Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 17.499
Filtrar
1.
Appl Microbiol Biotechnol ; 108(1): 360, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38836914

RESUMO

In the fight against hospital-acquired infections, the challenge posed by methicillin-resistant Staphylococcus aureus (MRSA) necessitates the development of novel treatment methods. This study focused on undermining the virulence of S. aureus, especially by targeting surface proteins crucial for bacterial adherence and evasion of the immune system. A primary aspect of our approach involves inhibiting sortase A (SrtA), a vital enzyme for attaching microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) to the bacterial cell wall, thereby reducing the pathogenicity of S. aureus. Verbascoside, a phenylethanoid glycoside, was found to be an effective SrtA inhibitor in our research. Advanced fluorescence quenching and molecular docking studies revealed a specific interaction between verbascoside and SrtA, pinpointing the critical active sites involved in this interaction. This molecular interaction significantly impedes the SrtA-mediated attachment of MSCRAMMs, resulting in a substantial reduction in bacterial adhesion, invasion, and biofilm formation. The effectiveness of verbascoside has also been demonstrated in vivo, as shown by its considerable protective effects on pneumonia and Galleria mellonella (wax moth) infection models. These findings underscore the potential of verbascoside as a promising component in new antivirulence therapies for S. aureus infections. By targeting crucial virulence factors such as SrtA, agents such as verbascoside constitute a strategic and potent approach for tackling antibiotic resistance worldwide. KEY POINTS: • Verbascoside inhibits SrtA, reducing S. aureus adhesion and biofilm formation. • In vivo studies demonstrated the efficacy of verbascoside against S. aureus infections. • Targeting virulence factors such as SrtA offers new avenues against antibiotic resistance.


Assuntos
Aminoaciltransferases , Antibacterianos , Aderência Bacteriana , Proteínas de Bactérias , Biofilmes , Cisteína Endopeptidases , Glucosídeos , Staphylococcus aureus Resistente à Meticilina , Simulação de Acoplamento Molecular , Fenóis , Infecções Estafilocócicas , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/antagonistas & inibidores , Aminoaciltransferases/antagonistas & inibidores , Aminoaciltransferases/metabolismo , Cisteína Endopeptidases/metabolismo , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/patogenicidade , Glucosídeos/farmacologia , Animais , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/microbiologia , Fenóis/farmacologia , Aderência Bacteriana/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Antibacterianos/farmacologia , Mariposas/microbiologia , Virulência/efeitos dos fármacos , Modelos Animais de Doenças , Fatores de Virulência/metabolismo , Inibidores Enzimáticos/farmacologia , Polifenóis
2.
BMC Biotechnol ; 24(1): 37, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38825715

RESUMO

BACKGROUND: As part of a publicly funded initiative to develop genetically engineered Brassicas (cabbage, cauliflower, and canola) expressing Bacillus thuringiensis Crystal (Cry)-encoded insecticidal (Bt) toxin for Indian and Australian farmers, we designed several constructs that drive high-level expression of modified Cry1B and Cry1C genes (referred to as Cry1BM and Cry1CM; with M indicating modified). The two main motivations for modifying the DNA sequences of these genes were to minimise any licensing cost associated with the commercial cultivation of transgenic crop plants expressing CryM genes, and to remove or alter sequences that might adversely affect their activity in plants. RESULTS: To assess the insecticidal efficacy of the Cry1BM/Cry1CM genes, constructs were introduced into the model Brassica Arabidopsis thaliana in which Cry1BM/Cry1CM expression was directed from either single (S4/S7) or double (S4S4/S7S7) subterranean clover stunt virus (SCSV) promoters. The resulting transgenic plants displayed a high-level of Cry1BM/Cry1CM expression. Protein accumulation for Cry1CM ranged from 5.18 to 176.88 µg Cry1CM/g dry weight of leaves. Contrary to previous work on stunt promoters, we found no correlation between the use of either single or double stunt promoters and the expression levels of Cry1BM/Cry1CM genes, with a similar range of Cry1CM transcript abundance and protein content observed from both constructs. First instar Diamondback moth (Plutella xylostella) larvae fed on transgenic Arabidopsis leaves expressing the Cry1BM/Cry1CM genes showed 100% mortality, with a mean leaf damage score on a scale of zero to five of 0.125 for transgenic leaves and 4.2 for wild-type leaves. CONCLUSIONS: Our work indicates that the modified Cry1 genes are suitable for the development of insect resistant GM crops. Except for the PAT gene in the USA, our assessment of the intellectual property landscape of components presents within the constructs described here suggest that they can be used without the need for further licensing. This has the capacity to significantly reduce the cost of developing and using these Cry1M genes in GM crop plants in the future.


Assuntos
Arabidopsis , Toxinas de Bacillus thuringiensis , Proteínas de Bactérias , Endotoxinas , Proteínas Hemolisinas , Plantas Geneticamente Modificadas , Plantas Geneticamente Modificadas/genética , Arabidopsis/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Proteínas Hemolisinas/genética , Animais , Endotoxinas/genética , Regiões Promotoras Genéticas/genética , Bacillus thuringiensis/genética , Mariposas/genética , Brassica/genética , Controle Biológico de Vetores/métodos , Inseticidas/farmacologia
3.
BMC Genom Data ; 25(1): 55, 2024 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-38851674

RESUMO

OBJECTIVES: The oak processionary moth (OPM) (Thaumetopoea processionea) is a species of moth (order: Lepidoptera) native to parts of central Europe. However, in recent years, it has become an invasive species in various countries, particularly in the United Kingdom and the Netherlands. The larvae of the OPM are covered with urticating barbed hairs (setae) causing irritating and allergic reactions at the three last larval stages (L3-L5). The aim of our study was to generate a de novo transcriptomic assembly for OPM larvae by including one non-allergenic stage (L2) and two allergenic stages (L4 and L5). A transcriptomic assembly will help identify potential allergenic peptides produced by OPM larvae, providing valuable information for developing novel therapeutic strategies and allergic immunodiagnostic assays. DATA: Transcriptomes of three larval stages of the OPM were de novo assembled and annotated using Trinity and Trinotate, respectively. A total of 145,251 transcripts from 99,868 genes were identified. Bench-marking universal single-copy orthologues analysis indicated high completeness of the assembly. About 19,600 genes are differentially expressed between the non-allergenic and allergenic larval stages. The data provided here contribute to the characterization of OPM, which is both an invasive species and a health hazard.


Assuntos
Larva , Mariposas , Transcriptoma , Animais , Mariposas/genética , Mariposas/imunologia , Larva/genética , Larva/metabolismo , Larva/imunologia , Perfilação da Expressão Gênica , Alérgenos/imunologia , Alérgenos/genética
4.
Commun Biol ; 7(1): 704, 2024 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-38851817

RESUMO

Aspergillus fumigatus represents a public health problem due to the high mortality rate in immunosuppressed patients and the emergence of antifungal-resistant isolates. Protein acetylation is a crucial post-translational modification that controls gene expression and biological processes. The strategic manipulation of enzymes involved in protein acetylation has emerged as a promising therapeutic approach for addressing fungal infections. Sirtuins, NAD+-dependent lysine deacetylases, regulate protein acetylation and gene expression in eukaryotes. However, their role in the human pathogenic fungus A. fumigatus remains unclear. This study constructs six single knockout strains of A. fumigatus and a strain lacking all predicted sirtuins (SIRTKO). The mutant strains are viable under laboratory conditions, indicating that sirtuins are not essential genes. Phenotypic assays suggest sirtuins' involvement in cell wall integrity, secondary metabolite production, thermotolerance, and virulence. Deletion of sirE attenuates virulence in murine and Galleria mellonella infection models. The absence of SirE alters the acetylation status of proteins, including histones and non-histones, and triggers significant changes in the expression of genes associated with secondary metabolism, cell wall biosynthesis, and virulence factors. These findings encourage testing sirtuin inhibitors as potential therapeutic strategies to combat A. fumigatus infections or in combination therapy with available antifungals.


Assuntos
Aspergilose , Aspergillus fumigatus , Sirtuínas , Aspergillus fumigatus/patogenicidade , Aspergillus fumigatus/genética , Aspergillus fumigatus/enzimologia , Sirtuínas/genética , Sirtuínas/metabolismo , Virulência , Animais , Camundongos , Aspergilose/microbiologia , Aspergilose/tratamento farmacológico , Acetilação , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Regulação Fúngica da Expressão Gênica , Fatores de Virulência/genética , Fatores de Virulência/metabolismo , Mariposas/microbiologia
5.
PeerJ ; 12: e17365, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38827314

RESUMO

The saturniid moth genus Automeris includes 145 described species. Their geographic distribution ranges from the eastern half of North America to as far south as Peru. Automeris moths are cryptically colored, with forewings that resemble dead leaves, and conspicuously colored, elaborate eyespots hidden on their hindwings. Despite their charismatic nature, the evolutionary history and relationships within Automeris and between closely related genera, remain poorly understood. In this study, we present the most comprehensive phylogeny of Automeris to date, including 80 of the 145 described species. We also incorporate two morphologically similar hemileucine genera, Pseudautomeris and Leucanella, as well as a morphologically distinct genus, Molippa. We obtained DNA data from both dry-pinned and ethanol-stored museum specimens and conducted Anchored Hybrid Enrichment (AHE) sequencing to assemble a high-quality dataset for phylogenetic analysis. The resulting phylogeny supports Automeris as a paraphyletic genus, with Leucanella and Pseudautomeris nested within, with the most recent common ancestor dating back to 21 mya. This study lays the foundation for future research on various aspects of Automeris biology, including geographical distribution patterns, potential drivers of speciation, and ecological adaptations such as antipredator defense mechanisms.


Assuntos
Mariposas , Filogenia , Animais , Mariposas/genética , Mariposas/classificação , Mariposas/anatomia & histologia , Evolução Biológica
6.
PeerJ ; 12: e17463, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38827315

RESUMO

Background: The use of antimicrobials to treat food animals may result in antimicrobial residues in foodstuffs of animal origin. The European Medicines Association (EMA) and World Health Organization (WHO) define safe antimicrobial concentrations in food based on acceptable daily intakes (ADIs). It is unknown if ADI doses of antimicrobials in food could influence the antimicrobial susceptibility of human-associated bacteria. Objectives: This aim of this study was to evaluate if the consumption of ADI doses of erythromycin could select for erythromycin resistance in a Galleria mellonella model of Streptococcus pneumoniae infection. Methods: A chronic model of S. pneumoniae infection in G. mellonella larvae was used for the experiment. Inoculation of larvae with S. pneumoniae was followed by injections of erythromycin ADI doses (0.0875 and 0.012 µg/ml according to EMA and WHO, respectively). Isolation of S. pneumoniae colonies was then performed on selective agar plates. Minimum inhibitory concentrations (MICs) of resistant colonies were measured, and whole genome sequencing (WGS) was performed followed by variant calling to determine the genetic modifications. Results: Exposure to single doses of both EMA and WHO ADI doses of erythromycin resulted in the emergence of erythromycin resistance in S. pneumoniae. Emergent resistance to erythromycin was associated with a mutation in rplA, which codes for the L1 ribosomal protein and has been linked to macrolide resistance in previous studies. Conclusion: In our in vivo model, even single doses of erythromycin that are classified as acceptable by the WHO and EMA induced significant increases in erythromycin MICs in S. pneumoniae. These results suggest the need to include the induction of antimicrobial resistance (AMR) as a significant criterion for determining ADIs.


Assuntos
Antibacterianos , Farmacorresistência Bacteriana , Eritromicina , Larva , Testes de Sensibilidade Microbiana , Mariposas , Streptococcus pneumoniae , Eritromicina/farmacologia , Animais , Streptococcus pneumoniae/efeitos dos fármacos , Streptococcus pneumoniae/genética , Antibacterianos/farmacologia , Mariposas/microbiologia , Mariposas/efeitos dos fármacos , Farmacorresistência Bacteriana/genética , Farmacorresistência Bacteriana/efeitos dos fármacos , Larva/microbiologia , Larva/efeitos dos fármacos , Infecções Pneumocócicas/tratamento farmacológico , Infecções Pneumocócicas/microbiologia , Modelos Animais de Doenças , Humanos
7.
Mol Biol Rep ; 51(1): 713, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38824247

RESUMO

BACKGROUND: Protease S (PrtS) from Photorhabdus laumondii belongs to the group of protealysin-like proteases (PLPs), which are understudied factors thought to play a role in the interaction of bacteria with other organisms. Since P. laumondii is an insect pathogen and a nematode symbiont, the analysis of the biological functions of PLPs using the PrtS model provides novel data on diverse types of interactions between bacteria and hosts. METHODS AND RESULTS: Recombinant PrtS was produced in Escherichia coli. Efficient inhibition of PrtS activity by photorin, a recently discovered emfourin-like protein inhibitor from P. laumondii, was demonstrated. The Galleria mellonella was utilized to examine the insect toxicity of PrtS and the impact of PrtS on hemolymph proteins in vitro. The insect toxicity of PrtS is reduced compared to protease homologues from non-pathogenic bacteria and is likely not essential for the infection process. However, using proteomic analysis, potential PrtS targets have been identified in the hemolymph. CONCLUSIONS: The spectrum of identified proteins indicates that the function of PrtS is to modulate the insect immune response. Further studies of PLPs' biological role in the PrtS and P. laumondii model must clarify the details of PrtS interaction with the insect immune system during bacterial infection.


Assuntos
Mariposas , Peptídeo Hidrolases , Photorhabdus , Animais , Mariposas/microbiologia , Peptídeo Hidrolases/metabolismo , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Hemolinfa/metabolismo , Proteômica/métodos , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/genética , Escherichia coli/genética , Escherichia coli/metabolismo
8.
J Med Microbiol ; 73(6)2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38836745

RESUMO

Introduction. The fungal pathogen Aspergillus fumigatus can induce prolonged colonization of the lungs of susceptible patients, resulting in conditions such as allergic bronchopulmonary aspergillosis and chronic pulmonary aspergillosis.Hypothesis. Analysis of the A. fumigatus secretome released during sub-lethal infection of G. mellonella larvae may give an insight into products released during prolonged human colonisation.Methodology. Galleria mellonella larvae were infected with A. fumigatus, and the metabolism of host carbohydrate and proteins and production of fungal virulence factors were analysed. Label-free qualitative proteomic analysis was performed to identify fungal proteins in larvae at 96 hours post-infection and also to identify changes in the Galleria proteome as a result of infection.Results. Infected larvae demonstrated increasing concentrations of gliotoxin and siderophore and displayed reduced amounts of haemolymph carbohydrate and protein. Fungal proteins (399) were detected by qualitative proteomic analysis in cell-free haemolymph at 96 hours and could be categorized into seven groups, including virulence (n = 25), stress response (n = 34), DNA repair and replication (n = 39), translation (n = 22), metabolism (n = 42), released intracellular (n = 28) and cellular development and cell cycle (n = 53). Analysis of the Gallerial proteome at 96 hours post-infection revealed changes in the abundance of proteins associated with immune function, metabolism, cellular structure, insect development, transcription/translation and detoxification.Conclusion. Characterizing the impact of the fungal secretome on the host may provide an insight into how A. fumigatus damages tissue and suppresses the immune response during long-term pulmonary colonization.


Assuntos
Aspergillus fumigatus , Proteínas Fúngicas , Larva , Mariposas , Animais , Aspergillus fumigatus/metabolismo , Larva/microbiologia , Mariposas/microbiologia , Proteínas Fúngicas/metabolismo , Proteínas Fúngicas/genética , Secretoma/metabolismo , Proteômica , Fatores de Virulência/metabolismo , Proteoma/análise , Hemolinfa/microbiologia , Hemolinfa/metabolismo , Virulência , Aspergilose/microbiologia , Aspergilose/metabolismo
9.
Syst Parasitol ; 101(4): 44, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38839661

RESUMO

Species of Diolcogaster parasitize Lepidoptera pests of commercial plants. The diversity of this genus is high, but few species of Diolcogaster have been described. The description of a new Diolcogaster species provides information for the biological control using this insect. This study presents the description and key notes on the biology of a new Diolcogaster parasitoid wasp. This species was reared from a caterpillar of Hypercompe brasiliensis collected after feeding on a Gloxinia perennis plant important to floriculture. Two complementary identification analyzes were performed on Diolcogaster adult bodies. The first was the analyses of its external morphology and the second its molecular analysis (mitochondrial DNA). The morphological analysis defined the insect as a new species of Diolcogaster, named Diolcogaster joanesi sp. nov. A maximum-likelihood (ML) analysis partially confirmed the morphological analysis, placing D. joanesi within a cluster including a previously identified species (Diolcogaster choi) and seven other morphospecies. The proximity of D. joanesi to D. choi is discussed and an updated key for all New World species of the xanthaspis group is provided. Twenty-eight adult wasps were obtained (22 females and six males) out of 50 cocoons which larvae emerged from the caterpillar host. The findings contribute to the broader understanding of Diolcogaster in the Neotropics and its potential for the biological control of lepidopteran defoliators.


Assuntos
Controle Biológico de Vetores , Especificidade da Espécie , Vespas , Animais , Brasil , Vespas/classificação , Vespas/anatomia & histologia , Mariposas/parasitologia , Lepidópteros/parasitologia , Filogenia , Larva , Feminino
10.
BMC Biol ; 22(1): 102, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38693535

RESUMO

BACKGROUND: Sex-limited chromosomes Y and W share some characteristics, including the degeneration of protein-coding genes, enrichment of repetitive elements, and heterochromatin. However, although many studies have suggested that Y chromosomes retain genes related to male function, far less is known about W chromosomes and whether they retain genes related to female-specific function. RESULTS: Here, we built a chromosome-level genome assembly of the Asian corn borer, Ostrinia furnacalis Guenée (Lepidoptera: Crambidae, Pyraloidea), an economically important pest in corn, from a female, including both the Z and W chromosome. Despite deep conservation of the Z chromosome across Lepidoptera, our chromosome-level W assembly reveals little conservation with available W chromosome sequence in related species or with the Z chromosome, consistent with a non-canonical origin of the W chromosome. The W chromosome has accumulated significant repetitive elements and experienced rapid gene gain from the remainder of the genome, with most genes exhibiting pseudogenization after duplication to the W. The genes that retain significant expression are largely enriched for functions in DNA recombination, the nucleosome, chromatin, and DNA binding, likely related to meiotic and mitotic processes within the female gonad. CONCLUSIONS: Overall, our chromosome-level genome assembly supports the non-canonical origin of the W chromosome in O. furnacalis, which experienced rapid gene gain and loss, with the retention of genes related to female-specific function.


Assuntos
Cromossomos de Insetos , Mariposas , Cromossomos Sexuais , Animais , Mariposas/genética , Feminino , Cromossomos Sexuais/genética , Cromossomos de Insetos/genética , Masculino , Evolução Molecular , Genoma de Inseto
11.
BMC Genomics ; 25(1): 541, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38822259

RESUMO

BACKGROUND: Flight can drastically enhance dispersal capacity and is a key trait defining the potential of exotic insect species to spread and invade new habitats. The phytophagous European spongy moths (ESM, Lymantria dispar dispar) and Asian spongy moths (ASM; a multi-species group represented here by L. d. asiatica and L. d. japonica), are globally invasive species that vary in adult female flight capability-female ASM are typically flight capable, whereas female ESM are typically flightless. Genetic markers of flight capability would supply a powerful tool for flight profiling of these species at any intercepted life stage. To assess the functional complexity of spongy moth flight and to identify potential markers of flight capability, we used multiple genetic approaches aimed at capturing complementary signals of putative flight-relevant genetic divergence between ESM and ASM: reduced representation genome-wide association studies, whole genome sequence comparisons, and developmental transcriptomics. We then judged the candidacy of flight-associated genes through functional analyses aimed at addressing the proximate demands of flight and salient features of the ecological context of spongy moth flight evolution. RESULTS: Candidate gene sets were typically non-overlapping across different genetic approaches, with only nine gene annotations shared between any pair of approaches. We detected an array of flight-relevant functional themes across gene sets that collectively suggest divergence in flight capability between European and Asian spongy moth lineages has coincided with evolutionary differentiation in multiple aspects of flight development, execution, and surrounding life history. Overall, our results indicate that spongy moth flight evolution has shaped or been influenced by a large and functionally broad network of traits. CONCLUSIONS: Our study identified a suite of flight-associated genes in spongy moths suited to exploration of the genetic architecture and evolution of flight, or validation for flight profiling purposes. This work illustrates how complementary genetic approaches combined with phenotypically targeted functional analyses can help to characterize genetically complex traits.


Assuntos
Voo Animal , Espécies Introduzidas , Mariposas , Animais , Mariposas/genética , Mariposas/fisiologia , Feminino , Estudo de Associação Genômica Ampla , Fenótipo , Transcriptoma , Complexo de Mariposas do Gênero Lymantria
12.
Environ Microbiol Rep ; 16(3): e13213, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38738810

RESUMO

Since a significant proportion of plant matter is consumed by herbivores, a necessary adaptation for many phyllosphere microbes could be to survive through the guts of herbivores. While many studies explore the gut microbiome of herbivores by surveying the microbiome in their frass, few studies compare the phyllosphere microbiome to the gut microbiome of herbivores. High-throughput metabarcode sequencing was used to track the fungal community from milkweed (Asclepias spp.) leaves to monarch caterpillar frass. The most commonly identified fungal taxa that dominated the caterpillar frass after the consumption of leaves were yeasts, mostly belonging to the Basidiomycota phylum. While most fungal communities underwent significant bottlenecks and some yeast taxa increased in relative abundance, a consistent directional change in community structure was not identified from leaf to caterpillar frass. These results suggest that some phyllosphere fungi, especially diverse yeasts, can survive herbivory, but whether herbivory is a key stage of their life cycle remains uncertain. For exploring phyllosphere fungi and the potential coprophilous lifestyles of endophytic and epiphytic fungi, methods that target yeast and Basidiomycota fungi are recommended.


Assuntos
Asclepias , Fungos , Herbivoria , Folhas de Planta , Animais , Folhas de Planta/microbiologia , Asclepias/microbiologia , Fungos/classificação , Fungos/genética , Fungos/isolamento & purificação , Fungos/fisiologia , Leveduras/classificação , Leveduras/isolamento & purificação , Leveduras/genética , Micobioma , Basidiomycota/classificação , Basidiomycota/genética , Basidiomycota/fisiologia , Basidiomycota/isolamento & purificação , Microbioma Gastrointestinal , Larva/microbiologia , Mariposas/microbiologia
13.
J Med Microbiol ; 73(5)2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38743467

RESUMO

Introduction . Acinetobacter baumannii is a critical priority pathogen for novel antimicrobials (World Health Organization) because of the rise in nosocomial infections and its ability to evolve resistance to last resort antibiotics. A. baumannii is thus a priority target for phage therapeutics. Two strains of a novel, virulent bacteriophage (LemonAid and Tonic) able to infect carbapenem-resistant A. baumannii (strain NCTC 13420), were isolated from environmental water samples collected through a citizen science programme.Gap statement. Phage-host coevolution can lead to emergence of host resistance, with a concomitant reduction in the virulence of host bacteria; a potential benefit to phage therapy applications.Methodology. In vitro and in vivo assays, genomics and microscopy techniques were used to characterize the phages; determine mechanisms and impact of phage resistance on host virulence, and the efficacy of the phages against A. baumannii.Results. A. baumannii developed resistance to both viruses, LemonAid and Tonic. Resistance came at a cost to virulence, with the resistant variants causing significantly reduced mortality in a Galleria mellonella larval in vivo model. A replicated 8 bp insertion increased in frequency (~40 % higher frequency than in the wild-type) within phage-resistant A. baumannii mutants, putatively resulting in early truncation of a protein of unknown function. Evidence from comparative genomics and an adsorption assay suggests this protein acts as a novel phage receptor site in A. baumannii. We find no evidence linking resistance to changes in capsule structure, a known virulence factor. LemonAid efficiently suppressed growth of A. baumanni in vitro across a wide range of titres. However, in vivo, while survival of A. baumannii infected larvae significantly increased with both remedial and prophylactic treatment with LemonAid (107 p.f.u. ml-1), the effect was weak and not sufficient to save larvae from morbidity and mortality.Conclusion. While LemonAid and Tonic did not prove effective as a treatment in a Galleria larvae model, there is potential to harness their ability to attenuate virulence in drug-resistant A. baumannii.


Assuntos
Infecções por Acinetobacter , Acinetobacter baumannii , Bacteriófagos , Acinetobacter baumannii/virologia , Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/patogenicidade , Acinetobacter baumannii/genética , Bacteriófagos/genética , Bacteriófagos/fisiologia , Virulência , Infecções por Acinetobacter/microbiologia , Animais , Mariposas/microbiologia , Mariposas/virologia , Terapia por Fagos , Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Larva/microbiologia , Larva/virologia
14.
Biol Lett ; 20(5): 20230610, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38747686

RESUMO

Echolocating bats and their eared insect prey are in an acoustic evolutionary war. Moths produce anti-bat sounds that startle bat predators, signal noxiousness, mimic unpalatable models and jam bat sonar. Tiger beetles (Cicindelidae) also purportedly produce ultrasound in response to bat attacks. Here we tested 19 tiger beetle species from seven genera and showed that they produce anti-bat signals to playback of authentic bat echolocation. The dominant frequency of beetle sounds substantially overlaps the sonar calls of sympatric bats. As tiger beetles are known to produce defensive chemicals such as benzaldehyde and hydrogen cyanide, we hypothesized that tiger beetle sounds are acoustically advertising their unpalatability. We presented captive big brown bats (Eptesicus fuscus) with seven different tiger beetle species and found that 90 out of 94 beetles were completely consumed, indicating that these tiger beetle species are not aposematically signalling. Instead, we show that the primary temporal and spectral characteristics of beetle warning sounds overlap with sympatric unpalatable tiger moth (Arctinae) sounds and that tiger beetles are probably Batesian mimics of noxious moth models. We predict that many insect taxa produce anti-bat sounds and that the acoustic mimicry rings of the night sky are hyperdiverse.


Assuntos
Quirópteros , Besouros , Ecolocação , Mariposas , Animais , Mariposas/fisiologia , Quirópteros/fisiologia , Besouros/fisiologia , Comportamento Predatório , Mimetismo Biológico
15.
Molecules ; 29(9)2024 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-38731627

RESUMO

A concise synthesis of the sex pheromones of elm spanworm as well as painted apple moth has been achieved. The key steps were the alkylation of acetylide ion, Sharpless asymmetric epoxidation and Brown's P2-Ni reduction. This approach provided the sex pheromone of the elm spanworm (1) in 31% total yield and those of the painted apple moth (2, 3) in 26% and 32% total yields. The ee values of three final products were up to 99%. The synthesized pheromones hold promising potential for use in the management and control of these pests.


Assuntos
Compostos de Epóxi , Mariposas , Atrativos Sexuais , Animais , Atrativos Sexuais/síntese química , Atrativos Sexuais/química , Compostos de Epóxi/química , Estrutura Molecular
16.
Front Cell Infect Microbiol ; 14: 1382145, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38736748

RESUMO

Carbapenem-resistant Acinetobacter baumannii (CRAB) has become a new threat in recent years, owing to its rapidly increasing resistance to antibiotics and new effective therapies are needed to combat this pathogen. Phage therapy is considered to be the most promising alternative for treating CRAB infections. In this study, a novel phage, Ab_WF01, which can lyse clinical CRAB, was isolated and characterized from hospital sewage. The multiplicity of infection, morphology, one-step growth curve, stability, sensitivity, and lytic activity of the phage were also investigated. The genome of phage Ab_WF01 was 41, 317 bp in size with a GC content of 39.12% and encoded 51 open reading frames (ORFs). tRNA, virulence, and antibiotic resistance genes were not detected in the phage genome. Comparative genomic and phylogenetic analyses suggest that phage Ab_WF01 is a novel species of the genus Friunavirus, subfamily Beijerinckvirinae, and family Autographiviridae. The in vivo results showed that phage Ab_WF01 significantly increased the survival rate of CRAB-infected Galleria mellonella (from 0% to 70% at 48 h) and mice (from 0% to 60% for 7 days). Moreover, after day 3 post-infection, phage Ab_WF01 reduced inflammatory response, with strongly ameliorated histological damage and bacterial clearance in infected tissue organs (lungs, liver, and spleen) in mouse CRAB infection model. Taken together, these results show that phage Ab_WF01 holds great promise as a potential alternative agent with excellent stability for against CRAB infections.


Assuntos
Infecções por Acinetobacter , Acinetobacter baumannii , Bacteriófagos , Carbapenêmicos , Genoma Viral , Terapia por Fagos , Filogenia , Esgotos , Acinetobacter baumannii/virologia , Acinetobacter baumannii/efeitos dos fármacos , Esgotos/virologia , Esgotos/microbiologia , Animais , Carbapenêmicos/farmacologia , Bacteriófagos/genética , Bacteriófagos/fisiologia , Bacteriófagos/classificação , Bacteriófagos/isolamento & purificação , Infecções por Acinetobacter/microbiologia , Camundongos , Antibacterianos/farmacologia , Fases de Leitura Aberta , Modelos Animais de Doenças , Mariposas/virologia , Mariposas/microbiologia , Composição de Bases
17.
PLoS One ; 19(5): e0302941, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38709777

RESUMO

Insecticidal Bacillus thuringiensis Berliner (Bt) toxins produced by transgenic cotton (Gossypium hirsutum L.) plants have become an essential component of cotton pest management. Bt toxins are the primary management tool in transgenic cotton for lepidopteran pests, the most important of which is the bollworm (Helicoverpa zea Boddie) (Lepidoptera: Noctuidae) in the United States (U.S.). However, bollworm larvae that survive after consuming Bt toxins may experience sublethal effects, which could alter interactions with other organisms, such as natural enemies. Experiments were conducted to evaluate how sublethal effects of a commercial Bt product (Dipel) incorporated into artificial diet and from Bt cotton flowers impact predation from the convergent lady beetle (Hippodamia convergens Guérin-Méneville) (Coleoptera: Coccinellidae), common in cotton fields of the mid-southern U.S. Sublethal effects were detected through reduced weight and slower development in bollworm larvae which fed on Dipel incorporated into artificial diet, Bollgard II, and Bollgard 3 cotton flowers. Sublethal effects from proteins incorporated into artificial diet were found to significantly alter predation from third instar lady beetle larvae. Predation of bollworm larvae also increased significantly after feeding for three days on a diet incorporated with Bt proteins. These results suggest that the changes in larval weight and development induced by Bt can be used to help predict consumption of bollworm larvae by the convergent lady beetle. These findings are essential to understanding the potential level of biological control in Bt cotton where lepidopteran larvae experience sublethal effects.


Assuntos
Bacillus thuringiensis , Besouros , Flores , Gossypium , Larva , Plantas Geneticamente Modificadas , Comportamento Predatório , Animais , Besouros/efeitos dos fármacos , Besouros/fisiologia , Gossypium/parasitologia , Gossypium/genética , Comportamento Predatório/efeitos dos fármacos , Larva/efeitos dos fármacos , Controle Biológico de Vetores , Mariposas/efeitos dos fármacos , Mariposas/fisiologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Toxinas de Bacillus thuringiensis
18.
Zhonghua Yu Fang Yi Xue Za Zhi ; 58(5): 649-655, 2024 May 06.
Artigo em Chinês | MEDLINE | ID: mdl-38715505

RESUMO

Objective: To evaluate the virulence levels of carbapenem-resistant Acinetobacter baumannii ST191, ST195, and ST208, and to analyze the differences in virulence factors among these epidemic clones. Methods: The study involved the genomic sequencing of 233 Acinetobacter baumannii strains that were isolated from the Fifth Medical Center of the Chinese People's Liberation Army General Hospital (North Hospital) between 2011 and 2019. The genomic data was cross-referenced with the Virulence Factor Database (VFDB) to examine the presence of virulence genes in the strains. Furthermore, a Galleria mellonella infection survival model was used to evaluate the virulence levels of the strains, and the association between virulence levels and virulence genes was analyzed. Results: The study included 38 strains of the ST191 clone, 104 strains of the ST195 clone, and 91 strains of the ST208 clone. In the Galleria mellonella infection survival experiment, the average mortality rate for ST191 was 23.0%, with 3 (7.9%) highly virulent strains. For ST195, the average mortality rate was 53.0%, with 34 (32.7%) highly virulent strains. For ST208, the average mortality rate was 47.0%, with 20 (21.9%) highly virulent strains. There was a significant statistical difference in mortality rates between ST191 and ST195 (χ2=13.9, P<0.001) as well as between ST191 and ST208 (χ2=15.2, P<0.001). A comparison of the strains with the VFDB revealed significant differences in the virulence genes carried by the clones. Specifically, the type Ⅵ secretion system-related genes (clpV/tssH, hcp/tssD, tagX, tssA, tssB, tssC, tssE, tssF, tssG, tssK, ssL, tssM) and the sugar transferase gene ACICU_RS00475 were found to be universally absent in ST191 strains (0%) while being prevalent in ST195 (100.0%) and ST208 (>82.0%) strains. Statistical analysis revealed an association between the mortality rate of the clones and the presence of virulence genes(clpV/tssH P<0.001, hcp/tssD P=0.001, tagX P<0.001, tssA P<0.001, tssB P=0.001, tssC P=0.001, tssE P=0.001, tssF P=0.001, tssG P<0.001, tssK P<0.001, tssL P<0.001, tssM P=0.001, ACICU_RS00475 P=0.001). Conclusion: Among the carbapenem-resistant epidemic clones of Acinetobacter baumannii, the ST191 clone shows lower mortality rates in Galleria mellonella, possibly because of the lack of type Ⅵ secretion system and sugar transferase genes.


Assuntos
Infecções por Acinetobacter , Acinetobacter baumannii , Carbapenêmicos , Fatores de Virulência , Acinetobacter baumannii/genética , Acinetobacter baumannii/patogenicidade , Carbapenêmicos/farmacologia , Virulência/genética , Infecções por Acinetobacter/microbiologia , Infecções por Acinetobacter/epidemiologia , Fatores de Virulência/genética , Animais , Mariposas/microbiologia , Antibacterianos/farmacologia , Humanos , Farmacorresistência Bacteriana
19.
Glob Chang Biol ; 30(5): e17294, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38738554

RESUMO

The potential for climate change to disrupt phenology-mediated interactions in interaction networks has attracted considerable attention in recent decades. Frequently, studies emphasize the fragility of ephemeral seasonal interactions, and the risks posed by phenological asynchrony. Here, we argue that the fitness consequences of asynchrony in phenological interactions may often be more buffered than is typically acknowledged. We identify three main forms that buffering may take: (i) mechanisms that reduce asynchrony between consumer and resource; (ii) mechanisms that reduce the costs of being asynchronous; and (iii) mechanisms that dampen interannual variance in performance across higher organizational units. Using synchrony between the hatching of winter moth caterpillars and the leafing of their host-plants as a case study, we identify a wide variety of buffers that reduce the detrimental consequences of phenological asynchrony on caterpillar individuals, populations, and meta-populations. We follow this by drawing on examples across a breadth of taxa, and demonstrate that these buffering mechanisms may be quite general. We conclude by identifying key gaps in our knowledge of the fitness and demographic consequences of buffering, in the context of phenological mismatch. Buffering has the potential to substantially alter our understanding of the biotic impacts of future climate change-a greater recognition of the contribution of these mechanisms may reveal that many trophic interactions are surprisingly resilient, and also serve to shift research emphasis to those systems with fewer buffers and towards identifying the limits of those buffers.


Assuntos
Mudança Climática , Mariposas , Animais , Larva/fisiologia , Larva/crescimento & desenvolvimento , Mariposas/fisiologia , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/fisiologia , Estações do Ano
20.
Nat Commun ; 15(1): 4036, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38740750

RESUMO

Microbial Ni2+ homeostasis underpins the virulence of several clinical pathogens. Ni2+ is an essential cofactor in urease and [NiFe]-hydrogenases involved in colonization and persistence. Many microbes produce metallophores to sequester metals necessary for their metabolism and starve competing neighboring organisms. The fungal metallophore aspergillomarasmine A (AMA) shows narrow specificity for Zn2+, Ni2+, and Co2+. Here, we show that this specificity allows AMA to block the uptake of Ni2+ and attenuate bacterial Ni-dependent enzymes, offering a potential strategy for reducing virulence. Bacterial exposure to AMA perturbs H2 metabolism, ureolysis, struvite crystallization, and biofilm formation and shows efficacy in a Galleria mellonella animal infection model. The inhibition of Ni-dependent enzymes was aided by Zn2+, which complexes with AMA and competes with the native nickelophore for the uptake of Ni2+. Biochemical analyses demonstrated high-affinity binding of AMA-metal complexes to NikA, the periplasmic substrate-binding protein of the Ni2+ uptake system. Structural examination of NikA in complex with Ni-AMA revealed that the coordination geometry of Ni-AMA mimics the native ligand, Ni-(L-His)2, providing a structural basis for binding AMA-metal complexes. Structure-activity relationship studies of AMA identified regions of the molecule that improve NikA affinity and offer potential routes for further developing this compound as an anti-virulence agent.


Assuntos
Proteínas de Bactérias , Níquel , Níquel/metabolismo , Níquel/química , Animais , Virulência/efeitos dos fármacos , Proteínas de Bactérias/metabolismo , Biofilmes/efeitos dos fármacos , Zinco/metabolismo , Zinco/química , Mariposas/microbiologia , Urease/metabolismo , Urease/antagonistas & inibidores , Transporte Biológico
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...