Actividad insecticida de aceites esenciales sobre Blatella germanica (Linneaus, 1767) (Dictyoptera: Blattellidae) / nsecticidal activity of essential oils against Blatella germanica (Linneaus, 1767) (Dictyoptera: Blattellidae)

Blattella germanica (Linneaus, 1767) es una especie de cucaracha considerada plaga de la salud pública por estar asociada a gran número de microorganismos causantes de enfermedades al hombre. Para su control se utilizan diferentes tipos de formulaciones a base de insecticidas sintéticos a los cuales en su gran mayoría es resistente. En este contexto existe un interés creciente por los insecticidas botánicos. En el siguiente trabajo se evaluaron los aceites de Citrus aurantium (L.,1753), Ocimum basilicum (L.,1753), Piper aduncum subsp ossanum (C.DC. Saralegui) y Eucalyptus globulus (Labill, 1800) mediante aplicación tópica de un microlitro en el primer esternito abdominal de los individuos. Los cuatro aceites mostraron actividad insecticida sobre adultos de B. germanica con CL50 que oscilaron entre 58 µg/µL para O. basilicum y 250 µg/µL para P. aduncum(AU)´

Blattella germanica (Linneaus, 1767) is a cockroach species considered a public health pest, since it is associated with a great number of disease-causing microorganisms in humans. For its control, different types of synthetic-based insecticidal formulations are used, to which it is mostly resistant. In this context, there is a growing interest in botanical insecticides. In this research, oils from Citrus aurantium (L., 1753), Ocimum basilicum (L., 1753), Piper aduncum subsp. ossanum (C.DC. Saralegui), and Eucalyptus globulus (Labill, 1800) were evaluated by topical application of 1 µL to the first abdominal sternum of the individuals. The four essential oils evaluated showed insecticidal activity against adult B. germanica with LC50 ranging from 58µg/µL for O. basilicum to 250µg/µL for P. aduncum(AU)´

German Cockroach Extract Induces Matrix Metalloproteinase-1 Expression, Leading to Tight Junction Disruption in Human Airway Epithelial Cells

PURPOSE: Cockroach exposure is a pivotal cause of asthma. Tight junctions are intercellular structures required for maintenance of the barrier function of the airway epithelium, which is impaired in this disease. Matrix metalloproteinases (MMPs) digest extracellular matrix components and are involved in asthma pathogenesis: MMP1 is a collagenase with a direct influence on airway obstruction in asthmatics. This study aimed to investigate the mechanism by which German cockroach extract (GCE) induces MMP1 expression and whether MMP1 release alters cellular tight junctions in human airway epithelial cells (NCI-H292). MATERIALS AND METHODS: mRNA and protein levels were determined using real-time PCR and ELISA. Tight junction proteins were detected using immunofluorescence staining. Epithelial barrier function was measured by transepithelial electrical resistance (TEER). The binding of a transcription factor to DNA molecules was determined by electrophoretic mobility shift assay, while the levels of tight junction proteins and phosphorylation were determined using Western blotting. RESULTS: GCE was shown to increase MMP1 expression, TEER, and tight junction degradation. Both an inhibitor and small interfering RNA (siRNA) of MMP1 significantly decreased GCE-induced tight junction disruption. Furthermore, transient transfection with ETS1 and SP1 siRNA, and anti-TLR2 antibody pretreatment prevented MMP1 expression and tight junction degradation. An extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK) inhibitor also blocked MMP1 release, ETS1/SP1 DNA binding, and tight junction alteration. CONCLUSION: GCE treatment increases MMP1 expression, leading to tight junction disruption, which is transcriptionally regulated and influenced by the ERK/MAPK pathway in airway epithelial cells. These findings may contribute to developing novel therapeutic strategies for airway diseases.

Allergenic Characterization of a Novel Allergen, Homologous to Chymotrypsin, from German Cockroach

PURPOSE: Cockroach feces are known to be rich in IgE-reactive components. Various protease allergens were identified by proteomic analysis of German cockroach fecal extract in a previous study. In this study, we characterized a novel allergen, a chymotrypsin-like serine protease. METHODS: A cDNA sequence homologous to chymotrypsin was obtained by analysis of German cockroach expressed sequence tag (EST) clones. The recombinant chymotrypsins from the German cockroach and house dust mite (Der f 6) were expressed in Escherichia coli using the pEXP5NT/TOPO vector system, and their allergenicity was investigated by ELISA. RESULTS: The deduced amino acid sequence of German cockroach chymotrypsin showed 32.7 to 43.1% identity with mite group 3 (trypsin) and group 6 (chymotrypsin) allergens. Sera from 8 of 28 German cockroach allergy subjects (28.6%) showed IgE binding to the recombinant protein. IgE binding to the recombinant cockroach chymotrypsin was inhibited by house dust mite chymotrypsin Der f 6, while it minimally inhibited the German cockroach whole body extract. CONCLUSIONS: A novel allergen homologous to chymotrypsin was identified from the German cockroach and was cross-reactive with Der f 6.

The insecticidal effect of diatomaceous earth against adults and nymphs of Blattella germanica

Objective: To evaluate the insecticidal effect of diatomaceous earth (DE) against adults and nymphs of Blattella germanica.Methods:cockroaches. Two stages, nymph and adult, were exposed to six dose rates of the DE, 2.5, 5, 10, 15, 20 and 25 g/m2, at 24, 48 and 72 h exposure period. Mortality (number of dead cockroaches) was assessed after 24 h. Other exposed specimens were transferred to the beakers contained food and water for counting the retard mortality rate after 1 week. This cross sectional study has been done on the laboratory strain of German Results: Increasing in dose rates of DE increased mortality rate, so that the lowest and highest mortality rates were observed in 2.5 and 25 g/m2, respectively. The results of the statistical analysis showed no significant difference in the lethality of 50% of DE plus water on the German cockroach nymphs.Conclusions:Due to the resistance of German cockroach against organochloride organophosphorus, carbamate and pyrethriodes insecticides, it is suggested to use DE for insect’s control.

The insecticidal effect of diatomaceous earth against adults and nymphs of Blattella germanica

<p><b>OBJECTIVE</b>To evaluate the insecticidal effect of diatomaceous earth (DE) against adults and nymphs of Blattella germanica.</p><p><b>METHODS</b>This cross sectional study has been done on the laboratory strain of German cockroaches. Two stages, nymph and adult, were exposed to six dose rates of the DE, 2.5, 5, 10, 15, 20 and 25 g/m(2), at 24, 48 and 72 h exposure period. Mortality (number of dead cockroaches) was assessed after 24 h. Other exposed specimens were transferred to the beakers contained food and water for counting the retard mortality rate after 1 week.</p><p><b>RESULTS</b>Increasing in dose rates of DE increased mortality rate, so that the lowest and highest mortality rates were observed in 2.5 and 25 g/m(2), respectively. The results of the statistical analysis showed no significant difference in the lethality of 50% of DE plus water on the German cockroach nymphs.</p><p><b>CONCLUSIONS</b>Due to the resistance of German cockroach against organochloride, organophosphorus, carbamate and pyrethriodes insecticides, it is suggested to use DE for insect's control.</p>

Preparation and Characterization of an Extract of German Cockroach From a Korean Source

PURPOSE: The cockroach (CR) is an important cause of respiratory allergic disorders. We prepared a German CR extract in a standardized way and analyzed its allergenic properties. METHODS: The extract was prepared from German CR (Blattella germanica) obtained from a Korean colony, and its allergenic activity was compared with that of the commercial Hollister-Stier (HS) extract. The concentrations of Bla g 1 and Bla g 2 were measured, and an in vitro specific IgE binding inhibition assay was performed to assess IgE reactivity. Proteolytic activity was examined by gelatin zymography. RESULTS: Bla g 1 and Bla g 2 were detected at 405 U/mg and 273 ng/mg, respectively, in the Korean extract, and at 187 U/mg and 56 ng/mg, respectively, in the HS extract. The Korean extract showed 94.2% inhibition of IgE reactivity, as compared with the HS extract. A similar pattern of IgE-reactive bands was detected for the two extracts, indicating that their allergenic components are similar. The proteolytic activities of the Korean and HS extracts were found to be similar in gelatin zymography. The endotoxin levels in the Korean and HS extracts were 3,440 EU/mL and 6,580 EU/mL, respectively. CONCLUSIONS: The German CR extract was prepared in a standardized way. The extract produced in this study will be useful for the development of allergy diagnostics and immunotherapeutic agents.

Field efficacy of siege gel bait in an IPM program on life stages of German cockroach (Blataria, Blattellidae) in a residential building.

Background: Current control strategies that rely on residual contact insecticides have resulted in insecticide resistance or tolerance to all the major groups of insecticides. New strategies are based on repeated monitoring, sanitation, educational programs and use of pesticides such as gel bait. Objective: Investigate the effectiveness of an Integrated Pest Management (IPM) program on life stages of German cockroaches at infested units of a residential building in southwestern Iran. Methods: Life stages (adult, nymph, and ootheca) of German cockroaches at 53 units (rooms) were monitored by sticky traps for eight months. The infested units were subjected randomly to IPM treatments and compared to controls following five weeks of monitoring. The IPM approach was based on an educational program using pamphlets, posters, lectures, sanitation with vacuuming, and application of hydramethylnon gel baits. Results: There was a high proportion of nymph population (76% of cockroach trap counts) before treatment. German cockroaches showed the highest frequency distribution in trap counts at surveyed residential units. Percentage reduction in nymphs was lower than the reduction in adults in the first week post treatment, although from the fourth to the twenty-sixth week, the percentage reduction was higher than in adults or equal when they reached 100% reduction. Mean total results showed significant reduction in adult and nymph stages throughout the treatment period. Reduction in ootheca fluctuated over the IPM program. Conclusion: Siege gel bait (Hydramethylnon 2%) in an IPM program successfully reduced adult and nymph stages of German cockroach infestation over the post treatment weeks especially after the fourth post treatment week.

Differential susceptibility of adults and nymphs of Blattella germanica (L.) (Blattodea: Blattellidae) to infection by Metarhizium anisopliae and assessment of delivery strategies

Microbial insecticides for cockroach control, such as those containing entomopathogenic fungi, may be an alternative to reduce contamination by chemicals in housing and food storage environments. Virulence of isolate ESALQ1037 belonging to the Metarhizium anisopliae complex against nymphs and adults of Blattella germanica (L.), and its infectivity following exposure of insects to a contaminated surface or to M. anisopliae-bait were determined under laboratory conditions. Estimated LD50 15 d following topical inoculation was 2.69 x 10(5) conidia per adult, whereas for nymphs the maximum mortality was lower than 50 percent. Baits amended with M. anisopliae conidia had no repellent effect on targets; adult mortality was inferior to 25 percent, and nymphs were not susceptible. All conidia found in the digestive tract of M. anisopliae-bait fed cockroaches were unviable, and bait-treated insects that succumbed to fungal infection showed a typical mycelial growth on mouthparts and front legs, but not on the hind body parts. As opposed to baits, the use of a M. anisopliae powdery formulation for surface treatment was effective in attaining high mortality rates of B. germanica. Both nymphs and adults were infected when this delivery strategy was used, and mycelia growth occurred all over the body surface. Our results suggest that the development of powders or similar formulations of M. anisopliae to control B. germanica may provide faster and better results than some of the strategies based on baits currently available.

Field Trial on the control effect of fipronil bait against German cockroaches

A field trial on the control effect of fipronil poison bait against German cockroaches (Blatella germanica) was carried out at different restaurant types in Sinchon, Seoul, Republic of Korea. Monitoring was performed applying food baited traps for 2 days per week. Reduction rates of German cockroaches by applying fipronil baits were 90.9% at Korean restaurants, 96.4% at Chinese restaurants, and 89.4% in beer hall kitchens after 4 weeks of the treatment. Overall average of the reduction rate was 93.9%. As the natural reduction rate at untreated restaurants was 11.5% after 4 weeks, a correction of the average reduction rate by applying the Abbot formula was 93.1%.

Caracterização da resistência de Blattella germanica (L. ) (Dictyoptera: Blattellidae) a Deltametrina e clorpirifós e relações de resistência cruzada com fipronil / Characterization of deltamethrin and chlorpyirifos resistance in Blattella germanica (L. ) (Dictyoptera: Blattellidae) and Cross-Resistance relationships to fipronil

Os objetivos deste trabalho foram o de caracterizar a resistência de Blattella germanica (L.) aos inseticidas deltametrina e clorpirifós e avaliar as relações de resistência cruzada desses inseticidas com fipronil. O isolamento da resistência foi realizado em condições de laboratório a partir de populações coletadas no campo. Três ciclos de pressão de seleção foram realizados com deltametrina e clorpirifós para a obtenção das linhagens Deltametrina-R e Clorpirifós-R. A DL50 estimada para deltametrina na linhagem suscetível (SUS) foi de 0,24 (IC 95 por cento 0,18 - 0,31) e na linhagem Deltametrina-R de 10,26 (IC 95 por cento 7,28 - 14,17) mig deltametrina/mg. Para clorpirifós, a DL50 estimada para a linhagem SUS foi de 4,16 (IC 95 por cento 2,80 - 5,33) e para a linhagem Clorpirifós-R foi de 24,98 (IC 95 por cento 20,90 - 30,28) mig clorpirifós/mg. Portanto, as razões de resistência foram de aproximadamente 43 e seis vezes para deltametrina e clorpirifós, respectivamente. Uma baixa intensidade de resistência cruzada (de aproximadamente duas vezes) foi verificada entre fipronil e os inseticidas deltametrina e clorpirifós. Sendo assim, fipronil mostrou ser viável como opção de controle em programas de manejo da resistência de B. germanica a deltametrina e clorpirifós.

The objectives of this study were to characterize the resistance of Blattella germanica (L.) to deltamethrin and chlorpyrifos and to evaluate their cross-resistance relationships to fipronil. The isolation of resistance was done under laboratory conditions from field-collected populations. Three cycles of selection pressure with deltamethrin and chlorpyrifos were conducted to obtain the Deltamethrin-R and Chlorpyrifos-R strains. The estimated LD50 for the susceptible (SUS) strain was 0.24 (IC 95 percent 0.18 - 0.31) and for Deltamethrin-R strain was 10.26 (IC 95 percent 7.28 - 14.17) mug deltametrina/mg. For chlorpyrifos, LD50 for the SUS strain was 4.16 (IC 95 percent 2.80 - 5.33) and for Chlorpyrifos-R strain was 24.98 (IC 95 percent 20.90 - 30.28) mug chlorpyrifos/mg. Therefore, the resistance ratios were approximately 43- and 6-fold to deltamethrin and chlorpyrifos, respectively. A low intensity of cross-resistance (approximately 2-fold) was observed between fipronil and the insecticides deltamethrin and chlorpyrifos. Thus, fipronil can be used as a good candidate in resistance management programs of B. germanica to deltamethrin and chlorpyrifos.

Identification of the German Cockroach Allergens in Korean Atopy Using SDS - PAGE and Western Blot Analysis

BACKGROUND: Cockroaches are important components of house dust allergens. In spite of significant subject reactivity to cockroach extracts, the specific source of the allergen remains unclear. OBJECTIVE: This study was performed to identify the important allergens in German cockroach whole body (GWBE), egg (GEE) and fecal (GFE) extracts in Korean atopy, and to compare the reactivity of GWBE and GEE by Western blot inhibition. METHODS: Sera from 11 subjects with Korean atopy were used for sodium dodecil sulfate polyacrylamide gel elctrophoresis (SDS-PAGE) and Western blot analysis. RESULTS: Allergenic fractions in German cockroach extracts were numerous and distributed throughout the wide range of molecular weights. The important allergens of GWBE, GFE and GEE were similar to each other by using SDS-PAGE and Western blot ysis. The aUergen bands at 55 kd showed the most significant reactivity; in GWBE, GFE and GEE 73%, 82%, 55%, respectively. Other bands exhibiting significant activity were the 67 kd band with 37%, 19% and 19%, the 64 kd band with 64%, 37% and 9% respectively. Furthermore, Western blot inhibition investigations revealed that either GWBE or GEE could almost completely inhibit the reactivity of the other extract. CONCLUSION: This study confirms that the 55 kd allergen can be considered as the major allergen in Korean atopy and demonstrated that the GWBE and GEE antigens have identical IgE-binding sites.

Identification and purification of IgE-reactive proteins in German cockroach extract

Cockroaches have been implicated as a cause of respiratory allergy in urban areas worldwide. IgE-reactive German cockroach proteins were identified with molecular weights (MWs) of 90, 66, 50, 43 and 36 KD by immunoblot analysis in both immune BALB/c mice and sensitized humans. Prominent IgE-reactive proteins were purified using FPLC by ion-exchange chromatography, gel filtration and hydrophobic chromatography. The N-terminal amino acid sequence of a purified protein with a MW of 66 KD on SDS-PAGE was Val-Thr-Leu-Lys-Lys(Val)-Met-Ile-Lys-Thr-Phe-Tyr. No homologous protein was found through a search of GenBank that indicated a novel IgE-reactive protein in German cockroach extract. Another purified protein with a MW of 36 KD reacted strongly with a monoclonal antibody against Bla g 2.

Identification and Characterization of German Cockroach Allergen / 소아알레르기및호흡기학회지

PURPOSE: Cockroaches have been reported one of the major causes of allergic disease such as bronchial asthma and allergic rhinitis. About 10% of children and 20% of adult respiratory allergy patients have positive results of allergy skin tests to cockroach allergen. This finding suggests that cockroach is also important allergen in Korea. Among 4,000 species, German cockroach seems predominant species in the Korean peninsula. Identification and charactrerization of the major allergen is the first step in German cockroach allergen research. But, there have been controversies. It may depends upon different identifying methods. The aim of our study was to identify the major allergen in German cockroach using Westernblot. METHODS: Crude German cockroach allergen extracts with or without protease inhibitor cocktail mixture were prepared, and protein patterns of these two extracts were compared using SDS-PAGE and Coommssie stain. Sera from 32 atopic asthmatic patients with positive allergy skin test against cockroach allergen were used for IgE immunoblot. RESULTS: Coomassie stain after SDS-PAGE demonstrated some discordance between the differently prepared crude allergen extracts. In comparison with the allergen extract which abolished endogenous protease activity, the untreated extract revealed new 32, 55 and 78 kD protein bands and 41 kD protein band was disappeared. About 60% of sera with positive allergy skin test revealed IgE binding bands in Westernblot. Among them, 10, 21, 25, 36 and 52 kD protein band might seemed important German cockroach allergen. CONCLUSION: Finding above may suggest that endogenous protease could denature allergenic proteins in the process of crude cockroach allergen extract. The 10, 21, 25, 36, and 52 kD might be the important allergens in German cockroach.

IgE binding patterns to German cockroach whole body extract in Korean atopic asthmatic children

It is widely known that the cockroach is an inhalant allergen in atopic asthma and allergic rhinitis. Even though Bla g I and Bla g II are considered as the major allergens, several relatively high-molecular weight (MW) cockroach allergens have also been recently identified by IgE-immunoblot in western countries. However, the environmental control and diagnostic tests mainly focussed on Bla g I and Bla g II. Furthermore there is no data about major IgE-binding cockroach antigens in Korea. We performed this study to identify the major German cockroach allergens in Korean atopic children. By the results of allergy skin tests, 14 children with atopic asthma (9 were cockroach-sensitive and 5 were cockroach-nonsensitive atopics) were enrolled in this study. We conducted IgE immunoblot and autoradiographic analysis using Yonsei-extract of German cockroach antigen produced in our laboratory, individual sera from 9 cockroach- sensitive children, and the pooled sera of 5 house-dust-mites-only-sensitive children. We performed an allergic skin test to cockroach mix, and a radioallergosorbent test (RAST) using German cockroach crude extract on all subjects. German cockroach-specific IgE was detected in 6 out of 9 subjects by RAST. We identified at least 15 IgE-binding protein bands, and among them, the components of MWs of 76, 64, 50, 38, and <14 kilodaltons (kDa) were the major German cockroach allergens in study subjects. Therefore, Bla g I (25-30 kDa) and Bla g II (36 kDa) could not be the absolute indicators of German cockroach sensitization and parameters of environmental control.