Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 403
Filtrar
1.
Syst Parasitol ; 98(4): 477-485, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34228275

RESUMO

Serpentirhabdias mamlambo n. sp. is described from the lung of the herald snake, Crotaphopeltis hotamboeia (Laurenti) in KwaZulu-Natal Province, South Africa. The new species is characterised by the small lips, the absence of the buccal capsule, the large excretory glands (1.5-2.3 times longer than the oesophagus), and the numerous eggs in uteri. Serpentirhabdias mamlambo n. sp. differs from other Serpentirhabdias spp. in the presence of M-shaped cuticular folds on dorsal and ventral sides of apical surface, the eye-shaped internal labial papillae, and the distinct dilatation of the oesophagus at its mid-length. Morphological differentiation of S. mamlambo n. sp. from its congeners is supported by molecular evidence based on cox1 mitochondrial gene, and ITS and partial 28S region of nuclear rDNA. Serpentirhabdias mamlambo n. sp. is the first species of the genus Serpentirhabdias described from the Afrotropical Realm.


Assuntos
Rhabditoidea/classificação , Serpentes/parasitologia , Animais , DNA Ribossômico/genética , Rhabditoidea/anatomia & histologia , Rhabditoidea/genética , África do Sul , Especificidade da Espécie
2.
Ecol Lett ; 24(9): 1955-1965, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34176205

RESUMO

Amphibian skin secretions (substances produced by the amphibian plus microbiota) plausibly act as a first line of defense against parasite/pathogen attack, but may also provide chemical cues for pathogens. To clarify the role of skin secretions in host-parasite interactions, we conducted experiments using cane toads (Rhinella marina) and their lungworms (Rhabdias pseudosphaerocephala) from the range-core and invasion-front of the introduced anurans' range in Australia. Depending on the geographical area, toad skin secretions can reduce the longevity and infection success of parasite larvae, or attract lungworm larvae and enhance their infection success. These striking differences between the two regions were due both to differential responses of the larvae, and differential effects of the skin secretions. Our data suggest that skin secretions play an important role in host-parasite interactions in anurans, and that the arms race between a host and parasite can rapidly generate spatial variation in critical features of that interaction.


Assuntos
Parasitos , Infecções por Rhabditida , Rhabditoidea , Animais , Bufo marinus , Sinais (Psicologia)
3.
Comput Biol Chem ; 92: 107464, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33667976

RESUMO

Parasitic nematodes constitute one of the major threats to human health, causing diseases of major socioeconomic importance worldwide. Recent estimates indicate that more than 1 billion people are infected with parasitic nematodes around the world. Current measures to combat parasitic nematode infections include anthelmintic drugs. However, heavy exposure to anthelmintics has selected populations of livestock parasitic nematodes that are no longer susceptible to the drugs, rendering several anthelmintics useless for parasitic nematode control in many areas of the world. The rapidity with which anthelmintic resistance developed in response to these drugs suggests that increasing the selective pressure on human parasitic nematodes will also rapidly generate resistant worm populations. Therefore, development of new anthelmintics is of major importance before resistance becomes widespread in human parasitic nematode populations. G-Protein Coupled Receptors (GPCRs) represent an important target for many pharmacological interventions due to their ubiquitous expression in various cell types. GPCRs contribute to numerous physiological processes, and their ligand binding sites located on cell surfaces make them accessible targets and attractive substrates in terms of druggability. In fact, ∼35 % of Food and Drug Administration (FDA) and European Medicines Agency (EMA) approved drugs target GPCRs and their associated proteins, with over 300 additional drugs targeting GPCRs at the clinical trial stage. Nematode Chemosensory GPCRs (NemChRs) are unique to nematodes, and therefore represent ideal substrates for target-based drug discovery. Here we set out to identify NemChRs that are transcriptionally active inside the host, and to use these NemChRs in a reverse pharmacological screen to impede parasitic development. Our data identified several NemChRs, and we focused on one that was expressed in neuronal cells and exhibited the highest fold change in transcription after host activation. Next, we performed homology modelling and molecular dynamics simulations of this NemChR in order to conduct a virtual screening campaign to identify candidate drug targets which were ranked and selected for experimental testing in bioassays. Taken together, our results identify and characterize a candidate NemChR drug target, and provide a chemogenomic pipeline for identifying nematicide substrates.


Assuntos
Anti-Helmínticos/farmacologia , Rhabditoidea/efeitos dos fármacos , Animais , Anti-Helmínticos/síntese química , Anti-Helmínticos/química , Avaliação Pré-Clínica de Medicamentos , Simulação de Dinâmica Molecular , Testes de Sensibilidade Parasitária
4.
Zootaxa ; 4926(3): zootaxa.4926.3.5, 2021 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-33756741

RESUMO

Several soil samples from different habitats in Badakhshan province of Afghanistan were collected to isolate and characterize bacteria feeding nematodes. The Galleria mellonella-baiting method was used for the isolation of the Afghan insect-associated nematodes. The nematodes were studied using morphological and morphometric data. The Oscheius specimen was characterized by a longer body (630-820 µm) and shorter pharynx (125-145 µm), whereas other morphological characters were not unusual. The Diploscapter specimen had an annulated cuticle, with lip region width 1.5 times shorter than the stoma, and had separated pharyngeal corpus from the isthmus and vulva located in the middle of the body. The molecular data were derived using three loci; 18S, 28S (D2/D3 segment), and ITS rRNA region, which were utilized to measure the genetic distance. The phylogenetic analysis was conducted to reconstruct the relationship tree. Both morphological and molecular approaches confirmed the identity of nematode isolates as Oscheius tipulae and Diploscapter coronatus. This is the first report of insect-associated nematodes from the soil of Afghanistan. Both species were capable of infecting and killing G. mellonella larvae in less than 96 h.


Assuntos
Nematoides , Rhabditoidea , Afeganistão , Animais , Feminino , Insetos , Nematoides/genética , Filogenia , Rhabditoidea/genética
5.
J Helminthol ; 95: e10, 2021 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-33622419

RESUMO

The gastropod parasitic nematode Phasmarhabditis hermaphrodita has been formulated into a successful biological control agent (Nemaslug®, strain DMG0001) used to kill slugs on farms and gardens. When applied to soil, P. hermaphrodita uses slug mucus and faeces to find potential hosts. However, there is little information on what cues other species of Phasmarhabditis (P. neopapillosa and P. californica) use to find hosts and whether there is natural variation in their ability to chemotax to host cues. Therefore, using chemotaxis assays, we exposed nine wild isolates of P. hermaphrodita, five isolates of P. neopapillosa and three isolates of P. californica to mucus from the pestiferous slug host Deroceras invadens, as well as 1% and 5% hyaluronic acid - a component of slug mucus that is highly attractive to these nematodes. We found P. hermaphrodita (DMG0010) and P. californica (DMG0018) responded significantly more to D. invadens mucus and 1% hyaluronic acid than other strains. Also, P. hermaphrodita (DMG0007), P. neopapillosa (DMG0015) and P. californica (DMG0017) were superior at locating 5% hyaluronic acid compared to other isolates of the same genera. Ultimately, there is natural variation in chemoattraction in Phasmarhabditis nematodes, with some strains responding significantly better to host cues than others.


Assuntos
Gastrópodes , Comportamento de Busca por Hospedeiro , Rhabditoidea , Animais , Sinais (Psicologia) , Gastrópodes/parasitologia , Rhabditoidea/fisiologia
6.
J Helminthol ; 94: e209, 2020 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-33138887

RESUMO

Rhabdias pocoto n. sp. is herein described from the lungs of the swamp frog Pseudopaludicola pocoto Magalhães, Loebmann, Nogueira, Kokubum, Baptista, Haddad & Garda, 2014, from the Caatinga biome in the state of Ceará, in north-eastern Brazil. The new species is characterized by a body that dilates posteriorly, six small lips (protuberances) and two rounded lateral expansions of cuticular inflation on the anterior end, each containing an amorphous gland-like structure inside and a short and conical tail. Additionally, molecular analysis and comparison of the partial mitochondrial cytochrome c oxidase I sequence of R. pocoto n. sp. revealed genetic divergence between the new species and the sequences of Rhabdias spp. previously deposited in GenBank. Phylogenetic analysis grouped the new taxon into the R. pseudosphaerocephala species complex + R. glaurungi clade. The new discovery represents the 19th species of Rhabdias spp. described in the Neotropical region, the ninth in Brazil and the first species of Rhabdias found parasitizing South American frogs of the genus Pseudopaludicola, as well as the first Caatinga biome species of Rhabdias.


Assuntos
Anuros/parasitologia , Infecções por Rhabditida/parasitologia , Rhabditoidea , Animais , Brasil , Complexo IV da Cadeia de Transporte de Elétrons/genética , Genes de Helmintos , Pulmão/parasitologia , Filogenia , Rhabditoidea/classificação , Rhabditoidea/genética , Rhabditoidea/isolamento & purificação , Rhabditoidea/parasitologia , América do Sul
7.
PLoS One ; 15(11): e0241413, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33166297

RESUMO

A new nematode species of the genus Phasmarhabditis was isolated from the body surface of a slug (Philomycus bilineatus Benson, PB). Morphological and molecular analyses confirmed this nematode as a new species. The nematode was named Phasmarhabditis zhejiangensis sp. nov. (Nematoda: Rhabditidae) and is dioecious. In males, the open bursa with genital papillae is characterized by the formula 1-1-1-2-1-3, and the spicule length is 58µm. In female, the vulva is located approximately in the middle of the body. The nematode belongs to papillosa group because of its tail shape pointed with filiform tip. The phasmids are rod-shaped. The posterior anus is slightly swollen. P. zhejiangensis was further characterized by internal transcribed spacer (ITS), 18S rDNA and 28S rDNA sequences. After the sequencing results were compared with sequences available from the National Center for Biotechnology Information (NCBI), the maximum similarities of ITS, 18S and 28S sequences were 89.81%, 96.22% and 95.28%, respectively. Phylogenetic analyses placed Phasmarhabditis zhejiangensis sp. nov. in the genus Phasmarhabditis.


Assuntos
Rhabditoidea/fisiologia , Animais , China , Feminino , Gastrópodes/parasitologia , Masculino , Rhabditoidea/anatomia & histologia , Rhabditoidea/ultraestrutura
8.
Zootaxa ; 4763(2): zootaxa.4763.2.2, 2020 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-33056864

RESUMO

Two new species, Prodontorhabditis robustus sp. n. and P. grandistoma sp. n. are described and illustrated from rotting banana rhizome and decaying organic matter respectively. P. robustus sp. n. is characterized by thin and slender females with L= 490-625 µm; a= 25.8-34.7; b= 4.9-6.4; c= 2.4-3.7, an arched cheilostom with curved walls bearing basal dorsal and subventral denticles at the same level, males with 20-23 µm long, robust spicules with prominent dorsal velum and lateral spurs at its bifurcated distal tip and gubernaculum with attenuated proximal end. P. grandistoma sp. n. is characterized by plump females with L= 440-552 µm; a= 23.9-25.5; b= 4.4-5.7; c= 2.9-4.2, a long, narrow stoma of length 6-7 times diameter; the cheilostom straight but, wider anteriorly with a basal dorsal denticle and anterior subventral denticles, rectum with dilated lumen, males with 17-20 µm long, relatively slender spicules and a terminally indented bursa. This is the first report of Prodontorhabditis species from India. An updated list of species, a key to their identification and a compendium of their morphometrics and diagnostic features is presented.


Assuntos
Nematoides , Rhabditoidea , Animais , Índia , Masculino
9.
BMC Evol Biol ; 20(1): 105, 2020 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-32811433

RESUMO

BACKGROUND: Pseudogamy is a reproductive system in which females rely on the sperm of males to activate their oocytes, generally parasitizing males of other species, but do not use the sperm DNA. The nematode Mesorhabditis belari uses a specific form of pseudogamy, where females produce their own males as a source of sperm. Males develop from rare eggs with true fertilization, while females arise by gynogenesis. Males thus do not contribute their genome to the female offspring. Here, we explored the diversity of reproductive mode within the Mesorhabditis genus and addressed species barriers in pseudogamous species. RESULTS: To this end, we established a collection of over 60 Mesorhabditis strains from soil and rotting vegetal matter. We found that males from pseudogamous species displayed a reduced size of their body, male tail and sperm cells compared to males of sexual Mesorhabditis species, as expected for males that face little competition. Using rDNA sequences and crosses, we could define 11 auto-pseudogamous biological species, with closely related species pairs and a possible single origin of pseudogamy in the Mesorhabditis genus. Most crosses between males and females of different species did not even produce female progeny. This surprising species barrier in pseudogamous egg activation was pre or postcopulatory depending on the species pair. In the latter case, when hybrid embryos were produced, most arrested before the first embryonic cell division. Hybrid incompatibility between auto-pseudogamous species was due to defective interaction between sperm and oocyte as well as defective reconstitution of zygotic centrosomes. CONCLUSIONS: We established a collection of sexual and pseudo-sexual species which offer an ideal framework to explore the origin and consequences of transition to asexuality. Our results demonstrate that speciation occurs in the pseudogamous state. Whereas genomic conflicts are responsible for hybrid incompatibility in sexual species, we here reveal that centrosomes constitute key organelles in the establishment of species barrier.


Assuntos
Fertilidade , Fertilização , Hibridização Genética , Rhabditoidea/genética , Rhabditoidea/fisiologia , Animais , DNA Ribossômico/genética , Feminino , Masculino , Reprodução , Especificidade da Espécie , Espermatozoides
10.
Sci Rep ; 10(1): 12312, 2020 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-32704134

RESUMO

Insect pathogens have adopted an array of mechanisms to subvert the immune pathways of their respective hosts. Suppression may occur directly at the level of host-pathogen interactions, for instance phagocytic capacity or phenoloxidase activation, or at the upstream signaling pathways that regulate these immune effectors. Insect pathogens of the family Baculoviridae, for example, are known to produce a UDP-glycosyltransferase (UGT) that negatively regulates ecdysone signaling. Normally, ecdysone positively regulates both molting and antimicrobial peptide production, so the inactivation of ecdysone by glycosylation results in a failure of host larvae to molt, and probably a reduced antimicrobial response. Here, we examine a putative ecdysteroid glycosyltransferase, Hba_07292 (Hb-ugt-1), which was previously identified in the hemolymph-activated transcriptome of the entomopathogenic nematode Heterorhabditis bacteriophora. Injection of recombinant Hb-ugt-1 (rHb-ugt-1) into Drosophila melanogaster flies resulted in diminished upregulation of antimicrobial peptides associated with both the Toll and Immune deficiency pathways. Ecdysone was implicated in this suppression by a reduction in Broad Complex expression and reduced pupation rates in r Hb-ugt-1-injected larvae. In addition to the finding that H. bacteriophora excreted-secreted products contain glycosyltransferase activity, these results demonstrate that Hb-ugt-1 is an immunosuppressive factor and that its activity likely involves the inactivation of ecdysone.


Assuntos
Peptídeos Catiônicos Antimicrobianos/genética , Drosophila melanogaster/genética , Drosophila melanogaster/parasitologia , Ecdisona/metabolismo , Regulação da Expressão Gênica , Glicosiltransferases/metabolismo , Rhabditoidea/enzimologia , Transdução de Sinais , Sequência de Aminoácidos , Animais , Peptídeos Catiônicos Antimicrobianos/metabolismo , Ecdisterona/metabolismo , Glicosilação , Glicosiltransferases/química , Larva/genética , Domínios Proteicos , Pupa/genética , Proteínas Recombinantes/metabolismo , Simbiose , Fatores de Transcrição/metabolismo , Regulação para Cima/genética , Uridina Difosfato Glucose/metabolismo
11.
J Invertebr Pathol ; 174: 107435, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32561403

RESUMO

Many terrestrial gastropods are pestiferous and pose a significant threat to agriculture, horticulture and floriculture. They are usually controlled by metaldehyde based pellets but an alternative control method is the slug parasitic nematode Phasmarhabditis hermaphrodita, which has been formulated into a biological control agent (Nemaslug®) for use by farmers and gardeners to kill certain pestiferous slug species in 4-21 days. The current strain of P. hermaphrodita (called DMG0001) has been used in commercial production since 1994, but there is little information about the pathogenicity of wild strains of P. hermaphrodita towards slugs. Here, we exposed the pestiferous slug Deroceras invadens to nine wild isolated strains of P. hermaphrodita (DMG0002, DMG0003, DMG0005, DMG0006, DMG0007, DMG0008, DMG0009, DMG0010 and DMG0011) and the commercial strain (DMG0001) to three doses (0, 500 and 1000 nematodes per ml). Survival and feeding were recorded over 14 days. All wild P. hermaphrodita strains (other than DMG0010) and P. hermaphrodita (DMG0001), applied at 500 nematodes per ml, caused significant mortality to D. invadens compared to an uninfected control. Similarly, all P. hermaphrodita strains applied at 1000 nematodes per ml, caused significant mortality to D. invadens compared to an uninfected control. Overall, all wild P. hermaphrodita strains (other than DMG0011) caused significantly more mortality than P. hermaphrodita DMG0001 at one or both nematode concentrations. In summary, we have found some wild P. hermaphrodita strains were more virulent than P. hermaphrodita (DMG0001). Ultimately, these strains could potentially be developed as alternative, efficient biological control agents for use against slugs.


Assuntos
Gastrópodes/parasitologia , Controle Biológico de Vetores , Rhabditoidea/patogenicidade , Animais , Inglaterra , Virulência
12.
Molecules ; 25(12)2020 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-32560032

RESUMO

Parasitic infections caused by different species of intestinal helminths still poses a threat to public health. There is a need to search for new, effective anthelmintic drugs. A series of novel thiosemicarbazides were synthesized and evaluated for their in vitro anthelmintic activity. The preliminary results showed that the most of synthesized compounds were very active. 4-Phenyl-1-[(1-methyl-4-nitroimidazol-2-yl)carbonyl]thiosemicarbazide and 4-(3-chlorophenyl)-1-[(1-methyl-4-nitroimidazol-2-yl)carbonyl]thiosemicarbazide showed a 100% mortality of nematodes and a high anthelmintic activity in both tested concentrations.


Assuntos
Antinematódeos , Rhabditoidea/crescimento & desenvolvimento , Semicarbazidas , Animais , Antinematódeos/síntese química , Antinematódeos/química , Antinematódeos/farmacologia , Estrutura Molecular , Semicarbazidas/síntese química , Semicarbazidas/química , Semicarbazidas/farmacologia
13.
Microbiology (Reading) ; 166(4): 335-348, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32209172

RESUMO

Different model systems have, over the years, contributed to our current understanding of the molecular mechanisms underpinning the various types of interaction between bacteria and their animal hosts. The genus Photorhabdus comprises Gram-negative insect pathogenic bacteria that are normally found as symbionts that colonize the gut of the infective juvenile stage of soil-dwelling nematodes from the family Heterorhabditis. The nematodes infect susceptible insects and release the bacteria into the insect haemolymph where the bacteria grow, resulting in the death of the insect. At this stage the nematodes feed on the bacterial biomass and, following several rounds of reproduction, the nematodes develop into infective juveniles that leave the insect cadaver in search of new hosts. Therefore Photorhabdus has three distinct and obligate roles to play during this life-cycle: (1) Photorhabdus must kill the insect host; (2) Photorhabdus must be capable of supporting nematode growth and development; and (3) Photorhabdus must be able to colonize the gut of the next generation of infective juveniles before they leave the insect cadaver. In this review I will discuss how genetic analysis has identified key genes involved in mediating, and regulating, the interaction between Photorhabdus and each of its invertebrate hosts. These studies have resulted in the characterization of several new families of toxins and a novel inter-kingdom signalling molecule and have also uncovered an important role for phase variation in the regulation of these different roles.


Assuntos
Insetos/microbiologia , Photorhabdus/fisiologia , Photorhabdus/patogenicidade , Rhabditoidea/microbiologia , Animais , Toxinas Bacterianas/genética , Toxinas Bacterianas/metabolismo , Trato Gastrointestinal/microbiologia , Interações entre Hospedeiro e Microrganismos , Insetos/parasitologia , Estágios do Ciclo de Vida , Rhabditoidea/crescimento & desenvolvimento , Rhabditoidea/patogenicidade , Rhabditoidea/fisiologia , Transdução de Sinais , Simbiose
14.
Exp Parasitol ; 208: 107802, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31730782

RESUMO

In insects, diet plays an important role in growth and development. Insects can vary their diet composition based on their physiological needs. In this study we tested the influence of diet composition involving varying concentrations of macronutrients and zinc on the immune-tolerance following parasite and pathogen exposure in Spodoptera litura larvae. We also tested the insecticidal potential of Mesorhabditis belari, Enterobacter hormaechei and its secondary metabolites on Spodoptera litura larvae. The results shows macronutrient composition does not directly affect the larval tolerance to nematode infection. However, Zinc supplemented diet improved the immune tolerance. While larvae exposed to bacterial infection performed better on carbohydrate rich diet. Secondary metabolites from bacteria produced an immune response in dose dependent mortality. The study shows that the larvae maintained on different diet composition show varied immune tolerance which is based on the type of infection.


Assuntos
Enterobacter/fisiologia , Controle Biológico de Vetores , Rhabditoidea/fisiologia , Spodoptera/imunologia , Análise de Variância , Animais , Bioensaio , Carboidratos/administração & dosagem , Cromatografia Líquida de Alta Pressão , Dieta , Enterobacter/imunologia , Enterobacter/patogenicidade , Cromatografia Gasosa-Espectrometria de Massas , Tolerância Imunológica , Larva/imunologia , Dose Letal Mediana , Proteínas/administração & dosagem , Rhabditoidea/imunologia , Rhabditoidea/patogenicidade , Espectroscopia de Infravermelho com Transformada de Fourier , Spodoptera/fisiologia , Simbiose , Virulência , Zinco/administração & dosagem
15.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 31(5): 565-566, 2019 May 08.
Artigo em Chinês | MEDLINE | ID: mdl-31713397

RESUMO

Rhabditis axei is a free-living nematode, which can occasionally invade into humans through drinking and contacting wastewater. It is usually parasitic in the digestive and urinary systems, causing the disease of rhabditelliasis axei. This paper reports a case of R. axei infection found in the urine routine examination.


Assuntos
Infecções por Rhabditida , Rhabditoidea , Animais , Humanos , Infecções por Rhabditida/urina
16.
Zootaxa ; 4652(1): zootaxa.4652.1.8, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31716888

RESUMO

A new species of the genus Metarhabditis, M. giennensis sp. n., collected from a riverbank poplar forest in the southern Iberian Peninsula, is described and illustrated, including SEM observations. The new species is characterized by its 1.01-1.16 mm long body in females and 0.77-0.98 in males, cuticle with very fine transverse striation, lip region 9-14 µm broad and consisting of six swollen rounded lips fused in pairs, stoma 14-25 µm long with tubular gymno-promesostegostom, pharynx with slightly swollen metacorpus and slender isthmus, nerve ring, excretory pore and deirids located at isthmus level, female reproductive system didelphic-amphidelphic, vulva equatorial (V = 49-50), female rectum length 1.2-1.7 times the anal body width, female tail conical-elongate with acute tip (123-199 µm, c = 5.8-8.2, c' = 8.2-11.1), male tail conical (34-56 µm, c = 15.5-25.7, c' = 2.4-3.5), bursa leptoderan, 32-41 µm long spicules with rounded and ventrally bent manubrium, and 17-20 µm long gubernaculum. An updated list of species of the genus and a key for their identification are also provided. [Zoobank URL: urn:lsid:zoobank.org:act:7EBAC9DB-A148-4A1A-97E5-3B796D0839BF].


Assuntos
Nematoides , Rabditídios , Rhabditoidea , Animais , Europa (Continente) , Feminino , Florestas , Masculino , Madeira
17.
Vet Parasitol ; 275: 108924, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31630049

RESUMO

Rhabditis spp., is a nematode known to cause otitis externa, an infection difficult to control, in cattle reared within tropical regions. The objective of this study was to assess the combined use of ivermectin 1%, dimethyl sulfoxide 1% and mineral oil 100% containing nematophagous fungi of both Duddingtonia flagrans (AC001) and Monacrosporium thaumasium (NF34) species to control in vitro Rhabditis spp. Thus, 12 experimental groups were designed with eight replicates each: G1 (nematodes + AC001); G2 (nematodes + NF34); G3 (nematodes + ivermectin 1%/positive control); G4 (nematodes + dimethyl sulfoxide 1%/positive control); G5 (nematodes + mineral oil 100%/positive control); G6 (nematodes + AC001 + ivermectin 1%); G7 (nematodes + NF34 + ivermectin 1%); G8 (nematodes + AC001 + mineral oil 100%); G9 (nematodes + NF34 + mineral oil 100%); G10 (nematodes + AC001 + dimethyl sulfoxide 1%); G11 (nematode + NF34 + dimethyl sulfoxide 1%); G12 (nematode + distilled water/negative control). The results demonstrated that all experimentally treated groups differed statistically (p < 0.01) from the control group. In the present study, the use of dimethyl sulfoxide 1% and mineral oil 100% in conjunction with conidia fungi portrayed noteworthy outcomes, which represents a future premise for the combined use of nematophagous fungi within these vehicles in both controlling Rhabditis spp.


Assuntos
Antiparasitários/farmacologia , Dimetil Sulfóxido/farmacologia , Ivermectina/farmacologia , Óleo Mineral/farmacologia , Infecções por Rhabditida/veterinária , Rhabditoidea/efeitos dos fármacos , Animais , Antiparasitários/uso terapêutico , Ascomicetos/fisiologia , Bovinos , Doenças dos Bovinos/tratamento farmacológico , Doenças dos Bovinos/parasitologia , Doenças dos Bovinos/prevenção & controle , Indústria de Laticínios , Dimetil Sulfóxido/uso terapêutico , Duddingtonia/fisiologia , Feminino , Ivermectina/uso terapêutico , Masculino , Óleo Mineral/uso terapêutico , Fungos Mitospóricos/fisiologia , Otite Externa/tratamento farmacológico , Otite Externa/parasitologia , Otite Externa/prevenção & controle , Otite Externa/veterinária , Infecções por Rhabditida/tratamento farmacológico , Infecções por Rhabditida/microbiologia , Infecções por Rhabditida/prevenção & controle , Rhabditoidea/microbiologia
18.
J Helminthol ; 94: e54, 2019 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-31630693

RESUMO

The genus Rhabdias Stiles & Hassal, 1905 includes about 83 species of nematodes parasitic in amphibians and reptiles worldwide. Herein, we describe Rhabdias glaurungi sp. nov. from the hylid frog Scinax gr. ruber (Laurenti, 1768) in the Gunma Ecological Park, Santa Bárbara municipality, state of Pará, Brazil. This species has six small lips, an inflated cuticle along the entire body and a cup-shaped buccal capsule with smooth internal surface of its anterior part and irregularly folded internal surface of its posterior part in apical view. From the 17 valid species recognized in the Neotropical realm, the new species can be distinguished by the number of lips, the morphology and size of its buccal capsule, as well as the extent and shape of its cuticular inflation; in addition, there are molecular differences. Sequences of the mitochondrial Cytochrome c Oxidase subunit I gene strongly support the status of this form as a separate species. Molecular phylogenetic analysis shows R. glaurungi sp. nov. nested within the R. pseudosphaerocephala Kuzmin, Tkach & Brooks, 2007 species complex. Rhabdias glaurungi sp. nov. is the second species of the genus described from hosts of the family Hylidae in the Neotropical realm. We conclude that the diversity of Rhabdias within the Neotropics is likely largely underestimated.


Assuntos
Anuros/parasitologia , Filogenia , Infecções por Rhabditida/parasitologia , Rhabditoidea/anatomia & histologia , Rhabditoidea/classificação , Animais , Brasil , Complexo IV da Cadeia de Transporte de Elétrons/genética , Genes Mitocondriais , Especificidade da Espécie
19.
BMC Infect Dis ; 19(1): 776, 2019 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-31488073

RESUMO

BACKGROUND: Due to the similarity of Strongyloides stercoralis with free-living nematodes of Rhabditis species they might be miss-diagnosed with each other in microscopical examination of stool samples. The aim of this study was molecular characterization and differentiation of human derived isolates of S. stercoralis and Rhabditis species based on the mitochondrial gene of cytochrome c oxidase subunit 1 (cox1) amplification. METHODS: Using parasitological methods, ten isolates of S. stercoralis and three isolates of Rhabditis spp. were obtained from fresh stool samples of patients and the genomic DNA of the samples were extracted. PCR amplification of cox1 gene was carried out for all the isolates and the products were sequenced. RESULTS: The phylogenetic analysis illustrated that S. stercoralis and Rhabditis spp. isolates were placed in two distinguishable separate clades. Inter-species genetic variation between isolates of S. stercoralis and Rhabditis spp. were ranged from 13.5 to 14.5%. CONCLUSIONS: Cox1 gene was a suitable marker for discrimination of S. stercoralis from Rhabditis spp. retrieved from human in the current study. The availability of gene sequence information will be helpful in the future development and validation of discriminatory PCR-based assays of these nematodes.


Assuntos
Complexo IV da Cadeia de Transporte de Elétrons/genética , Rhabditoidea/genética , Rhabditoidea/isolamento & purificação , Strongyloides stercoralis/genética , Strongyloides stercoralis/isolamento & purificação , Animais , DNA Mitocondrial/análise , DNA Mitocondrial/genética , Fezes/parasitologia , Variação Genética , Humanos , Irã (Geográfico) , Tipagem Molecular/métodos , Filogenia , Reação em Cadeia da Polimerase , Subunidades Proteicas/genética , Infecções por Rhabditida/diagnóstico , Infecções por Rhabditida/parasitologia , Estrongiloidíase/diagnóstico , Estrongiloidíase/parasitologia
20.
J Invertebr Pathol ; 167: 107247, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31521727

RESUMO

Xenorhabdus spp., entomopathogenic bacteria symbiotically associated with the nematodes of the Steinernematid family, are known to produce several toxic proteins that interfere with the cellular immune responses of insects. In order to identify novel cytotoxins from Xenorhabdus spp., a fosmid library of X. stockiae HN_xs01 strain was constructed and the cytotoxicity of fosmid clones was tested against insect midgut CF-203 cells. An FS2 clone bearing the srfABC operon, originally identified in Salmonella enterica, exhibited excellent cytotoxicity against CF-203 cells. The srfABC operon alone exhibited cytotoxic effects and all three components of SrfABC toxin were essential for full cytotoxicity. Immunofluorescence studies showed that SrfABC toxin could depolymerize microtubules and disrupt mitochrondria. Flow cytometer analysis demonstrated that SrfABC toxin significantly induced G2/M phase arrest and apoptosis in CF-203 cells. Furthermore, SrfABC toxin exhibits highly injectable insecticidal activity against Helicoverpa armigera larvae. As is often found in host-associated microorganisms, SrfABC toxin is thought to play an important role in host colonization.


Assuntos
Toxinas Bacterianas/farmacologia , Mariposas/microbiologia , Rhabditoidea/microbiologia , Xenorhabdus , Animais , Toxinas Bacterianas/genética , Toxinas Bacterianas/toxicidade , Ciclo Celular/efeitos dos fármacos , Linhagem Celular , Genoma Bacteriano , Biblioteca Genômica , Insetos/efeitos dos fármacos , Insetos/microbiologia , Insetos/parasitologia , Inseticidas/farmacologia , Mariposas/efeitos dos fármacos , Mariposas/parasitologia , Controle Biológico de Vetores , Xenorhabdus/genética , Xenorhabdus/metabolismo , Xenorhabdus/patogenicidade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...