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1.
PLoS One ; 15(2): e0228407, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32012188

RESUMO

Cell homeostasis requires the correct levels of reactive oxygen species (ROS) to be maintained as these regulate the proliferation and differentiation of cells, and control the immune response and inflammation. High levels of ROS can cause oxidative stress, leading to protein, lipid and DNA damage, or even cell death. Under physiological conditions, the rate of autophagy remains stable; however, it can be accelerated by a number of exogenous stimuli such as oxidative stress, starvation or hypoxia, leading to cell death. The present paper examines the effect of Conidiobolus coronatus infection on the immune response, oxidative stress processes and autophagy in the greater wax moth, Galleria mellonella. Fungal infection was found to result in the disorganization of the cytoskeleton of the larval immune cells and the enhancement of oxidative defense processes. Lipid peroxidation and autophagy were also induced in the hemocytes. Our findings show that G. mellonella is an ideal model for exploring immune mechanisms.


Assuntos
Autofagia , Conidiobolus/patogenicidade , Hemócitos/imunologia , Interações Hospedeiro-Patógeno/imunologia , Larva/imunologia , Mariposas/imunologia , Estresse Oxidativo , Animais , Hemócitos/microbiologia , Larva/microbiologia , Mariposas/microbiologia
2.
PLoS Biol ; 18(2): e3000609, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32097403

RESUMO

The final body size of any given individual underlies both genetic and environmental constraints. Both mammals and insects use target of rapamycin (TOR) and insulin signaling pathways to coordinate growth with nutrition. In holometabolous insects, the growth period is terminated through a cascade of peptide and steroid hormones that end larval feeding behavior and trigger metamorphosis, a nonfeeding stage during which the larval body plan is remodeled to produce an adult. This irreversible decision, termed the critical weight (CW) checkpoint, ensures that larvae have acquired sufficient nutrients to complete and survive development to adulthood. How insects assess body size via the CW checkpoint is still poorly understood on the molecular level. We show here that the Drosophila transcription factor Snail plays a key role in this process. Before and during the CW checkpoint, snail is highly expressed in the larval prothoracic gland (PG), an endocrine tissue undergoing endoreplication and primarily dedicated to the production of the steroid hormone ecdysone. We observed two Snail peaks in the PG, one before and one after the molt from the second to the third instar. Remarkably, these Snail peaks coincide with two peaks of PG cells entering S phase and a slowing of DNA synthesis between the peaks. Interestingly, the second Snail peak occurs at the exit of the CW checkpoint. Snail levels then decline continuously, and endoreplication becomes nonsynchronized in the PG after the CW checkpoint. This suggests that the synchronization of PG cells into S phase via Snail represents the mechanistic link used to terminate the CW checkpoint. Indeed, PG-specific loss of snail function prior to the CW checkpoint causes larval arrest due to a cessation of endoreplication in PG cells, whereas impairing snail after the CW checkpoint no longer affected endoreplication and further development. During the CW window, starvation or loss of TOR signaling disrupted the formation of Snail peaks and endocycle synchronization, whereas later starvation had no effect on snail expression. Taken together, our data demonstrate that insects use the TOR pathway to assess nutrient status during larval development to regulate Snail in ecdysone-producing cells as an effector protein to coordinate endoreplication and CW attainment.


Assuntos
Ciclo Celular/fisiologia , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/crescimento & desenvolvimento , Fatores de Transcrição da Família Snail/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Animais , Peso Corporal , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Ecdisona/metabolismo , Células Endócrinas/metabolismo , Endorreduplicação , Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Larva/genética , Larva/crescimento & desenvolvimento , Larva/microbiologia , Metamorfose Biológica , Nutrientes/metabolismo , Transdução de Sinais , Fatores de Transcrição da Família Snail/genética , Serina-Treonina Quinases TOR/genética
3.
Ecotoxicol Environ Saf ; 192: 110323, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32066008

RESUMO

The black soldier fly larvae (BSFL) have become a promising candidate for waste disposal and are an ideal feed source for animal nutrition. The uptake of heavy metals could influence the growth of BSFL, but the effects of heavy metal pressures on the gut microbiota of BSFL are largely uncharacterized. Here, we examine the influences of Cu and Cd on the growth and gut microbiota of BSFL as well as the distribution of accumulated heavy metals in the larvae and their feces. Exposure to Cu (from 100 to 800 mg/kg) and Cd (from 10 to 80 mg/kg) did not significantly inhibit the weight gain of BSFL. With elevated exposure doses, the contents of both Cu and Cd accumulated in the bodies and feces of BSFL were remarkably increased. In the BSFL feces, Cu mainly existed as residues, while Cd mainly existed as either water-soluble states (in the low-exposure groups) or residues (in the high-exposure groups). Cd was more readily enriched (47.1%-91.3%) than Cu (<30%) in vivo. More importantly, exposure to Cu and Cd remarkably altered the gut microbiota of BSFL, particularly in the phyla Proteobacteria, Firmicutes and Bacteroidetes. High exposure to the metals (i.e., Cu-800 and Cd-80 groups) substantially decreased the abundances of most of the dominant families, but significantly stimulated the enrichment of Brucellaceae, Enterobacteriaceae, Alcaligenaceae, Campylobacteraceae, and Enterococcaceae. Moreover, the bacterial diversity in the BSFL gut was significantly reduced following high exposure to the metals. These results may fill a gap in our knowledge of the effects of heavy metals on the intestinal microbiome of BSFL.


Assuntos
Dípteros/efeitos dos fármacos , Microbioma Gastrointestinal/efeitos dos fármacos , Metais Pesados/farmacologia , Animais , Bactérias/isolamento & purificação , Bioacumulação , Cádmio/farmacocinética , Cádmio/farmacologia , Cobre/farmacocinética , Cobre/farmacologia , Dípteros/crescimento & desenvolvimento , Dípteros/metabolismo , Dípteros/microbiologia , Fezes/química , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Larva/metabolismo , Larva/microbiologia , Metais Pesados/farmacocinética , Eliminação de Resíduos
4.
Naturwissenschaften ; 107(1): 7, 2020 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-31900598

RESUMO

Insects employ different defense strategies against fungal infections and chemicals. We aimed to identify the lipid compositions of the fat body of Zophobas morio larvae before and after fungal infection with the entomopathogenic fungus Metarhizium flavoviride. We used gas chromatography-mass spectrometry to analyze lipid extracts of the fat body isolated of Z. morio 2, 5, and 7 days after fungal infection (treatment group) and compared it with the lipid extracts in a control group injected with physiological isotonic saline. In all the samples, fatty acids were the most abundant compound found in the fat body extracts, with hexadecanoic acid/C16:0 being the most abundant lipid. However, the types and concentrations of lipids changed after fungal infection, likely as an immune response. The most considerable changes occurred in the concentrations of long-chain fatty acids, i.e., hexadecanoic acid/C16:0, octadecenoic acid/C18:1, and octadecanoic acid/C18:0. Contents of methyl ester increased significantly after infection, but that of other esters, especially octanoic acid decyl ester/OADE, decreased on the 5th day after infection. To the best of our knowledge, this is the first detailed analysis of the changes in the lipid composition of the fat body of Z. morio larvae as a result of fungal infection. Our results suggest that entomopathogenic fungal infection affects the internal lipid composition of insects, potentially as a way of adjusting to such infection. These results can help understand infection processes and defense strategies of insects against fungal infection. Ultimately, they can contribute to the creation of more effective chemicals against pest insects.


Assuntos
Besouros/microbiologia , Lipídeos/química , Metarhizium/fisiologia , Animais , Besouros/química , Corpo Adiposo/química , Corpo Adiposo/microbiologia , Larva/microbiologia
5.
Arch Insect Biochem Physiol ; 103(4): e21654, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31916310

RESUMO

To study dietary pH effects on Lymantria dispar asiatica larvae and provide a theoretical basis for its control in different forests, phosphate buffers (PBs) of pH 6, 7, and 8 were used to prepare experimental diets. The diet prepared with pH 6 PB was named as DPB6, with pH 8 PB as DPB8, and with pH 7 PB as DPB7 (control). The dietary pH was 5.00 in DPB6, 6.05 in control, and 6.50 in DPB8. After feeding on the diets with different pH values for 84 hr, fourth-instar caterpillars were randomly collected. Growth and various physiological traits were determined and 16S recombinant DNA sequencing was performed using the intestinal microflora of surviving larvae. Results showed that the mortality was 30% in DPB6, and 10% in DPB8, while no mortality was observed in control. The partial least squares discriminant analyses suggested that diets prepared with PB of different pH resulted in different food intake, amount of produced feces, weight gain, digestive enzyme activities, and antioxidant enzyme activities in larvae. Interestingly, both the highest weight gain and the lowest total antioxidant capacities were seen in control larvae. Results also showed that the larval gut microbiota community structure was significantly affected by dietary pH. Moreover, linear discriminant analysis effect size suggested that the family Acetobacteraceae in control, genus Prevotella in DPB8, and genus Lactococcus, family Flavobacteriaceae, family Mitochondria, and family Burkholderiaceae in DPB6 contributed to the diversity of the larval gut microbial community.


Assuntos
Ração Animal/análise , Microbioma Gastrointestinal/efeitos dos fármacos , Mariposas/crescimento & desenvolvimento , Mariposas/microbiologia , Animais , Dieta , Concentração de Íons de Hidrogênio , Larva/crescimento & desenvolvimento , Larva/microbiologia
6.
Arch Insect Biochem Physiol ; 103(4): e21655, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31953886

RESUMO

Some studies have highlighted benefits for Lobesia botrana by adding Botrytis cinerea mycelium to an artificial larval diet and have suggested a mutualistic relationship between the two organisms on grapevine, hypothesizing that fungal sterols were the nutritional factor involved. Because the nutritional quality of an artificial diet should be similar to grapes to allow extrapolation of the results to the field conditions, in the current study L. botrana larval performance was compared when larvae were fed on grapes (berries) or two artificial diets either with or without enrichment with B. cinerea. Based on sterol analysis, the two artificial diets had high cholesterol content, but relative to berries showed comparable and low phytosterol contents, respectively (high- and low-phytosterol, HPh, and LPh). While larval fitness on the HPh diet was similar to berries, the LPh diet led to higher mortality and worse larval performance. The addition of the fungus compensated for the shortage in the LPh diet but did not improve the HPh diet. Supplementing the LPh diet with linoleic acid, which is supplied also from B. cinerea, partially improved larval performance. In a field experiment, females did not show any egg-laying preferences towards naturally botrytized bunches. The positive effect of B. cinerea on the moth's next generation that is reported in the literature could be a consequence of fungus developed inside berry tunnels bored by larvae. Therefore, based on our data and previous reports the existence of a mutualistic relationship between L. botrana and B. cinerea is not well-founded.


Assuntos
Botrytis/fisiologia , Mariposas/microbiologia , Mariposas/fisiologia , Simbiose , Ração Animal/análise , Animais , Dieta , Larva/crescimento & desenvolvimento , Larva/microbiologia , Larva/fisiologia , Mariposas/crescimento & desenvolvimento , Oviposição , Vitis
7.
PLoS Pathog ; 16(1): e1008288, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31961911

RESUMO

Insects rely on the innate immune system for defense against pathogens, some aspects of which are under hormonal control. Here we provide direct experimental evidence showing that the juvenile hormone-binding protein (mJHBP) of Aedes aegypti is required for the regulation of innate immune responses and the development of mosquito blood cells (hemocytes). Using an mJHBP-deficient mosquito line generated by means of CRISPR-Cas9 gene editing technology we uncovered a mutant phenotype characterized by immunosuppression at the humoral and cellular levels, which profoundly affected susceptibility to bacterial infection. Bacteria-challenged mosquitoes exhibited significantly higher levels of septicemia and mortality relative to the wild type (WT) strain, delayed expression of antimicrobial peptides (AMPs), severe developmental dysregulation of embryonic and larval hemocytes (reduction in the total number of hemocytes) and increased differentiation of the granulocyte lineage. Interestingly, injection of recombinant wild type mJHBP protein into adult females three-days before infection was sufficient to restore normal immune function. Similarly, injection of mJHBP into fourth-instar larvae fully restored normal larval/pupal hemocyte populations in emerging adults. More importantly, the recovery of normal immuno-activation and hemocyte development requires the capability of mJHBP to bind JH III. These results strongly suggest that JH III functions in mosquito immunity and hemocyte development in a manner that is perhaps independent of canonical JH signaling, given the lack of developmental and reproductive abnormalities. Because of the prominent role of hemocytes as regulators of mosquito immunity, this novel discovery may have broader implications for the understanding of vector endocrinology, hemocyte development, vector competence and disease transmission.


Assuntos
Aedes/crescimento & desenvolvimento , Aedes/imunologia , Proteínas de Transporte/imunologia , Proteínas de Insetos/imunologia , Aedes/genética , Aedes/microbiologia , Animais , Proteínas de Transporte/genética , Feminino , Hemócitos/imunologia , Hemócitos/microbiologia , Imunidade Inata , Proteínas de Insetos/genética , Hormônios Juvenis/imunologia , Larva/genética , Larva/crescimento & desenvolvimento , Larva/imunologia , Larva/microbiologia , Masculino , Serratia marcescens/fisiologia
8.
Int J Syst Evol Microbiol ; 70(3): 1924-1930, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31976851

RESUMO

A bacterium that was Gram-staining-positive, facultatively anaerobic, non-motile, rod- or filamentous-shaped, designated as strain 2JSPR-7T, was isolated from a gut of larvae of Allomyrina dichotoma which were raised at the National Institute of Agricultural Sciences, Wanju-gun, Republic of Korea. 2JSPR-7T had the highest 16S rRNA gene sequence similarity to Xylanibacterium ulmi XIL08T (98.1 %), Xylanimicrobium pachnodae NBRC 107786T (97.8 %) and Xylanimonas cellulosilytica DSM 15894T (97.5 %). Optimum growth conditions were at 28-30 °C, pH 7-8 and 0 % salt concentration. The cellular fatty acids mainly consisted of anteiso-C15 : 0, C14 : 0 and C16 : 0. The polar lipids were diphosphatidylglycerol, four unidentified phospholipids and two unidentified glycophospholipids. The major menaquinones were MK-8(H4) and MK-9(H4). The peptidoglycan structure was suggested to be the type A3α (A11.14) l-Lys-l-Ser with the presence of d-Ala, l-Ala, d-Glu, l-Ser and l-Lys. Whole cell sugars were rhamnose, ribose and glucose. The DNA G+C content was 72.7 mol%. We encountered difficulty in selecting a suitable genus to accommodate strain 2JSPR-7T from any of the genera Xylanimonas, Xylanimicrobium and Xylanibacterium based on the polyphasic approach including phylogenetic and phenotypic characterization. Therefore, it is proposed to combine the genera Xylanimicrobium and Xylanibacterium with the genus Xylanimonas considering the priority of publication and to classify strain 2JSPR-7T in the genus as Xylanimonas allomyrinae sp. nov. The type strain of the novel species is 2JSPR-7T (=KACC 19330T=NBRC 113052T). In addition, the description of the genus Xylanimonas is emended, and Xylanibacterium ulmi and Xylanimicrobium pachnodae are reclassified as Xylanimonas ulmi comb. nov. and Xylanimonas pachnodae comb. nov., respectively.


Assuntos
Actinobacteria/classificação , Besouros/microbiologia , Trato Gastrointestinal/microbiologia , Filogenia , Actinobacteria/isolamento & purificação , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Larva/microbiologia , Peptidoglicano/química , Fosfolipídeos/química , RNA Ribossômico 16S/genética , República da Coreia , Análise de Sequência de DNA
9.
Insect Biochem Mol Biol ; 116: 103258, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31678582

RESUMO

The protease inhibitors found in silkworm cocoons can be divided into several families, a majority of which contain serpin, TIL, or Kunitz domains. Previously, it has been reported that TIL-type protease inhibitors have antimicrobial activity. To date, however, it has not been determined whether the Kunitz-type protease inhibitor BmSPI51, the most abundant of cocoon protease inhibitors, plays an antimicrobial role. Thus, in this study, we sought to determine the biological role of BmSPI51 in silkworm cocoons. Our results obtained from real-time quantitative reverse transcription PCR and immunofluorescence analyses indicate that BmSPI51 is expressed exclusively in the silk glands during the larval fifth instar stage and is subsequently secreted into cocoon silk. Moreover, at a molar ratio of 1:1, BmSPI51 produced via prokaryotic expression exhibited inhibitory activity against trypsin and also proved to be highly stable over wide ranges of temperature and pH values. The expression of BmSPI51 was also found to be significantly upregulated in the larval fat body after infection with three species of fungi, namely, Candida albicans, Beauveria bassiana, and Saccharomyces cerevisiae. In vitro inhibition tests revealed that BmSPI51 significantly inhibited the sporular growth of all three of these fungal species. Further, results obtained from a binding assay showed that BmSPI51 binds to ß-d-glucan and mannan on the surface of fungal cells. In this study, we, thus, revealed the antimicrobial activity of BmSPI51 and its underlying mechanism in silkworm, thereby contributing to our present understanding of defense mechanisms in silkworm cocoons.


Assuntos
Bombyx/metabolismo , Bombyx/microbiologia , Proteínas de Insetos/genética , Inibidores de Serino Proteinase/genética , Animais , Antifúngicos/metabolismo , Beauveria/fisiologia , Bombyx/crescimento & desenvolvimento , Candida albicans/fisiologia , Corpo Adiposo/química , Proteínas de Insetos/metabolismo , Larva/crescimento & desenvolvimento , Larva/metabolismo , Larva/microbiologia , Saccharomyces cerevisiae/fisiologia , Inibidores de Serino Proteinase/metabolismo
10.
Environ Pollut ; 256: 113443, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31733951

RESUMO

During their lifetime honey bees (Apis mellifera) rarely experience optimal conditions. Sometimes, a simultaneous action of multiple stressors, natural and chemical, results in even greater effect than of any stressor alone. Therefore, integrative investigations of different factors affecting honey bees have to be carried out. In this study, adult honey bees exposed to thiamethoxam in larval and/or adult stage and infected with Nosema ceranae were examined. Newly emerged bees from colonies, non-treated or treated with thiamethoxam, were organized in six groups and kept in cages. Thiamethoxam treated bees were further exposed to either thiamethoxam or Nosema (groups TT and TN), or simultaneously to both (group TTN). Newly emerged bees from non-treated colonies were exposed to Nosema (group CN). From both, treated and non-treated colonies two groups were organized and further fed only with sugar solution (groups C and TC). Here, we present the expression profile of 19 genes in adult worker honey bees comprising those involved in immune, detoxification, development and apoptosis response. Results showed that gene expression patterns changed with time and depended on the treatment. In group TC at the time of emergence the majority of tested genes were downregulated, among which nine were significantly altered. The same gene pattern was observed on day six, where the only significantly upregulated gene was defensin-1. On day nine most of analyzed genes in all experimental groups showed upregulation compared to control group, where upregulation of antimicrobial peptide genes abaecin, defensin-1 and defensin-2 was significant in groups TT and TTN. On day 15 we observed a similar pattern of expression in groups TC and TT exposed to thiamethoxam only, where most of the detoxification genes were downregulated. Additionally RNA loads of Nosema and honey bee viruses were recorded. We detected a synergistic interaction of thiamethoxam and Nosema, reflected in lowest honey bee survival.


Assuntos
Abelhas/fisiologia , Inseticidas/toxicidade , Nosema , Tiametoxam/toxicidade , Animais , Peptídeos Catiônicos Antimicrobianos , Abelhas/efeitos dos fármacos , Abelhas/microbiologia , Expressão Gênica , Proteínas de Insetos , Larva/efeitos dos fármacos , Larva/microbiologia , Larva/fisiologia , Microsporidiose/veterinária
11.
Int J Syst Evol Microbiol ; 70(2): 1259-1265, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31851604

RESUMO

An actinobacterial strain, designated FW100M-8T, was isolated from a gut sample of larva of Protaetia brevitarsis seulensis at the National Institute of Agricultural Sciences, Wanju-gun, South Korea. Cells were Gram-stain-positive, microaerophilic to aerobic, non-spore forming and non-motile. It grew at pH 7.0-9.0 (optimum, pH 8.0), at 15-35 °C (optimum, 28 °C) and 0-3.0 % (w/v) NaCl (optimum, 0 %). According to the 16S rRNA gene analysis, strain FW100M-8T shared the highest sequence similarity with Agromyces mediolanus DSM 20152T (98.4 %), Agromyces ulmi XIL01T (98.3 %), Agromyces indicus NIO-1018T (98.3 %), Agromyces soli MJ21T (98.3 %), and Agromyces arachidis AK-1T (97.9 %). Phylogenetic trees showed that strain FW100M-8T fell into the lineage of the genus Agromyces. The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, an unidentified glycolipid and an unidentified lipid. The menaquinones of strain FW100M-8T were MK-12 (46 %), MK-11 (36 %), MK-10 (14 %) and MK-13 (4 %). The major fatty acids were anteiso-C15 : 0, anteiso-C17 : 0 and iso-C16 : 0. The peptidoglycan type was supposed to be the type B1, comprising d-Ala, d-Glu, Gly and l-A2bu. The G+C content of the genomic DNA is 70.5 mol%. On the basis of the genotypic and phenotypic data, we conclude that strain FW100M-8T represents a novel species of the genus Agromyces, for which the name Agromyces protaetiae sp. nov. is proposed with strain FW100M-8T (=KACC 19308T=NBRC 113048T) as the type strain.


Assuntos
Actinobacteria/classificação , Besouros/microbiologia , Trato Gastrointestinal/microbiologia , Filogenia , Actinobacteria/isolamento & purificação , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Glicolipídeos/química , Larva/microbiologia , Peptidoglicano/química , Fosfolipídeos/química , RNA Ribossômico 16S/genética , República da Coreia , Análise de Sequência de DNA , Vitamina K 2/química
12.
Acta Trop ; 201: 105204, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31574253

RESUMO

Gut microbiota communities in mosquitoes are influenced among others, by developmental stage. There is evidence that the aquatic environment where larvae feed influences the mosquito gut bacterial community composition with only a subgroup of these bacteria been transmitted trans-stadially to adults. This study evaluated the gut bacterial composition of Anopheles albimanus larvae, emerged and circulating mosquitoes, as well as water from the larval habitat, to elucidate transitions in these bacterial communities and determine the final composition in circulating mosquitoes. A 16S rRNA Illumina sequencing allowed to determine that Proteobacteria was the most abundant phylum in larvae (72.4%), emerged mosquitoes (75%), circulating adults (45.4%) and water from the larval habitat (79.1%). A core microbiome analysis evidenced that Enterobacter, Bacillus and Staphylococcus genera were the core bacterial microbiota (OTUs detected in >90%) in the four groups evaluated. PCoA cluster based on Jaccard and Bray Curtis distances showed two main bacterial clusters, one comprising the emerged and circulating adults, and the other the larvae. The results indicated that the gut microbiota of An. albimanus larvae is composed of bacteria acquired from the larval habitat; then, a rearrangement of the bacterial communities occurs in the trans-stadial passage. However, the higher bacterial richness detected in circulating adults suggests bacterial acquisition from the terrestrial environment where the mosquito feeds. Finally, the trans-stadially passage of some bacteria makes of interest their evaluation as candidates for paratransgenic control.


Assuntos
Anopheles/genética , Anopheles/microbiologia , Microbioma Gastrointestinal/genética , Larva/genética , Larva/microbiologia , Pupa/microbiologia , Fatores Etários , Animais , Colômbia , Pupa/genética
13.
PLoS One ; 14(12): e0218837, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31860650

RESUMO

The gut microbiota of insects is composed of a wide range of microorganisms which produce bioactive compounds that protect their host from pathogenic attack. In the present study, we isolate and identify the fungus Chrysosporium multifidum from the gut of Hermetia illucens larvae. Extract from C. multifidum culture broth supernatant showed moderate activity against a strain of methicillin-resistant Staphylococcus aureus (MRSA). Bioguided isolation of the extract resulted in the characterization of six α-pyrone derivatives (1-6) and one diketopiperazine (7). Of these compounds, 5,6-dihydro-4-methoxy-6-(1-oxopentyl)-2H-pyran-2-one (4) showed the greatest activity (IC50 = 11.4 ± 0.7 µg/mL and MIC = 62.5 µg/mL) against MRSA.


Assuntos
Anti-Infecciosos/isolamento & purificação , Chrysosporium/química , Dípteros/microbiologia , Animais , Chrysosporium/isolamento & purificação , Fungos/química , Fungos/isolamento & purificação , Microbioma Gastrointestinal/genética , Microbioma Gastrointestinal/fisiologia , Larva/microbiologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana
14.
BMC Biotechnol ; 19(Suppl 2): 95, 2019 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-31847841

RESUMO

BACKGROUND: The Queensland fruit fly, Bactrocera tryoni (Froggatt) (Diptera, Tephritidae) is the most significant insect pest of Australian horticulture. Bactrocera tryoni is controlled using a range of tools including the Sterile Insect Technique (SIT). Mass-rearing and irradiation of pupae in SIT can reduce the fitness and quality of the released sterile insects. Studies have also showed reduced microbial gut diversity in domesticated versus wild tephritids. RESULTS: Transmission electron microscopy confirmed the presence of the bacterial isolates in the mid-gut of mass-reared larvae, and plate counts from individual larval guts showed increased numbers of bacteria in supplemented larvae. Several developmental and fitness parameters were tested including larval development time (egg-hatch to pupation), pupal weight, emergence, flight ability, sex-ratio, and time to adult eclosion (egg-hatch to adult eclosion). Enterobacter sp. and Asaia sp. shortened larval development time, while this was delayed by Lactobacillus sp., Leuconostoc sp. and a blend of all four bacteria. The mean time from egg hatch to adult eclosion was significantly reduced by Leuconostoc sp. and the blend for males and females, indicating that the individual bacterium and consortium affect flies differently depending on the life stage (larval or pupal). There was no impact of bacterial supplemented larvae on pupal weight, emergence, flight ability, or sex ratio. CONCLUSIONS: Our findings show that bacteria fed to the larval stage of B. tryoni can impart fitness advantages, but the selection of probiotic strains (individual or a consortium) is key, as each have varying effects on the host. Bacteria added to the larval diet particularly Leuconostoc sp. and the blend have the capacity to reduce costs and increase the number of flies produced in mass-rearing facilities by reducing time to adult eclosion by 1.3 and 0.8 mean days for males, and 1.2 and 0.8 mean days for females.


Assuntos
Ração Animal/microbiologia , Bactérias/classificação , RNA Ribossômico 16S/genética , Tephritidae/fisiologia , Animais , Bactérias/genética , Bactérias/crescimento & desenvolvimento , DNA Bacteriano/genética , DNA Ribossômico/genética , Feminino , Microbioma Gastrointestinal , Aptidão Genética , Controle de Insetos , Larva/microbiologia , Larva/fisiologia , Masculino , Microscopia Eletrônica de Transmissão , Filogenia , Comportamento Sexual Animal , Tephritidae/microbiologia
15.
BMC Biotechnol ; 19(Suppl 2): 92, 2019 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-31847844

RESUMO

BACKGROUND: The Mediterranean fruit fly Ceratitis capitata is a major pest in horticulture. The development of fly larvae is mediated by bacterial decay in the fruit tissue. Despite the importance of bacteria on larval development, very little is known about the interaction between bacteria and larvae in their true ecological context. Understanding their relationship and inter-dependence in the host fruit is important for the development of new pest control interfaces to deal with this pest. RESULTS: We find no negative effects on egg hatch or larval development brought about by the bacterial isolates tested. The various symbionts inhabiting the fly's digestive system differ in their degree of contribution to the development of fly larvae depending on the given host and their sensitivity to induced inhibition caused by female produced antimicrobial peptides. These differences were observed not only at the genus or species level but also between isolates of the same species. We demonstrate how the microbiota from the mother's gut supports the development of larvae in the fruit host and show that larvae play a major role in spreading the bacterial contagion in the infected fruit itself. In addition, we present (for the first time) evidence for horizontal transfer of bacteria between larvae of different maternal origin that develop together in the same fruit. CONCLUSIONS: Larvae play a major role in the spread and shaping of the microbial population in the fruit. The transfer of bacteria between different individuals developing in the same fruit suggests that the infested fruit serves as a microbial hub for the amplification and spread of bacterial strains between individuals.


Assuntos
Bactérias/crescimento & desenvolvimento , Ceratitis capitata/crescimento & desenvolvimento , Prunus persica/parasitologia , Animais , Peptídeos Catiônicos Antimicrobianos/metabolismo , Peptídeos Catiônicos Antimicrobianos/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Ceratitis capitata/metabolismo , Ceratitis capitata/microbiologia , Sistema Digestório/microbiologia , Feminino , Larva/crescimento & desenvolvimento , Larva/microbiologia , Simbiose
16.
BMC Biotechnol ; 19(Suppl 2): 93, 2019 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-31847845

RESUMO

BACKGROUND: The olive fly, Bactrocera oleae, is the most important insect pest in olive production, causing economic damage to olive crops worldwide. In addition to extensive research on B. oleae control methods, scientists have devoted much effort in the last century to understanding olive fly endosymbiosis with a bacterium eventually identified as Candidatus Erwinia dacicola. This bacterium plays a relevant role in olive fly fitness. It is vertically transmitted, and it benefits both larvae and adults in wild populations; however, the endosymbiont is not present in lab colonies, probably due to the antibiotics and preservatives required for the preparation of artificial diets. Endosymbiont transfer from wild B. oleae populations to laboratory-reared ones allows olive fly mass-rearing, thus producing more competitive flies for future Sterile Insect Technique (SIT) applications. RESULTS: We tested the hypothesis that Ca. E. dacicola might be transmitted from wild, naturally symbiotic adults to laboratory-reared flies. Several trials have been performed with different contamination sources of Ca. E. dacicola, such as ripe olives and gelled water contaminated by wild flies, wax domes containing eggs laid by wild females, cages dirtied by faeces dropped by wild flies and matings between lab and wild adults. PCR-DGGE, performed with the primer set 63F-GC/518R, demonstrated that the transfer of the endosymbiont from wild flies to lab-reared ones occurred only in the case of cohabitation. CONCLUSIONS: Cohabitation of symbiotic wild flies and non-symbiotic lab flies allows the transfer of Ca. E. dacicola through adults. Moreover, PCR-DGGE performed with the primer set 63F-GC/518R was shown to be a consistent method for screening Ca. E. dacicola, also showing the potential to distinguish between the two haplotypes (htA and htB). This study represents the first successful attempt at horizontal transfer of Ca. E. dacicola and the first step in acquiring a better understanding of the endosymbiont physiology and its relationship with the olive fly. Our research also represents a starting point for the development of a laboratory symbiotic olive fly colony, improving perspectives for future applications of the Sterile Insect Technique.


Assuntos
Animais de Laboratório/microbiologia , Erwinia/isolamento & purificação , Olea/parasitologia , Tephritidae/fisiologia , Animais , Animais de Laboratório/crescimento & desenvolvimento , DNA Bacteriano/genética , Erwinia/genética , Feminino , Controle de Insetos , Larva/crescimento & desenvolvimento , Larva/microbiologia , Masculino , Comportamento Sexual Animal , Simbiose , Tephritidae/crescimento & desenvolvimento , Tephritidae/microbiologia
17.
BMC Biotechnol ; 19(Suppl 2): 94, 2019 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-31847853

RESUMO

BACKGROUND: The Oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), is an important polyphagous pest of horticultural produce. The sterile insect technique (SIT) is a proven control method against many insect pests, including fruit flies, under area-wide pest management programs. High quality mass-rearing process and the cost-effective production of sterile target species are important for SIT. Irradiation is reported to cause severe damage to the symbiotic community structure in the mid gut of fruit fly species, impairing SIT success. However, studies have found that target-specific manipulation of insect gut bacteria can positively impact the overall fitness of SIT-specific insects. RESULTS: Twelve bacterial genera were isolated and identified from B. dorsalis eggs, third instars larval gut and adults gut. The bacterial genera were Acinetobacter, Alcaligenes, Citrobacter, Pseudomonas, Proteus, and Stenotrophomonas, belonging to the Enterobacteriaceae family. Larval diet enrichment with the selected bacterial isolate, Proteus sp. was found to improve adult emergence, percentage of male, and survival under stress. However, no significant changes were recorded in B. dorsalis egg hatching, pupal yield, pupal weight, duration of the larval stage, or flight ability. CONCLUSIONS: These findings support the hypothesis that gut bacterial isolates can be used in conjunction with SIT. The newly developed gel-based larval diet incorporated with Proteus sp. isolates can be used for large-scale mass rearing of B. dorsalis in the SIT program.


Assuntos
Ração Animal/microbiologia , Bactérias/classificação , RNA Ribossômico 16S/genética , Tephritidae/fisiologia , Animais , Bactérias/genética , Bactérias/isolamento & purificação , DNA Bacteriano/genética , DNA Ribossômico/genética , Feminino , Microbioma Gastrointestinal , Controle de Insetos , Larva/microbiologia , Larva/fisiologia , Masculino , Comportamento Sexual Animal , Tephritidae/microbiologia
18.
Crit Rev Eukaryot Gene Expr ; 29(2): 95-103, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31679264

RESUMO

As the beekeeping industry develops, increases in honey yield is dependent on colony health. The honeybee gut bacteria originate from their natural habitat and food, nectar, pollen, and water intake. Extensive studies have been carried out to determine specific suitable probiotic bacteria for honeybees. The main goal of this research is to control diseases, not increase honey production; however, a healthier colony will certainly produce more honey. It has been shown that lactic acid bacteria isolated from honeybees has beneficial effects on bee health and reduces the prevalence of pathogens. Adding a mixture of Lactobacillus to the feed of larvae leads to a reduction in infection. Knowledge of molecular mechanisms of probiotics in protecting honeybee colonies against pathogens is important.


Assuntos
Abelhas/microbiologia , Lactobacillus/fisiologia , Probióticos , Ração Animal/microbiologia , Animais , Trato Gastrointestinal/microbiologia , Larva/microbiologia
19.
Pestic Biochem Physiol ; 161: 77-85, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31685200

RESUMO

The incidence of mosquito-borne disease poses a significant threat to human and animal health throughout the world, with effective chemical control interventions limited by widespread insecticide resistance. Recent evidence suggests that gut bacteria of mosquitoes, known to be essential in nutritional homeostasis and pathogen defense, may also play a significant role in facilitating insecticide resistance. This study investigated the extent to which bacteria contribute to the general esterase and cytochrome P450 monooxygenase (P450)-mediated detoxification of the insecticides propoxur and naled, as well as the insecticidal activity of these chemistries to the yellow fever mosquito, Aedes aegypti. Experiments conducted using insecticide synergists that reduce general esterase and P450 activity demonstrate a role for both groups of enzymes in the metabolic detoxification of propoxur and naled. Furthermore, reduction of bacteria in mosquito larvae using broad-spectrum antibiotics was found to decrease the metabolic detoxification of propoxur and naled, suggesting that the bacteria themselves may be contributing to the in vivo metabolic detoxification of these insecticides. This was supported by in vitro assays using culturable gut bacteria isolated from mosquito larvae which demonstrated that the bacteria were capable of reducing insecticide toxicity. More work is needed, however, to fully elucidate the contribution of bacteria in Ae. aegypti larvae to the metabolic detoxification of insecticides.


Assuntos
Aedes/efeitos dos fármacos , Bactérias/metabolismo , Inseticidas/farmacologia , Naled/farmacologia , Propoxur/farmacologia , Acetilcolinesterase/metabolismo , Aedes/embriologia , Aedes/microbiologia , Aedes/virologia , Animais , Antibacterianos/farmacologia , Sistema Enzimático do Citocromo P-450/metabolismo , Inativação Metabólica , Larva/efeitos dos fármacos , Larva/microbiologia
20.
Arch Insect Biochem Physiol ; 102(3): e21593, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31612553

RESUMO

The diamondback moth, Plutella xylostella, is one of the most destructive pests worldwide and its management relies exclusively on frequent application of chemical insecticides. Resistance to common insecticides is now widespread, and novel classes of insecticides are needed. Entomopathogenic bacteria and their related products play an important role in the management of this pest. In the present work, one bacterial strain was separated from infected pupae of P. xylostella collected from field and its pathogenicity was evaluated. On the basis of the 16S ribosomal RNA sequencing, BLASTN, and phylogenetic analysis, this bacterial isolate was identified as Pseudomonas cedrina. Oral administration of P. cedrina at levels above 10,000 CFU/ml gave significant mortality to P. xylostella larvae. The pathogenicity was also observed by reduced longevity and fecundity in adult females. However, when live bacterial cells were removed, the cultured broth lost any pathogenicity. In response to the bacterial infection, P. xylostella expressed antimicrobial and stress-associated genes. A mixture treatment of P. cedrina and Bacillus thuringiensis showed an additive effect on larval mortality of P. xylostella. These results indicated that P. cedrina is an opportunistic entomopathogen without secretion of toxins. Furthermore, the additive effect of P. cedrina and B. thuringiensis provide a new insight to develop new strategy for controlling P. xylostella.


Assuntos
Mariposas/microbiologia , Pseudomonas/isolamento & purificação , Animais , Feminino , Fertilidade , Perfilação da Expressão Gênica , Larva/microbiologia , Longevidade , Mariposas/genética , Mariposas/metabolismo , Controle Biológico de Vetores/métodos , Filogenia , Pseudomonas/classificação , Pseudomonas/patogenicidade , Pupa/microbiologia , RNA Ribossômico 16S
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