Identification Of Mites Research Articles

Visual Diagnosis: A Family That Has an Itchy Rash

1. Tamar Stricker, MD* 2. Felix H. Sennhauser, MD* 1. 2. *University Childres’s Hospital, Zurich, Switzerland. A brother and sister are brought to the clinic for evaluation of an itchy rash of 4 months’ duration. The 4-year-old girl and 8-month-old boy each have a red, raised, and scaly rash extending over their trunk and extremities. In the previous week, they had developed inflamed, cracked bumps on their feet that intermittently bled and had a yellow discharge. Both parents also have an itchy rash. There is no history of recent illness or use of any topical agents. The family had been living in crowded conditions in Switzerland for 6 months, having emigrated from eastern Europe as refugees. Both children had received their primary immunizations for diphtheria, tetanus, pertussis, polio, Haemophilus influenzae type b, and hepatitis B upon arrival in Switzerland. The girl also had received immunization against mumps, measles, and rubella. On physical examination, the girl is afebrile and appears well. Her height and weight are normal (75th to 90th percentile and 50th to 75th percentile, respectively). Dry, abraded skin lesions with occasional thickening and crusting are present over the scalp, nape of the neck, trunk, buttocks, and extremities. The lesions are more pronounced in the axillae and flexor surfaces of the legs and have an annular configuration (Fig. 1⇓ ). Honey-colored crusts with surrounding erythema cover the lower legs and feet. Results of the remainder of the physical examination are normal. Figure 1. Annular, dry, abraded lesions on lower leg. The 8-month-old boy, also afebrile and well-appearing, has …

Identification of cecidophyopsis mites (Acari: Eriophyidae) based on variable simple sequence repeats of ribosomal DNA internal transcribed spacer-1 sequences via multiplex PCR.

A PCR multiplex technique was developed for identifying Cecidophyopsis mites using species-specific differences in rDNA ITS-1 sequences. Four PCR primers derived from ITS-1 were used for the simultaneous amplification (multiplex PCR) of interspecifically variable simple sequence repeats (vSSRs). Mites were identified by electrophoresing PCR products alongside those obtained from plasmids containing ITS copies of known mite species. The multiplex PCR assay was rapid, reproducible and had a sensitivity comparable to sequencing. It was used to identify mite specimens on Ribes from around the world. It also identified a profile from mites on R. rubrum that had no equivalent amongst the known Cecidophyopsis species. Sequence and ecological analysis of this mite suggest that it is a new species of nongall-forming Cecidophyopsis mite.

Oribatid mite biodiversity in agroecosystems: role for bioindication

The general ecology, biology, life history, and available sources for identification of oribatid mites (including Astigmata), the most numerically dominant arachnid group in the organic horizons of most soils, is reviewed. I use this information as the basis to evaluate data on their role for bioindication in agroecosystems, with the following conclusions: (a) oribatid mites with their low metabolic rates, slow development and low fecundity cannot respond rapidly to resource flushes: astigmatic mites with their contrasting life history traits can respond rapidly; (b) because many agroecosystems represent early successional stages, the oribatid species present are those found in heavily disturbed or early successional habitats, wherever these occur; (c) use of oribatid mites for bioindication must incorporate information on life history traits, and habitat and niche profiles for species.

Taxonomy and identification of dust mites.

Taxonomy provides the basis for the identity of species, allowing the construction of keys and the reliable, reproducible identification of dust mites for ecologic purposes and other studies. Details are given of nomenclatorial conventions in taxonomy as applied to dust mites, and taxonomically problematic entities are highlighted, such as Blomia kulagini and the sibling species Dermatophagoides farinae and D. microceras. Current keys to dust mites and advances in interactive computer keys are reviewed. An hypothesis of the phylogeny of the family Pyroglyphidae is presented, based on habitat specificity, geographic distribution, and association with birds. The value of predictive classifications based on phylogenies is stressed. Finally, a pictorial key is presented to the mites found in house dust in Scandinavia.

Dermatophagoides sp. and IgE anti-D. pteronyssinus and D. farinae detection in a Venezuelan community at more than 2000 m above the sea level.

It has been reported that the concentration of Dermatophagoides sp. population, the main trigger of asthma in sensitized atopic subjects, is inversely related with altitude and probably directly with humidity and that this population are scarcely found over 1750 m above sea level. We studied the presence of Dermatophagoides sp. in a Venezuelan community between 2040 and 2600 m above sea level, and also the IgE response to D. pteronnyssinus and D. farinae in atopic subjects living on that region. The presence of Dermatophagoides sp. was determined by microscopic identification of mites in dust, obtained by brushing the mattresses surface in 93 randomly selected houses between 2040 and 2600 m above sea level. The indoor relative humidity was also measured. The specific IgE serum levels were studied in 65 subjects classified as asthmatics, allergic non-asthmatics and non-allergic. A mean concentration of 188 mites/g of room dust was determined in 82.4% of houses with an indoor relative humidity ranging from 89% and 92% independently of altitude. The density of Dermatophagoides sp. was sufficiently high to sensitize the atopic subjects, IgE levels were 6.8 PRU mean value for asthmatic, against 0.38 PRU in non-atopic. We conclude that: (a) Dermatophagoides sp. can be found up to 2600 m above sea level in a Venezuelan neotropical region where a high indoor relative humidity is characteristic of most dwellings; (b) sensitization by D. pteronyssinus and D. farinae were demonstrated in atopic subjects resident at that region.

Two genetically distinct populations of Varroa jacobsoni with contrasting reproductive abilities on Apis mellifera

SUMMARYThis paper demonstrates the presence of two genetically distinct populations of Varroa jacobsoni that show contrasting abilities to reproduce on Apis mellifera and can be identified easily using simple molecular techniques. When Australian-reared A. mellifera sister queens were transported to Germany and Papua New Guinea and established in varroa-infested colonies, the female V. jacobsoni in Germany readily reproduced on their brood whereas in Papua New Guinea they did not. These observations indicate that the cause of the reported inability of female V. jacobsoni to reproduce on A. mellifera in Papua New Guinea does not rest with the resident A mellifera population. DNA sequences of a 454 base-pair region of the cytochrome oxidase subunit 1 (CO1) gene obtained from reproducing V. jacobsoni collected from A. mellifera colonies in Germany differed by 6.8% from similar sequences obtained from non-reproducing V. jacobsoni from A. mellifera colonies in Papua New Guinea. The presence of a Xho I restriction endonuclease (RE) site in the German but not in the Papua New Guinea sequences, and a Sac I RE site in the Papua New Guinea but not in the German sequences, allowed for the rapid identification of individual mites of the German (GER) and Papua New Guinea (PNG) genotypes. Further studies confirmed that non-reproducing female V. jacobsoni that were the only V. jacobsoni present in A. mellifera colonies in Java, Indonesia, prior to 1993 were of the PNG genotype. However, reproducing female V. jacobsoni that suddenly appeared in A. mellifera colonies in Java in 1993 were of the GER genotype. Following 1993, reproducing mites of the GER genotype and non-reproducing mites of the PNG genotype were detected in a single A. mellifera colony in Java and in another single colony in another region of Indonesia. These results clearly demonstrate that differences in mite genotype can explain observed differences and changes in the virulence of V. jacobsoni toward A. mellifera.

Mite-contaminated foods as a cause of anaphylaxis

Although insect and arthropod contamination of certain foods has been recognized for many years, allergic manifestations caused by ingestion of mite allergens have only rarely been reported. The purpose of this study is to present clinical observations in patients who experienced acute anaphylaxis after eating mite-contaminated foods. Thirty atopic subjects who were first seen with systemic anaphylaxis precipitated by the ingestion of wheat-containing foods underwent skin prick tests with inhalant and food extracts, as well as with uncontaminated and mite-contaminated wheat flour. Flour samples were examined microscopically for identification and counting of mites. Der p 1 and Der f 1 levels were quantitated by using immunochemical methods. The most common symptoms were breathlessness, angioedema, wheezing, and rhinorrhea, which started between 10 and 240 minutes after eating. Abundant mites were present in the flour obtained from 28 patients; Suidasia spp. mites were found in grated bread from the other two patients. Positive prick test responses to Dermatophagoides farinae-and mite-contaminated flour and negative skin test responses to wheat extract, other food extracts, and uncontaminated wheat flour were found in all patients. Skin test responses were positive in volunteers with mite allergy even after heating the mite-contaminated flour at 100 degrees C. Screening of 35 unselected flour samples demonstrated the presence of mites in 13 of them (37.1%). Systemic anaphylaxis can occur after the ingestion of heated or unheated mite-contaminated foods. This problem may be more prevalent in tropical and subtropical countries than previously recognized.

Occupational Allergic Disease in Cereal Workers by Stored Grain Pests

It is well known that workers occupationally exposed to grain dust have a high prevalence of respiratory symptoms, but their pathogenesis remains obscure when sensitization to cereal flour cannot be demonstrated. Storage mites, tenebroids, and cockroaches are stored-grain pests found in grain and cereal products frequently in our area, where the cereal industry is the most important industry. An epidemiological analysis of sensitization to these stored-grain pests was performed on 4379 patients residing in an area of cereal industries. Fifty grain workers were selected for in vivo diagnostic tests with nine genera of mites, Tenebrio molitor and Blatta orientalis. Specific IgE antibodies to the extracts were demonstrated by prick tests and RAST. Association between respiratory symptoms and occupational exposure was confirmed by challenge tests (specific and methacholine). The prevalence of mite sensitization in the total sample studied (4379) was 18.96% (SEM 0.58, 95% CI 16.93-19.19). The prevalence of sensitization to storage mites among mite-sensitive patients was 11.88% (SEM 1.15, 95% CI 9.63-14.3). Among the 50 selected patients the most frequent sensitization was that to Dermatophagoides pteronyssinus (58%), followed by Dermatophagoides frinae (48%), Lepidoglyphus destructor and Tyrophagus putrescentiae (38%), Blomia kulagini (34%), and Acarus siro and Chortoglyphus arcuatus (24%). In addition, 22% of the patients presented negative prick tests and RAST for Dermatophagoides species with positive test to storage mites. Fifty percent of the 50 patients were sensitizated to Tenebrio molitor (SEM 0.7, CI 95% 36–64), and 36% to Blatta orientalis (SEM 0.67, CI 95% 23–49). The identification of mites, tenebroids, and cockroaches in dust samples yields useful data for the diagnosis of our patients.

Identification and occurrence of phytoseiid mites (Gamasina: Phytoseiidae) in Finnish apple plantations and their surroundings

Twelve species in eight genera of the family Phytoseiidae have been found to occur on apple trees and an additional eight species on various trees or bushes in their surroundings in Finland. Identification keys, supported by figures, are presented for 23 species, including three introduced species. The keys are based on published literature and on the examination of adult females collected in 1985-1991. The aim of the keys and descriptions is to help non-taxonomist researchers with identification. Notes on the occurrence of the species on apple and other host plants in Finland are included.

Expertise in expert systems: knowledge acquisition for biological expert systems.

In this paper it is argued that an expert system requires more than factual knowledge before it can display expertise in a given domain. The additional knowledge consists of the heuristics or 'rules of thumb' used by an expert to manipulate and interpret the factual knowledge. The knowledge acquisition phase of an expert system project involves determining the factual knowledge (which may be obtained from published sources) and the heuristics used by an expert to manipulate that knowledge--these heuristics can only be obtained from an expert. In reviewing existing biological expert systems it is apparent that many contain only the factual knowledge relating to the domain, and lack the heuristics that enable such systems to show expertise. This paper reviews a number of knowledge acquisition techniques which could be used for acquiring heuristic knowledge and discusses when their use is appropriate. The knowledge acquisition techniques discussed are those suitable for the development of small-scale expert systems as these are most likely to be of interest to biologists. The techniques include the use of questionnaires, interview techniques and protocol analysis; particular emphasis is placed on a modification to the 'twenty questions' interview technique which was developed specifically to elicit taxonomic knowledge relating to water mite identification.

Pictorial keys for the identification of domestic mites.

Pictorial keys for the identification of domestic mites.

Identification of house-dust mites

The term house-dust mite usually refers to those species of the mite family Pyroglyphidae, that are known to commonly occur, although sometimes regionally, in the dust of human dwellings. These species belong to five genera:Dermatophagoides, Euroglyphus, Hirstia, andMalayoglyphus. Related species ofDermatophagoides have the most world-wide occurrence, the commonest being:D. farinae, D. microceras, andD. pteronyssinus.

Altitude and house dust mites

The effects of altitude on house dust mites (one of the allergenic components of house dust) and the synthesis of anti-acari IgE antibodies were studied. Flotation extraction, counting, and identification of mites were performed each season for 1 yr on 218 mattress-dust samples taken from the Briancon region in the Alps, 900 to 3170 meters in altitude. Of the total dust samples, 41 were repeatedly positive and 177 repeatedly negative. The percentage of positive samples and the concentration of mites varied inversely with the altitude (40% positive with seven mites per 100 mg of dust at 900 to 1100 m, 14% and 4/100 mg at 1200 to 1350 m, 6% and 2/100 mg at 1400 to 1600 m, and 0% at higher altitudes). Species did not vary with altitude ( Dermatophagoides pteronyssinus 17%, Euroglyphus maynei 51%). In contrast, on the plain we found 80% of 77 dust samples positive (88 mites/100 mg of dust, 65% D. pteronyssinus ), with the peak in autumn. Total and specific IgE were measured initially and every 3 mo in 42 asthmatic children with positive skin tests to D. pteronyssinus and subjected to a 9-mo stay in Briancon (the highest city in Europe, 1365 m altitude). Geometric mean of initial total IgE (1047 U/ml) dropped to 40% (p≤0.001); specific IgE to D. pteronyssinus also fell. The value of climate change as a therapeutic modality in asthma is not supported by convincing data but may be attributed in some cases to removal of antigenic stimulation. The decrease in the number of mites and in IgE levels at higher altitudes supports this hypothesis.

Identification of mites and establishment of screening method in ear canker of rabbits (author's transl)

当施設では過去数年にわたりウサギの耳疥癬症の蔓延に悩まされてきた。そこで, 本症の治療, 撲滅および予防法を確立するために一連の研究を始めた。本研究では原因ダニの同定と簡単なダニのスクリーニング法の確立を試み, 次の結果を得た。1, 当施設のウサギの耳疥癬症はPsoroptes cuniculi (ウサギキュウセンヒゼンダニ) によることがわかった。2.簡単なダニのスクリーニング法として「接着ダニ検査法 (mite adhering test) 」を考案した。この検査法により, ダニが肉眼的病巣を形成する以前に, ダニの寄生の有無を調べることができた。3.接着ダニ検査法と肉眼的観察の併用により, 本症を非常に早期に発見できることを明らかにした。この併用により当施設で飼育中のウサギ216匹中75匹 (34.7%) が耳疥癬症と診断された。

Three new ophidian lung mites of the subfamily Entonyssinae Ewing, 1922

1. Three new species of dermanyssid mites of the subfamily Entonyssinae are described. These are: Entonyssus heterodontos n.sp. from Heterodon contortrix contortrix, Ophiopneumicola elaphes n.sp. from Elaphe obsolete, obsoleta, Ophiopneumicola natricis n.sp. from Natrix sipedon pictiventris.2. Keys for the identification of male and female mites of the Entonyssinae are given.3. 141 snakes, representing thirty-five species, were examined for lung mites. Thirteen individuals, representing eight species, were found to be infested.4. Two species incertae sedis, one from Pituophis sayi, the other from Coluber constrictor flaviventris, are discussed.5. Problems of classification and distribution of this group of parasites are discussed.