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1.
Vet Parasitol ; 299: 109583, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34583143

RESUMO

Cercopithifilaria bainae is a filarioid nematode of dogs shown to use Rhipicephalus sanguineus sensu lato (s.l.), the brown dog tick, as the vector. Previously in the United States, C. bainae infections have been reported in a dog from Florida, and in dogs and ticks in Oklahoma, but data are lacking from other areas of the country. Here, we tested brown dog ticks from across the United States for C. bainae DNA to assess the geographic distribution of where this novel parasite may be cycling in ticks and dogs. Archival brown dog ticks were available for testing through the national tick survey Show Us Your Ticks. Ticks were morphologically identified, dissected, and tested by PCR to detect filarioid mitochondrial DNA. A total of 1400 brown dog ticks were tested from 321 separate animals from 23 states, with 5.7 % (80/1400) of the ticks testing positive for C. bainae DNA. At least one positive tick was detected in submissions from 9 states in addition to Florida and Oklahoma. Cercopithifilaria bainae DNA was detected in larval, nymphal, and adult stages of brown dog ticks and only in ticks removed from dogs. Of all dogs with brown dog ticks collected from them, 17.6 % (55/312) were infested with at least one tick that harbored C. bainae DNA. Findings from this study demonstrate a wider geographic range of C. bainae than previously known, and that dogs are commonly infested with brown dog ticks with molecular evidence of C. bainae infection.


Assuntos
Doenças do Cão , Filarioidea , Rhipicephalus sanguineus , Animais , Doenças do Cão/diagnóstico , Doenças do Cão/epidemiologia , Cães , Larva , Ninfa , Estados Unidos/epidemiologia
2.
J Parasitol ; 107(2): 320-335, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33902110

RESUMO

The genus Litomosoides Chandler, 1931, includes species that as adults occur in the thoracic and abdominal cavity of mammalian hosts and are presumably vectored by mites. The vertebrate hosts include a variety of Neotropical mammals such as phyllostomid and mormoopid bats; cricetid, sciurid, and hystricognath rodents; and didelphid marsupials. It has been suggested that Litomosoides is not a monophyletic group and that rampant horizontal transfer explains their presence in disparate groups of mammals. Herein we present a phylogenetic reconstruction including mitochondrial genes of 13 vouchered species. This phylogeny is used to reconstruct the evolutionary history of these parasites and the ancestral states of key characters used in species classification, namely, the configuration of the spicules. The historical association of these filarioids with 6 groups of mammals, as well as their ancestral geographic distributions, were reconstructed using Bayesian statistical approaches comparing alternative models of biogeography and evolution and fossil states in selected nodes of the phylogeny. The optimal reconstruction suggests a model of dispersal, extinction, and cladogenesis (DEC) driving the evolution of Litomosoides; the results suggest an origin of Litomosoides in South America and association of ancestors with phyllostomids, and strong evidence of at least 2 host-switching events: 1 of these involving cricetid rodents and the other mormoopid bats. The latter event included a simultaneous geographic expansion of the parasite lineage across South and North America. The host-switching event from phyllostomid bats into cricetid rodents occurred once these rodents diversified across South America; subsequent diversification of the latter clade resulted in 2 branches, each showing expansion of the parasites back into North America. This result suggests that both parasites and cricetid rodents established an association in South America, underwent diversification, and then dispersed into North America. Further, this clade of cricetid-dwelling species includes parasites featuring the "sigmodontis" spicule type. The identification of a single host-switching event involving the disparate lineages of Chiroptera and Rodentia offers a framework to reconstruct the gene evolution and diversification of this lineage after the host-switching event. This will help in predicting the ability of these parasites to infect sympatric mammals.


Assuntos
Arvicolinae/parasitologia , Quirópteros/parasitologia , Filariose/veterinária , Filarioidea/fisiologia , Doenças dos Roedores/parasitologia , Animais , Teorema de Bayes , Filariose/parasitologia , Filariose/transmissão , Filarioidea/anatomia & histologia , Filarioidea/classificação , Genes de Helmintos , Genes Mitocondriais , Marcadores Genéticos , Interações Hospedeiro-Parasita , Funções Verossimilhança , Filogenia , Doenças dos Roedores/transmissão
3.
Parasit Vectors ; 14(1): 199, 2021 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-33849643

RESUMO

BACKGROUND: Onchocerca lupi and Cercopithifilaria spp. are vector-borne filarioids of dogs, which harbour skin microfilariae (mfs), the former being of zoonotic concern. Proper treatment studies using compounds with microfilaricidal activity have not been performed. Therefore, this study aimed to assess the efficacy of a commercially available spot-on formulation containing moxidectin 2.5%/imidacloprid 10% for the treatment of O. lupi or Cercopithifilaria spp. skin-dwelling mfs in naturally infected dogs. METHODS: Privately owned dogs (n = 393) from southern Portugal were sampled via skin biopsies to identify and count mfs in 20 µl of skin sediment. A total of 22 mfs-positive dogs were allocated to treatment group (n = 11; G1) or left untreated as a control (n = 11; G2). As a pilot investigation to test the treatment efficacy, five dogs assigned to G1 were treated four times at monthly intervals with moxidectin 2.5%/imidacloprid 10% spot-on formulation on SDs 0, 28 (± 2), 56 (± 2), and 84 (± 2). Based on the negative results for both O. lupi and/or Cercopithifilaria spp. mfs of dogs in the pilot study from SD28 onwards, the remaining six dogs in G1 were treated at SD0 and assessed only at SD28. RESULTS: Of the 393 animals sampled, 78 (19.8%) scored positive for skin-dwelling mfs. At the pilot investigation, a mean number of 19.6 mfs for O. lupi was recorded among five infected dogs whereas no mfs were detected at SD28. At SD0, the mean number of Cercopithifilaria spp. larvae was 12.6 for G1 and 8.7 for G2. The mean number of mfs for G2 was 20.09. CONCLUSIONS: Results herein obtained suggest that a single treatment with moxidectin 2.5%/imidacloprid 10% spot-on formulation is efficacious against skin-dwelling mfs in dogs. The microfilaricidal effect of moxidectin could also be useful in reducing the risk of O. lupi infection for humans.


Assuntos
Anti-Helmínticos/farmacologia , Doenças do Cão/tratamento farmacológico , Filariose/veterinária , Filarioidea/efeitos dos fármacos , Macrolídeos/farmacologia , Neonicotinoides/farmacologia , Nitrocompostos/farmacologia , Onchocerca/efeitos dos fármacos , Oncocercose/veterinária , Animais , Anti-Helmínticos/química , Doenças do Cão/parasitologia , Cães , Composição de Medicamentos , Feminino , Filariose/tratamento farmacológico , Filariose/parasitologia , Filarioidea/crescimento & desenvolvimento , Macrolídeos/química , Masculino , Neonicotinoides/química , Nitrocompostos/química , Onchocerca/crescimento & desenvolvimento , Oncocercose/tratamento farmacológico , Oncocercose/parasitologia , Projetos Piloto , Portugal , Resultado do Tratamento
4.
Parasit Vectors ; 14(1): 137, 2021 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-33673865

RESUMO

BACKGROUND: Blood parasites have been the subject of much research, with numerous reports of the presence of microfilariae in the peripheral blood (circulating microfilariae) of birds belonging to many orders. Current limitations in molecular characterization methods and species identification using morphological characters of circulating microfilariae are major obstacles to improving our understanding the biology of Filarioidea species, particularly in wildlife. The aim of this study was to partially fill these gaps, with particular emphasis on morphological features of microfilariae, which are the most readily accessible stages of these pathogens. METHODS: Peripheral blood samples of 206 birds belonging to genera Acrocephalus (five species) and Sylvia (five species) were examined using the buffy coat method to process the blood samples for the presence of microfilariae. Positive birds were dissected to collect adult nematodes. Microfilariae and adult nematodes were described, and sequences of their mitochondrial cytochrome c oxidase subunit I and nuclear 28S rDNA gene fragments were obtained and used for molecular characterization and Bayesian phylogenetic inferences. RESULTS: Overall prevalence of microfilariae was 2.9%. Microfilariae were found in the blood samples from six birds (2 Acrocephalus scirpaceus and 1 each of A. arundinaceus, Sylvia atricapilla, S. borin and S. curruca), which were dissected. All parasite species observed were new. Eufilaria acrocephalusi sp. n. and Eufilaria sylviae sp. n. were present in subcutaneous, peritracheal and periesophageal connective tissues in A. scirpaceus and S. borin, respectively. Splendidofilaria bartletti sp. n. was found in finger joins of S. atricapilla. Illustrations of microfilariae and adult nematodes are shown, and morphological and phylogenetic analyses identified the DNA barcode haplotypes that are associated with these species. Phylogenetic analysis places the parasites of different genera in different closely related clades. CONCLUSIONS: Adult nematode morphological characters, which have been traditionally used in the taxonomy of Filarioidea species, have a phylogenetic value. Importantly, in our study parasites of different genera were readily distinguishable based on the morphology of their microfilariae. The link between molecular and morphology data requires more study in Filarioidea species research, particularly because this approach provides new knowledge on species identity using only readily accessible blood stages (microfilariae), thereby avoiding host dissection and thus minimizing harm to wildlife during research.


Assuntos
Aves/parasitologia , Filariose/veterinária , Filarioidea/anatomia & histologia , Filarioidea/genética , Microfilárias/anatomia & histologia , Microfilárias/genética , Filogenia , Animais , Animais Selvagens/parasitologia , Teorema de Bayes , Feminino , Filariose/sangue , Filariose/parasitologia , Filarioidea/classificação , Filarioidea/isolamento & purificação , Masculino , Microfilárias/classificação , Microfilárias/isolamento & purificação , Análise de Sequência de DNA
5.
Parasitol Res ; 120(12): 4125-4143, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33547508

RESUMO

Filariae are vector-borne parasitic nematodes that are endemic worldwide, in tropical and subtropical regions. Important human filariae spp. include Onchocerca volvulus, Wuchereria bancrofti and Brugia spp., and Loa loa and Mansonella spp. causing onchocerciasis (river blindness), lymphatic filariasis (lymphedema and hydrocele), loiasis (eye worm), and mansonelliasis, respectively. It is estimated that over 1 billion individuals live in endemic regions where filarial diseases are a public health concern contributing to significant disability adjusted life years (DALYs). Thus, efforts to control and eliminate filarial diseases were already launched by the WHO in the 1970s, especially against lymphatic filariasis and onchocerciasis, and are mainly based on mass drug administration (MDA) of microfilaricidal drugs (ivermectin, diethylcarbamazine, albendazole) to filarial endemic areas accompanied with vector control strategies with the goal to reduce the transmission. With the United Nations Sustainable Development Goals (SDGs), it was decided to eliminate transmission of onchocerciasis and stop lymphatic filariasis as a public health problem by 2030. It was also requested that novel drugs and treatment strategies be developed. Mouse models provide an important platform for anti-filarial drug research in a preclinical setting. This review presents an overview about the Litomosoides sigmodontis and Acanthocheilonema viteae filarial mouse models and their role in immunological research as well as preclinical studies about novel anti-filarial drugs and treatment strategies.


Assuntos
Acanthocheilonema , Filariose Linfática , Filarioidea , Loíase , Animais , Filariose Linfática/tratamento farmacológico , Filariose Linfática/epidemiologia , Humanos , Loíase/tratamento farmacológico , Loíase/epidemiologia , Masculino , Camundongos , Modelos Animais
6.
Biomed Pharmacother ; 137: 111292, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33581654

RESUMO

Human filarial infections are vector-borne nematode infections, which include lymphatic filariasis, onchocerciasis, loiasis, and mansonella filariasis. With a high prevalence in developing countries, filarial infections are responsible for some of the most debilitating morbidities and a vicious cycle of poverty and disease. Global initiatives set to eradicate these infections include community mass treatments, vector control, provision of care for morbidity, and search for vaccines. However, there are growing challenges associated with mass treatments, vector control, and antifilarial vaccine development. With the emergence of genome editing tools and successful applications in other infectious diseases, the integration of genetic editing techniques in future control strategies for filarial infections would offer the best option for eliminating filarial infections. In this review, we briefly discuss the mechanisms of the three main genetic editing techniques and explore the potential applications of these powerful tools to control filarial infections.


Assuntos
Sistemas CRISPR-Cas , Filariose/terapia , Filarioidea/genética , Edição de Genes , Terapia Genética , Animais , Proteína 9 Associada à CRISPR/genética , Proteína 9 Associada à CRISPR/metabolismo , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Filariose/genética , Filariose/parasitologia , Filaricidas/uso terapêutico , Filarioidea/efeitos dos fármacos , Filarioidea/patogenicidade , Humanos , Vacinas Protozoárias/uso terapêutico
7.
Acta Trop ; 213: 105735, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33159896

RESUMO

Vector-borne diseases in the United States have recently increased as a result of the changing nature of vectors, hosts, reservoirs, parasite/pathogens, and the ecological and environmental conditions. While most focus has been on mosquito-borne pathogens affecting humans, little is known regarding parasites of companion animal, livestock and wildlife and their potential mosquito hosts in the United States. This study assessed the prevalence of mature infections of Dirofilaria immitis and avian malaria parasites (Haemosporida) within urban mosquito (Diptera, Culicidae) communities in Oklahoma. 2,620 pools consisting of 12,686 mosquitoes from 13 species collected over two summers were tested for the presence of filarioid and haemosporidian DNA. Dirofilaria immitis-infected mosquitoes were detected only in Aedes albopictus (MIR=0.18-0.22) and Culex pipiens complex (MIR=0.12) collected in cities in central and southern Oklahoma. Two other filarioid nematode species with 91-92% similarity with Onchocerca spp. and Mansonella spp. were also detected. Haemosporidian DNA was detected in 13 mosquito pools (0.9% of pools tested) from seven mosquito species out of 13 species tested. Plasmodium DNA in four species (Cx. coronator, Cx. pipiens complex, Cx. tarsalis, and Psorophora columbiae) had high homology with published sequences of avian Plasmodium species while DNA in four other species (Cx. nigripalpus, Ps. columbiae, Anopheles quadrimaculatus, and An. punctipennis) were closely related to Plasmodium species from deer. One pool of Cx. tarsalis was positive with a 100% sequence identity of Haemoproteus sacharovi. This study provides a baseline concerning the diversity of parasites in different mosquito species present in the southern Great Plains. These studies provide important information for understanding the factors of transmission involving the mosquito community, potential hosts, and different mosquito-borne parasites in this important region involved in livestock management and wildlife conservation.


Assuntos
Culicidae/parasitologia , Filarioidea/isolamento & purificação , Haemosporida/isolamento & purificação , Mosquitos Vetores/parasitologia , Plasmodium/isolamento & purificação , Aedes/parasitologia , Animais , Anopheles/parasitologia , Aves , Culex/parasitologia , Cervos , Dirofilaria immitis/genética , Dirofilaria immitis/isolamento & purificação , Filarioidea/genética , Haemosporida/genética , Humanos , Malária Aviária/epidemiologia , Malária Aviária/parasitologia , Malária Aviária/transmissão , Oklahoma , Plasmodium/genética
8.
Emerg Infect Dis ; 27(1): 297-300, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33350933

RESUMO

We report a human case of ocular filariasis, caused by a species of Breinlia nematode, from Queensland, Australia. Morphological and molecular evidence indicated that the nematode Breinlia (Johnstonema) annulipapillata, or a closely related taxon, likely transmitted from a macropodid marsupial host was involved, which might represent an accidental finding or an emerging zoonosis.


Assuntos
Filariose , Filarioidea , Animais , Austrália/epidemiologia , Filariose/diagnóstico , Filariose/epidemiologia , Filarioidea/genética , Humanos , Queensland , Zoonoses
9.
J Vet Med Sci ; 83(2): 208-213, 2021 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-33311003

RESUMO

This study aimed to detect filarial parasites in blood samples of Japanese black bears (Ursus thibetanus japonicus) collected from Iwate Prefecture, Japan. Positive amplicons were obtained from 26 out of 30 samples by nested PCR targeting 18S ribosomal RNA gene and first internal transcribed spacer regions. DNA sequences of Mansonella sp. close to M. ozzardi and Dirofilaria sp. were detected for eight and 11 positive amplicons, respectively. Co-infection was detected for the remaining seven amplicons. Dirofilaria sp. was identified as D. ursi by further genetic analysis of 5S ribosomal RNA gene sequence. The results of this study will contribute to further investigations of Japanese black bears for monitoring their risk as a reservoir of possible zoonotic filarial parasites.


Assuntos
Filariose/veterinária , Filarioidea/isolamento & purificação , Ursidae/parasitologia , Animais , Feminino , Filariose/diagnóstico , Filariose/epidemiologia , Filariose/parasitologia , Filarioidea/classificação , Filarioidea/genética , Japão/epidemiologia , Masculino , RNA Ribossômico 18S/genética
10.
Results Probl Cell Differ ; 69: 423-451, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33263882

RESUMO

Wolbachia symbionts, first observed in the 1920s, are now known to be present in about 30-70% of tested arthropod species, in about half of tested filarial nematodes (including the majority of human filarial nematodes), and some plant-parasitic nematodes. In arthropods, they are generally viewed as parasites while in nematodes they appear to be mutualists although this demarcation is not absolute. Their presence in arthropods generally leads to reproductive anomalies, while in nematodes, they are generally required for worm development and reproduction. In mosquitos, Wolbachia inhibit RNA viral infections, leading to populational reductions in human RNA virus pathogens, whereas in filarial nematodes, their requirement for worm fertility and survival has been channeled into their use as drug targets for filariasis control. While much more research on these ubiquitous symbionts is needed, they are viewed as playing significant roles in biological processes, ranging from arthropod speciation to human health.


Assuntos
Artrópodes/microbiologia , Filarioidea/microbiologia , Simbiose , Wolbachia , Animais , Interações entre Hospedeiro e Microrganismos
11.
PLoS Negl Trop Dis ; 14(12): e0008930, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33284808

RESUMO

Current efforts to eliminate the neglected tropical diseases onchocerciasis and lymphatic filariasis, caused by the filarial nematodes Onchocerca volvulus and Wuchereria bancrofti or Brugia spp., respectively, are hampered by lack of a short-course macrofilaricidal-adult-worm killing-treatment. Anti-wolbachial antibiotics, e.g. doxycycline, target the essential Wolbachia endosymbionts of filariae and are a safe prototype adult-worm-sterilizing and macrofilaricidal regimen, in contrast to standard treatments with ivermectin or diethylcarbamazine, which mainly target the microfilariae. However, treatment regimens of 4-5 weeks necessary for doxycycline and contraindications limit its use. Therefore, we tested the preclinical anti-Wolbachia drug candidate Corallopyronin A (CorA) for in vivo efficacy during initial and chronic filarial infections in the Litomosoides sigmodontis rodent model. CorA treatment for 14 days beginning immediately after infection cleared >90% of Wolbachia endosymbionts from filariae and prevented development into adult worms. CorA treatment of patently infected microfilaremic gerbils for 14 days with 30 mg/kg twice a day (BID) achieved a sustained reduction of >99% of Wolbachia endosymbionts from adult filariae and microfilariae, followed by complete inhibition of filarial embryogenesis resulting in clearance of microfilariae. Combined treatment of CorA and albendazole, a drug currently co-administered during mass drug administrations and previously shown to enhance efficacy of anti-Wolbachia drugs, achieved microfilarial clearance after 7 days of treatment at a lower BID dose of 10 mg/kg CorA, a Human Equivalent Dose of 1.4 mg/kg. Importantly, this combination led to a significant reduction in the adult worm burden, which has not yet been published with other anti-Wolbachia candidates tested in this model. In summary, CorA is a preclinical candidate for filariasis, which significantly reduces treatment times required to achieve sustained Wolbachia depletion, clearance of microfilariae, and inhibition of embryogenesis. In combination with albendazole, CorA is robustly macrofilaricidal after 7 days of treatment and fulfills the Target Product Profile for a macrofilaricidal drug.


Assuntos
Filariose/tratamento farmacológico , Filaricidas/uso terapêutico , Filarioidea/efeitos dos fármacos , Lactonas/uso terapêutico , Wolbachia/efeitos dos fármacos , Animais , Feminino , Filariose/parasitologia , Filarioidea/microbiologia , Camundongos , Camundongos Endogâmicos BALB C , Simbiose/efeitos dos fármacos
12.
Microb Genom ; 6(12)2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33295865

RESUMO

Wolbachia are alpha-proteobacteria symbionts infecting a large range of arthropod species and two different families of nematodes. Interestingly, these endosymbionts are able to induce diverse phenotypes in their hosts: they are reproductive parasites within many arthropods, nutritional mutualists within some insects and obligate mutualists within their filarial nematode hosts. Defining Wolbachia 'species' is controversial and so they are commonly classified into 17 different phylogenetic lineages, termed supergroups, named A-F, H-Q and S. However, available genomic data remain limited and not representative of the full Wolbachia diversity; indeed, of the 24 complete genomes and 55 draft genomes of Wolbachia available to date, 84 % belong to supergroups A and B, exclusively composed of Wolbachia from arthropods. For the current study, we took advantage of a recently developed DNA-enrichment method to produce four complete genomes and two draft genomes of Wolbachia from filarial nematodes. Two complete genomes, wCtub and wDcau, are the smallest Wolbachia genomes sequenced to date (863 988 bp and 863 427 bp, respectively), as well as the first genomes representing supergroup J. These genomes confirm the validity of this supergroup, a controversial clade due to weaknesses of the multilocus sequence typing approach. We also produced the first draft Wolbachia genome from a supergroup F filarial nematode representative (wMhie), two genomes from supergroup D (wLsig and wLbra) and the complete genome of wDimm from supergroup C. Our new data confirm the paradigm of smaller Wolbachia genomes from filarial nematodes containing low levels of transposable elements and the absence of intact bacteriophage sequences, unlike many Wolbachia from arthropods, where both are more abundant. However, we observe differences among the Wolbachia genomes from filarial nematodes: no global co-evolutionary pattern, strong synteny between supergroup C and supergroup J Wolbachia, and more transposable elements observed in supergroup D Wolbachia compared to the other supergroups. Metabolic pathway analysis indicates several highly conserved pathways (haem and nucleotide biosynthesis, for example) as opposed to more variable pathways, such as vitamin B biosynthesis, which might be specific to certain host-symbiont associations. Overall, there appears to be no single Wolbachia-filarial nematode pattern of co-evolution or symbiotic relationship.


Assuntos
Filarioidea/microbiologia , Análise de Sequência de DNA/métodos , Wolbachia/classificação , Animais , Bases de Dados Genéticas , Evolução Molecular , Tamanho do Genoma , Genoma Bacteriano , Genômica , Anotação de Sequência Molecular , Filogenia , Wolbachia/genética , Wolbachia/isolamento & purificação
13.
Parasit Vectors ; 13(1): 551, 2020 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-33160409

RESUMO

BACKGROUND: Pulmonary manifestations are regularly reported in both human and animal filariasis. In human filariasis, the main known lung manifestations are the tropical pulmonary eosinophilia syndrome. Its duration and severity are correlated with the presence of microfilariae. Litomosoides sigmodontis is a filarial parasite residing in the pleural cavity of rodents. This model is widely used to understand the immune mechanisms that are established during infection and for the screening of therapeutic molecules. Some pulmonary manifestations during the patent phase of infection with L. sigmodontis have been described in different rodent hosts more or less permissive to infection. METHODS: Here, the permissive Mongolian gerbil (Meriones unguiculatus) was infected with L. sigmodontis. Prevalence and density of microfilariae and adult parasites were evaluated. Lungs were analyzed for pathological signatures using immunohistochemistry and 3D imaging techniques (two-photon and light sheet microscopy). RESULTS: Microfilaremia in gerbils was correlated with parasite load, as amicrofilaremic individuals had fewer parasites in their pleural cavities. Fibrotic polypoid structures were observed on both pleurae of infected gerbils. Polyps were of variable size and developed from the visceral mesothelium over the entire pleura. The larger polyps were vascularized and strongly infiltrated by immune cells such as eosinophils, macrophages or lymphocytes. The formation of these structures was induced by the presence of adult filariae since small and rare polyps were observed before patency, but they were exacerbated by the presence of gravid females and microfilariae. CONCLUSIONS: Altogether, these data emphasize the role of host-specific factors in the pathogenesis of filarial infections.


Assuntos
Eosinófilos/imunologia , Filariose/patologia , Gerbillinae/parasitologia , Microfilárias/patogenicidade , Cavidade Pleural/parasitologia , Pólipos/imunologia , Animais , Feminino , Fibrose , Filariose/imunologia , Filariose/parasitologia , Filarioidea/patogenicidade , Pulmão/parasitologia , Pulmão/patologia , Masculino , Microfilárias/imunologia , Carga Parasitária , Cavidade Pleural/imunologia , Cavidade Pleural/patologia , Pólipos/parasitologia , Pólipos/patologia
14.
Parasitol Res ; 119(12): 4267-4270, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33079270

RESUMO

Molecular characterization studies on Setaria equina are limited. The present study aimed to characterize S. equina at the cytochrome c oxidase gene and to examine its phylogenetic relationships with other filarid species. Sequence analysis showed 100% nucleotide homology with an S. equina sequence from Italy (AJ544873). However, both sequences exhibited 7 nucleotide substitutions from a S. equina donkey isolate from Egypt (MK541847). Overall, S. equina formed a monophyletic sister group to Setaria tundra. All Setaria spp. examined formed a separate group on the phylogenetic tree that was related to corresponding Onchocerca spp. and Dirofilaria spp. clades. Human filarid worms-Brugia spp. and Wuchereria spp. grouped in a separate clade alongside Theilezia spp. Dipetalonema spp.-formed a separate group at the top of the tree.


Assuntos
Filogenia , Setaria (Nematoide)/classificação , Animais , Complexo IV da Cadeia de Transporte de Elétrons/genética , Filariose/parasitologia , Filarioidea/classificação , Filarioidea/genética , Filarioidea/isolamento & purificação , Variação Genética , Proteínas de Helminto/genética , Humanos , Setaria (Nematoide)/genética , Setaria (Nematoide)/isolamento & purificação
15.
PLoS Negl Trop Dis ; 14(10): e0008644, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-33044958

RESUMO

The global decline in prevalence of lymphatic filariasis has been one of the major successes of the WHO's NTD programme. The recommended strategy of intensive, community-wide mass drug administration, aims to break localised transmission by either reducing the prevalence of microfilaria positive infections to below 1%, or antigen positive infections to below 2%. After the threshold is reached, and mass drug administration is stopped, geographically defined evaluation units must pass Transmission Assessment Surveys to demonstrate that transmission has been interrupted. In this study, we use an empirically parameterised stochastic transmission model to investigate the appropriateness of 1% microfilaria-positive prevalence as a stopping threshold, and statistically evaluate how well various monitoring prevalence-thresholds predict elimination or disease resurgence in the future by calculating their predictive value. Our results support the 1% filaremia prevalence target as appropriate stopping criteria. However, because at low prevalence-levels random events dominate the transmission dynamics, we find single prevalence measurements have poor predictive power for predicting resurgence, which suggests alternative criteria for restarting MDA may be beneficial.


Assuntos
Filariose Linfática/epidemiologia , Filariose Linfática/prevenção & controle , Monitoramento Epidemiológico , Filarioidea/isolamento & purificação , Animais , Filariose Linfática/transmissão , Feminino , Humanos , Masculino , Administração Massiva de Medicamentos , Modelos Estatísticos , Mosquitos Vetores/parasitologia , Prevalência
16.
J Helminthol ; 94: e202, 2020 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-33059788

RESUMO

Lungworms are a common finding in seals and fur seals around the world. However, from existing records, the biogeographical distribution of filaroid helminths appears to be restricted, and these parasites are endemic in only certain areas and species, mainly in the Northern Hemisphere. The occurrence of infection in pinniped species in the Southern Hemisphere is scarce. The objective of this work is to verify the prevalence of lungworms in Arctocephalus australis in waters off the southern coast of Brazil. Twenty subadult specimens of A. australis found recently dead on the southern coast of Brazil were necropsied and their lungs were examined. Parasitic cysts were found in only one specimen (prevalence of 5%). The helminths were morphologically identified as Parafilaroides normani (Metastrongyloidea: Filaroididae). This helminth species has been reported in pinnipeds from Australia, New Zealand and South Africa. This is the first record of P. normani in A. australis and for the western South Atlantic, providing additional data regarding the biogeographic distribution of the parasite.


Assuntos
Distribuição Animal , Filariose/epidemiologia , Filariose/veterinária , Filarioidea/anatomia & histologia , Animais , Austrália , Brasil/epidemiologia , Feminino , Filarioidea/isolamento & purificação , Filarioidea/fisiologia , Otárias/parasitologia , Geografia , Masculino , Nova Zelândia , Filogenia , Prevalência , África do Sul
17.
Sci Rep ; 10(1): 15246, 2020 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-32943684

RESUMO

Sandflies are insects of public health interest due to their role as vectors of parasites of the genus Leishmania, as well as other pathogens. Psychodopygus carrerai carrerai is considered an important sylvatic vector of Leishmania (Viannia) braziliensis in Amazonia. In this study, sandflies were collected in a forested area in the Xapuri municipality, in the State of Acre (Northern Brazil). Two Ps. carrerai carrerai females were found parasitized with a larval form of a filarial worm, one in the labium of the proboscis, the other after the head was squashed, suggesting they were infective larvae. Sandflies were identified through morphological characters as well as amplification and sequencing of the cytochrome oxidase gene (COI). This was the first sequence obtained for Ps. carrerai carrerai for this marker. The obtained nematodes were also characterized through direct sequencing of a fragment of COI and 12S genes, both mitochondrial, and ITS1, a nuclear marker. Phylogenetic analyses revealed that the filarial nematodes belong to a species without sequences for these markers in the database, part of family Onchocercidade and closely related to genus Onchocerca (12S tree). Although sandfly infection with nematodes including members of the Onchocercidae has been reported in the Old World, this is the first report of sandfly infection by a member of the Onchocercidae family in the New World, to the best of our knowledge. Considering that the phylogenetic relationships and location in the insect, it can be expected that this is a parasite of mammals and the transmission cycle should be clarified.


Assuntos
Filarioidea/patogenicidade , Insetos Vetores/parasitologia , Leishmania braziliensis , Leishmaniose Cutânea/transmissão , Psychodidae/parasitologia , Animais , Brasil , Complexo IV da Cadeia de Transporte de Elétrons/genética , Feminino , Filarioidea/classificação , Filarioidea/genética , Genes de Helmintos , Genes de Insetos , Humanos , Leishmaniose Cutânea/parasitologia , Masculino , Filogenia , Psychodidae/enzimologia , Psychodidae/genética
18.
Parasitol Res ; 119(10): 3145-3164, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32748037

RESUMO

Parasites and bacteria have co-evolved with humankind, and they interact all the time in a myriad of ways. For example, some bacterial infections result from parasite-dwelling bacteria as in the case of Salmonella infection during schistosomiasis. Other bacteria synergize with parasites in the evolution of human disease as in the case of the interplay between Wolbachia endosymbiont bacteria and filarial nematodes as well as the interaction between Gram-negative bacteria and Schistosoma haematobium in the pathogenesis of urinary bladder cancer. Moreover, secondary bacterial infections may complicate several parasitic diseases such as visceral leishmaniasis and malaria, due to immunosuppression of the host during parasitic infections. Also, bacteria may colonize the parasitic lesions; for example, hydatid cysts and skin lesions of ectoparasites. Remarkably, some parasitic helminths and arthropods exhibit antibacterial activity usually by the release of specific antimicrobial products. Lastly, some parasite-bacteria interactions are induced as when using probiotic bacteria to modulate the outcome of a variety of parasitic infections. In sum, parasite-bacteria interactions involve intricate processes that never cease to intrigue the researchers. However, understanding and exploiting these interactions could have prophylactic and curative potential for infections by both types of pathogens.


Assuntos
Infecções Bacterianas/complicações , Filarioidea/microbiologia , Doenças Parasitárias/complicações , Schistosoma haematobium/microbiologia , Wolbachia/crescimento & desenvolvimento , Animais , Antibacterianos/uso terapêutico , Artrópodes/microbiologia , Humanos , Parasitos/microbiologia , Probióticos/uso terapêutico , Simbiose , Neoplasias da Bexiga Urinária/microbiologia , Neoplasias da Bexiga Urinária/parasitologia , Neoplasias da Bexiga Urinária/patologia
19.
PLoS Negl Trop Dis ; 14(7): e0008534, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32735561

RESUMO

Mast cells are innate effector cells that due to their localization in the tissue form the first line of defense against parasites. We have previously shown that specifically mucosal mast cells were essential for the termination of the intestinal Strongyloides ratti infection. Here, we analyze the impact of mast cells on the immune response and defense against the tissue-dwelling filarial nematode Litomosoides sigmodontis using mast cell-deficient Cpa3cre mice. Despite an increase and an activation of mast cells at the site of infection in wildtype BALB/c mice the outcome of L. sigmodontis infection was not changed in mast cell-deficient BALB/c Cpa3cre mice. In Cpa3cre mice neither vascular permeability induced by blood-sucking mites nor the migration of L3 was altered compared to Cpa3 wildtype littermates. Worm burden in the thoracic cavity was alike in the presence and absence of mast cells during the entire course of infection. Although microfilaremiae in the peripheral blood increased in mast cell-deficient mice at some time points, the infection was cleared with comparable kinetics in the presence and absence of mast cells. Moreover, mast cell deficiency had no impact on the cytokine and antibody response to L. sigmodontis. In summary, our findings suggest that mast cells are not mandatory for the initiation of an appropriate immune response and host defense during L. sigmodontis infection in mice.


Assuntos
Filariose/imunologia , Filarioidea/imunologia , Mastócitos/fisiologia , Animais , Permeabilidade Capilar , Carboxipeptidases A/genética , Carboxipeptidases A/metabolismo , Filariose/parasitologia , Camundongos , Camundongos Endogâmicos BALB C , Infestações por Ácaros , Mutação
20.
PLoS Negl Trop Dis ; 14(7): e0008427, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32628671

RESUMO

A major impediment to eliminate lymphatic filariasis and onchocerciasis is the lack of effective short-course macrofilaricidal drugs or regimens that are proven to be safe for both infections. In this study we tested oxfendazole, an anthelmintic shown to be well tolerated in phase 1 clinical trials. In vitro, oxfendazole exhibited modest to marginal motility inhibition of adult worms of Onchocerca gutturosa, pre-adult worms of Onchocerca volvulus and Onchocerca lienalis microfilariae. In vivo, five days of oral treatments provided sterile cure with up to 100% macrofilaricidal efficacy in the murine Litomosoides sigmodontis model of filariasis. In addition, 10 days of oral treatments with oxfendazole inhibited filarial embryogenesis in patent L. sigmodontis-infected jirds and subsequently led to a protracted but complete clearance of microfilaremia. The macrofilaricidal effect observed in vivo was selective, as treatment with oxfendazole of microfilariae-injected naïve mice was ineffective. Based on pharmacokinetic analysis, the driver of efficacy is the maintenance of a minimal efficacious concentration of approximately 100 ng/ml (based on subcutaneous treatment at 25 mg/kg in mice). From animal models, the human efficacious dose is predicted to range from 1.5 to 4.1 mg/kg. Such a dose has already been proven to be safe in phase 1 clinical trials. Oxfendazole therefore has potential to be efficacious for treatment of human filariasis without causing adverse reactions due to drug-induced microfilariae killing.


Assuntos
Benzimidazóis/farmacologia , Filariose Linfática/tratamento farmacológico , Filarioidea/efeitos dos fármacos , Animais , Anti-Helmínticos/uso terapêutico , Modelos Animais de Doenças , Filariose Linfática/parasitologia , Feminino , Filarioidea/embriologia , Gerbillinae/parasitologia , Camundongos , Camundongos Endogâmicos BALB C , Microfilárias/efeitos dos fármacos , Onchocerca/efeitos dos fármacos , Onchocerca volvulus/efeitos dos fármacos , Oncocercose/tratamento farmacológico
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