837 resultados para Mite Infestations
Resumo:
Brazil has the third richest bird diversity of the world; however, there are few data concerning ticks (Acari: Ixodidae) parazitizing birds. The aim of the study was to report tick infestations on wild birds from an Atlantic rain forest region of Brazil. During 2 yr, ticks were collected from birds and from the environment in 12 forest sites. A total of 1,725 birds were captured representing 80 species from 24 families. In total, 223 (13%) birds were found infested by immature stages of Amblyomma ticks: 1,800 larvae and 539 nymphs. The prevalence of ticks was higher among-birds from the families Thamnophilidae, Conopophagidae, and Momotidae. The most common tick parasitizing birds was Amblyomma nodosum Koch. Other tick species, Amblyomma coelebs Neumann, Amblyomma cajennense (F.), Amblyomma ovale Koch, Amblyomma longirostre (Koch), Amblyomma calcaratum Neumann, and Amblyomma naponense (Packard), were found sporadically. Among free-living ticks collected in the environment, A. cajennense was the most common, followed by A. coelebs, A. naponense, Amblyomma brasilense Aragao, and Hemaphysalis juxtakochi Cooley.
Resumo:
Bovines present contrasting, heritable phenotypes of infestations with the cattle tick, Rhipicephalus (Boophilus) microplus. Tick salivary glands produce IgG-binding proteins (IGBPs) as a mechanism for escaping from host antibodies that these ectoparasites ingest during blood meals. Allotypes that occur in the constant region of IgG may differ in their capacity to bind with tick IGBPs; this may be reflected by the distribution of distinct allotypes according to phenotypes of tick infestations. In order to test this hypothesis, we investigated the frequency of haplotypes of bovine IgG2 among tick-resistant and tick-susceptible breeds of bovines. Sequencing of the gene coding for the heavy chain of IgG2 from 114 tick-resistant (Bos taurus indicus, Nelore breed) and tick-susceptible (B. t. taurus, Holstein breed) bovines revealed SNPs that generated 13 different haplotypes, of which 11 were novel and 5 were exclusive of Holstein and 3 of Nelore breeds. Alignment and modeling of coded haplotypes for hinge regions of the bovine IgG2 showed that they differ in the distribution of polar and hydrophobic amino acids and in shape according to the distribution of these amino acids. We also found that there was an association between genotypes of the constant region of the IgG2 heavy chain with phenotypes of tick infestations. These findings open the possibility of investigating if certain IgG allotypes hinder the function of tick IGBPs. If so, they may be markers for breeding for resistance against tick infestations.
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A survey of the floors of 3001 empty sea cargo containers in storage was undertaken to estimate the quarantine risk of importing exotic insect pests into Australia, with special reference to pests of timber. More than 7400 live and dead insects were collected from 1174 containers. No live infestations of timber-feeding insects were recorded, but feeding damage detected in one floor indicates a low risk of importing colonies of timber pests in containers. The survey collection of dead insects demonstrates that containers are regularly exposed to economically important quarantinable insects, including timber pests (bostrichids, curculionids, cerambycids, siricids and termites), agricultural pests (including Adoretus sinicus, Adoretus sp., Carpophilus obsoletus and Philaenus spumarius), and nuisance pests (vespids and Solenopsis sp.). Stored product pests were found in more than 10% of containers. The assessment of pest risk associated with shipping containers is discussed in terms of the quantity and quality of opportunities for exotic insects to establish via this pathway.
Resumo:
The Australian Neoseiulus Hughes and Typhlodromips de Leon (Acari: Phytoseiidae: Amblyseiinae) are revised and diagnosed, and three new related genera, Knopkirie, gen. nov., Olpiseius, gen. nov. and Pholaseius, gen. nov. are proposed and diagnosed. In Australia, Neoseiulus contains at least 44 species, 18 of which are newly described here, in six species-groups: the barkeri-group, womersleyi-group, cucumeris-group, cangaro-group, paloratus-group, and the paspalivorus-group. Typhlodromips contains six species, two previously described and four new species. Knopkirie contains four species, three of which are newly described here, in two species-groups: the petri-group and the banksiae-group. Olpiseius contains three species, one of which is newly described, all placed in the noncollyerae-group, and Pholaseius is monotypic, with one newly described species. Diagnoses and keys are provided for all Australian species in each of the above genera, as are keys to the amblyseiine genera currently recognised in Australia.
Resumo:
We sequenced part of the mitochondrial 12S ribosomal RNA gene of 23 specimens of Sarcoptes scabiei from eight wombats, one dog and three humans. Twelve of the 326 nucleotide positions varied among these mites and there were nine haplotypes (sequences) that differed by 1-8 nucleotides. Phylogenetic analyses indicated that these mites were from two lineages: (1) mites from wombats from Victoria, Australia, and mites from the humans and dog from the Northern Territory, Australia (haplotypes 1-4, 9); and (2) mites from the humans and dog from the Northern Territory (haplotypes 5-8). Mites from the three different hosts (wombats, a dog and humans) had not diverged phylogenetically; rather, these mites had similar 12S sequences. Thus, we conclude that these mites from wombats, humans and a dog are closely related, and that they diverged from a common ancestor relatively recently. This conclusion is consistent with the argument that people and/or their dogs introduced to Australia the S. scabiei mites that infect wombats Australia. So, S. scabiei, which has been blamed for the extinction of populations of wombats in Australia, may be a parasitic mite that was introduced to Australia with people and/or their dogs. These data show that the mitochondrial 12S rRNA gene may be a suitable population marker of S. scabiei from wombats, dogs and humans in Australia.
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Scabies ('Itch Mite') is truly a Great Neglected Disease that inflicts misery on millions. Molecular approaches, while still in their infancy, are providing a better understanding of the parasite and will have important implications for control and prevention. It has long been thought that dogs may act as a reservoir for human infections. However, genetic studies cast doubt over this supposition.
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The ability of introduced organisms to invade undisturbed native habitats is a major concern in conservation biology and has resulted in a re-evaluation of the introduction of exotic biocontrol agents, especially of generalist predators. One such agent is Stratiolaelaps miles (Berlese), a predatory mite described from Italy, known from throughout the Holarctic, and apparently accidentally introduced to other areas of the world, including Australia. Initial investigations revealed that putative S. miles could be found in both disturbed and relatively pristine habitats in Queensland, Australia. However, analysis of the mitochondrial DNA of five populations showed most to be highly divergent genetically. Subsequent morphological analysis established two species groups: the lamington-group from cool-temperate to subtropical rainforests in Eastern Australia and the more eurytopic miles-group with a cosmopolitan distribution. We describe two new species from each of these complexes (Stratiolaelaps womersleyi, Stratiolaelaps lamington; Stratiolaelaps marilyn, Stratiolaelaps lorna, respectively), and resurrect Stratiolaelaps scimitus (Womersley), a species which often appears to have been confused with S. miles. Additionally, the large genetic distances among morphologically homogenous species in the miles-group suggest that the apparently cosmopolitan S. miles may be composed of a suite of cryptic species of potentially varying utility in biological control. (C) 2002 Elsevier Science (USA). All rights reserved.
Resumo:
A plant feeding mite, Sinobryobia fani n. sp. (Tetranychidae: Bryobiinae: Bryobiini) is described from Australia. It is the first record of the genus for Australia and the second record of the genus for the world. A key to the Species of Sinobryobia is provided.
Resumo:
Since the pioneering work of Charles Nicolle in 1909 [see Gross (1996) Proc Natl Acad Sci USA 93:10539-10540] most medical officers and scientists have assumed that body lice are the sole vectors of Rickettsia prowazekii, the aetiological agent of louse-borne epidemic typhus (LBET). Here we review the evidence for the axiom that head lice are not involved in epidemics of LBET. Laboratory experiments demonstrate the ability of head lice to transmit R. prowazekii, but evidence for this in the field has not been reported. However, the assumption that head lice do not transmit R. prowazekii has meant that head lice have not been examined for R. prowazekii during epidemics of LBET. The strong association between obvious (high) infestations of body lice and LBET has contributed to this perception, but this association does not preclude head lice as vectors of R. prowazekii. Indeed, where the prevalence and intensity of body louse infections may be high (e.g. during epidemics of LBET), the prevalence and intensity of head louse infestations is generally high as well. This review of the epidemiology of head louse and body louse infestations, and of LBET, indicates that head lice are potential vectors of R. prowazekii in the field. Simple observations in the field would reveal whether or not head lice are natural vectors of this major human pathogen.
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The mite family Stigmaeidae (Acari:Prostigmata) is of considerable importance in biological control, but its genera are often poorly defined and have never been subjected to cladistic analysis. Herein, we report the stigmaeid genus Ledermuelleriopsis Willmann from Australia for the first time, present a preliminary phylogenetic analysis that demonstrates that Eustigmaeus Berlese and Ledermuelleriopsis Willman are distinct, review the genus at the world level, and provide diagnostic characters of the adult females for each of the 21 known species. We also catalogue habitats, distributions and localities of holotypes. Four new species from Australia are described and illustrated: L. parvilla, sp. nov. from old dune sand, L. barbellata, sp. nov. from wet-sandy heath litter, and L. pustulosa, sp. nov. and L. claviseta, sp. nov. from dry eucalypt forest litter. A key to adult females of all known Ledermuelleriopsis species is provided. The Australian species and L. incisa Wood from New Zealand can be separated from all other members of the genus by a synapomorphy: the reduction of the number of setae on the aggenital shield to one pair. Results of a preliminary morphological cladistic analysis for those stigmaeid genera in which the larvae and adults of both sexes are known, indicate that Ledermuelleriopsis is basal to a clade containing Cheylostigmaeus Willman and Eustigmaeus.
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OBJECTIVE: To determine the intensity of Pediculus capitis infestation (abundance) among Argentinean schoolchildren. Children's sex and social stratum were analyzed as modifiers of the general prevalence and degree of parasitism. METHODS: The study included 1,370 schoolchildren (692 girls, 678 boys) from 26 schools of the province of La Rioja (21 public schools, five private schools). Classic prevalence was obtained as the percentage of children with nits and/or lice. Moreover, five degrees of parasitism were classified: 0) children with no signs of pediculosis; 0+) children with evidence of past infestation; 1) children with a recent infestation and low probability of active parasitism; 2) children with a recent infestation and high probability of active parasitism; 3) children with mobile lice (active pediculosis). RESULTS: The general prevalence was 61.4% (girls: 79%; boys: 44%, p<0.001). Private schools showed lower prevalence than public schools (p=0.02), especially due to the low prevalence in boys. Fifty percent of children were classified in classes 0 and 0+, 22% in class 1; and 28% in grades 2 and 3. The proportion of children in grade 3 was higher in public schools than in private schools. There were significant sexual differences in the intensity of parasitism for grades 2 and 3, where girls' rates exceeded twice those of boys'. CONCLUSIONS: Sex and social stratum are important modifiers of P. capitis general prevalence and degree of infestation. The classification of children by intensity of infestation allowed a more precise delimitation of this condition, which is especially important for disease surveillance and application of control measures.
Resumo:
Uma das actividades musicais mais importantes na nossa cultura é o canto: cantamos juntos numa festa de aniversário, de casamento, ou cantamos a um bebé no berço ou até quando estamos sozinhos. O canto per - mite ao indivíduo exprimir-se, comunicar, partilhar. Quando é que as crianças começam a cantar? Quando é que podem aprender as primeiras canções, isto é, repeti-las com uma certa aproximação? Quando é que começam a inventar? Depois de muitos estudos centrados na faixa etária dos 3 aos 6 anos, começou a investi - gar-se o que pode acontecer antes, ou seja, a partir do primeiro funcionamento do ouvido. No presente estudo, depois de fazer algumas referências aos estudos sobre as primeiras produções vocais, apresentarei uma fase intermediária da investigação longitudinal de seis anos que estou a realizar com a minha colega Donatella Villa. Trata-se de um projecto investigativo que pretende estudar as consequências de um programa educativo sobre o desenvolvimento das capacidades musicais e, em particular, da capacidade de cantar afinado. O programa tem sido começado pelas mães já desde os últimos meses de gravidez e continua a desenvolver-se em encontros semanais com as crianças. As mães têm a tarefa de continuar as actividades em casa, anotar no diário preparado por nós as reacções das crianças, e gravar cassetes com as produções vocais delas. Aqui apresentar-se-ão as capacidades demonstradas pelas crianças na etapa dos 2 aos 3 anos de idade em repetir canções conhecidas, inventar palavras sobre as mesmas e inventar canções.
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Although usually considered a non-pathogenic parasite in parasitological textbooks, Demodex folliculorum has been implicated as a causative agent for some dermatological conditions, such as rosacea-like eruptions and some types of blepharitis. Several anecdotal reports have demonstrated unequivocal tissue damage directly related to the presence of the parasite. However, this seems to be exceedingly rare, in contrast with the marked prevalence of this infestation. We have had the opportunity to observe one of such cases. A 38-year-old woman presented with rosacea-like papular lesions in her right cheek. Histopathological examination revealed granulomatous dermal inflammation with a well-preserved mite phagocytized by a multinucleated giant cell. This finding may be taken as an evidence for the pathogenicity of the parasite, inasmuch as it does not explain how such a common parasite is able to produce such a rare disease.
Resumo:
The authors report a confirmed case of hantavirus pulmonary syndrome in the rural area of the municipality of Anajatuba, state of Maranhão. Two other suspected cases from the same region are also described. The confirmed case involved a previously healthy young woman who died with signs and symptoms of acute respiratory insufficiency 5 days after presenting fever, myalgia and a dry cough. The patient was a student who was helping her parents with work in the fields; it was a habit of the family to store rice inside the house. The suspected cases involved two first-degree relatives working as field hands who died of acute respiratory insufficiency 24 and 48 hours, respectively, after presenting fever, myalgia and a dry cough. Both stored rice and corn inside their home. People living in the region reported massive infestations with rats in the woods and fields.