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Coby Schal - One of the best experts on this subject based on the ideXlab platform.
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allergen content in german Cockroach extracts and sensitization profiles to a new expanded set of Cockroach allergens determine in vitro extract potency for ige reactivity
The Journal of Allergy and Clinical Immunology, 2019Co-Authors: Jill Glesner, Coby Schal, Martin D. Chapman, Stephanie Filep, Lisa D Vailes, Sabina Wunschmann, Giovanni Birrueta, April Frazier, Kyoung Yong Jeong, Leonard B BacharierAbstract:Background Cockroach allergens are an important cause of IgE-mediated sensitization in inner-city asthmatic patients. However, Cockroach extracts used for diagnosis and immunotherapy are not standardized. Objective We sought to determine the allergen content of nonstandardized German Cockroach extracts and the levels of sensitization to an expanded set of Cockroach allergens as determinants of in vitro extract potency for IgE reactivity. Methods Twelve German Cockroach extracts were compared for allergen content and potency of IgE reactivity. Bla g 1, Bla g 2, and Bla g 5 were measured by using immunoassays. IgE antibody levels to 8 purified recombinant allergens from groups 1, 2, 4, 5, 6, 7, 9, and 11 were measured by using ImmunoCAP. IgE antibody binding inhibition assays were performed to assess extract in vitro potencies (concentration inhibiting 30% of the total IgE antibody-binding inhibition) relative to an arbitrarily selected reference extract in 5 patients with Cockroach allergy. Results Allergen levels were highly variable. Three new major allergens (groups 6, 9, and 11), were identified among highly Cockroach-sensitized subjects (CAP class ≥ 3). Sensitization profiles were unique per subject without immunodominant allergens. The sum of IgE to 8 allergen components showed a good correlation with Cockroach-specific IgE levels (r = 0.88, P Conclusions The in vitro potency of German Cockroach extracts for IgE reactivity depends on allergen content and allergen-specific IgE titers of patients with Cockroach allergy. These factors are relevant for selection of potent extracts to be used for immunotherapy and for the design and interpretation of data from immunotherapy trials.
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A single intervention for Cockroach control reduces Cockroach exposure and asthma morbidity in children.
The Journal of allergy and clinical immunology, 2017Co-Authors: Felicia A. Rabito, John C. Carlson, Derek Werthmann, Coby SchalAbstract:Background Exposure to Cockroaches is an important asthma trigger, particularly for children with asthma living in inner cities. Integrated pest management is the recommended approach to Cockroach abatement; however, it is costly and difficult to implement. The impact of reducing Cockroach exposure on asthma outcomes is not known. Objective We sought to test the use of a single intervention, insecticidal bait, to reduce Cockroach exposure in the home of children with asthma in New Orleans and to examine the impact of Cockroach reduction on asthma outcomes. Methods One hundred two children aged 5 to 17 years with moderate to severe asthma were enrolled in a 12-month randomized controlled trial testing the use of insecticidal bait on Cockroach counts and asthma morbidity. Homes were visited 6 times and asthma symptoms were assessed every 2 months. Results After adjustment, intervention homes had significantly fewer Cockroaches than did control homes (mean change in Cockroaches trapped, 13.14; 95% CI, 6.88-19.39; P P = .03; 1.17, 95% CI, 0.11-2.24, P = .03, respectively) and a higher proportion of children with FEV 1 of less than 80% predicted (odds ratio, 5.74; 95% CI, 1.60-20.57; P = .01) compared with children living in intervention homes. Conclusions Previous research has demonstrated improvement in asthma health outcomes using multifaceted interventions. The strategic placement of insecticidal bait, which is inexpensive, has low toxicity, and is widely available, resulted in sustained Cockroach elimination over 12 months and was associated with improved asthma outcomes. This single intervention may be an alternative to multifaceted interventions currently recommended to improve asthma morbidity.
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German Cockroach Allergen Levels in North Carolina Schools: Comparison of Integrated Pest Management and Conventional Cockroach Control
Journal of medical entomology, 2009Co-Authors: Godfrey Nalyanya, J. Chad Gore, H. Michael Linker, Coby SchalAbstract:Cockroach suppression is fundamental to Cockroach allergen mitigation in infested homes. The effects of various Cockroach control strategies on Cockroach populations and allergen concentration have not been examined in schools. This study was conducted to compare the effectiveness of integrated pest management (IPM) and conventional pest control in controlling German Cockroach (Blattella germanica L.) infestations and concentrations of the Cockroach allergen Bla g 1 in public school buildings. Two school districts included six schools that used conventional pest control and one district included seven schools that used IPM to control pests. Cockroach traps were deployed to assess the level of infestation, settled dust samples were collected in food service areas, classrooms, and other school areas, and the Bla g 1 allergen was quantified by ELISA. Both Cockroach counts and Bla g 1 concentrations were dependent on the pest control approach, with highly significant differences between IPM-treated schools and conventionally treated schools in both the Cockroach mean trap counts (0 versus 82.6 ± 17.3 Cockroaches/trap/wk, respectively) and in the amount of Bla g 1 in dust samples (2.8 ± 0.3 versus 30.6 ± 3.4 U/g dust). Cockroaches and Bla g 1 were primarily associated with food preparation and food service areas and much less with classrooms and offices. Our data extend recent findings from studies in homes, showing that Cockroach allergens can be reduced by Cockroach elimination alone or by integrating several tactics including education, cleaning, and pest control. IPM is not only effective at controlling Cockroaches but also can lead to long-term reductions in Cockroach allergen concentrations, resulting in a healthier environment for students and school personnel.
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Cockroach allergen reduction by Cockroach control alone in low-income urban homes: a randomized control trial.
The Journal of allergy and clinical immunology, 2007Co-Authors: Michelle L Sever, Herman Mitchell, J. Chad Gore, Coby Schal, Samuel J. Arbes, Richard G. Santangelo, Ben Vaughn, Darryl C. ZeldinAbstract:Background We previously reported significant reductions in Cockroach allergen concentrations in urban homes by reducing Cockroach infestations. Objective To determine the effectiveness of pest control performed by professional entomologists, compared with commercial companies, in reducing Cockroach allergen. Methods This 3-arm randomized controlled trial enrolled 60 Cockroach-infested homes in North Carolina. Homes were randomly assigned to a control group or 1 of 2 treatment groups. Treatment 1 had insecticide baits placed by entomologists from North Carolina State University. Treatment 2 received pest control from a randomly assigned commercial company. Vacuumed dust sampling and Cockroach trapping were conducted at 0, 6, and 12 months. Dust samples were analyzed by ELISA. Results In treatment 1 homes, there were significant reductions in geometric mean trap counts compared with control and treatment 2 homes at 12 months. Relative to control, significant 12-month reductions in Bla g 1 were evident in treatment 1 homes at all sampled sites, except bedroom floor. From baseline to month 12, geometric mean Bla g 1 concentrations (U/g) decreased from 64.2 to 5.6 in kitchen, 10.6 to 1.1 in living room, 10.7 to 1.9 on bedroom floor, and 3.6 to 2.3 in bed. Treatment 2 homes showed no significant 12-month allergen reductions versus control. Conclusion Reductions in Bla g 1 in Cockroach-infested homes can be achieved by reducing infestations; however, the magnitude of allergen reduction is dependent on the thoroughness and effectiveness of Cockroach eradication efforts. Clinical implications Elimination of Cockroaches is an effective method for reducing exposure to Cockroach allergen.
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Cockroach allergen biology and mitigation in the indoor environment.
Annual review of entomology, 2007Co-Authors: J. Chad Gore, Coby SchalAbstract:For nearly a half century, Cockroaches have been recognized as a major cause of asthma morbidity in the urban, inner-city environment. Several Cockroach-produced allergens have been identified and characterized, and a few have been produced as recombinant proteins. Recent research has moved beyond clinical, patient-based investigations to a more entomological perspective that addresses the production, physiological regulation, and developmental expression of Cockroach allergens, thus providing insight into their functional biology and their relationship to current Cockroach control strategies. Although successful removal of Cockroach allergens from the infested environment has been difficult to accomplish with remedial sanitation, large-scale reductions in Cockroach allergens below clinically relevant thresholds have recently been realized through suppression of Cockroach populations. Here we review the current understanding of Cockroach allergen biology and the demographics associated with human exposure and sensitization. We also critically evaluate allergen mitigation studies from an entomological perspective, highlighting disparities between successful and failed attempts to lessen the Cockroach allergen burden in homes.
Anna Pomés - One of the best experts on this subject based on the ideXlab platform.
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ige and t cell reactivity to a comprehensive panel of Cockroach allergens in relation to disease
Frontiers in Immunology, 2021Co-Authors: Anna Pomés, Veronique Schulten, Jill Glesner, Ricardo Da Silva Antunes, Aaron Sutherland, Leonard B Bacharier, Avraham Beigelman, Paula J BusseAbstract:IgE sensitization to Cockroach allergens is associated with development of allergic diseases, such as asthma. To understand the relevance of different Cockroach allergens for diagnosis and immunotherapy, a comprehensive analysis of IgE antibody levels and T cell reactivity to an expanded set of Cockroach allergens and their relationship to disease was performed in a cohort of USA Cockroach sensitized patients. IgE antibody levels to recombinant chitinase and hemocyanin were measured for 23 subjects by custom-made ImmunoCAPs and compared with IgE levels to eight Cockroach allergens we previously reported for the same cohort. Ex vivo T cell activation (Ox40/PDL-1 expression) of PBMCs stimulated with peptide pools derived from 11 German Cockroach proteins, including nine official Cockroach allergens, plus chitinase and vitellogenin, was determined by flow cytometry. IgE prevalences to chitinase (17%) and hemocyanin (44%) were comparable to values for the other eight allergens that we previously reported (21-57%). Hemocyanin (Bla g 3), was a major allergen (one to which more than 50% of patients with an allergy to its source react) for a sub-group of 15 highly Cockroach-sensitized subjects (IgE > 3.5 kUA/L: 53%). Chitinase was officially named as new allergen Bla g 12. Cockroach-specific IgE levels in plasma showed excellent correlation with the sum of 10 allergen-specific IgE (r = 0.94, p < 0.001). T cell reactivity to 11 proteins was highly variable among subjects, the highest being for vitellogenin, followed by Bla g 3. The main finding was that Cockroach allergen-specific IgE and T cell reactivity patterns were unique per subject, and lacked immunodominant allergens and correlation with clinical phenotype/disease severity in the studied cohort. Knowing the subject-specific B/T cell reactivity profiles to a comprehensive panel of Cockroach allergens will contribute to diagnosis of Cockroach allergy and will be important for planning and assessing allergen immunotherapy outcomes, according to the allergen content in therapeutic Cockroach extracts.
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Cockroach allergen component analysis of children with or without asthma and rhinitis in an inner city birth cohort
The Journal of Allergy and Clinical Immunology, 2019Co-Authors: Anna Pomés, Meyer Kattan, Robert A Wood, George T Oconnor, Jill Glesner, Leonard B Bacharier, Agustin Calatroni, Cindy M Visness, Lisa M Wheatley, James E GernAbstract:Background Cockroach is one of the most important sources of indoor allergens and can lead to IgE sensitization and development of rhinitis and asthma. Objective We sought to perform a Cockroach allergen component analysis to determine the allergens and antibody levels and patterns of sensitization associated with asthma and rhinitis. Methods Antibody (IgE, IgG, and IgG4) levels to total Cockroach and 8 Cockroach allergens were determined in 2 groups of Cockroach-sensitized 10-year-old children with (n = 19) or without (n = 28) asthma and rhinitis. Allergen-specific antibody levels were measured in streptavidin ImmunoCAPs loaded with each of the recombinant allergens from groups 1, 2, 4, 5, 6, 7, 9, and 11, and total Cockroach-specific IgE levels were measured with the i6 ImmunoCAP. Results IgE antibody levels to Cockroach allergens and extract, but not IgG or IgG4 antibody levels, differed between subjects with and without asthma and rhinitis. Specifically, recognition of more Cockroach allergens with higher allergen-specific IgE levels was associated with disease. Variable patterns of sensitization with no immunodominant allergens were found in both groups. There was a good correlation between the sum of allergen-specific IgE and total Cockroach IgE levels (r = 0.86, P Conclusions Component analysis of 8 Cockroach allergens revealed significant differences in IgE reactivity associated with the presence of asthma and rhinitis. Allergen-specific IgE titers and sensitization profiles were associated with asthma and rhinitis.
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Recombinant Allergens for Diagnosis of Cockroach Allergy
Current Allergy and Asthma Reports, 2014Co-Authors: L. Karla Arruda, Michelle C. R. Barbosa, Ana Beatriz R. Santos, Adriana S. Moreno, Martin D. Chapman, Anna PomésAbstract:Molecular cloning of Cockroach allergens and their expression as recombinant proteins have allowed a better understanding of the mechanisms of Cockroach allergic disease. Recombinant Cockroach allergens have been used for skin testing or in vitro methods to measure IgE antibody levels in serum. Early studies evaluating selected U.S. patients revealed that a cocktail of four Cockroach allergens, Bla g 1, Bla g 2, Bla g 4, and Bla g 5, would identify 95 % of Cockroach allergic patients. More recent studies pointed to an important role of sensitization to tropomyosin among certain populations, and suggested that a cocktail of five allergens Bla g 1 and/or Per a 1, Bla g 2, Bla g 4, Bla g 5, and Bla g 7, and/or Per a 7, would be expected to diagnose 50– 64 % of Cockroach-allergic patients worldwide. Variation in IgE reactivity profiles could be in part due to IgE responses to cross-reactive homologous allergens from different origins. The availability of purified natural or recombinant Cockroach allergens provides the capacity to improve diagnosis of Cockroach allergy and to develop novel forms of immunotherapy for Cockroach-allergic patients.
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Investigating Cockroach allergens: aiming to improve diagnosis and treatment of Cockroach allergic patients.
Methods (San Diego Calif.), 2013Co-Authors: Anna Pomés, Luisa Karla P. ArrudaAbstract:Abstract Cockroach allergy is an important health problem associated with the development of asthma, as a consequence of chronic exposure to low levels of allergens in susceptible individuals. In the last 20 years, progress in understanding the disease has been possible, thanks to the identification and molecular cloning of Cockroach allergens and their expression as recombinant proteins. Assays for assessment of environmental allergen exposure have been developed and used to measure Bla g 1 and Bla g 2, as markers of Cockroach exposure. IgE antibodies to Cockroach extracts and to specific purified allergens have been measured to assess sensitization and analyze association with exposure and disease. With the development of the field of structural biology and the expression of recombinant Cockroach allergens, insights into allergen structure, function, epitope mapping and allergen–antibody interactions have provided further understanding of mechanisms of Cockroach allergic disease at the molecular level. This information will contribute to develop new approaches to allergen avoidance and to improve diagnosis and therapy of Cockroach allergy.
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Every Cockroach Is Beautiful to Its Mother
International archives of allergy and immunology, 2013Co-Authors: Luisa Karla P. Arruda, Anna PomésAbstract:Cockroaches are considered to be among the oldest insects on our planet, predating dinosaurs by more than 150 million years, and humans by more than 300 million (1). Some fossils attributed to Cockroaches date back to the Carboniferous period, around 325 million B.C. However, an uncertain evolutionary link between Cockroach-like fossils from the Carboniferous period (Paleozoic era), and “modern” Cockroaches, originated in the Cretaceous period (Mesozoic era) as did most other insects, has also been suggested, due to morphological differences (2). Regardless of their origin, Cockroaches have undergone very little changes over time, and the diversification of species and adaptation to multiple habitats are remarkable, reflecting their tremendous success at surviving throughout evolution (1). Over 4,000 Cockroach species have been identified, with tropical forests as their preferred habitat (3). However, a few species, including the German Cockroach (Blattella germanica) and the American Cockroach (Periplaneta americana), brought from Africa to the Americas on slave ships, have adapted to live near people, turning into household pests.
Martin D. Chapman - One of the best experts on this subject based on the ideXlab platform.
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allergen content in german Cockroach extracts and sensitization profiles to a new expanded set of Cockroach allergens determine in vitro extract potency for ige reactivity
The Journal of Allergy and Clinical Immunology, 2019Co-Authors: Jill Glesner, Coby Schal, Martin D. Chapman, Stephanie Filep, Lisa D Vailes, Sabina Wunschmann, Giovanni Birrueta, April Frazier, Kyoung Yong Jeong, Leonard B BacharierAbstract:Background Cockroach allergens are an important cause of IgE-mediated sensitization in inner-city asthmatic patients. However, Cockroach extracts used for diagnosis and immunotherapy are not standardized. Objective We sought to determine the allergen content of nonstandardized German Cockroach extracts and the levels of sensitization to an expanded set of Cockroach allergens as determinants of in vitro extract potency for IgE reactivity. Methods Twelve German Cockroach extracts were compared for allergen content and potency of IgE reactivity. Bla g 1, Bla g 2, and Bla g 5 were measured by using immunoassays. IgE antibody levels to 8 purified recombinant allergens from groups 1, 2, 4, 5, 6, 7, 9, and 11 were measured by using ImmunoCAP. IgE antibody binding inhibition assays were performed to assess extract in vitro potencies (concentration inhibiting 30% of the total IgE antibody-binding inhibition) relative to an arbitrarily selected reference extract in 5 patients with Cockroach allergy. Results Allergen levels were highly variable. Three new major allergens (groups 6, 9, and 11), were identified among highly Cockroach-sensitized subjects (CAP class ≥ 3). Sensitization profiles were unique per subject without immunodominant allergens. The sum of IgE to 8 allergen components showed a good correlation with Cockroach-specific IgE levels (r = 0.88, P Conclusions The in vitro potency of German Cockroach extracts for IgE reactivity depends on allergen content and allergen-specific IgE titers of patients with Cockroach allergy. These factors are relevant for selection of potent extracts to be used for immunotherapy and for the design and interpretation of data from immunotherapy trials.
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Recombinant Allergens for Diagnosis of Cockroach Allergy
Current Allergy and Asthma Reports, 2014Co-Authors: L. Karla Arruda, Michelle C. R. Barbosa, Ana Beatriz R. Santos, Adriana S. Moreno, Martin D. Chapman, Anna PomésAbstract:Molecular cloning of Cockroach allergens and their expression as recombinant proteins have allowed a better understanding of the mechanisms of Cockroach allergic disease. Recombinant Cockroach allergens have been used for skin testing or in vitro methods to measure IgE antibody levels in serum. Early studies evaluating selected U.S. patients revealed that a cocktail of four Cockroach allergens, Bla g 1, Bla g 2, Bla g 4, and Bla g 5, would identify 95 % of Cockroach allergic patients. More recent studies pointed to an important role of sensitization to tropomyosin among certain populations, and suggested that a cocktail of five allergens Bla g 1 and/or Per a 1, Bla g 2, Bla g 4, Bla g 5, and Bla g 7, and/or Per a 7, would be expected to diagnose 50– 64 % of Cockroach-allergic patients worldwide. Variation in IgE reactivity profiles could be in part due to IgE responses to cross-reactive homologous allergens from different origins. The availability of purified natural or recombinant Cockroach allergens provides the capacity to improve diagnosis of Cockroach allergy and to develop novel forms of immunotherapy for Cockroach-allergic patients.
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specific ige and igg antibody binding patterns to recombinant Cockroach allergens
The Journal of Allergy and Clinical Immunology, 2005Co-Authors: S M Satinover, Martin D. Chapman, Anna Pomés, Amanda J Reefer, Thomas A E Plattsmills, Judith A WoodfolkAbstract:Background The specificity of serum antibody responses to different Cockroach allergens has not been studied. Objective We sought to quantitate serum IgE and IgG antibodies to a panel of purified Cockroach allergens among Cockroach-sensitized subjects. Methods IgE antibodies to recombinant Cockroach allergens (rBla g 1, rBla g 2, rBla g 4, rBla g 5, and rPer a 7) were measured in sera containing IgE antibodies to Blattella germanica extract (n=118) by using a streptavidin CAP assay and a multiplex flow cytometric assay. Specific IgG antibodies were determined by using radioimmunoprecipitation techniques. Results Specific IgE antibodies measured by means of CAP assay and multiplex assay were strongly correlated ( r =0.8, P Conclusion The techniques described offer a new approach for defining the hierarchy of purified allergens. IgE antibodies directed against 5 allergens constitute the majority of the IgE antibody repertoire for Cockroach. Such distinct patterns of IgE-IgG responsiveness to different Cockroach allergens highlight the complexity of B-cell responses to environmental allergens.
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Cockroach allergens and asthma.
The Journal of allergy and clinical immunology, 2001Co-Authors: L. Karla Arruda, Ana Beatriz R. Santos, Anna Pomés, Lisa D Vailes, Virgínia Paes Leme Ferriani, Martin D. ChapmanAbstract:Asthma and allergy are the most common diseases associated with Cockroach infestation of houses in the United States and other parts of the world. Sensitization and exposure to Cockroach allergens is associated with increased asthma morbidity in the United States, especially among lower socioeconomic groups, including African American and Hispanic populations. Exposure to Cockroach allergens in the first 3 months of life has been associated with repeated wheezing and asthma. The principal domestic Cockroach species are Blattella germanica and Periplaneta americana. Both species produce several potent allergens, including Bla g 2 (inactive aspartic proteinase), Bla g 4 (calycin), Bla g 5 (glutathione-S-transferase), the group 1 cross-reactive allergens Bla g 1 and Per a 1, and tropomyosin. Structural homology between tropomyosins from Cockroaches, mites, and shrimp may explain clinical cases of the oral allergy syndrome. The 3-dimensional structures of several Cockroach allergens are known, and biologically active recombinant allergens have been produced in high-level expression vectors. The use of recombinant Cockroach allergens should allow mechanisms of Cockroach-induced asthma to be investigated and may lead to the development of new approaches to asthma treatment. Environmental allergen measurements of Bla g 1 and Bla g 2 have allowed exposure levels that cause allergic sensitization to be established. Abatement studies have shown that a sustained decrease in Cockroach allergen levels is difficult but can be accomplished by professional application of insecticides, together with rigorous household cleaning. Cockroach asthma is an important public health problem that affects patients who are the least likely to be compliant with treatment with asthma medications or environmental control. Patient education, improvements in the housing stock, and improvements in environmental and immunologic treatment strategies are likely to be the most successful approaches to reduce the prevalence of Cockroach-induced asthma.
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Cockroach allergens and asthma in brazil identification of tropomyosin as a major allergen with potential cross reactivity with mite and shrimp allergens
The Journal of Allergy and Clinical Immunology, 1999Co-Authors: A B R Santos, Martin D. Chapman, Lisa D Vailes, Virgínia Paes Leme Ferriani, Rob C Aalberse, Constance Oliver, Candida M Rizzo, Charles K Naspitz, Karla L ArrudaAbstract:Background: Cockroaches produce several proteins that induce IgE antibody responses. Although Cockroaches are abundant in warm and humid areas, sensitization to Cockroach allergens has not been investigated in Brazil. Objective: The aims of this study were to investigate the frequency of Cockroach allergy among patients with asthma, rhinitis, or both in Brazil and to identify American Cockroach allergens. Methods: Skin tests using Cockroach extracts were performed on children and young adults with asthma, rhinitis, or both. A Periplaneta americana complementary (c)DNA library was screened by using IgE antibodies from Brazilian patients allergic to Cockroaches. Reactivity of an mAb directed to Dermatophagoides pteronyssinus tropomyosin against Cockroach tissue was examined by immunofluorescence. Results: Cockroach allergy was present in 55% and 79% of the patients, as determined by using skin prick tests alone or combined prick and intradermal tests, respectively. Five cDNA clones reacted with IgE antibody and contained the same sequence. A representative clone (1300 bp), pa12, coded for a protein that reacted with 50% of the sera from patients allergic to Cockroaches on plaque immunoassay and showed a high degree of homology to tropomyosins, particularly those from invertebrates. P americana tropomyosin showed 80%, 81%, and 82% sequence identity to tropomyosins from D pteronyssinus, D farinae, and shrimp, respectively, which have been previously defined as important allergens. An mAb directed against D pteronyssinus tropomyosin, which also recognizes shrimp tropomyosin, showed binding to Cockroach striated muscle. Conclusion: Our results support the recommendation that Cockroach extracts should be routinely used for the evaluation of patients with asthma, rhinitis, or both in Brazil. The identification of P americana tropomyosin as an important allergen will make it possible to investigate cross-reactivity among Cockroaches, mites, and food derived from invertebrates. (J Allergy Clin Immunol 1999;104:329-37.)
Colette Rivault - One of the best experts on this subject based on the ideXlab platform.
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Habitat selection and coexistence of invasive Cockroach species (Dictyoptera) in sugar-cane fields on Reunion island
Acta Oecologica, 2006Co-Authors: Stéphane Boyer, Colette RivaultAbstract:Selection of habitat has a profound influence on interactions among species and the assembly of ecological communities. We investigated habitat preferences to understand how different Cockroach species coexist in sugar-cane fields on Reunion island. Cockroach populations belonging to a guild of seven species were surveyed during one annual cycle in eight sugar-cane fields that differed by several environmental factors, in order to investigate ecological features of Cockroach species and their patterns of coexistence. Structure variations of the Cockroach communities were analyzed at the field scale, at the sample unit scale, and according to variations of environmental conditions related to the annual sugar-cane growth cycle. A canonical correspondence analysis (CCA) was used to elucidate relationships between species diversity, population abundance and environmental characteristics. The examination of partitioning at different spatial and temporal scales evidenced that each species occupied a particular type of habitat. The main factors influencing spatial habitat selection were at the sample unit scale: presence of ants, edge effect, soil moisture and granulometry, at the field scale: irrigation, annual rainfall, altitude and age of the field. Although a pair of species shared the same type of habitat, annual population peaks of each species did not coincide in time. This suggests that resource partitioning is based both on ecological factors and interspecific competition. Factors enhancing Cockroach coexistence and factors favoring population outbursts are discussed as well as specific invasive capacities of these Cockroaches and the role of the Cockroach community in the sugar-cane trophic web. (c) 2005 Elsevier SAS. All rights reserved.
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Improvement of German Cockroach (Dictyoptera : Blattellidae) population control by fragmented distribution of gel baits
Journal of Economic Entomology, 2003Co-Authors: Virginie Durier, Colette RivaultAbstract:The aim of this study was to test the efficiency of gels in relation to fragmentation of baits and population density against the German Cockroach, Blattella germanica (L.). We hypothesized that the efficiency of Cockroach control could be improved by fragmentation of gel baits, i.e., by distributing the same amount of bait in several small drops instead of one large one. Our results show that bait fragmentation increased the number of Cockroaches gaining access to the gel. However, bait fragmentation increased Cockroach mortality only at high population densities. Our results allow us to recommend modulation of bait application in relation to Cockroach population density. At low population densities (42 individuals/m(2)), the recommended dose, one single 30-mg drop/m(2), can be applied. At high population densities (greater than or equal to208 individuals/m(2)), the same recommended dose would be more efficient if applied as several 3-mg drops.
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Outcome of insecticide control of Cockroaches (Dictyoptera: Blattellidae) in public housing in France
Journal of Environmental Management, 1997Co-Authors: Colette Rivault, Ann CloarecAbstract:The current situation in high-rise blocks of low-income flats in the French city of Rennes concerning Cockroach (Blattella germanica (L.)) presence and insecticide control was investigated. Based on the indications of an enquiry involving 838 flats, an improved control protocol was drawn up and applied during a 2 year campaign of insecticide treatments in 232 flats. This campaign showed that the proportion of flats where Cockroaches were found was in fact lower than the proportion of flats in which during the inquiry residents reported seeing Cockroaches. During the campaign we found that there was a significantly higher proportion of Cockroach infested flats where residents refused treatment than could be revealed by the inquiry. During our campaign, information given to residents and precise knowledge of the Cockroach situation in each flat enabled us to reduce the number of flats treated unnecessarily. However, the proportion of flats treated was still important. The results of our campaign stressed two points important for the success of a Cockroach control operation using insecticides: (1) Access to all of the flats is absolutely necessary, and (2) the exact evaluation of the Cockroach population in each flat is difficult, particularly for small populations.
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Limits of Insecticide Cockroach Control in Council Flats in France
Journal of Environmental Management, 1995Co-Authors: Colette Rivault, Ann CloarecAbstract:The aim of our study was to analyse the results of controlled series of professional insecticide treatments on feral Cockroach populations in council flats in three similar multi-family buildings, and to try to understand why control success could be so low. Cockroach abundance and six general environmental characteristics were recorded after each treatment for each flat treated. Cockroach abundance was divided into five levels. The environmental characteristics recorded for each flat were: nationality of residents, duration of occupation, number of residents/m(2), application of domestic pesticides, reactions of residents to the presence of Cockroaches, and degree of cleanliness. This series of treatments, proposed every two months, did not improve the situation as greatly as expected. The presence or the absence of Cockroaches in flats can be explained at least partly by some environmental factors like human density in the flat, building effect and cleanliness, but no single factor explains the size of the Cockroach population. The usual reasons evoked to explain pest control failures, such as Cockroach insecticide resistance, inefficiency of treatments due to formulation, proportion of constituent in compound, periodicity of application, etc., all influence the result of a treatment, of course, but our data show that the part played by the residents in a given dwelling has been greatly underestimated so far. When the results of treatments were analysed, the results depended largely on the residents' attitude. (C) 1995 Academic Press Limited
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Infestation Dynamics of Blatticola-Blattae Graeffe (nematoda, Thelastomatidae), a Parasite of Blattella-Germanica L (dictyoptera, Blattellidae)
International Journal for Parasitology, 1992Co-Authors: Serge Morand, Colette RivaultAbstract:The life-cycle of the thelastomatid nematode Blatticola blattae Graeffe, a parasite of the Cockroach Blattella germanica L., was experimentally studied. Male thelastomatids developed more rapidly than females. Analysis of the distribution of the nematode within a Cockroach population revealed an important regulation of parasitic dynamics. The parasites were underdistributed in the samples of the host population. However, they were aggregated in first instar Cockroach larvae. The sex ratio was unbalanced, in favour of males in younger Cockroach larvae and in favour of females in older Cockroaches. Analysis of the variations of this parasitism in relation to spatial structure of the population and host developmental stage revealed that infestation occurred mainly during the first three Cockroach larval instars, and can originate from parasites in gravid female hosts. Finally, a strong regulation affects infrapopulations of the parasite, thus limiting males to one and females to one or two per host. These results can be compared with data on oxyurids parasitizing Cockroaches of New Zealand.
Leonard B Bacharier - One of the best experts on this subject based on the ideXlab platform.
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ige and t cell reactivity to a comprehensive panel of Cockroach allergens in relation to disease
Frontiers in Immunology, 2021Co-Authors: Anna Pomés, Veronique Schulten, Jill Glesner, Ricardo Da Silva Antunes, Aaron Sutherland, Leonard B Bacharier, Avraham Beigelman, Paula J BusseAbstract:IgE sensitization to Cockroach allergens is associated with development of allergic diseases, such as asthma. To understand the relevance of different Cockroach allergens for diagnosis and immunotherapy, a comprehensive analysis of IgE antibody levels and T cell reactivity to an expanded set of Cockroach allergens and their relationship to disease was performed in a cohort of USA Cockroach sensitized patients. IgE antibody levels to recombinant chitinase and hemocyanin were measured for 23 subjects by custom-made ImmunoCAPs and compared with IgE levels to eight Cockroach allergens we previously reported for the same cohort. Ex vivo T cell activation (Ox40/PDL-1 expression) of PBMCs stimulated with peptide pools derived from 11 German Cockroach proteins, including nine official Cockroach allergens, plus chitinase and vitellogenin, was determined by flow cytometry. IgE prevalences to chitinase (17%) and hemocyanin (44%) were comparable to values for the other eight allergens that we previously reported (21-57%). Hemocyanin (Bla g 3), was a major allergen (one to which more than 50% of patients with an allergy to its source react) for a sub-group of 15 highly Cockroach-sensitized subjects (IgE > 3.5 kUA/L: 53%). Chitinase was officially named as new allergen Bla g 12. Cockroach-specific IgE levels in plasma showed excellent correlation with the sum of 10 allergen-specific IgE (r = 0.94, p < 0.001). T cell reactivity to 11 proteins was highly variable among subjects, the highest being for vitellogenin, followed by Bla g 3. The main finding was that Cockroach allergen-specific IgE and T cell reactivity patterns were unique per subject, and lacked immunodominant allergens and correlation with clinical phenotype/disease severity in the studied cohort. Knowing the subject-specific B/T cell reactivity profiles to a comprehensive panel of Cockroach allergens will contribute to diagnosis of Cockroach allergy and will be important for planning and assessing allergen immunotherapy outcomes, according to the allergen content in therapeutic Cockroach extracts.
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Cockroach allergen component analysis of children with or without asthma and rhinitis in an inner city birth cohort
The Journal of Allergy and Clinical Immunology, 2019Co-Authors: Anna Pomés, Meyer Kattan, Robert A Wood, George T Oconnor, Jill Glesner, Leonard B Bacharier, Agustin Calatroni, Cindy M Visness, Lisa M Wheatley, James E GernAbstract:Background Cockroach is one of the most important sources of indoor allergens and can lead to IgE sensitization and development of rhinitis and asthma. Objective We sought to perform a Cockroach allergen component analysis to determine the allergens and antibody levels and patterns of sensitization associated with asthma and rhinitis. Methods Antibody (IgE, IgG, and IgG4) levels to total Cockroach and 8 Cockroach allergens were determined in 2 groups of Cockroach-sensitized 10-year-old children with (n = 19) or without (n = 28) asthma and rhinitis. Allergen-specific antibody levels were measured in streptavidin ImmunoCAPs loaded with each of the recombinant allergens from groups 1, 2, 4, 5, 6, 7, 9, and 11, and total Cockroach-specific IgE levels were measured with the i6 ImmunoCAP. Results IgE antibody levels to Cockroach allergens and extract, but not IgG or IgG4 antibody levels, differed between subjects with and without asthma and rhinitis. Specifically, recognition of more Cockroach allergens with higher allergen-specific IgE levels was associated with disease. Variable patterns of sensitization with no immunodominant allergens were found in both groups. There was a good correlation between the sum of allergen-specific IgE and total Cockroach IgE levels (r = 0.86, P Conclusions Component analysis of 8 Cockroach allergens revealed significant differences in IgE reactivity associated with the presence of asthma and rhinitis. Allergen-specific IgE titers and sensitization profiles were associated with asthma and rhinitis.
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allergen content in german Cockroach extracts and sensitization profiles to a new expanded set of Cockroach allergens determine in vitro extract potency for ige reactivity
The Journal of Allergy and Clinical Immunology, 2019Co-Authors: Jill Glesner, Coby Schal, Martin D. Chapman, Stephanie Filep, Lisa D Vailes, Sabina Wunschmann, Giovanni Birrueta, April Frazier, Kyoung Yong Jeong, Leonard B BacharierAbstract:Background Cockroach allergens are an important cause of IgE-mediated sensitization in inner-city asthmatic patients. However, Cockroach extracts used for diagnosis and immunotherapy are not standardized. Objective We sought to determine the allergen content of nonstandardized German Cockroach extracts and the levels of sensitization to an expanded set of Cockroach allergens as determinants of in vitro extract potency for IgE reactivity. Methods Twelve German Cockroach extracts were compared for allergen content and potency of IgE reactivity. Bla g 1, Bla g 2, and Bla g 5 were measured by using immunoassays. IgE antibody levels to 8 purified recombinant allergens from groups 1, 2, 4, 5, 6, 7, 9, and 11 were measured by using ImmunoCAP. IgE antibody binding inhibition assays were performed to assess extract in vitro potencies (concentration inhibiting 30% of the total IgE antibody-binding inhibition) relative to an arbitrarily selected reference extract in 5 patients with Cockroach allergy. Results Allergen levels were highly variable. Three new major allergens (groups 6, 9, and 11), were identified among highly Cockroach-sensitized subjects (CAP class ≥ 3). Sensitization profiles were unique per subject without immunodominant allergens. The sum of IgE to 8 allergen components showed a good correlation with Cockroach-specific IgE levels (r = 0.88, P Conclusions The in vitro potency of German Cockroach extracts for IgE reactivity depends on allergen content and allergen-specific IgE titers of patients with Cockroach allergy. These factors are relevant for selection of potent extracts to be used for immunotherapy and for the design and interpretation of data from immunotherapy trials.