Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “MITES”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,333 records · Page 74Linked to original sources
PubMed2004

Growth and pathogenicity of isolates of the fungus Metarhizium anisopliae against the parasitic mite, Psoroptes ovis: effects of temperature and formulation.

Psoroptes mites (Acari: Psoroptidae) are important ectoparasites of mammals, and are of particular economic significance as the agents of mange in sheep. To be effective against mites, putative fungal biocontrol agents must be able to operate at the relatively high temperatures and humidities found at the sheep skin surface. To consider this, the growth rates of different isolates of the entomopathogenic fungus Metarhizium anisopliae (Metschnikoff) Sorokin (Deuteromycotina: Hyphomycetes) were compared and the pathogenicity of these isolates against Psoroptes derived from rabbits (Psoroptes ovis Hering, syn P cuniculi) were evaluated at temperatures between 28 degrees C and 40 degrees C, and when formulated in either Tween 80 or silicone oil. For this study four multi-conidia, arthropod-derived, isolates of M anisopliae were used: from the USA, France, Denmark and Brazil. One single-conidia culture derived from the US isolate was also included in the investigation. Fungal growth was higher at the lower temperatures and none of the isolates grew at 40 degrees C. The growth of the US and single-conidia isolate declined markedly with temperature. In contrast, the Danish, French and Brazilian isolates grew almost as well at 32 degrees C and 35 degrees C as at 28 degrees C and 30 degrees C. The French and Brazilian isolates showed some growth at 37.5 degrees C but the Danish and US isolates did not. The number of fatal infections which resulted from exposure of mites to the fungal isolates was also strongly influenced by temperature. At 30 degrees C all isolates gave between 70 and 90% infection. The number of infections declined with increasing temperature and no infections were seen at 40 degrees C. However, the French and Danish isolates of M anisopliae gave higher numbers of infections than the other isolates at elevated temperatures. When formulated in silicone oil, significantly higher levels of infection were obtained than when formulated in Tween 80, even at the relatively high temperature of 37.5 degrees C. It is suggested that high-temperature adapted isolates of M anisopliae formulated in silicone oil offer good candidates as control agents under the conditions found at the sheep skin surface.

Animals↗
PubMed2002

Fluorometric microplate assay to measure glutathione S-transferase activity in insects and mites using monochlorobimane.

Elevated levels of glutathione S-transferases (GSTs) play a major role as a mechanism of resistance to insecticides and acaricides in resistant pest insects and mites, respectively. Such compounds are either detoxicated directly via phase I metabolism or detoxicated by phase II metabolism of metabolites as formed by microsomal monooxygenases. Here we used monochlorobimane (MCB) as an artificial substrate and glutathione to determine total GST activity in equivalents of single pest insects and spider mites in a sensitive 96-well plate-based assay system by measuring the enzymatic conversion of MCB to its fluorescent bimane-glutathione adduct. The differentiation by their GST activity between several strains of the two-spotted spider mite, Tetranychus urticae (Acari: Tetranychidae), with different degrees of resistance to numerous acaricides was more sensitive with MCB compared to the commonly used substrate 1-chloro-2,4-dinitrobenzene (CDNB). Compared to an acaricide-susceptible reference strain, one field population of T. urticae showed a more than 10-fold higher GST activity measured with MCB, in contrast to a less than 2-fold higher activity when CDNB was used. Furthermore, we showed that GST activity can be sensitively assessed with MCB in homogenates of pest insects such as Heliothis virescens, Spodoptera frugiperda (Lepidoptera: Noctuidae), Plutella xylostella (Lepidoptera: Yponomeutidae), and Myzus persicae (Hemiptera: Aphididae).

Animals↗
PubMed2000

Significant evidence for linkage of mite-sensitive childhood asthma to chromosome 5q31-q33 near the interleukin 12 B locus by a genome-wide search in Japanese families.

Childhood-onset asthma is frequently found in association with atopy. Although asthmatic children may develop IgE antibodies against variety of allergens, asthma is associated primarily with allergy to house-dust mites, molds, or other allergens. In this study, we conducted a genome-wide linkage search in 47 Japanese families (197 members) with more than two mite-sensitive atopic asthmatics (65 affected sib-pairs) using 398 markers. Multipoint linkage analysis was carried out for atopic asthma as a qualitative trait using the MAPMAKER/SIB program. We observed significant evidence for linkage with maximum lod scores (MLS) of 4.8 near the interleukin 12 B gene locus on chromosome 5q31-q33. In addition, suggestive evidence on 4q35 with MLS = 2.7 and on 13q11 with MLS = 2.4 was obtained. The other possible linkage regions included 6p22-p21.3 (MLS = 2.1), 12q21-q23 (MLS = 1.9), and 13q14.1-q14.3 (MLS = 2.0). Many of the linkage loci suggested in this study were at or close to those suggested by genome-wide studies for asthma in Caucasian populations. The present study suggests the contribution of the interleukin 12 B gene or nearby gene(s) to mite-sensitive atopic asthma and a considerable number of genetic variants common across Caucasians and Japanese populations contributing to asthma, although the relative importance of various variants may differ between the groups.

Adolescent↗
PubMed2000

A recombinant group 1 house dust mite allergen, rDer f 1, with biological activities similar to those of the native allergen.

Serum IgE directed against Der f 1, a protease found in the feces of Dermatophagoides farinae, correlates well with allergic sensitization to house dust mite in humans and is a risk factor for developing asthma. Native Der f 1 (nDer f 1) is produced as a pre-pro form and processed to an approximately 25-kDa mature form. We have expressed recombinant forms of Der f 1 (rDer f 1) in Pichia pastoris using AOX1-promoter expression vectors. Fusion of either the pro-enzyme form or the mature form to the Saccharomyces cerevisiae alpha factor pre-pro sequence resulted in secretion of the mature form of the protein from P. pastoris. The secreted protein was heterogeneously glycosylated at a single N-glycosylation site and had an apparent molecular mass of 35-50 kDa. Both the alpha factor signal peptide and the pro-enzyme region were efficiently processed during secretion. A version of the pro-enzyme with a mutated consensus N-linked glycosylation site was secreted from P. pastoris as a mature, unglycosylated, approximately 25-kDa protein. The IgE binding activity of this unglycosylated rDer f 1 was similar to that of glycosylated forms produced by P. pastoris and to nDer f 1 obtained from mites. Thus, oligosaccharides are not required for secretion from P. pastoris or for IgE binding in vitro. Recombinant and native versions of Der f 1 displayed protease activity on casein zymogram gels. The availability of a highly purified recombinant Der f 1 will facilitate experimental and clinical studies of mite allergy.

Allergens↗
PubMed1995

Distribution of Dermatophagoides mite (Acari: Pyroglyphidae) antigens in homes of allergic patients in Japan.

Dust samples collected in 61 homes of patients with mite allergies and 11 homes of non-allergic people as controls were examined for antigen levels of Dermatophagoides farinae Hughes and Dermatophagoides pteronyssinus (Trouessart) to reveal the current distribution of allergenic mites in homes in Japan. Patient homes had higher antigen levels than control homes in comforters and pillows but not in futons, carpets, tatamis and wooden floors. Samples with antigen levels of > or = 10 micrograms m-2 were more frequent in and around summer (approximately April-October) than other seasons of the year in most materials and the differences between patient and control homes in comforters and pillows observed in yearly totals was also observed during this period. Wooden structures showed higher antigen levels than concrete structures in comforters, futons, pillows, carpets and tatamis in patient homes. Mite contamination in patient homes in relation to environmental factors was discussed.

Adult↗
PubMed1986

Incidence of mites associated with stored seeds and food products in upper Egypt.

A survey on mites associated with stored seeds, flour and foodstuffs in Fayoum Governorate, Upper Egypt, proved the occurrence of about 24 species. Of these, 15 species in 8 families belong to Prostigmata, 6 species in 3 families belong to Astigmata and 3 species in 2 families belong to Mesostigmata. Members of the families Cheyletidae and Acaridae were the most common mites, found in many samples. Those of Caligonellidae, Ascidae and Raphignathidae were fairly common, but occurred in fewer types of samples. No mites were found in samples of lupine and camomile.

Animal Feed↗
PubMed1988

Reducing house-dust mites by vacuuming.

Two types of nozzles were compared for efficiency in extracting dust and house-dust mites from textile floor-coverings. From 21 homes, 2 m2 from the wall-to-wall floor-covering in the bedrooms were vacuumed. On 1-m2 the non-motorized nozzle was used, on the other 1-m2 a motorized nozzle was used. Before this sampling both test surfaces were vacuumed using the non-motorized nozzle in order to assess the mite numbers at the beginning of the experiment. The motorized nozzle appeared to be significantly more effective in extracting dust; however, for the mites no such difference could be noted.

Animals↗
PubMed1990

House-dust mite (Pyroglyphidae) populations in mattresses, and their control by electric blankets.

A reduction in house-dust-mite populations of 19-84% in beds in regular use could be achieved by heating the mattresses with electric blankets, when the beds were not being slept on. The effect of the heating treatment on the temperature and relative humidity inside the mattress is discussed. House-dust mites in the heated portions of the mattress migrated deeper inside the mattress to a depth of 3.5-5.0 cm. Evidence was also found that house-dust mites in non-heated mattresses do not only live near the surface, but that they are also present deep inside the mattress.

Animals↗
PubMed1990

Effect of heat treatments on the house-dust mites Dermatophagoides pteronyssinus and D. farinae (Acari: Pyroglyphidae) in a mattress-like polyurethane foam block.

The behaviour and survival of the house-dust mites Dermatophagoides pteronyssinus and D. farinae were studied under laboratory conditions in a mattress-like polyurethane foam block that was heated by an electric blanket. Mites obtained from a laboratory culture were introduced into the foam block which was sliced into seven horizontal layers and covered with an electric blanket. Measurements of temperature and relative humidity were taken between the layers and the number of living mites was established using the heat-escape method.

Animals↗
PubMed1988

Optimal efficacy of a fungicide preparation, natamycin, in the control of the house-dust mite, Dermatophagoides pteronyssinus.

The efficacy of a fungicidal preparation, natamycin, for the effective control of Dermatophagoides pteronyssinus (Trouessart), was determined at different concentrations on mattress-dust microsites, including ticking. One treatment with the commercially available natamycin concentration (Tymasil) resulted in a 65% reduction of house-dust mite populations within 4 weeks of treatment. The acaricidal control could be proven despite the protective role of mattress fibres such as ticking. However, mite fecundity was much more affected after treatment with twice the commercial concentration, which then assured a long-term control. Concentrations below the commercially available one were not effective. In a maritime climate, six sequential treatments three times a year would be effective for an adequate long-term control because of the high growth of house-dust fungi and the close interaction between the mite and the mould Aspergillus penicilloides.

Animals↗
PubMed1991

A review of the biology and allergenicity of the house-dust mite Euroglyphus maynei (Acari: Pyroglyphidae) [corrected].

Euroglyphus maynei is a commonly occurring mite species in house dust throughout the world, but studies of its biology and allergenicity have been relatively scarce because it is difficult to culture, and because species of the genus Dermatophagoides have attracted most attention of research workers. Euroglyphus maynei has been increasingly recognized as an important source of mite-derived allergens to which patients with house-dust mite allergy are exposed. There is a need for knowledge of its biology and allergenicity, in order to be able to grow it in vitro, and to establish whether or not it produces any unique allergens which do not cross-react with those of Dermatophagoides spp. and which may be of clinical significance. This article reviews published and unpublished data on taxonomy and identification, geographical and habitat distribution, seasonal population fluctuations, life-history and the effects of temperature and humidity, culture techniques and allergenicity of E. maynei.

Animals↗
PubMed2005

[Mites, lice and fleas. Ectoparasitoses in infancy and childhood].

Ectoparasitoses or epizoonoses are skin disorders caused by animal parasites living on the body surface. Worldwide they are among the most frequent dermatoses, particularly in infancy and childhood. Distinguishing between conditions caused by permanent and temporary ectoparasites is important for the course and the required therapy. Permanent ectoparasites, such as scabies mite and head louse, spend all their life in or on the skin and have to be killed on the patient with suitable acaricides or pediculicides. In contrast, temporary ectoparasites, as animal mites or fleas, attack humans only for feeding. Symptomatic topical therapy is usually sufficient, eventually in combination with decontamination measures in the environment. This article summarizes skin conditions caused by mites, lice and fleas with special emphasis on distinctive features in children.

Animals↗
PubMed2000

[Reduction of colonization of new mattresses with bacteria, moulds and house dust mites by complete mattress covers].

BACKGROUND AND OBJECTIVE: We investigated if the colonisation of new mattresses with house dust mites, bacteria, and fungi could be reduced by using synthetic mattress covers as compared to common cotton covers. PATIENTS/METHODS: 84 healthy volunteers were assigned to two groups. Group A (n = 43) received the cotton covers, group B (n = 41) the synthetic covers which were made of a polyester microfaser with a polyurethane surface layer (Pro-Tex, Germed, Schwarzenbek, Germany). RESULTS: The mite antigen concentration after six months was significantly lower in group B. Three months after the start of the study counts of bacteria and moulds were significantly higher in group A compared to group B. CONCLUSIONS: It can be recommended that patients suffering from an allergy to mites or moulds may reduce their domestic allergen exposure by using the synthetic mattress covers tested in this study. Since cotton covers are very likely to become colonised by bacteria and moulds, they must be cleaned periodically (at least every 2nd-3d month).

Animals↗
PubMed2002

Vasa expression and germ-cell specification in the spider mite Tetranychus urticae.

The specification of germ cells is an important process during the development of all animals. Expression of an evolutionarily conserved gene such as vasa can be used as a marker for germ cell fate. We have isolated a vasa-related gene from the two-spotted spider mite (Tetranychus urticae) and used it to examine the segregation of germ cells in this animal. In spider mites, vasa expression first appears in a group of cells that do not join the initial blastoderm surface. Instead, these cells remain in the interior of the blastoderm and then migrate to posterior regions of the embryo, where they form a cluster that appears in regions of the embryo consistent with the gonads. The expression pattern of this spider mite vasa homologue implies a novel process acts to specify germ cells in this species and that the specification of germ cells is an evolutionarily labile process.

Amino Acid Sequence↗
PubMed2004

Mitochondrial DNA and RAPD polymorphisms in the haploid mite Brevipalpus phoenicis (Acari: Tenuipalpidae).

Brevipalpus phoenicis (Geijskes) (Acari: Tenuipalpidae) is recognized as the vector of citrus leprosis virus that is a significant problem in several South American countries. Citrus leprosis has been reported from Florida in the past but no longer occurs on citrus in North America. The disease was recently reported in Central America, suggesting that B. phoenicis constitutes a potential threat to the citrus industries of North America and the Caribbean. Besides B. phoenicis, B. obovatus Donnadieu, and B. californicus (Banks) have been incriminated as vectors of citrus leprosis virus and each species has hundreds of host plants. In this study, Brevipalpus mite specimens were collected from different plants, especially citrus, in the States of Florida (USA) and São Paulo (Brazil), and reared on citrus fruit under standard laboratory conditions. Mites were taken from these colonies for DNA extraction and for morphological species identification. One hundred and two Random Amplified Polymorphic DNA (RAPD) markers were scored along with amplification and sequencing of a mitochondrial cytochrome oxidase subunit I gene fragment (374 bp). Variability among the colonies was detected with consistent congruence between both molecular data sets. The mites from the Florida and Brazilian colonies were morphologically identified as belonging to B. phoenicis, and comprise a monophyletic group. These colonies could be further diagnosed and subdivided geographically by mitochondrial DNA analysis.

Animals↗
PubMed2005

Biology and phenology of the eriophyid mite, Floracarus perrepae, on its native host in Australia, Old World climbing fern, Lygodium microphyllum.

The biology and phenology of the eriophyid mite, Floracarus perrepae Knihinicki and Boczek, a potential biological control agent of Lygoditon microphyllun (Cav.) R. Br., was studied in its native range--Queensland, Australia. F. perrepae forms leaf roll galls on the subpinnae of L. mnicrophyllum. It has a simple biology, with females and males produced throughout the year. The population was female biased at 10.5 to 1. The immature development time was 8.9 +/- 0.1 and 7.0 +/- 0.1 days; adult longevity was 30.6 +/- 1.6 and 19.4 +/- 1.2 days and mean fecundity per female was 54.5 +/- 3.2 and 38.5 +/- 1.6 eggs at 21 and 26 degrees C, all respectively. Field studies showed that the mite was active year round, with populations peaking when temperatures were cool and soil moisture levels were highest. Two species of predatory mites, Tarsonemus sp. and a species of Tydeidae, along with the pathogen Hirsutella thompsonii, had significant effects on all life stages of F. perrepae. Despite high levels of predators and the pathogen, F. perrepae caused consistent damage to L. microphyllum at all the field sites over the entire 2 years of the study.

Animals↗
PubMed2005

Correlation between olfactory responses, dispersal tendencies, and life-history traits of the predatory mite Neoseiulus womersleyi (Acari: Phytoseiidae) of eight local populations.

To investigate the relationship between foraging behavior and life-history traits of the predatory mite Neoseiulus womersleyi, the olfactory responses, dispersal ratios from a prey patch, predation rates, fecundity, and developmental times in eight local populations of N. womersleyi were investigated. Significant differences among local populations were found in all these traits except fecundity. None of the life-history traits correlated with foraging behavior. A significant positive correlation was found only between the olfactory response and the dispersal ratio. These results suggested that predatory mites with low olfactory responses would stay in a prey patch longer than predatory mites with high olfactory responses.

Animals↗
PubMed2005

Systemic use of spinosad to control the two-spotted spider mite (Acari: Tetranychidae) on tomatoes grown in rockwool.

Spinosad is a reduced-risk insecticide derived as a fermentation product from the soil actinomycete Saccharopolyspora spinosa. It is toxic by ingestion and contact and has a unique mode of action on the insect nervous system. Spinosad exhibits a high degree of selective toxicity towards the insect orders Lepidoptera, Diptera and Thysanoptera, but is less toxic to many beneficial arthropods. To determine if spinosad could be valuable as an alternative acaricide for the control of Tetranychus urticae, laboratory toxicity experiments with leaf-disk bio-assays were performed on a laboratory susceptible and several resistant strains. LC50 values were rather high in comparison with newly developed commercial acaricides. Surprisingly, when spinosad was applied to the roots of tomato plants in rock wool, excellent control of spider mites was obtained. Apparently, spinosad has systemic properties and quantities as low as 1 mg/plant could protect tomato plants from mite infestation. Different substrates with varying percentage of clay and organic matter were tested in comparison with rockwool and showed that sufficient control was restricted to the rockwool substrate. Consequently, a dose-response experiment with tomato plants grown in rockwool was set up. The persistence of spinosad toxicity when applied via the roots was determined, and pointed to a long lasting control (up to 30 DAT). Spinosad amounts in leaves after systemic application were determined with an immunological technique to quantify spinosad uptake. Correlations between mite control, spinosad uptake and leaf concentrations can be helpful to determine the necessary dose in field situations.

Animals↗