scholarly journals Eating in a losing cause: anorexia and macronutrient manipulation by a cockroach fails to boost immunity

2019 ◽  
Author(s):  
Thorben Sieksmeyer ◽  
Shulin He ◽  
Benno Kuropka ◽  
Christoph Weise ◽  
Paul R. Johnston ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Feeding Behaviour ◽  
Secondary Compounds ◽  
General Mechanism ◽  
Host Feeding ◽  
List Type ◽  
Self Medication ◽  
Dietary Preference ◽  
Blatta Orientalis ◽  
Dietary Regulation

SummaryHost-pathogen interactions can lead to dramatic changes in host feeding behaviour. One aspect of this includes self-medication, where infected individuals consume substances such as toxins, minerals or secondary compounds or alter their macronutrient consumption to enhance immune competence. Another aspect includes illness-induced anorexia, which is a general mechanism adopted by animals following infection. Anorexia is thought to assist host immunity directly or by limiting the nutritional resources available to pathogens.Here, we recorded macronutrient preferences of the global pest cockroach, Blatta orientalis to investigate how shifts in host macronutrient dietary preference and quantity interact with immunity following sublethal bacterial infection.We compared the survival of uninfected and infected individuals on diets enriched with carbohydrate (C) or protein (P) and conducted food-choice experiments after challenging hosts with the common entomopathogenic soil bacterium Pseudomonas entomophila. We then carried out a quantitative proteomic analysis and an antimicrobial activity assay of hemolymph from infected individuals that had been restricted to diets with defined macronutrient compositions.We find that diets enriched for P reduce cockroach survival. However, following immune challenge by P. entomophila, cockroaches significantly reduced their overall nutrient intake, particularly of carbohydrates, and increased the ratio of protein (P:C) consumed. Surprisingly, these behavioural shifts did not significantly improve cockroach immunity or survival, with negligible differences in immune protein abundance and antimicrobial activity between infected individuals placed on P- or C-rich diets.We show that cockroach feeding behaviour can be dynamically modulated by a pathogen, resulting in an illness-induced anorexia-like feeding response and preference for P-enriched food. Interestingly however, our results also demonstrate that these responses hold no special advantage for the host’s immune response. The lack of a benefit following the host’s behavioural shift highlights a possible decoupling of dietary regulation from immunity in these invasive animals.

scholarly journals Characterization of bacteriocin and chitinase producing bacterial isolates with broad-spectrum antimicrobial activities

2021 ◽  
Vol 3 (8) ◽  
Author(s):  
Muhammad Yasir ◽  
Basit Zeshan ◽  
Nur Hardy A. Daud ◽  
Izzah Shahid ◽  
Hafza Khalid
Keyword(s):  
Antimicrobial Activity ◽  
Inhibitory Activity ◽  
Antifungal Drugs ◽  
Proteinase K ◽  
Diffusion Method ◽  
List Type ◽  
Bacterial Isolates ◽  
E Coli ◽  
Inhibitory Potential

Abstract There is a need for more efficient and eco-friendly approaches to overcome increasing microbial infections. Bacteriocins and chitinases from Bacillus spp. can be powerful alternatives to conventional antibiotics and antifungal drugs, respectively. The purpose of this study was to assess the inhibitory potential of bacteriocins and chitinase enzymes against multiple resistant bacterial and fungal pathogens. Bacterial isolates were selected by growth on minimal salts medium and after that were morphologically and biochemically characterized. The physiochemical characterization of bacteriocins was carried out. The inhibitory potential of bacteriocins towards six pathogenic bacteria was determined by the well diffusion assay while chitinase activity towards three fungal strains was determined by the dual plate culture assay. Two bacterial strains (WW2P1 and WRE4P2), out of nine showed inhibition of K. pneumonia, P. aeruginosa, E. coli and MRSA while WW4P2 was positive against S. typhimurium and E. coli and WRE10P2 against P. aeruginosa, S. pneumoniae. Two bacterial isolates (WW3P1 and WRE10P2) were chosen for further study on the basis of their antifungal activities. Of these, WW3P1 isolate was more effective against A. fumigatus as well as A. niger. The proteinaceous nature of the bacteriocins was confirmed by treatment of the crude extract with proteinase K. It was found that the inhibitory activity of strain WW3P1 against E. coli was highest at 20 °C, and against S. pneumoniae it was at 20 °C and pH 10 after treatment with EDTA. Inhibition by strain the WRE10P2 against P. aeruginosa was highest at 20 °C and pH 14. It was found that EDTA increased the inhibitory activity of strain WW2P1 against P. aeruginosa, K. pneumoniae and E. coli by 2 ± 0.235, 3.5 ± 0.288, 2.5 ± 1.040 times, respectively, of strain WRE4P2 against P. aeruginosa and E. coli by 2.5 ± 0.763, 2.7 ± 0.5 times, respectively, and of strain WRE10P2 against S. pneumoniae by 3 ± 0.6236 times. The isolates have promising inhibitory activity, which should be further analyzed for the commercial production of antimicrobials. Article highlights The current study aimed to isolate the microbiome from wheat plant (Triticum aestivum L.), to screen for bacteriocin production and to assess its antimicrobial activity against human pathogens. Forty-one phenotypically different bacterial colonies were subjected to bacteriocin purification from which 25 colonies showed positive reactions. These 25 bacterial isolates were screened against six different human bacterial pathogens using the well diffusion method to check the antimicrobial activity. Out of nine bacterial isolates, WW3P1 and WRE10P2 were able to degrade the chitin and utilize it as their sole energy source. Strain WRE4P2 exhibited partial inactivation in its activity against MRSA after treatment with proteinase K.

Effect of age and hunger on host-feeding behaviour by femaleTrichogramma euproctidis(Hymenoptera: Trichogrammatidae)

2013 ◽  
Vol 145 (1) ◽  
pp. 53-60 ◽  
Author(s):  
Émilie Lessard ◽  
Guy Boivin
Keyword(s):  
Sex Ratio ◽  
Feeding Behaviour ◽  
Strategic Choice ◽  
Host Feeding ◽  
Feeding Frequency ◽  
Duration Distribution ◽  
Adult Parasitoid ◽  
Old Females ◽  
Effect Of Age

AbstractAdult parasitoid females can obtain proteins and lipid by consuming the haemolymph of their host. InTrichogrammaWestwood (Hymenoptera: Trichogrammatidae) species, host feeding on the host egg occurs after oviposition and leads to smaller offspring. We tested the effect of age and hunger on host-feeding behaviour of femaleTrichogramma euproctidisGirault. Young and old females, either starved, water fed, or honey fed, were observed and the host-feeding frequency, duration, distribution, and number of hosts used for nutrition were measured. The sex ratio (proportion of males) allocated to parasitised hosts where host feeding occurred and time taken to parasitise 10 hosts (indicator of female mobility) were also noted. The majority of females host fed on the first host encountered. Age had no impact on frequency, duration, number of hosts used, and mobility ofT. euproctidis. Starved females host fed longer and were less mobile. The sex ratio of the progeny emerging from the first host parasitised was more male biased when host feeding occurred. Host feeding had no effect on the sex ratio deposited elsewhere in the sequence of hosts encountered. Age of female had no effect on host feeding, possibly because host feeding incurs little cost for this species. To host feed on the first host parasitised, in which a male is allocated, is less costly in terms of fitness and represents a strategic choice for the female.

Tobacco smoking and schizophrenia: re-examining the evidence

2019 ◽  
Vol 25 (6) ◽  
pp. 363-372
Author(s):  
Amila Isuru ◽  
Mahesh Rajasuriya
Keyword(s):  
Risk Factor ◽  
Nicotine Dependence ◽  
Tobacco Smoking ◽  
Mental Illnesses ◽  
The Self ◽  
List Type ◽  
Self Medication ◽  
Genetic Vulnerability ◽  
Shared Genetic

SUMMARYTobacco smoking among people with mental illnesses can be explained by biological, psychological and social factors. The prevalence of smoking in people diagnosed with schizophrenia is higher than in people with other mental disorders and in the general population. This article explores three current hypotheses that explain this higher prevalence of smoking in schizophrenia. The first, the self-medication hypothesis, is increasingly countered by a growing body of evidence indicating that smokers experience more severe symptoms of schizophrenia. Numerous researchers have already identified smoking as a possible risk factor for the development of schizophrenia, which is the second hypothesis. The third hypothesis (shared genetic vulnerability) identifies certain genes that confer vulnerability for both schizophrenia and nicotine dependence. Understanding the reasons behind the higher prevalence of smoking among people with schizophrenia is vital in planning effective primary, secondary and tertiary smoking prevention for these individuals.LEARNING OBJECTIVESAt the end of this article, readers will be able to: •understand the self-medication hypothesis in relation to tobacco smoking by people with schizophrenia•understand the role of tobacco smoking as a possible risk factor for causation of schizophrenia•understand the role of shared genetic vulnerability in the causation of both schizophrenia and nicotine dependence.

scholarly journals Essential Oil of Calotropis procera: Comparative Chemical Profiles, Antimicrobial Activity, and Allelopathic Potential on Weeds

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 5203
Author(s):  
Saud L. Al-Rowaily ◽  
Ahmed M. Abd-ElGawad ◽  
Abdulaziz M. Assaeed ◽  
Abdelbaset M. Elgamal ◽  
Abd El-Nasser G. El Gendy ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Biological Activities ◽  
Principal Component ◽  
Secondary Compounds ◽  
Antimicrobial Activities ◽  
Climatic Conditions ◽  
Calotropis Procera ◽  
Bidens Pilosa ◽  
Allelopathic Potential ◽  
Chemical Profiles

Plants are considered green resources for thousands of bioactive compounds. Essential oils (EOs) are an important class of secondary compounds with various biological activities, including allelopathic and antimicrobial activities. Herein, the present study aimed to compare the chemical profiles of the EOs of the widely distributed medicinal plant Calotropis procera collected from Saudi Arabia and Egypt. In addition, this study also aimed to assess their allelopathic and antimicrobial activities. The EOs from Egyptian and Saudi ecospecies were extracted by hydrodistillation and analyzed via GC-MS. The correlation between the analyzed EOs and those published from Egypt, India, and Nigeria was assessed by principal component analysis (PCA) and agglomerative hierarchical clustering (AHC). The allelopathic activity of the extracted EOs was tested against two weeds (Bidens pilosa and Dactyloctenium aegyptium). Moreover, the EOs were tested for antimicrobial activity against seven bacterial and two fungal strains. Ninety compounds were identified from both ecospecies, where 76 compounds were recorded in Saudi ecospecies and 33 in the Egyptian one. Terpenes were recorded as the main components along with hydrocarbons, aromatics, and carotenoids. The sesquiterpenes (54.07%) were the most abundant component of EO of the Saudi sample, while the diterpenes (44.82%) represented the mains of the Egyptian one. Hinesol (13.50%), trans-chrysanthenyl acetate (12.33%), 1,4-trans-1,7-cis-acorenone (7.62%), phytol (8.73%), and myristicin (6.13%) were found as the major constituents of EO of the Saudi sample, while phytol (38.02%), n-docosane (6.86%), linoleic acid (6.36%), n-pentacosane (6.31%), and bicyclogermacrene (4.37%) represented the main compounds of the Egyptian one. It was evident that the EOs of both ecospecies had potent phytotoxic activity against the two tested weeds, while the EO of the Egyptian ecospecies was more effective, particularly on the weed D. aegyptium. Moreover, the EOs showed substantial antibacterial and antifungal activities. The present study revealed that the EOs of Egyptian and Saudi ecospecies were different in quality and quantity, which could be attributed to the variant environmental and climatic conditions. The EOs of both ecospecies showed significant allelopathic and antimicrobial activity; therefore, these EOs could be considered as potential green eco-friendly resources for weed and microbe control, considering that this plant is widely grown in arid habitats.

scholarly journals Animal self-medication and ethno-medicine: exploration and exploitation of the medicinal properties of plants

2003 ◽  
Vol 62 (2) ◽  
pp. 371-381 ◽  
Author(s):  
Michael A. Huffman
Keyword(s):  
Pan Paniscus ◽  
Intestinal Parasites ◽  
Secondary Compounds ◽  
Biologically Active ◽  
Sub Saharan Africa ◽  
Herbal Remedies ◽  
Self Medication ◽  
Synthetic Drugs ◽  
Chemical Defences ◽  
Intestinal Nematode

Early in the co-evolution of plant-animal relationships, some arthropod species began to utilize the chemical defences of plants to protect themselves from their own predators and parasites. It is likely, therefore, that the origins of herbal medicine have their roots deep within the animal kingdom. From prehistoric times man has looked to wild and domestic animals for sources of herbal remedies. Both folklore and living examples provide accounts of how medicinal plants were obtained by observing the behaviour of animals. Animals too learn about the details of self-medication by watching each other. To date, perhaps the most striking scientific studies of animal self-medication have been made on the African great apes. The great ape diet is often rich in plants containing secondary compounds of non-nutritional, sometimes toxic, value that suggest medicinal benefit from their ingestion. Chimpanzees (Pan troglodytes), bonobos (Pan paniscus) and gorillas (Gorilla gorilla) are known to swallow whole and defecate intact leaves. The habit has been shown to be a physical means of purging intestinal parasites. Chimpanzees and man co-existing in sub-Saharan Africa are also known to ingest the bitter pith of Vernonia amygdalina for the control of intestinal nematode infections. Phytochemical studies have demonstrated a wide array of biologically-active properties in this medicinal plant species. In light of the growing resistance of parasites and pathogens to synthetic drugs, the study of animal self-medication and ethno-medicine offers a novel line of investigation to provide ecologically-sound methods for the treatment of parasites using plant-based medicines in populations and their livestock living in the tropics.

scholarly journals Role of coiled-coil registry shifts in activation of human Bicaudal D2 for dynein recruitment upon cargo-binding

2019 ◽  
Author(s):  
Crystal R. Noell ◽  
Jia Ying Loh ◽  
Erik W. Debler ◽  
Kyle M. Loftus ◽  
Heying Cui ◽  
...  
Keyword(s):  
Muscle Development ◽  
Muscular Atrophy ◽  
Coiled Coil ◽  
Coiled Coils ◽  
General Mechanism ◽  
List Type ◽  
Transport Pathways ◽  
Dynamics Simulations ◽  
Dependent Transport ◽  
Cargo Binding

SUMMARYDynein adaptors such as Bicaudal D2 (BicD2) recognize cargo for dynein-dependent transport. BicD2-dependent transport pathways are important for brain and muscle development. Cargo-bound adaptors are required to activate dynein for processive transport, but the mechanism of action is elusive. Here, we report the structure of the cargo-binding domain of human BicD2 that forms a dimeric coiled-coil with homotypic registry, in which both helices are aligned. To investigate if BicD2 can switch to an asymmetric registry, where a portion of one helix is vertically shifted, we performed molecular dynamics simulations. Both registry types are stabilized by distinct conformations of F743. For the F743I variant, which increases dynein recruitment in the Drosophila homolog, and for the human R747C variant, which causes spinal muscular atrophy, spontaneous coiled-coil registry shifts are observed, which may cause the BicD2-hyperactivation phenotype and disease. We propose that a registry shift upon cargo-binding activates auto-inhibited BicD2 for dynein recruitment.HighlightsStable, bona fide BicD2 coiled-coils with distinct registries can be formed.We provide evidence that a human disease mutation causes a coiled-coil registry shift.A coiled-coil registry shift could relieve BicD2-autoinhibition upon cargo-binding.The ability to undergo registry shifts may be an inherent property of coiled-coils.In BriefOur results support that stable coiled-coils of BicD2 with distinct registries can be formed, and suggest a molecular mechanism for such registry switches. We provide evidence that disease-causing mutations in coiled-coils may alter the equilibrium between registry-shifted conformers, which we propose as a general mechanism of pathogenesis for coiled-coils.Graphical Abstract

scholarly journals Strong selective pressure by parasitoids mitigates the costs of consuming chemically defended plants

2021 ◽  
Author(s):  
Deidra J. Jacobsen
Keyword(s):  
Manduca Sexta ◽  
Natural Enemies ◽  
Developmental Stages ◽  
Parasitoid Wasp ◽  
Field Measurements ◽  
Secondary Compounds ◽  
List Type ◽  
Plant Secondary Compounds ◽  
Defensive Compounds ◽  
Cotesia Congregata

AbstractCo-evolutionary interactions between plants and herbivores have led to a range of plant defenses that minimize insect damage and a suite of counter-adaptations that allow herbivores to feed on defended plants. Consumption of plant secondary compounds results in herbivore growth and developmental costs but can be beneficial if eating these secondary compounds results in deterrence or harm to natural enemies.To test the role of secondary compounds on herbivore fitness in the context of natural enemies, I combined field measurements of the prevalence of a parasitoid wasp (Cotesia congregata) with detailed measurements of the costs of plant secondary compounds on growth, immune, and fitness traits across developmental stages in the herbivore Manduca sexta. When M. sexta larvae consume defended plants, Cotesia congregata are known to have reduced success. However, this anti-enemy benefit to the M. sexta host must be considered in relationship to parasitoid abundance and the type and strength of the fitness costs M. sexta incurs feeding on plant secondary compounds.I found that Cotesia congregata parasitoids exert large negative selective pressures, killing 31-57% of M. sexta larvae in the field. Manduca sexta developed fastest during the instars most at risk for parasitoid oviposition but growth was slowed by consumption of plant secondary compounds (nicotine and rutin). These negative size effects at the larval stage carried over to influence adult traits associated with flight and mating but there were no immune, survival, or fecundity costs of consuming plant defensive compounds as larvae.Synthesis. These results suggest that the developmental costs experienced by M. sexta herbivores consuming defensive compounds may be outweighed by a survival benefit in the face of abundant enemy pressures.

scholarly journals SAFB2 enables the processing of suboptimal stem-loop structures in clustered primary miRNA transcripts

2019 ◽  
Author(s):  
Katharina Hutter ◽  
Michael Lohmüller ◽  
Almina Jukic ◽  
Felix Eichin ◽  
Seymen Avci ◽  
...  
Keyword(s):  
Noncoding Rnas ◽  
General Mechanism ◽  
List Type ◽  
Loop Structure ◽  
Stem Loop ◽  
Protein Coding ◽  
Mirna Processing ◽  
Small Noncoding Rnas ◽  
Stem Loop Structure ◽  
Attachment Factor

SummaryMicroRNAs (miRNAs) are small noncoding RNAs that post-transcriptionally silence most protein-coding genes in mammals. They are generated from primary transcripts containing single or multiple clustered stem-loop structures that are thought to be recognized and cleaved by the DGCR8/DROSHA Microprocessor complex as independent units. Contrasting this view, we here report an unexpected mode of processing of a bicistronic cluster of the miR-15 family, miR-15a-16-1. We find that the primary miR-15a stem-loop is a poor Microprocessor substrate and is consequently not processed on its own, but that the presence of the neighboring primary miR-16-1 stem-loop on the same transcript can compensate for this deficiency in cis. Using a CRISPR/Cas9 screen, we identify SAFB2 (scaffold attachment factor B2) as an essential co-factor in this miR-16-1-assisted pri-miR-15 cleavage, and describe SAFB2 as a novel accessory protein of DROSHA. Notably, SAFB2-mediated cluster assistance expands to other clustered pri-miRNAs including miR-15b, miR-92a and miR-181b, indicating a general mechanism. Together, our study reveals an unrecognized function of SAFB2 in miRNA processing and suggests a scenario in which SAFB2 enables the binding and processing of suboptimal DGCR8/DROSHA substrates in clustered primary miRNA transcripts.Highlightsthe primary miR-15a stem-loop structure per se is a poor Microprocessor substratecleavage of pri-miR-15a requires the processing of an additional miRNA stem-loop on the same RNAsequential pri-miRNA processing or “cluster assistance” is mediated by SAFB proteinsSAFB2 associates with the Microprocessor

scholarly journals Host feeding behaviour of Dermacentor reticulatus males in relation to the transmission of pathogens

2019 ◽  
Vol 26 (2) ◽  
pp. 227-230
Author(s):  
Katarzyna Bartosik ◽  
Alicja Buczek ◽  
Weronika Buczek ◽  
Alicja Buczek ◽  
Dorota Kulina ◽  
...  
Keyword(s):  
Feeding Behaviour ◽  
Dermacentor Reticulatus ◽  
Host Feeding
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