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1.
Front Cell Infect Microbiol ; 14: 1383774, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38947126

RESUMO

Silkworm (Bombyx mori) larvae are expected to be useful as an ingredient in entomophagy. They are full of nutrients, including indigestible proteins; however, there have been few studies on the effects of the consumption of the entire body of silkworms on the intestinal microflora. We prepared a customized diet containing silkworm larval powder (SLP), and investigated the effects of ad libitum feeding of the SLP diet on the intestinal microbiota and the amount of short-chain fatty acids (SCFAs) in mice. We found that the diversity of the cecal and fecal microbiota increased in the mice fed the SLP diet (SLP group), and that the composition of their intestinal microbiota differed from that of the control mice. Furthermore, a genus-level microbiota analysis showed that in the SLP group, the proportions of Alistipes, Lachnospiraceae A2, and RF39, which are associated with the prevention of obesity, were significantly increased, while the proportions of Helicobacter and Anaerotruncus, which are associated with obesity, were significantly decreased. Additionally, the level of butyrate was increased in the SLP group, and Clostridia UCG 014 and Lachnospiraceae FCS020 were found to be associated with the level of butyrate, one of the major SCFAs. These findings indicated that silkworm powder may be useful as an insect food that might also improve obesity.


Assuntos
Bombyx , Ácidos Graxos Voláteis , Microbioma Gastrointestinal , Larva , Animais , Bombyx/microbiologia , Bombyx/metabolismo , Larva/microbiologia , Camundongos , Ácidos Graxos Voláteis/metabolismo , Fezes/microbiologia , Bactérias/classificação , Bactérias/metabolismo , Bactérias/genética , Pós , Dieta , Ceco/microbiologia , Ceco/metabolismo , Masculino , Obesidade/microbiologia , Obesidade/metabolismo , Ração Animal
2.
Front Cell Infect Microbiol ; 14: 1411286, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38947124

RESUMO

Background: Convergence of Klebsiella pneumoniae (KP) pathotypes has been increasingly reported in recent years. These pathogens combine features of both multidrug-resistant and hypervirulent KP. However, clinically used indicators for hypervirulent KP identification, such as hypermucoviscosity, appear to be differentially expressed in convergent KP, potential outbreak clones are difficult to identify. We aimed to fill such knowledge gaps by investigating the temperature dependence of hypermucoviscosity and virulence in a convergent KP strain isolated during a clonal outbreak and belonging to the high-risk sequence type (ST)307. Methods: Hypermucoviscosity, biofilm formation, and mortality rates in Galleria mellonella larvae were examined at different temperatures (room temperature, 28°C, 37°C, 40°C and 42°C) and with various phenotypic experiments including electron microscopy. The underlying mechanisms of the phenotypic changes were explored via qPCR analysis to evaluate plasmid copy numbers, and transcriptomics. Results: Our results show a temperature-dependent switch above 37°C towards a hypermucoviscous phenotype, consistent with increased biofilm formation and in vivo mortality, possibly reflecting a bacterial response to fever-like conditions. Furthermore, we observed an increase in plasmid copy number for a hybrid plasmid harboring carbapenemase and rmpA genes. However, transcriptomic analysis revealed no changes in rmpA expression at higher temperatures, suggesting alternative regulatory pathways. Conclusion: This study not only elucidates the impact of elevated temperatures on hypermucoviscosity and virulence in convergent KP but also sheds light on previously unrecognized aspects of its adaptive behavior, underscoring its resilience to changing environments.


Assuntos
Biofilmes , Infecções por Klebsiella , Klebsiella pneumoniae , Temperatura , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/patogenicidade , Klebsiella pneumoniae/classificação , Biofilmes/crescimento & desenvolvimento , Virulência/genética , Animais , Infecções por Klebsiella/microbiologia , Larva/microbiologia , Plasmídeos/genética , Mariposas/microbiologia , Humanos , Fatores de Virulência/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Lepidópteros/microbiologia , Viscosidade , Fenótipo , Perfilação da Expressão Gênica
3.
PLoS One ; 19(7): e0306634, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38976712

RESUMO

In rearing systems for the Japanese eel Anguilla japonica, although it is assumed that microorganisms influence larval survival and mortality, particularly during the early stages of growth, the effects of bacterial communities on larval survival have yet to be sufficiently determined. In this study, we compared the bacterial communities associated with larval survival at three stages of eel growth. To artificially alter bacterial communities and assess larval survival, eel larvae were treated with 11 types of antibiotic, and larval survival and bacterial characteristics were compared between the antibiotic-treated and antibiotic-free control groups. Throughout the three growth stages, eels treated with four antibiotics (polymyxin B, tetracycline, novobiocin, and erythromycin) had survival rates higher than those in the control groups. The bacterial communities of surviving larvae in the control and antibiotic groups and dead larvae in the control groups were subsequently analyzed using 16S rRNA gene amplicon sequencing. PERMANOVA analysis indicated that these three larval groups were characterized by significantly different bacterial communities. We identified 14 biomarker amplicon sequence variants (ASVs) of bacterial genera such as Oceanobacter, Alcanivorax, Marinobacter, Roseibium, and Sneathiella that were enriched in surviving larvae in the antibiotic treatment groups. In contrast, all four biomarker ASVs enriched in dead larvae of the control groups were from bacteria in the genus Vibrio. Moreover, 52 bacterial strains corresponding to nine biomarkers were isolated using a culture method. To the best of our knowledge, this is the first study to evaluate the bacterial communities associated with the survival and mortality of larvae in during the early stages of Japanese eel growth and to isolate biomarker bacterial strains. These findings will provide valuable insights for enhancing larval survival in the eel larval rearing systems from a microbiological perspective.


Assuntos
Anguilla , Antibacterianos , Biomarcadores , Larva , Animais , Larva/microbiologia , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Anguilla/microbiologia , Anguilla/crescimento & desenvolvimento , Antibacterianos/farmacologia , RNA Ribossômico 16S/genética , Bactérias/genética , Bactérias/efeitos dos fármacos , Bactérias/classificação , Bactérias/isolamento & purificação , Bactérias/crescimento & desenvolvimento
4.
Mycoses ; 67(7): e13766, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39007526

RESUMO

BACKGROUND: The resistance of Aspergillus flavus to the azole antifungal drugs is an emerging problem. Mutations in the molecular targets of the azole antifungals - CYP 51 A, B and C - are possible mechanisms of resistance, but data to confirm this hypothesis are scarce. In addition, the behaviour of resistant strains in vitro and in vivo is not yet understood. OBJECTIVES: This study had 3 objectives. The first was to compare the sequences of CYP51 A, B and C in resistant and susceptible strains of A. flavus. The second was to look for the existence of a fitness cost associated with resistance. The third was to evaluate the activity of voriconazole and posaconazole on resistant strains in the Galleria mellonella model. METHODS: The CYP51 A, B and C sequences of seven resistant strains with those of four susceptible strains are compared. Fitness costs were assessed by growing the strains in RPMI medium and testing their virulence in G. mellonella larvae. In addition, G. mellonella larvae infected with strains of A. flavus were treated with voriconazole and posaconazole. RESULTS: In the CYP51A sequences, we found the A91T, C708T and A1296T nucleotide substitutions only in the resistant strains. The resistant strains showed a fitness cost with reduced in vitro growth and reduced virulence in G. mellonella. In vivo resistance to posaconazole is confirmed in a strain with the highest MIC for this antifungal agent. CONCLUSIONS: These results allow to conclude that some substitutions in CYP51 genes, in particular CYP51A, contribute to resistance to azole drugs in A. flavus. The study of the relationship between drug dosage and treatment duration with resistance and the reduction of fitness costs in resistant strains is a major perspective of this study. This work could help to establish recommendations for the treatment of infections with resistant strains of A. flavus.


Assuntos
Antifúngicos , Aspergillus flavus , Azóis , Sistema Enzimático do Citocromo P-450 , Farmacorresistência Fúngica , Larva , Testes de Sensibilidade Microbiana , Voriconazol , Aspergillus flavus/efeitos dos fármacos , Aspergillus flavus/genética , Antifúngicos/farmacologia , Farmacorresistência Fúngica/genética , Animais , Voriconazol/farmacologia , Azóis/farmacologia , Sistema Enzimático do Citocromo P-450/genética , Larva/microbiologia , Triazóis/farmacologia , Proteínas Fúngicas/genética , Mariposas/microbiologia , Aspergilose/microbiologia , Aspergilose/tratamento farmacológico , Virulência , Aptidão Genética , Modelos Animais de Doenças
5.
Arch Microbiol ; 206(8): 349, 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-38992278

RESUMO

Candida auris, a rapidly spreading multi-drug-resistant fungus, is causing lethal infections under certain conditions globally. Baicalin (BE), an active ingredient extracted from the dried root of Scutellaria baicalensis Georgi, exhibits antifungal activity. However, studies have shown the distinctive advantages of Traditional Chinese medicine in combating fungal infections, while the effect of BE, an active ingredient extracted from the dried roots of Scutellaria baicalensis Georgi, on C. auris, remains unknown. Therefore, this study aims to evaluate the potential of BE as an antifungal agent against the emerging multidrug-resistant C. auris. Various assays and models, including microbroth dilution, time growth curve analysis, spot assays, adhesion tests, flocculation test, cell surface hydrophobicity assay, hydrolase activity assays, XTT assay, violet crystal assay, scanning electron microscope (SEM), confocal laser scanning microscope (CLSM), flow cytometry, Live/dead fluorescent staining, reactive oxygen species (ROS), cell wall assay, aggregation assay, porcine skin model, Galleria mellonella larvae (G. mellonella larvae) infection model, and reverse transcription-quantitative polymerase chain reaction (RT-PCR) were utilized to investigate how baicalein suppresses C. auris through possible multifaceted mechanisms. The findings indicate that BE strongly inhibited C. auris growth, adhesion, and biofilm formation. It also effectively reduced drug resistance and aggregation by disrupting the cell membrane and cell wall while reducing colonization and invasion of the host. Transcriptome analysis showed significant modulation in gene expression related to different virulence factors post-BE treatment. In conclusion, BE exhibits significant effectiveness against C. auris, suggesting its potential as a viable treatment option due to its multifaceted suppression mechanisms.


Assuntos
Antifúngicos , Candida auris , Flavanonas , Fatores de Virulência , Flavanonas/farmacologia , Fatores de Virulência/metabolismo , Fatores de Virulência/genética , Animais , Antifúngicos/farmacologia , Candida auris/efeitos dos fármacos , Candida auris/genética , Testes de Sensibilidade Microbiana , Scutellaria baicalensis/química , Candidíase/tratamento farmacológico , Candidíase/microbiologia , Espécies Reativas de Oxigênio/metabolismo , Suínos , Larva/microbiologia , Mariposas/microbiologia , Biofilmes/efeitos dos fármacos , Extratos Vegetais/farmacologia , Flavonoides
6.
Parasit Vectors ; 17(1): 294, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38982472

RESUMO

BACKGROUND: Microsporidia MB (MB) is a naturally occurring symbiont of Anopheles and has recently been identified as having a potential to inhibit the transmission of Plasmodium in mosquitoes. MB intensity is high in mosquito gonads, with no fitness consequences for the mosquito, and is linked to horizontal (sexual) and vertical (transovarial) transmission from one mosquito to another. Maximising MB intensity and transmission is important for maintaining heavily infected mosquito colonies for experiments and ultimately for mosquito releases. We have investigated how diet affects the MB-Anopheles arabiensis symbiosis phenotypes, such as larval development and mortality, adult size and survival, as well as MB intensity in both larvae and adults. METHODS: F1 larvae of G0 females confirmed to be An. arabiensis and infected with MB were either combined (group lines [GLs]) or reared separately (isofemale lines [IMLs]) depending on the specific experiment. Four diet regimes (all mg/larva/day) were tested on F1 GLs: Tetramin 0.07, Tetramin 0.3, Gocat 0.3 and Cerelac 0.3. GLs reared on Tetramin 0.3 mg/larva/day were then fed either a 1% or 6% glucose diet to determine adult survival. Larvae of IMLs were fed Tetramin 0.07 mg and Tetramin 0.3 mg for larval experiments. The mosquitoes in the adult experiments with IMLs were reared on 1% or 6% glucose. RESULTS: Amongst the four larval diet regimes tested on An. arabiensis development in the presence of MB, the fastest larval development highest adult emergence, largest body size of mosquitoes, highest prevalence and highest density of MB occurred in those fed Tetramin 0.3 mg/larva/day. Although adult MB-positive mosquitoes fed on 6% glucose survived longer than MB-negative mosquitoes, there was no such effect for those fed on the 1% glucose diet. Development time, wing length and adult survival were not significantly different between MB-infected and uninfected An. arabiensis fed on the Tetramin 0.07 mg/larva/day diet, demonstrating that the MB-conferred fitness advantage was diet-dependent. CONCLUSIONS: Microsporidia MB does not adversely impact the development and fitness of An. arabiensis, even under limited dietary conditions. The diet regime of Tetramin 0.3 mg/larva/day + 6% glucose for adults is the superior diet for the mass rearing of MB-infected An. arabiensis mosquitoes. These results are important for rearing MB-infected An. arabiensis in the laboratory for experiments and the mass rearing required for field releases.


Assuntos
Anopheles , Dieta , Larva , Microsporídios , Animais , Anopheles/microbiologia , Anopheles/fisiologia , Anopheles/parasitologia , Feminino , Larva/microbiologia , Larva/crescimento & desenvolvimento , Microsporídios/fisiologia , Simbiose , Mosquitos Vetores/microbiologia , Mosquitos Vetores/fisiologia
7.
Microb Ecol ; 87(1): 91, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38960913

RESUMO

Coelopidae (Diptera), known as kelp flies, exhibit an ecological association with beached kelp and other rotting seaweeds. This unique trophic specialization necessitates significant adaptations to overcome the limitations of an algal diet. We aimed to investigate whether the flies' microbiome could be one of these adaptive mechanisms. Our analysis focused on assessing composition and diversity of adult and larval microbiota of the kelp fly Coelopa frigida. Feeding habits of the larvae of this species have been subject of numerous studies, with debates whether they directly consume kelp or primarily feed on associated bacteria. By using a 16S rRNA metabarcoding approach, we found that the larval microbiota displayed considerably less diversity than adults, heavily dominated by only four operational taxonomic units (OTUs). Phylogenetic placement recovered the most dominant OTU of the larval microbiome, which is the source of more than half of all metabarcoding sequence reads, as an undescribed genus of Orbaceae (Gammaproteobacteria). Interestingly, this OTU is barely found among the 15 most abundant taxa of the adult microbiome, where it is responsible for less than 2% of the metabarcoding sequence reads. The other three OTUs dominating the larval microbiome have been assigned as Psychrobacter (Gammaproteobacteria), Wohlfahrtiimonas (Gammaproteobacteria), and Cetobacterium (Fusobacteriota). Moreover, we also uncovered a distinct shift in the functional composition between the larval and adult stages, where our taxonomic profiling suggests a significant decrease in functional diversity in larval samples. Our study offers insights into the microbiome dynamics and functional composition of Coelopa frigida.


Assuntos
Bactérias , Dípteros , Larva , Microbiota , Filogenia , RNA Ribossômico 16S , Animais , Dípteros/microbiologia , Larva/microbiologia , RNA Ribossômico 16S/genética , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Código de Barras de DNA Taxonômico , Kelp/microbiologia
8.
Mol Biol Rep ; 51(1): 800, 2024 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-39001994

RESUMO

BACKGROUND: Mosquitoes are widespread globally and have contributed to transmitting pathogens to humans and the burden of vector-borne diseases. They are effectively controlled at their larval stages by biocontrol agents. Unravelling natural sources for microbial agents can lead us to novel potential candidates for managing mosquito-borne diseases. In the present study, an attempt was made to isolate a novel bacterium from the field-collected agricultural soil for larvicidal activity and promising bacterial metabolites for human healthcare. METHODS AND RESULTS: Field-collected soil samples from the Union territory of Puducherry, India, have been used as the source of bacteria. Isolate VCRC B655 belonging to the genus Lysinibacillus was identified by 16S rRNA gene sequencing and exhibited promising larvicidal activity against different mosquito species, including Culex (Cx.) quinquefasciatus, Anopheles (An.) stephensi, and Aedes (Ae.) aegypti. The lethal concentration (LC) of Lysinibacillus sp. VCRCB655 was observed to be high for Cx. quiquefasciatus: LC50 at 0.047 mg/l, LC90 at 0.086 mg/l, followed by An. stephensi and Ae. aegypti (LC50: 0.6952 mg/l and 0.795 mg/l) respectively. Additionally, metabolic profiling of the culture supernatant was carried out through Gas chromatography and Mass spectrophotometry (GC/MS) and identified 15 major secondary metabolites of different metabolic classes. Diketopiperazine (DKPs), notably pyro lo [1, 2-a] pyrazine1, 4-dione, are the abundant compounds reported for antioxidant activity, and an insecticide compound benzeneacetic acid was also identified. CONCLUSIONS: A new bacterial isolate, Lysinibacillus sp. VCRC B655 has been identified with significant larvicidal activity against mosquito larvae with no observed in non-target organisms. GC-MS analysis revealed diverse bioactive compounds with substantial biological applications. In conclusion, Lysinibacillus sp. VCRC B655 showed promise as an alternative biocontrol agent for mosquito vector control, with additional biological applications further enhancing its significance.


Assuntos
Bacillaceae , Cromatografia Gasosa-Espectrometria de Massas , Larva , Controle de Mosquitos , RNA Ribossômico 16S , Animais , Bacillaceae/isolamento & purificação , Bacillaceae/metabolismo , Bacillaceae/genética , Cromatografia Gasosa-Espectrometria de Massas/métodos , Controle de Mosquitos/métodos , Larva/microbiologia , RNA Ribossômico 16S/genética , Índia , Microbiologia do Solo , Anopheles/microbiologia , Culex/microbiologia , Filogenia , Aedes/microbiologia , Inseticidas/farmacologia
9.
Front Cell Infect Microbiol ; 14: 1436547, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39027136

RESUMO

Introduction: In this study, the seasonal differences in the intestinal microbiota of Chinese mitten crab (Eriocheir sinensis) larvae were investigated at different sites in the intertidal zone of the Yangtze River Estuary. Methods: 16S rRNA high-throughput sequencing technology was used to compare and analyze the microbial community structure in the intestines of juvenile crab from different seasons. Results: The results showed that the main microbial phyla in all seasons and sites were Proteobacteria, Bacteroidetes, Firmicutes, and Actinobacteria, which accounted for 97.1% of the total microbiota. Composition analysis revealed that the relative abundance of Proteobacteria decreased from summer to winter at each station, whereas Bacteroidetes showed the opposite trend. Alpha diversity analysis showed that species richness increased from summer to winter at the upstream site (P < 0.05), but decreased at the downstream site (P < 0.05), with no significant differences observed in other comparisons. Biomarker species analysis showed that juvenile crab exhibited a more specialized microbial community in summer compared with autumn and winter. Co-occurrence network analysis revealed that microbial interaction network complexity was lower in autumn compared with summer and autumn. Functional prediction analysis showed that the microbial community only exhibited seasonal differences in amino acid biosynthesis, cofactor, prosthetic group, electron carrier, and vitamin biosynthesis, aromatic compound degradation, nucleotide and nucleoside degradation, and tricarboxylic acid cycle pathways. Discussion: The results indicated that the microbiota did not significantly differ among sites, and seasonal variation was a main factor influencing the differences in intestinal microbiota of Chinese mitten juvenile crab. Moreover, the microbial community was more complex in summer compared with autumn and winter.


Assuntos
Braquiúros , Estuários , Microbioma Gastrointestinal , RNA Ribossômico 16S , Estações do Ano , Animais , Braquiúros/microbiologia , RNA Ribossômico 16S/genética , China , Sequenciamento de Nucleotídeos em Larga Escala , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Filogenia , Biodiversidade , Larva/microbiologia , Bacteroidetes/classificação , Bacteroidetes/genética , Bacteroidetes/isolamento & purificação , Proteobactérias/genética , Proteobactérias/classificação , Proteobactérias/isolamento & purificação , Firmicutes/genética , Firmicutes/classificação , Firmicutes/isolamento & purificação , DNA Bacteriano/genética , Rios/microbiologia
10.
Methods Mol Biol ; 2833: 1-10, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38949695

RESUMO

There is an increasing need for new treatment regimens to combat antibiotic-resistant strains of bacteria. Staphylococcus aureus is a clinically important, opportunist pathogen that has developed resistance to a range of antibiotics. The zebrafish larval model of systemic disease has been increasingly utilized to elucidate S. aureus virulence mechanisms and host-pathogen interactions. Here, we outline how this model can be used to investigate the effects of different antibiotics alone and in combination against S. aureus.


Assuntos
Antibacterianos , Modelos Animais de Doenças , Larva , Infecções Estafilocócicas , Staphylococcus aureus , Peixe-Zebra , Animais , Peixe-Zebra/microbiologia , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Staphylococcus aureus/efeitos dos fármacos , Larva/microbiologia , Larva/efeitos dos fármacos , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/microbiologia , Quimioterapia Combinada , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Testes de Sensibilidade Microbiana
11.
Lett Appl Microbiol ; 77(7)2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38970380

RESUMO

Alternative strategies for controlling Staphylococcus aureus and other pathogens have been continuously investigated, with nisin, a bacteriocin widely used in the food industry as a biopreservative, gaining increasing attention. In addition to its antimicrobial properties, bacteriocins have significant effects on genome functionality even at inhibitory concentrations. This study investigated the impact of subinhibitory concentrations of nisin on S. aureus. Culturing in the presence of 0.625 µmol l-1 nisin, led to the increased relative expression of hla, saeR, and sarA, genes associated with virulence while expression of the sea gene, encoding staphylococcal enterotoxin A (SEA), decreased. In an in vivo experiment, Galleria mellonella larvae inoculated with S. aureus cultured in the presence of nisin exhibited 97% mortality at 72 h post-infection, compared to over 40% of larvae mortality in larvae infected with S. aureus. A comprehensive understanding of the effect of nisin on the transcriptional response of virulence genes and the impact of these changes on the virulence of S. aureus can contribute to assessing the application of this bacteriocin in food and medical contexts.


Assuntos
Antibacterianos , Larva , Mariposas , Nisina , Staphylococcus aureus , Nisina/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/genética , Staphylococcus aureus/patogenicidade , Animais , Virulência/genética , Larva/microbiologia , Larva/efeitos dos fármacos , Antibacterianos/farmacologia , Mariposas/microbiologia , Infecções Estafilocócicas/microbiologia , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Fatores de Virulência/genética , Testes de Sensibilidade Microbiana
12.
Artigo em Inglês | MEDLINE | ID: mdl-39023139

RESUMO

A bacterial strain designated PU5-4T was isolated from the mealworm (the larvae of Tenebrio molitor) intestines. It was identified to be Gram-stain-negative, strictly aerobic, rod-shaped, non-motile, and non-spore-forming. Strain PU5-4T was observed to grow at 10-40 °C, at pH 7.0-10.0, and in the presence of 0-3.0 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain PU5-4T should be assigned to the genus Sphingobacterium. The 16S rRNA gene sequence similarity analysis showed that strain PU5-4T was closely related to the type strains of Sphingobacterium lactis DSM 22361T (98.49 %), Sphingobacterium endophyticum NYYP31T (98.11 %), Sphingobacterium soli NCCP 698T (97.69 %) and Sphingobacterium olei HAL-9T (95.73 %). The predominant isoprenoid quinone is MK-7. The major fatty acids were identified as iso-C15 : 0, iso-C17 : 03-OH and summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c) and summed feature 9 (iso-C17 : 0 ω9c). The polar lipids are phosphatidylethanolamine, one unidentified phospholipid, and six unidentified lipids. The genomic DNA G+C content of strain PU5-4T is 40.24 mol%. The average nucleotide identity of strain PU5-4T exhibited respective values of 73.88, 73.37, 73.36 and 70.84 % comparing to the type strains of S. lactis DSM 22361T, S. soli NCCP 698T, S. endophyticum NYYP31T and S. olei HAL-9T, which are below the cut-off level (95-96 %) for species delineation. Based on the above results, strain PU5-4T represents a novel species of the genus Sphingobacterium, for which the name Sphingobacterium temoinsis sp. nov. is proposed. The type strain is PU5-4T (=CGMCC 1.61908T=JCM 36663T).


Assuntos
Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano , Ácidos Graxos , Intestinos , Filogenia , RNA Ribossômico 16S , Análise de Sequência de DNA , Sphingobacterium , Tenebrio , Vitamina K 2 , RNA Ribossômico 16S/genética , Ácidos Graxos/análise , DNA Bacteriano/genética , Sphingobacterium/genética , Sphingobacterium/isolamento & purificação , Sphingobacterium/classificação , Animais , Intestinos/microbiologia , Vitamina K 2/análogos & derivados , Vitamina K 2/análise , Tenebrio/microbiologia , Fosfatidiletanolaminas , Larva/microbiologia , Fosfolipídeos/análise
13.
PLoS One ; 19(6): e0304908, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38905245

RESUMO

The dung beetle primarily feeds on the feces of herbivorous animals and play a crucial role in ecological processes like material cycles and soil improvement. This study aims to explore the diversity and composition of the gut microbiota of Catharsius molossus (a renowned dung beetle originating from China and introduced to multiple countries for its ecological value) and exploring whether these gut microbes are transmitted vertically across generations. Using 16S rRNA and ITS rRNA gene sequencing techniques, we described the diversity and composition of gut microbes in C. molossus from different localities and different developmental stages (Egg, young larvae and old larvae). We discovered that the diversity of gut microbiota of dung beetles varied obviously among different geographical localities and different developmental stages, and we also discussed the potential influencing factors. Interestingly, the microbial community structure within the brood balls is more similar to male dung beetle than to that of females, which is consistent with the observation that the brood ball is constructed by the male dung beetle, with the female laying egg in it at the final step. This unique breeding method facilitates offspring in inheriting microbial communities from both the mother and the father. Initially, the larvae's gut microbiota closely mirrors that of the parental gift in these brood balls. As larvae grow, significant changes occur in their gut microbiota, including an increase in symbiotic bacteria like Lactococcus and Enterococcus. Analysis of the gut bacteria of adult dung beetles across various localities and different developmental stages identified nine core genera in adults, contributing to 67.80% of the total microbial abundance, and 11 core genera in beetles at different developmental stages, accounting for 49.13% of the total. Notably, seven genera were common between these two core groups. Our results suggest that Parental gifts can play a role in the vertical transmission of microbes, and the abundance of probiotics increases with larval development, supporting the hypothesis that "larval feeding behavior occurs in two stages: larvae first feed on parental gifts to acquire necessary microbes, then enrich symbiotic microbiota through consuming their own feces."


Assuntos
Besouros , Microbioma Gastrointestinal , Larva , RNA Ribossômico 16S , Animais , Besouros/microbiologia , Feminino , Masculino , Larva/microbiologia , RNA Ribossômico 16S/genética , Bactérias/genética , Bactérias/classificação , Biodiversidade , China , Filogenia
14.
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
15.
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
16.
Microb Ecol ; 87(1): 81, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38829379

RESUMO

Koinobiont endoparasitoids regulate the physiology of their hosts through altering host immuno-metabolic responses, processes which function in tandem to shape the composition of the microbiota of these hosts. Here, we employed 16S rRNA and ITS amplicon sequencing to investigate whether parasitization by the parasitoid wasps, Diachasmimorpha longicaudata (Ashmaed) (Hymenoptera: Braconidae) and Psyttalia cosyrae (Wilkinson) (Hymenoptera: Braconidae), induces gut dysbiosis and differentially alter the gut microbial (bacteria and fungi) communities of an important horticultural pest, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae). We further investigated the composition of bacterial communities of adult D. longicaudata and P. cosyrae to ascertain whether the adult parasitoids and parasitized host larvae share microbial taxa through transmission. We demonstrated that parasitism by D. longicaudata induced significant gut perturbations, resulting in the colonization and increased relative abundance of pathogenic gut bacteria. Some pathogenic bacteria like Stenotrophomonas and Morganella were detected in both the guts of D. longicaudata-parasitized B. dorsalis larvae and adult D. longicaudata wasps, suggesting a horizontal transfer of microbes from the parasitoid to the host. The bacterial community of P. cosyrae adult wasps was dominated by Arsenophonus nasoniae, whereas that of D. longicaudata adults was dominated by Paucibater spp. and Pseudomonas spp. Parasitization by either parasitoid wasp was associated with an overall reduction in fungal diversity and evenness. These findings indicate that unlike P. cosyrae which is avirulent to B. dorsalis, parasitization by D. longicaudata induces shifts in the gut bacteriome of B. dorsalis larvae to a pathobiont-dominated community. This mechanism possibly enhances its virulence against the pest, further supporting its candidacy as an effective biocontrol agent of this frugivorous tephritid fruit fly pest.


Assuntos
Bactérias , Microbioma Gastrointestinal , Larva , RNA Ribossômico 16S , Tephritidae , Vespas , Animais , Tephritidae/microbiologia , Tephritidae/parasitologia , Vespas/microbiologia , Vespas/fisiologia , Bactérias/genética , Bactérias/classificação , Bactérias/isolamento & purificação , Larva/microbiologia , Larva/parasitologia , Larva/crescimento & desenvolvimento , RNA Ribossômico 16S/genética , Fungos/genética , Fungos/fisiologia , Interações Hospedeiro-Parasita , Microbiota , Disbiose/microbiologia , Disbiose/parasitologia
17.
PeerJ ; 12: e17450, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38860210

RESUMO

Background: Spodoptera frugiperda, the fall armyworm is a destructive invasive pest, and S. litura the tobacco cutworm, is a native species closely related to S. frugiperda. The gut microbiota plays a vital role in insect growth, development, metabolism and immune system. Research on the competition between invasive species and closely related native species has focused on differences in the adaptability of insects to the environment. Little is known about gut symbiotic microbe composition and its role in influencing competitive differences between these two insects. Methods: We used a culture-independent approach targeting the 16S rRNA gene of gut bacteria of 5th instar larvae of S. frugiperda and S. litura. Larvae were reared continuously on maize leaves for five generations. We analyzed the composition, abundance, diversity, and metabolic function of gut microbiomes of S. frugiperda and S. litura larvae. Results: Firmicutes, Proteobacteria, and Bacteroidetes were the dominant bacterial phyla in both species. Enterococcus, ZOR0006, Escherichia, Bacteroides, and Lactobacillus were the genera with the highest abundance in S. frugiperda. Enterococcus, Erysipelatoclostridium, ZOR0006, Enterobacter, and Bacteroides had the highest abundance in S. litura. According to α-diversity analysis, the gut bacterial diversity of S. frugiperda was significantly higher than that of S. litura. KEGG analysis showed 15 significant differences in metabolic pathways between S. frugiperda and S. litura gut bacteria, including transcription, cell growth and death, excretory system and circulatory system pathways. Conclusion: In the same habitat, the larvae of S. frugiperda and S. litura showed significant differences in gut bacterial diversity and community composition. Regarding the composition and function of gut bacteria, the invasive species S. frugiperda may have a competitive advantage over S. litura. This study provides a foundation for developing control strategies for S. frugiperda and S. litura.


Assuntos
Microbioma Gastrointestinal , Larva , RNA Ribossômico 16S , Spodoptera , Animais , Microbioma Gastrointestinal/genética , Spodoptera/microbiologia , Spodoptera/genética , Larva/microbiologia , RNA Ribossômico 16S/genética , Proteobactérias/genética , Proteobactérias/isolamento & purificação , Bacteroidetes/genética , Bacteroidetes/isolamento & purificação , Firmicutes/genética , Firmicutes/isolamento & purificação , Bactérias/genética , Bactérias/classificação , Lactobacillus/genética , Lactobacillus/isolamento & purificação , Enterococcus/genética , Bacteroides/genética , Simbiose
18.
Int J Mol Sci ; 25(11)2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38892422

RESUMO

OBJECTIVES: Eumycetoma is a neglected tropical disease (NTD) characterized by subcutaneous lesions and the formation of grains. Attempts to treat eumycetoma involve a combination of antifungal treatment and surgery, although the outcome is frequently disappointing. Therefore, there is a need to identify novel antifungal drugs to treat eumycetoma. In this respect, Medicines for Malaria Venture (MMV) has assembled libraries of compounds for researchers to use in drug discovery research against NTD. Therefore, we screened two MMVOpen compound libraries to identify novel leads for eumycetoma. METHODS: A total of 400 compounds from the COVID Box and the Global Health Priority Box were screened in vitro at 100 µM and 25 µM against the most common causative agents of eumycetoma, namely Madurella mycetomatis and Falciformispora senegalensis, and the resulting IC50 and MIC50 values were obtained. Compounds with an IC50 < 8 µM were identified for possible in vivo efficacy studies using an M. mycetomatis grain model in Galleria mellonella larvae. RESULTS: Out of the 400 compounds, 22 were able to inhibit both M. mycetomatis and F. senegalensis growth at 100 µM and 25 µM, with compounds MMV1593278, MMV020335, and MMV1804559 being selected for in vivo testing. Of these three, only the pyrazolopyrimidine derivative MMV1804559 was able to prolong the survival of M. mycetomatis-infected G. mellonella larvae. Furthermore, the grains in MMV1804559-treated larvae were significantly smaller compared to the PBS-treated group. CONCLUSION: MMV1804559 shows promising in vitro and in vivo activity against M. mycetomatis.


Assuntos
Antifúngicos , Madurella , Micetoma , Madurella/efeitos dos fármacos , Micetoma/tratamento farmacológico , Micetoma/microbiologia , Antifúngicos/farmacologia , Animais , Testes de Sensibilidade Microbiana , Larva/efeitos dos fármacos , Larva/microbiologia , Humanos
19.
Ticks Tick Borne Dis ; 15(5): 102362, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38852539

RESUMO

A promising alternative approach to conventional vector and rodent control practices is the use of a bait containing a rodenticide and acaricide in controlling vectors and pathogen reservoirs concurrently. In the United States, Lyme disease continues to be the most prevalent vector-borne disease with approximately 500,000 Lyme disease cases estimated each year. Previous research has demonstrated the usefulness of a low dose fipronil bait in controlling Ixodes scapularis larvae feeding on white-footed mice. However, considering white-footed mice can be an unwanted species because of their association with tick-borne disease and hantaviruses, a combination rodent and tick bait (RTB) might provide a useful alternative to encourage additional community participation in integrated tick management (ITM) efforts. The purpose of this research was to evaluate the use of RTB (0.025 % warfarin, 0.005 % fipronil) in controlling white-footed mice and I. scapularis larvae. Studies were designed in part based on Environmental Protection Agency (EPA) guidelines. A laboratory choice test was conducted to evaluate the use of RTB in controlling white-footed mice over 15-day exposure when they were exposed to an alternative diet. Mice were observed every day for mortality and signs of warfarin toxicity. A simulated field test was conducted to evaluate the use of RTB, presented in the presence of an alternative diet, in controlling I. scapularis parasitizing white-footed mice over 4-day exposure. Mice were fitted with capsules and manually infested with I. scapularis larvae. The inside of each capsule was observed to evaluate tick attachment. Replete larvae detaching from each mouse were collected. Blood was collected from all treatment group mice via cardiac puncture to determine the fipronil sulfone concentration in plasma for each animal. Results indicated that RTB would be adequately consumed in the presence of an alternative diet under laboratory and simulated field conditions. Treatment with RTB resulted in 100 % mortality of white-footed mice during 15-day exposure and prevented 100 % larvae from feeding to repletion during 4-day exposure. All mice succumbing to RTB showed signs of warfarin toxicity. All mice parasitized with ticks that were exposed to RTB had fipronil sulfone detectable in plasma, with even the lowest concentration detected (8.1 parts per billion) controlling 100 % parasitizing I. scapularis larvae. The results suggest that RTB could be a useful means of rodent and tick control for use in ITM programs.


Assuntos
Ixodes , Doença de Lyme , Peromyscus , Controle de Ácaros e Carrapatos , Animais , Ixodes/microbiologia , Ixodes/fisiologia , Peromyscus/parasitologia , Doença de Lyme/prevenção & controle , Doença de Lyme/transmissão , Controle de Ácaros e Carrapatos/métodos , Infestações por Carrapato/veterinária , Infestações por Carrapato/prevenção & controle , Larva/microbiologia , Rodenticidas/farmacologia , Acaricidas/farmacologia , Pirazóis/farmacologia , Feminino , Vetores Aracnídeos/microbiologia
20.
Front Biosci (Elite Ed) ; 16(2): 15, 2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38939914

RESUMO

BACKGROUND: Fall armyworm (Spodoptera frugiperda) is a highly destructive maize pest that significantly threatens agricultural productivity. Existing control methods, such as chemical insecticides and entomopathogens, lack effectiveness, necessitating alternative approaches. METHODS: Gut-associated bacteria were isolated from the gut samples of fall armyworm and screened based on their chitinase and protease-producing ability before characterization through 16S rRNA gene sequence analysis. The efficient chitinase-producing Bacillus licheniformis FGE4 and Enterobacter cloacae FGE18 were chosen to test the biocontrol efficacy. As their respective cell suspensions and extracted crude chitinase enzyme, these two isolates were applied topically on the larvae, supplemented with their feed, and analyzed for their quantitative food use efficiency and survivability. RESULTS: Twenty-one high chitinase and protease-producing bacterial isolates were chosen. Five genera were identified by 16S rRNA gene sequencing: Enterobacter, Enterococcus, Bacillus, Pantoea, and Kocuria. In the biocontrol efficacy test, the consumption index and relative growth rate were lowered in larvae treated with Enterobacter cloacae FGE18 by topical application and feed supplementation. Similarly, topical treatment of Bacillus licheniformis FGE4 to larvae decreased consumption index, relative growth rate, conversion efficiency of ingested food, and digested food values. CONCLUSION: The presence of gut bacteria with high chitinase activity negatively affects insect health. Utilizing gut-derived bacterial isolates with specific insecticidal traits offers a promising avenue to control fall armyworms. This research suggests a potential strategy for future pest management.


Assuntos
Quitinases , Spodoptera , Animais , Spodoptera/microbiologia , Quitinases/metabolismo , Quitinases/genética , RNA Ribossômico 16S/genética , Bactérias/enzimologia , Bacillus licheniformis/genética , Bacillus licheniformis/enzimologia , Enterobacter cloacae/genética , Enterobacter cloacae/enzimologia , Larva/microbiologia , Controle Biológico de Vetores/métodos , Trato Gastrointestinal/microbiologia
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