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1.
Plant Cell Environ ; 47(6): 2228-2239, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38483021

RESUMO

The selection of oviposition sites by female moths is crucial in shaping their progeny performance and survival, and consequently in determining insect fitness. Selecting suitable plants that promote the performance of the progeny is referred to as the Preference-Performance hypothesis (or 'mother-knows-best'). While root infestation generally reduces the performance of leaf herbivores, little is known about its impact on female oviposition. We investigated whether maize root infestation by the Western corn rootworm (WCR) affects the oviposition preference and larval performance of the European corn borer (ECB). ECB females used leaf volatiles to select healthy plants over WCR-infested plants. Undecane, a compound absent from the volatile bouquet of healthy plants, was the sole compound to be upregulated upon root infestation and acted as a repellent for first oviposition. ECB larvae yet performed better on plants infested below-ground than on healthy plants, suggesting an example of 'bad motherhood'. The increased ECB performance on WCR-infested plants was mirrored by an increased leaf consumption, and no changes in the plant primary or secondary metabolism were detected. Understanding plant-mediated interactions between above- and below-ground herbivores may help to predict oviposition decisions, and ultimately, to manage pest outbreaks in the field.


Assuntos
Larva , Mariposas , Oviposição , Folhas de Planta , Raízes de Plantas , Compostos Orgânicos Voláteis , Zea mays , Animais , Oviposição/efeitos dos fármacos , Zea mays/fisiologia , Zea mays/parasitologia , Compostos Orgânicos Voláteis/metabolismo , Compostos Orgânicos Voláteis/farmacologia , Mariposas/fisiologia , Feminino , Larva/fisiologia , Raízes de Plantas/parasitologia , Raízes de Plantas/fisiologia , Folhas de Planta/fisiologia , Herbivoria
2.
PLoS Biol ; 19(2): e3001114, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33600420

RESUMO

Plants produce complex mixtures of primary and secondary metabolites. Herbivores use these metabolites as behavioral cues to increase their fitness. However, how herbivores combine and integrate different metabolite classes into fitness-relevant foraging decisions in planta is poorly understood. We developed a molecular manipulative approach to modulate the availability of sugars and benzoxazinoid secondary metabolites as foraging cues for a specialist maize herbivore, the western corn rootworm. By disrupting sugar perception in the western corn rootworm and benzoxazinoid production in maize, we show that sugars and benzoxazinoids act as distinct and dynamically combined mediators of short-distance host finding and acceptance. While sugars improve the capacity of rootworm larvae to find a host plant and to distinguish postembryonic from less nutritious embryonic roots, benzoxazinoids are specifically required for the latter. Host acceptance in the form of root damage is increased by benzoxazinoids and sugars in an additive manner. This pattern is driven by increasing damage to postembryonic roots in the presence of benzoxazinoids and sugars. Benzoxazinoid- and sugar-mediated foraging directly improves western corn rootworm growth and survival. Interestingly, western corn rootworm larvae retain a substantial fraction of their capacity to feed and survive on maize plants even when both classes of chemical cues are almost completely absent. This study unravels fine-grained differentiation and combination of primary and secondary metabolites into herbivore foraging and documents how the capacity to compensate for the lack of important chemical cues enables a specialist herbivore to survive within unpredictable metabolic landscapes.


Assuntos
Benzoxazinas/metabolismo , Besouros/fisiologia , Açúcares/metabolismo , Zea mays/metabolismo , Animais , Comportamento Apetitivo/fisiologia , Besouros/crescimento & desenvolvimento , Herbivoria , Larva/crescimento & desenvolvimento , Larva/fisiologia , Metaboloma , Raízes de Plantas/metabolismo , Zea mays/genética
4.
Curr Microbiol ; 81(8): 240, 2024 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-38910178

RESUMO

One Gram-negative, rod-shaped bacterial strain, isolated from an undescribed Heterorhabditis entomopathogenic nematode species was characterized to determine its taxonomic position. The 16S rRNA gene sequences indicate that it belongs to the class Gammaproteobacteria, to the family Morganellaceae, to the genus Photorhabdus, and likely represents a novel bacterial species. This strain, designated here as CRI-LCT, was therefore molecularly, biochemically, and morphologically characterized to describe the novel bacterial species. Phylogenetic reconstructions using 16S rRNA gene sequences show that CRI-LCT is closely related to P. laumondii subsp. laumondii TT01T and to P. laumondii subsp. clarkei BOJ-47T. The 16rRNA gene sequences between CRI-LCT and P. laumondii subsp. laumondii TT01T are 99.1% identical, and between CRI-LCT and P. laumondii subsp. clarkei BOJ-47T are 99.2% identical. Phylogenetic reconstructions using whole genome sequences show that CRI-LCT is closely related to P. laumondii subsp. laumondii TT01T and to P. laumondii subsp. clarkei BOJ-47T. Moreover, digital DNA-DNA hybridization (dDDH) values between CRI-LCT and its two relative species P. laumondii subsp. laumondii TT01T and P. laumondii subsp. clarkei BOJ-47T are 65% and 63%, respectively. In addition, we observed that average nucleotide identity (ANI) values between CRI-LCT and its two relative species P. laumondii subsp. laumondii TT01T and P. laumondii subsp. clarkei BOJ-47T are 95.8% and 95.5%, respectively. These values are below the 70% dDDH and the 95-96% ANI divergence thresholds that delimits prokaryotic species. Based on these genomic divergence values, and the phylogenomic separation, we conclude that CRI-LCT represents a novel bacterial species, for which we propose the name Photorhabdus africana sp. nov. with CRI-LCT (= CCM 9390T = CCOS 2112T) as the type strain. The following biochemical tests allow to differentiate P. africana sp. nov. CRI-LCT from other species of the genus, including its more closely related taxa: ß-Galactosidase, citrate utilization, urease and tryptophan deaminase activities, indole and acetoin production, and glucose and inositol oxidation. Our study contributes to a better understanding of the taxonomy and biodiversity of this important bacterial group with great biotechnological and agricultural potential.


Assuntos
DNA Bacteriano , Photorhabdus , Filogenia , RNA Ribossômico 16S , Photorhabdus/genética , Photorhabdus/classificação , Photorhabdus/isolamento & purificação , Animais , RNA Ribossômico 16S/genética , DNA Bacteriano/genética , Rhabditoidea/microbiologia , Rhabditoidea/genética , Rhabditoidea/classificação , Análise de Sequência de DNA , Técnicas de Tipagem Bacteriana
5.
Orthod Craniofac Res ; 27(2): 297-302, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37936546

RESUMO

INTRODUCTION: This study aimed to evaluate the perception of facial attractiveness when nose and teeth, together or isolated, present different degrees of disharmony. The secondary objective was to compare the perception of laypersons with that of dentists. MATERIALS AND METHODS: This cross-sectional observational study included 112 individuals (58 laypersons and 54 dentists) that evaluated 6 manipulated images of the face of the same model, scoring their attractiveness using 10 cm Visual Analogue Scales (VAS), with least and most attractive at the left and right anchors, respectively. The images contained manipulations performed only on the nose (laterorhinia) and mouth (misaligned teeth), as follows: (1) standard photograph, with symmetrical nose + aligned teeth; (2) 2 mm nasal deviation + aligned teeth; (3) 4 mm nasal deviation + aligned teeth; (4) symmetrical nose + misaligned teeth; (5) 2 mm nasal deviation + misaligned teeth and (6) 4 mm nasal deviation + misaligned teeth. We used the repeated measures ANOVA test and Tukey's post-test for intra-group comparison of the images. The independent t-test was used for inter-group comparison of each image. RESULTS: In the laypersons' group, the highest grades were given to images with aligned teeth and the lowest to misaligned teeth (smallest mean difference = 2.88 cm). For this group, there was no statistically significant difference (P-values ranged from .988 to 1.000) between scores of the three images in which teeth were aligned (range of 7.70-7.78 cm). In the group of dentists, highest grades were given to images with aligned teeth and the lowest to misaligned teeth. Difference between images 3 and 4 was not statistically significant (P = .204). All other differences between any image of straight teeth and any image with misaligned teeth were significant and the smallest mean difference between the two groups of images was 1.87 (P = .039). However, in the images with aligned teeth, there was also a statistically significant difference with higher scores to the images with symmetrical nose in contrast with those with significant laterorhinia (mean difference = 1.03 cm). CONCLUSION: Teeth disharmonies had a more negative impact on the aesthetic perception of the face than did nose deviations, for both dentists and laypersons.


Assuntos
Estética Dentária , Má Oclusão , Humanos , Estudos Transversais , Má Oclusão/terapia , Nariz , Percepção , Sorriso
6.
Mem Inst Oswaldo Cruz ; 119: e240015, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38922217

RESUMO

The coinfection between malaria (ML) and arboviral diseases represents a major global public health problem, particularly in tropical and subtropical countries. Despite its relevance, this topic is still insufficiently discussed in the current literature. Here, we aimed to investigate the worldwide distribution, symptoms, and diagnosis during coinfection between ML and arboviral diseases. We conducted a systematic review following the Preferred reporting items for systematic reviews and meta-analyses (PRISMA) statement and assessed the selection and eligibility criteria, created and diagrammed maps, and analysed major symptoms with 95% confidence intervals (CI) using prevalence ratio and effect size, also performing latent class analysis. A total of 85,485 studies were retrieved, of which 56 were included: 57.14% in Asia, 25% in Africa, 14.30% in South America, and 3.56% in Europe. A total of 746 individuals were reported to be coinfected with Plasmodium and arbovirus. Concurrent ML, Dengue (DEN), Chikungunya (CHIK), and Zika (ZIK) patients are more likely to present headache and skin rash. Regarding diagnosis, 58,253 were made, of which 38,176 were positive (ML and at least one arboviral disease). The magnitude of these pathogens' coexistence points out the pressing need for improvements in public health policies towards diagnosis and prevention of both diseases, especially in endemic areas.


Assuntos
Infecções por Arbovirus , Coinfecção , Malária , Humanos , Coinfecção/epidemiologia , Malária/epidemiologia , Malária/complicações , Malária/diagnóstico , Infecções por Arbovirus/epidemiologia , Infecções por Arbovirus/diagnóstico , Saúde Global , Prevalência
7.
Chem Biodivers ; 21(5): e202301467, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38471006

RESUMO

Cervical cancer is a specific type of cancer that affects women around the world, with an incidence of 604 thousand new cases per year and 341 thousand deaths. There is a high demand for new effective antineoplastic drugs with few side effects. In this sense, recent research highlights the potential of compounds of natural origin in treating and preventing different types of cancer. Myrciaria glazioviana is a Brazilian native species belonging to the Myrtaceae family, which has previously described biological activities such as antimicrobial, anti-inflammatory, and antioxidant properties. This study aims to evaluate the anticancer activity of the dichloromethane extract (MGD) and ethyl acetate extract (MGA) of M. glazioviana leaves against human cervical cancer cell line (HeLa), as well as to identify their bioactive compounds. Using HPLC-HRESIMS technique, ten compounds were characterized in both samples: quinic acid, ellagic acid, Tri-O-methyl ellagic acid, two derivatives of Tetra-O-methyl flavellagic acid, quercetrin, Di-O-methyl ellagic acid, and three derivatives of pentamethyl coruleoellagic acid. Through MTT assays using HeLa cells and NIH/3T3 cells, it was observed that MGD and MGA were selective against tumor cells, with IC50 values of 24.31 and 12.62 µg/mL, respectively. The samples induced the tumor cell death by apoptosis, as evidenced by the activation of caspases 3/7, cell shrinkage, and pyknotic nuclei. Both samples were also able to inhibit the migration of HeLa cells after 24 hours of treatment, indicating a potential antimetastatic effect. Therefore, the present research highlights the antiproliferative and antimigratory potential of this species against HeLa cells.


Assuntos
Antineoplásicos Fitogênicos , Apoptose , Proliferação de Células , Ensaios de Seleção de Medicamentos Antitumorais , Myrtaceae , Extratos Vegetais , Neoplasias do Colo do Útero , Humanos , Células HeLa , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Proliferação de Células/efeitos dos fármacos , Antineoplásicos Fitogênicos/farmacologia , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Neoplasias do Colo do Útero/tratamento farmacológico , Neoplasias do Colo do Útero/patologia , Myrtaceae/química , Cromatografia Líquida de Alta Pressão , Apoptose/efeitos dos fármacos , Feminino , Relação Dose-Resposta a Droga , Camundongos , Folhas de Planta/química , Animais , Sobrevivência Celular/efeitos dos fármacos , Espectrometria de Massas por Ionização por Electrospray
8.
J Esthet Restor Dent ; 36(6): 941-950, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38475977

RESUMO

OBJECTIVES: To investigate the effect of cumulative doses of radiation on the pushout bond strength (BS) of a universal resin cement used in the self-etch (SE) and self-adhesive (SA) modes to the intraradicular dentin. MATERIALS AND METHODS: Forty-eight human teeth were distributed into three groups (n = 16) according to the radiation therapy dose (RT): NoRT (no-radiotherapy), 70RT (70 Gy), and 70 + 70RT (70 Gy + 70 Gy). The teeth were redistributed into two subgroups (n = 8), according to the adhesive mode: SE (NoRT-SE, 70RT-SE, and 70 + 70RT-SE) and SA (NoRT-SA, 70RT-SA, and 70 + 70RT-SA). Data were statistically compared after BS test (ANOVA, Tukey's post hoc test, and Fisher's exact test). RESULTS: In the SA mode, BS was significantly higher in nonirradiated teeth compared with 70RT and 70 + 70RT (p < 0.0001). There were no significant differences between SE and SA modes in nonirradiated teeth (p = 0.14). In the 70RT group, SE mode increased BS compared with SA mode (p < 0.0001). Most specimens had adhesive and mixed failures in SA and SE modes, respectively. CONCLUSIONS: The universal resin cement in the SE mode had greater BS to the irradiated dentin. When teeth were re-irradiated, the universal resin cement had similar performance in terms of BS, regardless of the adhesive approach. CLINICAL SIGNIFICANCE: There is no research establishing a correlation between radiotherapy and its impact on the BS of a universal resin cement used in SE and SA modes to intraradicular dentin.


Assuntos
Colagem Dentária , Cimentos de Resina , Humanos , Cimentos de Resina/química , Colagem Dentária/métodos , Dentina , Análise do Estresse Dentário , Teste de Materiais , Adesivos Dentinários/química , Condicionamento Ácido do Dente
9.
BMC Oral Health ; 24(1): 481, 2024 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-38643087

RESUMO

OBJECTIVES: This prospective randomized multicenter clinical trial (PRMCT) investigated postoperative pain after single-visit root canal treatments in teeth affected by pulp necrosis (PN), and asymptomatic apical periodontitis (AAP) (with apical radiolucent areas) or normal periradicular tissues (without apical radiolucent areas) comparing different instruments' kinematics and apical instrumentation limits. METHODS: Before chemomechanical preparation, 240 patients/teeth were randomly distributed into four groups (n = 60) according to the instruments' kinematics (rotary or reciprocating) and apical instrumentation limits (with or without intentional foraminal enlargement [IFE]). After that, specimens were submitted to the same irrigation and obturation techniques, and the patients were referred to undergo the definitive restorations. No medication was prescribed, but the patients were instructed to take either paracetamol (750 mg every 6 h for three days) or ibuprofen (600 mg every 6 h for three days) in pain cases. Postoperative pain incidence and levels were assessed at 24-, 48-, and 72 h following treatment completion according to a verbal rating scale (VRS) following a score. The Kolmogorov-Smirnov test was applied to assess the normality of the data. Mann-Whitney U, Chi-square, Friedman's ANOVA, and Friedman's multiple 2 to 2 comparison tests were employed to identify potential significant statistical differences among the variables in the study groups (P < .05). RESULTS: Significant statistical differences were only observed among the groups considering tooth, periradicular status, and the occurrence of overfilling (sealer extrusion) (P < 0.00). Patients with teeth instrumented through rotary kinematics and without IFE experienced lower rates of postoperative pain; however, this difference was relevant only at 24 h (P < 0.05). CONCLUSIONS: Postoperative pain was lower after using a rotary file system (Profile 04) inserted up to the apical constriction (AC). However, this finding was just statistically meaningful at 24 h. TRIAL REGISTRATION: This PRMCT was approved by the Human Research Ethics Committee of the Paranaense University - UNIPAR, Francisco Beltrão, PR, Brazil (CAAE. 46,774,621.6.0000.0109) on 02/09/2021. It was registered at The Brazilian Registry of Clinical Trials - ReBEC (RBR-3r967t) on 01/06/2023, was performed according to the Principles of the Helsinki Declaration and is reported following the Consolidated Standards of Reporting Trials Statement.


Assuntos
Cavidade Pulpar , Preparo de Canal Radicular , Humanos , Cavidade Pulpar/cirurgia , Estudos Prospectivos , Fenômenos Biomecânicos , Dor Pós-Operatória/etiologia , Dor Pós-Operatória/epidemiologia
10.
Cytokine ; 169: 156264, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37327529

RESUMO

BACKGROUND: The immunopathology during malaria depends on the level of inflammatory response generated. In this scenario, the TREM-1 has been associated with the severity of infectious diseases and could play an important role in the inflammatory course of malaria. We aimed to describe the allelic and genotypic frequency of four polymorphisms in the trem-1 gene in Plasmodium vivax-infected patients and to verify the association of these polymorphisms with clinical and immunological factors in a frontier area of the Brazilian Amazon. METHODS: We included 76 individuals infected with P. vivax and 144 healthy controls living in the municipality of Oiapoque, Amapá, Brazil. The levels of TNF-α, IL-10, IL-2, IL-4, IL-5, and IFN-γ were measured by flow cytometry, while IL-6, sTREM-1, and antibodies against PvMSP-119 were evaluated by ELISA. The SNPs were genotyped by qPCR technique. Polymorphisms analysis, allelic and genotype, frequencies, and HWE calculation were determined by x2 test in R Software. The association between the parasitemia, gametocytes, antibodies, cytokines, and sTREM-1 with the genotypes of malaria and control groups was performed using the Kruskal-Wallis test, these analyzes were conducted in SPSS Software, at 5% significance level. RESULTS: All SNPs were successfully genotyped. Allelic and genotypic distribution was in Hardy-Weinberg Equilibrium. Furthermore, several associations were identified between malaria and control groups, with increased levels of IL-5, IL-6, IL-10, TNF-α, and IFN-γ in the infected individuals with rs6910730A, rs2234237T, rs2234246T, rs4711668C alleles compared to the homozygous wild-type and heterozygous genotypes of the controls (p-value < 0.05). No association was found for these SNPs and the levels of IL-2, and sTREM-1. CONCLUSIONS: The SNPs on the trem-1 gene are associated with the effector molecules of the innate immunity and may contribute to the identification and effective participation of trem-1 in the modulation of the immune response. This association may be essential for the establishment of immunization strategies against malaria.


Assuntos
Malária Vivax , Malária , Humanos , Citocinas/genética , Plasmodium vivax/genética , Interleucina-10/genética , Brasil , Receptor Gatilho 1 Expresso em Células Mieloides/genética , Fator de Necrose Tumoral alfa/genética , Interleucina-6/genética , Interleucina-2/genética , Interleucina-5/genética , Malária Vivax/genética , Polimorfismo de Nucleotídeo Único/genética
11.
Cytokine ; 169: 156278, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37356261

RESUMO

BACKGROUND: The innate immune response plays an important role during malaria. Toll-like receptors (TLR) are capable of recognizing pathogen molecules. We aimed to evaluate five polymorphisms in TLR-4, TLR-6, and TLR-9 genes and their association with cytokine levels and clinical parameters in malaria from the Brazil-French Guiana border. METHODS: A case-control study was conducted in Amapá, Brazil. P. vivax patients and individuals not infected were evaluated. Genotyping of five SNPs was carried out by qPCR. Circulating cytokines were measured by CBA. The MSP-119 IgG antibodies were performed by ELISA. RESULTS: An association between TLR4 A299G with parasitemia was observed. There was an increase for IFN-ɤ, TNF-ɑ, IL-6, and IL-10 in the TLR-4 A299G and T3911, TLR-6 S249P, and TLR-9 1486C/T, SNPs for the studied malarial groups. There were significant findings for the TLR-4 variants A299G and T3911, TLR-9 1237C/T, and 1486C/T. For the reactivity of MSP-119 antibodies levels, no significant results were found in malaria, and control groups. CONCLUSIONS: The profile of the immune response observed by polymorphisms in TLRs genes does not seem to be standard for all types of malaria infection around the world. This can depend on the human population and the species of Plasmodium.


Assuntos
Malária Vivax , Malária , Humanos , Malária Vivax/genética , Receptor Toll-Like 9 , Receptor 4 Toll-Like/genética , Receptor 6 Toll-Like/genética , Estudos de Casos e Controles , Brasil , Guiana Francesa , Proteína 1 de Superfície de Merozoito/genética , Genótipo , Predisposição Genética para Doença , Receptores Toll-Like/genética , Polimorfismo de Nucleotídeo Único/genética , Plasmodium vivax/genética
12.
Artigo em Inglês | MEDLINE | ID: mdl-37171451

RESUMO

Six Gram-negative, rod-shaped bacterial strains isolated from Heterorhabditis amazonensis entomopathogenic nematodes were characterized to determine their taxonomic position. 16S rRNA and gyrB gene sequences indicate that they belong to the class Gammaproteobacteria, family Morganellaceae and genus Photorhabdus, and that some of them are conspecifics. Two of them, APURET and JART, were selected for further molecular characterization using whole genome- and whole-proteome-based phylogenetic reconstructions and sequence comparisons. Phylogenetic reconstructions using whole genome and whole proteome sequences show that strains APURET and JART are closely related to Photorhabdus luminescens subsp. luminescens ATCC 29999T and to P. luminescens subsp. mexicana MEX47-22T. Moreover, digital DNA-DNA hybridization (dDDH) values between APURET and P. luminescens subsp. luminescens ATCC 29999T, APURET and P. luminescens subsp. mexicana MEX47-22T, and APURET and JART are 61.6, 61.2 and 64.1 %, respectively. These values are below the 70 % divergence threshold that delimits prokaryotic species. dDDH scores between JART and P. luminescens subsp. luminescens ATCC 29999T and between JART and P. luminescens subsp. mexicana MEX47-22T are 71.9 and 74.8 %, respectively. These values are within the 70 and 79 % divergence thresholds that delimit prokaryotic subspecies. Based on these genomic divergence values, APURET and JART represent two different taxa, for which we propose the names: Photorhabdus aballayi sp. nov. with APURET (=CCM 9236T =CCOS 2019T) as type strain and Photorhabdus luminescens subsp. venezuelensis subsp. nov. with JART (=CCM 9235T =CCOS 2021T) as type strain. Our study contributes to a better understanding of the biodiversity of an important bacterial group with enormous biotechnological and agricultural potential.


Assuntos
Nematoides , Photorhabdus , Animais , Filogenia , RNA Ribossômico 16S/genética , Proteoma/genética , Técnicas de Tipagem Bacteriana , Análise de Sequência de DNA , DNA Bacteriano/genética , Composição de Bases , Ácidos Graxos/química , Nematoides/microbiologia
13.
Artigo em Inglês | MEDLINE | ID: mdl-37103464

RESUMO

Four Gram-negative bacterial strains isolated from Steinernema africanum entomopathogenic nematodes were biochemically and molecularly characterized to determine their taxonomic position. Results of 16S rRNA gene sequencing indicated that they belong to the class Gammaproteobacteria, family Morganellaceae, genus Xenorhabdus, and that they are conspecific. The average 16S rRNA gene sequence similarity between the newly isolated strains and the type strain of its more closely related species, Xenorhabdus bovienii T228T, is 99.4 %. We therefore selected only one of them, XENO-1T, for further molecular characterization using whole genome-based phylogenetic reconstructions and sequence comparisons. Phylogenetic reconstructions show that XENO-1T is closely related to the type strain of X. bovienii, T228T, and to several other strains that are thought to belong to this species. To clarify their taxonomic identities, we calculated average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values. We observed that the ANI and dDDH values between XENO-1T and X. bovienii T228T are 96.3 and 71.2 %, respectively, suggesting that XENO-1T represents a novel subspecies within the X. bovienii species. Noteworthy, the dDDH values between XENO-1T and several other X. bovienii strains are between 68.7 and 70.9 % and ANI values are between 95.8 and 96.4 %, which could be interpreted, in some instances, as that XENO-1T represents a new species. Considering that for taxonomic description the genomic sequences of the type strains are compared, and to avoid future taxonomic conflicts, we therefore propose to assign XENO-1T to a new subspecies within X. bovienii. ANI and dDDH values between XENO-1T and any other of the species with validly published names of the genus are lower than 96 and 70 %, respectively, supporting its novel status. Biochemical tests and in silico genomic comparisons show that XENO-1T exhibit a unique physiological profile that differs from all the Xenorhabdus species with validly published names and from their more closely related taxa. Based on this, we propose that strain XENO-1T represents a new subspecies within the X. bovienii species, for which we propose the name X. bovienii subsp. africana subsp. nov, with XENO-1T (=CCM 9244T=CCOS 2015T) as the type strain.


Assuntos
Rabditídios , Xenorhabdus , Animais , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , DNA Bacteriano/genética , Técnicas de Tipagem Bacteriana , Composição de Bases , Ácidos Graxos/química , Rabditídios/genética , Rabditídios/microbiologia , Hibridização de Ácido Nucleico , Nucleotídeos
14.
Curr Microbiol ; 80(9): 300, 2023 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-37493817

RESUMO

Three bacterial strains, XENO-2T, XENO-7T, and XENO-10T, isolated from Steinernema entomopathogenic nematodes, were found to represent novel Xenorhabdus species. In this study, we describe these new species by whole-genome and whole-proteome phylogenomic reconstructions, by calculating sequence identity scores using core genome sequences, and by phenotypic characterization. Phylogenomic reconstructions using ribosomal and house-keeping genes, and whole-genome and whole-proteome sequences show that XENO-2T and XENO-10T are closely related to Xenorhabdus japonica DSM 16522T and that XENO-7T is closely related to Xenorhabdus bovienii subsp. africana XENO-1T and to X. bovienii subsp. bovienii T228T. The dDDH values between XENO-2T and XENO-10T and between XENO-2T and X. japonica DSM 16522T are 56.4 and 51.8%, respectively. The dDDH value between XENO-10T and X. japonica DSM 16522T is 53.4%. The dDDH values between XENO-7T and X. bovienii subsp. africana XENO-1T and between XENO-7T and X. bovienii subsp. bovienii T228T are 63.6 and 69.4%, respectively. These dDDH values are below the 70% divergence threshold for prokaryotic species delineation. The newly described species are highly pathogenic to G. mellonella larvae, grow at pH between 5 and 9 (optimum 5-7), at salt concentrations of 1-3% (optimum 1-2%), and temperatures between 20 and 37 °C (optimum 28-30 °C). Biochemical tests such as lysine decarboxylase, ornithine decarboxylase, urease, gelatinase, citrate utilization, indole and acetoin production, and cytochrome oxidase tests allow to differentiate the novel species from their more closely related species. Considering these genetic and phenotypic divergencies, we propose the following new species: Xenorhabdus aichiensis sp. nov. with XENO-7T (= CCM 9233T = CCOS 2024T) as the type strain, Xenorhabdus anantnagensis sp. nov., with XENO-2T (= CCM 9237T = CCOS 2023T) as the type strain, and Xenorhabdus yunnanensis sp. nov., with XENO-10T (= CCM 9322T = CCOS 2071T) as the type strain. Our study contributes to a better understanding of the biodiversity and phylogenetic relationships of entomopathogenic bacteria associated with insect parasitic nematodes.


Assuntos
Rabditídios , Xenorhabdus , Animais , Filogenia , Proteoma/genética , Simbiose , RNA Ribossômico 16S/genética , Rabditídios/genética , Rabditídios/microbiologia , DNA Bacteriano/genética , Análise de Sequência de DNA , Técnicas de Tipagem Bacteriana , Ácidos Graxos
15.
J Invertebr Pathol ; 199: 107953, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37336478

RESUMO

Entomopathogenic nematodes (EPNs) are soil-dwelling parasitic roundworms commonly used as biocontrol agents of insect pests in agriculture. EPN dauer juveniles locate and infect a host in which they will grow and multiply until resource depletion. During their free-living stage, EPNs face a series of internal and environmental stresses. Their ability to overcome these challenges is crucial to determine their infection success and survival. In this review, we provide a comprehensive overview of EPN response to stresses associated with starvation, low/elevated temperatures, desiccation, osmotic stress, hypoxia, and ultra-violet light. We further report EPN defense strategies to cope with biotic stressors such as viruses, bacteria, fungi, and predatory insects. By comparing the genetic and biochemical basis of these strategies to the nematode model Caenorhabditis elegans, we provide new avenues and targets to select and engineer precision nematodes adapted to specific field conditions.


Assuntos
Nematoides , Animais , Nematoides/fisiologia , Insetos/parasitologia , Agricultura , Solo/parasitologia , Caenorhabditis elegans
16.
J Nematol ; 55(1): 20230029, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37455851

RESUMO

Three entomopathogenic nematode populations were isolated from agricultural fields in the Anantnag district of Jammu and Kashmir (India). Sequences of multiple gene regions and phenotypic features show that they are conspecific and represent a novel species. Molecular and morphological features provided evidence for placing the new species into the "Kushidai" clade. Within this clade, analysis of sequence data of the internal transcribed spacer (ITS) gene, the D2D3 region of the 28S rRNA gene, the mitochondrial cytochrome oxidase I (mtCOI) gene, and the mitochondrial 12S (mt12S) gene depicted the novel species as a distinctive entity closely related to Steinernema akhursti, S. kushidai, and S. populi. Phylogenetic analyses also show that the new species is a sister species to S. akhursti, and these two species are closely related to S. kushidai and S. populi. Additionally, the new species does not mate or produce fertile progeny with any of the closely related species, reinforcing its uniqueness from a biological species concept standpoint. The new species is further characterized by the third-stage infective juveniles with almost straight bodies (0.7-0.8 mm length), poorly developed stoma and pharynx, and conoid-elongate tail (49-66 µm) with hyaline posterior part. Adult females are characterized by short and conoid tails bearing a short mucron in the first generation and long conoid tails with thin mucron in the second generation. Adult males have ventrally curved spicules in both generations. Moreover, the first-generation male has rounded manubrium, fusiform gubernaculum, conoid and slightly ventrally curved tails with minute mucron, and the second generation has rhomboid manubrium anteriorly ventrad bent, and tails with long and robust mucron. The morphological, morphometrical, molecular, and phylogenetic analyses support the new species status of this nematode, which is hereby described as Steinernema anantnagense n. sp. The bacterial symbiont associated with S. anantnagense n. sp. represents a novel species, closely related to Xenorhabdus japonica. These findings shed light on the diversity of entomopathogenic nematodes and their symbiotic bacteria, providing valuable information for future studies in this field.

17.
Chem Rec ; 22(2): e202100215, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34669242

RESUMO

The use of laccases applied in bioremediation processes has been increasingly studied, given the urgent need to overcome the environmental problems caused by emerging contaminants. It is known that immobilized enzymes have better operational stability under reaction conditions, allowing for greater applicability. However, given the lack of commercially available immobilized laccases, the search for immobilization materials and methods continues to gain effort. The use of polyacrylonitrile (PAN) to immobilize enzymes has been investigated since it is a low-cost material and can be modified and functionalized to well interact with the enzyme. This polymer can be used with different morphologies such as fibers, beads, and core-shell, presenting as an easily applicable alternative. This review presents the missing link between polymer and enzyme through an overview of PAN's current use as support for laccase immobilization and polymer functionalization methods, considering the importance of immobilized laccases in several industrial sectors.


Assuntos
Enzimas Imobilizadas , Lacase , Resinas Acrílicas , Biodegradação Ambiental
18.
Int J Syst Evol Microbiol ; 72(10)2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36223180

RESUMO

One motile, Gram-negative, non-spore-forming and rod-shaped symbiotic bacterium, strain UCH-936T, was isolated from Heterorhabditis atacamensis nematodes. Results of biochemical, physiological, molecular and genomic analyses suggest that it represents a new species, which we propose to name Photorhabdus antumapuensis sp. nov. Digital DNA-DNA hybridization shows that strain UCH-936T is more closely related to Photorhabdus kleinii DSM 23513T, but shares solely 50.5 % similarity, which is below the 70% cut-off value that delimits species boundaries in bacteria. Phylogenetic reconstructions using whole-genome sequences show that strain UCH-936T forms a unique clade, suggesting its novel and distinct taxonomic status again. Similarly, comparative genomic analyses shows that the virulence factor flagella-related gene fleR, the type IV pili-related gene pilL and the vibriobactin-related gene vibE are present in the genome of strain UCH-936T but absent in the genomes of its closest relatives. Biochemically and physiologically, UCH-936T differs also from all closely related Photorhabdus species. Therefore, Photorhabdus antumapuensis sp. nov. is proposed as a new species with the type strain UCH-936T (CCCT 21.06T=CCM 9188T=CCOS 1991T).


Assuntos
Nematoides , Photorhabdus , Rhabditoidea , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Photorhabdus/genética , Filogenia , RNA Ribossômico 16S/genética , Rhabditoidea/microbiologia , Análise de Sequência de DNA , Fatores de Virulência
19.
Int Microbiol ; 25(1): 207-216, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34553287

RESUMO

Soil inhabiting organisms are important determinants of agroecosystem productivity. Understanding the composition, the abundance, and the type of interactions established by soil microorganisms is therefore crucial to design strategies to improve agricultural practices and agroecosystem management. In this study, we collected Zeldia punctata nematodes in maize fields in South Africa and profiled their associated bacterial communities using next-generation sequencing. We observed that Z. punctata nematodes establish associations with ecologically diverse bacterial species. The most abundant species observed are Pseudomonas syringae, a phytopathogenic bacterial complex; Lactobacillus paraplantarum, a broadly distributed bacterial species that is present in soils, water bodies, and animal intestinal tracts and has certain probiotic and antimicrobial properties; and Melissococcus plutonius, a serious pathogenic bacterial species that causes brood disease in honeybees. Our study contributes to a better understanding of the soil bacterial communities associated with nematodes in maize agricultural soils in South Africa and unravels the presence of diverse detrimental and beneficial nematode-associated bacteria.


Assuntos
Nematoides , Solo , Agricultura , Animais , Bactérias/genética , Microbiologia do Solo
20.
J Chem Ecol ; 48(1): 71-78, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34738202

RESUMO

Most known species of entomopathogenic nematodes (EPNs) are generalist obligate parasites of insects. They kill their hosts within days after infection and mortality is mainly caused by toxins produced by bacteria that co-infect the hosts and serve as food for the nematodes. EPNs can infect a very broad spectrum of insects and these insects can therefore be expected to have evolved strategies to avoid infection. Indeed, ants are known to avoid feeding on EPN-infected insect cadavers, most likely because they are repelled by semiochemicals that emanate from the cadavers. The source and nature of these repellents are so far unknown. In a series of behavioral and chemical analytical experiments we identified hexadecanal and 2-heptadecanone as two compounds that are emitted by insect larva that are infected by the EPN Steinernema feltiae, but not by uninfected larvae. When spiking honey water with the two semiochemicals, they were confirmed to be highly deterrent to the ant Lasius niger. The environmentally benign hexadecanal and 2-heptadecanone could be employed to ward off ants and possibly other pests. Additional experiments are needed to fully determine their application potential.


Assuntos
Formigas , Rabditídios , Animais , Cadáver , Insetos , Larva , Controle Biológico de Vetores
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