-
Experimental & Applied Acarology May 2024Varroa destructor is a significant mite pest of western honey bees (Apis mellifera). Developing a method to rear and maintain populations of V. destructor in vitro would...
Varroa destructor is a significant mite pest of western honey bees (Apis mellifera). Developing a method to rear and maintain populations of V. destructor in vitro would provide year-round access to the mites, allowing scientists to study their biology, behavior, and control more rapidly. In this study, we determined the impact of various rearing parameters on V. destructor survival and reproduction in vitro. This was done by collecting V. destructor from colonies, placing them in gelatin capsules containing honey bee larvae, and manipulating the following conditions experimentally: rearing temperature, colony source of honey bee larva, behavioral/developmental stages of V. destructor and honey bee larva, and mite:bee larva ratio. Varroa destructor survival was significantly impacted by temperature, colony source of larvae and mite behavioral stage. In addition, V. destructor reproduction was significantly impacted by mite: larva ratio, larval developmental stage, colony source of larva, and temperature. The following conditions optimized mite survival and reproduction in vitro: using a 4:1 mite:larva ratio, beginning the study with late stage uncapped larvae, using mites collected from adult bees, maintaining the rearing temperature at 34.5° C, and screening larval colony source. Ultimately, this research can be used to improve V. destructor in vitro rearing programs.
Topics: Animals; Varroidae; Bees; Larva; Beekeeping; Reproduction; Temperature
PubMed: 38478141
DOI: 10.1007/s10493-024-00905-8 -
The Medical Letter on Drugs and... Jun 2024
Topics: Humans; Blepharitis; Animals; Mite Infestations; Mites
PubMed: 38905524
DOI: 10.58347/tml.2024.1705b -
Annals of Allergy, Asthma & Immunology... Mar 2024A lower adherence rate existed in patients receiving allergen-specific immunotherapy due to its lengthy period and adverse effects even though it is the only curative... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
A lower adherence rate existed in patients receiving allergen-specific immunotherapy due to its lengthy period and adverse effects even though it is the only curative treatment for IgE-mediated allergies. Therefore, exploring innovative allergen-specific immunotherapy routes is necessary.
OBJECTIVE
To explore the efficacy and safety of the intratonsillar injection of house dust mite (HDM) extract in patients with HDM-induced allergic rhinitis (AR).
METHODS
A randomized, double-blind, placebo-controlled clinical trial was conducted. A total of 80 patients with HDM-induced AR were randomized to receive 6 intratonsillar injections with HDM extract or placebo in 3 months. The total nasal symptom score (TNSS), visual analogue scale of nasal symptoms, combined symptom and medication score, mini rhinoconjunctivitis quality of life questionnaire, and serum allergen-specific IgG4 to Dermatophagoides pteronyssinus were all monitored at baseline and 3 months, 6 months, and 12 months after the treatment was finished. The intent-to-treat and per-protocol set (PPS) are both analyzed.
RESULTS
The primary end points TNSS and ΔTNSS were improved significantly at 3 months after the patients with AR finished a 3-month 6-injection intratonsillar immunotherapy compared with those in the placebo treatment in both intent-to-treat and PPS. Results of visual analogue scale, combined symptom and medication score, and mini rhinoconjunctivitis quality of life questionnaire were also improved significantly at 3 months after the treatment in PPS. However, the improvement effect of intratonsillar immunotherapy at 6 and 12 months was limited and uncertain based on the data. The increase of serum Der p IgG4 in the active group was significantly higher than that in the placebo group at 3, 6, and 12 months after the treatment was finished. Adverse events were monitored, and no systemic adverse reactions were observed.
CONCLUSION
The clinical trial revealed that intratonsillar injection with HDM extract was safe and effective in patients with AR. Optimizing the protocol and allergen formulations is expected to increase and maintain the efficacy of this novel approach.
TRIAL REGISTRATION
https://www.chictr.org.cn/index.html, identifier: ChiCTR-TRC-13003600.
Topics: Animals; Humans; Quality of Life; Pyroglyphidae; Sublingual Immunotherapy; Treatment Outcome; Antigens, Dermatophagoides; Rhinitis, Allergic; Allergens; Rhinitis, Allergic, Perennial; Double-Blind Method; Conjunctivitis; Immunoglobulin G
PubMed: 37913839
DOI: 10.1016/j.anai.2023.10.029 -
Microbial Ecology Aug 2023The importance of species that connect the different types of interactions is becoming increasingly recognized, and this role may be related to specific attributes of...
The importance of species that connect the different types of interactions is becoming increasingly recognized, and this role may be related to specific attributes of these species. Multilayer networks have two or more layers, which represent different types of interactions, for example, between different parasites and hosts that are nonetheless connected. The understanding of the ecological relationship between bats, ectoparasites, and vector-borne bacteria could shed some light on the complex transmission cycles of these pathogens. In this study, we investigated a multilayer network in Brazil formed by interactions between bat-bacteria, bat-ectoparasite, and ectoparasite-bacteria, and asked how these interactions overlap considering different groups and transmission modes. The multilayer network was composed of 31 nodes (12 bat species, 14 ectoparasite species, and five bacteria genera) and 334 links, distributed over three layers. The multilayer network has low modularity and shows a core-periphery organization, that is, composed of a few generalist species with many interactions and many specialist species participating in few interactions in the multilayer network. The three layers were needed to accurately describe the multilayer structure, while aggregation leads to loss of information. Our findings also demonstrated that the multilayer network is influenced by a specific set of species that can easily be connected to the behavior, life cycle, and type of existing interactions of these species. Four bat species (Artibeus lituratus, A. planirostris, Phyllostomus discolor, and Platyrrhinus lineatus), one ectoparasite species (Steatonyssus) and three bacteria genera (Ehrlichia, hemotropic Mycoplasma and Neorickettsia) are the most important species for the multilayer network structure. Finally, our study brings an ecological perspective under a multilayer network approach on the interactions between bats, ectoparasites, and pathogens. By using a multilayer approach (different types of interactions), it was possible to better understand these different ecological interactions and how they affect each other, advancing our knowledge on the role of bats and ectoparasites as potential pathogen vectors and reservoirs, as well as the modes of transmission of these pathogens.
Topics: Animals; Chiroptera; Brazil; Mites
PubMed: 36166070
DOI: 10.1007/s00248-022-02108-3 -
Journal of Invertebrate Pathology Jun 2024The two-spotted spider mite (Tetranychus urticae Koch) is an agriculturally serious polyphagous pest that has acquired strong resistance against acaricides because of...
The two-spotted spider mite (Tetranychus urticae Koch) is an agriculturally serious polyphagous pest that has acquired strong resistance against acaricides because of its short life cycle and continuous exposure to acaricides. As an alternative, mite-pathogenic fungi with different modes of action could be used to control the mites. The spider mite has symbiotic microorganisms that could be involved in the physiological and ecological adaptations to biotic stresses. In this study, mite-pathogenic fungi were used to control female adults, and the microbiomes changes in the fungus-infected mites were analyzed. The acaricidal activity of 77 fungal isolates was tested, and Akanthomyces attenuatus JEF-147 exhibited the highest acaricidal activity. Subsequently a dose-response assay and morphological characterization was undertaken For microbiome analysis in female adults infected with A. attenuatus JEF-147, 16S rDNA and ITS1 were sequenced using Illumina Miseq. Infected mite showed a higher Shannon index in bacterial diversity but lower index in fungal diversity. In beta diversity using principal component analysis, JEF-147-treated mites were significantly different from non-treated controls in both bacteria and fungi. Particularly in bacterial abundance, arthropod defense-related Rickettsia increased, but arthropod reproduction-associated Wolbachia decreased. The change in major bacterial abundance in the infected mites could be explained by a trade-off between reproduction and immunity against the early stage of fungal attack. In fungal abundance, Akanthomyces showed up as expected. Foremost, this work reports microbiome changes in a fungus-infected mite and suggests a possible trade-off in mites against fungal pathogens. Future studies will focus on gene-based investigations related to this topic.
Topics: Animals; Tetranychidae; Microbiota; Female; Pest Control, Biological
PubMed: 38604562
DOI: 10.1016/j.jip.2024.108102 -
American Journal of Rhinology & Allergy Jul 2024Inhalant allergens provide a source of environmental factors that contribute to the development of clinical symptoms in patients with atopic dermatitis (AD). (Review)
Review
BACKGROUND
Inhalant allergens provide a source of environmental factors that contribute to the development of clinical symptoms in patients with atopic dermatitis (AD).
OBJECTIVE
To review the relationship between inhalant allergens and AD.
METHODS
A literature review was conducted using three databases: PubMed/MEDLINE, ClinicalKey, and Web of Science. Search terms, including "atopic dermatitis," "atopic eczema," and "eczema," were used in combination with "inhalant allergen," "inhaled allergen," and "aeroallergen" to identify relevant published manuscripts that highlight the relationship between AD and exposures to inhalant allergens.
RESULTS
Fifteen articles were suitable for review. The studies included in the review investigated the effect of inhalant allergens on the clinical manifestations of AD through bronchial provocation, direct skin contact, and allergen sensitization.
CONCLUSION
There is a significant relationship between exposures to inhalant allergens and AD. Inhalant allergens may aggravate AD symptoms by either bronchial provocation or direct skin contact. Sensitization of inhalant allergens, mainly house dust mites, follows a specific age-related pattern.
Topics: Humans; Dermatitis, Atopic; Allergens; Animals; Pyroglyphidae; Bronchial Provocation Tests; Inhalation Exposure
PubMed: 38623643
DOI: 10.1177/19458924241246855 -
Parasitology Aug 2023Rodents are known hosts for various ectoparasite taxa such as fleas, lice, ticks and mites. South Africa is recognized for its animal diversity, yet little is published...
Rodents are known hosts for various ectoparasite taxa such as fleas, lice, ticks and mites. South Africa is recognized for its animal diversity, yet little is published about the parasite diversity associated with wild rodent species. By focusing on a wildlife-human/domestic animal interface, the study aims to record ectoparasite diversity and levels of infestations of the Bushveld gerbil, , and to establish the relationship between ectoparasite infestation parameters and host- and habitat factors. Rodents ( = 127) were trapped in 2 habitat types (natural and agricultural) during 2014–2020. More than 6500 individuals of 32 epifaunistic species represented by 21 genera and belonging to 5 taxonomic groups (fleas, sucking lice, ticks, mesostigmatan mites and trombiculid mites) were collected. Mesostigmatan mites and lice were the most abundant and fleas and mesostigmatan mites the most prevalent groups. Flea and mesostigmatan mite numbers and mesostigmatan mite species richness was significantly higher on reproductively active male than female rodents. Only ticks were significantly associated with habitat type, with significantly higher tick numbers and more tick species on rodents in the natural compared to the agricultural habitat. We conclude that the level of infestation by ectoparasites closely associated with the host (fleas and mites) was affected by host-associated factors, while infestation by ectoparasite that spend most of their life in the external environment (ticks) was affected by habitat type.
Topics: Animals; Male; Female; Humans; Gerbillinae; Ectoparasitic Infestations; Mites; Ticks; Flea Infestations; Siphonaptera; Phthiraptera; Trombiculidae; Ecosystem
PubMed: 37272490
DOI: 10.1017/S0031182023000562 -
Journal of Economic Entomology Dec 2023Severe bermudagrass mite (Aceria cynodoniensis Sayed) infestation stunts turfgrass growth and reduces the aesthetic and recreational value of managed bermudagrass....
Severe bermudagrass mite (Aceria cynodoniensis Sayed) infestation stunts turfgrass growth and reduces the aesthetic and recreational value of managed bermudagrass. Management practices, such as fertilization, mowing, and irrigation, may impact bermudagrass mite infestation and damage, but empirical evidence is lacking. Two 20 wk experiments were conducted with potted bermudagrass in a greenhouse or nursery to evaluate the effect of varying nitrogen rates (0, 24.5, or 49 kg N/ha), mowing heights (1.3, 2.5, 3.8, or 5 cm), and irrigation rates (60%, 100%, or 140% evapotranspiration [ET] rate) on the densities of witch's brooms (i.e., stunted and deformed terminals symptomatic of infestation) and bermudagrass mites. Increasing nitrogen fertility from 0 to 49 kg N/ha increased witch's broom and bermudagrass mite densities by 292% and 339%, respectively. Bermudagrass fertilized with nitrogen maintained higher turf quality than unfertilized grass despite greater mite damage. Decreasing irrigation from 140% to 60% of the ET rate also increased witch's broom densities by 124%. Mowing height did not consistently affect witch's broom or mite densities. Witch's broom and mite densities were positively correlated and followed a general trend with greater densities in April-August and a decline in densities in August-October. These findings suggest that nitrogen fertilization and water stress influence bermudagrass mite damage. Thus, limiting nitrogen fertilization to a level necessary to maintain turfgrass health and quality (0.5 kg N/ha) and minimizing turfgrass water stress can complement current chemical control strategies as part of an integrated pest management program.
Topics: Animals; Mites; Cynodon; Nitrogen; Dehydration; Fertility
PubMed: 37950912
DOI: 10.1093/jee/toad205 -
Otolaryngology--head and Neck Surgery :... Mar 2024To evaluate the efficacy and safety of dust mite subcutaneous immunotherapy (SCIT) in monosensitized and polysensitized children with allergic rhinitis (AR).
OBJECTIVE
To evaluate the efficacy and safety of dust mite subcutaneous immunotherapy (SCIT) in monosensitized and polysensitized children with allergic rhinitis (AR).
STUDY DESIGN
Prospective cohort study.
SETTING
Tertiary referral center.
METHODS
One hundred thirty children were enrolled and categorized into 2 groups: monosensitized to only dust mites and polysensitized to at least 1 additional allergen beyond dust mites. All patients received SCIT targeting dust mites for 3 years, followed by a 5-year monitoring period. The Total Nasal Symptom Score (TNSS), Symptom and Medication Score (SMS), Visual Analogue Scale (VAS), and Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) were assessed before SCIT (T0); at 1 (T1) and 2 (T2) years of SCIT; immediately after SCIT (T3); and 2 years post-SCIT (T5). Safety was assessed based on adverse events (AEs).
RESULTS
Fifty-one monosensitized and 50 polysensitized children completed the study. At T3, 47 monosensitized and 46 polysensitized children were effectively treated, with no significant between-group difference in efficacy (P > .05). The TNSS, SMS, VAS scores, and RQLQ score were significantly lower at T1, T2, T3, and T5 than at T0 in both groups (P < .05). The differences in the TNSS, SMS, VAS score, and RQLQ score between the 2 groups were nonsignificant at T0, T1, T2, and T3 (P > .05), but significant at T5 (P < .05). No serious AEs were reported.
CONCLUSION
Monosensitized and polysensitized children exhibited similar beneficial efficacy and safety after 3 years of dust mite SCIT. Monosensitized children derived more benefits 2 years after discontinuation.
Topics: Child; Animals; Humans; Prospective Studies; Quality of Life; Sublingual Immunotherapy; Treatment Outcome; Antigens, Dermatophagoides; Rhinitis, Allergic; Allergens; Pyroglyphidae; Immunotherapy; Dust
PubMed: 38104318
DOI: 10.1002/ohn.614 -
Respiratory Research Feb 2024Asthma is a heterogeneous disease characterized by airway inflammation and remodeling, whose pathogenetic complexity was associated with abnormal responses of various...
BACKGROUND
Asthma is a heterogeneous disease characterized by airway inflammation and remodeling, whose pathogenetic complexity was associated with abnormal responses of various cell types in the lung. The specific interactions between immune and stromal cells, crucial for asthma pathogenesis, remain unclear. This study aims to determine the key cell types and their pathological mechanisms in asthma through single-cell RNA sequencing (scRNA-seq).
METHODS
A 16-week mouse model of house dust mite (HDM) induced asthma (n = 3) and controls (n = 3) were profiled with scRNA-seq. The cellular composition and gene expression profiles were assessed by bioinformatic analyses, including cell enrichment analysis, trajectory analysis, and Gene Set Enrichment Analysis. Cell-cell communication analysis was employed to investigate the ligand-receptor interactions.
RESULTS
The asthma model results in airway inflammation coupled with airway remodeling and hyperresponsiveness. Single-cell analysis revealed notable changes in cell compositions and heterogeneities associated with airway inflammation and remodeling. GdT17 cells were identified to be a primary cellular source of IL-17, related to inflammatory exacerbation, while a subpopulation of alveolar macrophages exhibited numerous significantly up-regulated genes involved in multiple pathways related to neutrophil activities in asthma. A distinct fibroblast subpopulation, marked by elevated expression levels of numerous contractile genes and their regulators, was observed in increased airway smooth muscle layer by immunofluorescence analysis. Asthmatic stromal-immune cell communication significantly strengthened, particularly involving GdT17 cells, and macrophages interacting with fibroblasts. CXCL12/CXCR4 signaling was remarkedly up-regulated in asthma, predominantly bridging the interaction between fibroblasts and immune cell populations. Fibroblasts and macrophages could jointly interact with various immune cell subpopulations via the CCL8/CCR2 signaling. In particular, fibroblast-macrophage cell circuits played a crucial role in the development of airway inflammation and remodeling through IL1B paracrine signaling.
CONCLUSIONS
Our study established a mouse model of asthma that recapitulated key pathological features of asthma. ScRNA-seq analysis revealed the cellular landscape, highlighting key pathological cell populations associated with asthma pathogenesis. Cell-cell communication analysis identified the crucial ligand-receptor interactions contributing to airway inflammation and remodeling. Our findings emphasized the significance of cell-cell communication in bridging the possible causality between airway inflammation and remodeling, providing valuable hints for therapeutic strategies for asthma.
Topics: Mice; Animals; Ligands; Asthma; Lung; Inflammation; Cell Communication; Single-Cell Analysis; Airway Remodeling; Pyroglyphidae; Disease Models, Animal
PubMed: 38317239
DOI: 10.1186/s12931-024-02706-4