol 8 (28) ◽  
pp. 1-25 ◽  
Author(s):  
Annette Plüddemann ◽  
Subhankar Mukhopadhyay ◽  
Siamon Gordon
Keyword(s):  
Immune Response ◽  
Early Recognition ◽  
Adaptive Immune Response ◽  
Innate Immune ◽  
Surface Proteins ◽  
Scavenger Receptors ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Macrophage Receptors

Innate immune receptors play a key role in the early recognition of invading bacterial pathogens and initiate the crucial innate immune response. The diverse macrophage receptors recognise Gram-positive and Gram-negative bacteria via conserved structures on the bacterial surface and facilitate phagocytosis and/or signalling, providing the trigger for the adaptive immune response. These receptors include scavenger receptors, C-type lectins, integrins, Toll-like receptors and siglecs. The bacterial ligands generally recognised by these receptors range from lipopolysaccharides on Gram-negative bacteria to peptidoglycan and lipoteichoic acid on Gram-positive bacteria. However, emerging evidence indicates that bacterial proteins are also important ligands; for example, surface proteins from Neisseria meningitidis have been shown to be ligands for class A scavenger receptors. In addition, a group of cytosolic receptors, the NBS-LRR proteins, have been implicated in recognition of bacterial breakdown products. It is becoming increasingly apparent that macrophage receptors can act in conjunction with one another to deliver an appropriate response.

scholarly journals Soil Type-Dependent Responses to Phenanthrene as Revealed by Determining the Diversity and Abundance of Polycyclic Aromatic Hydrocarbon Ring-Hydroxylating Dioxygenase Genes by Using a Novel PCR Detection System

2010 ◽  
Vol 76 (14) ◽  
pp. 4765-4771 ◽  
Author(s):  
Guo-Chun Ding ◽  
Holger Heuer ◽  
Sebastian Zühlke ◽  
Michael Spiteller ◽  
Geertje Johanna Pronk ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbon ◽  
Aromatic Hydrocarbon ◽  
Soil Type ◽  
Gram Negative Bacteria ◽  
Cloning And Sequencing ◽  
Gram Positive ◽  
Soil Dna ◽  
Gram Negative ◽  
Wide Range ◽  
Polycyclic Aromatic

ABSTRACT A novel PCR primer system that targets a wide range of polycyclic aromatic hydrocarbon ring-hydroxylating dioxygenase (PAH-RHDα) genes of both Gram-positive and Gram-negative bacteria was developed and used to study their abundance and diversity in two different soils in response to phenanthrene spiking. The specificities and target ranges of the primers predicted in silico were confirmed experimentally by cloning and sequencing of PAH-RHDα gene amplicons from soil DNA. Cloning and sequencing showed the dominance of phnAc genes in the contaminated Luvisol. In contrast, high diversity of PAH-RHDα genes of Gram-positive and Gram-negative bacteria was observed in the phenanthrene-spiked Cambisol. Quantitative real-time PCR based on the same primers revealed that 63 days after phenanthrene spiking, PAH-RHDα genes were 1 order of magnitude more abundant in the Luvisol than in the Cambisol, while they were not detected in both control soils. In conclusion, sequence analysis of the amplicons obtained confirmed the specificity of the novel primer system and revealed a soil type-dependent response of PAH-RHDα gene-carrying soil bacteria to phenanthrene spiking.

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