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Nguya K Maniania - One of the best experts on this subject based on the ideXlab platform.
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spatial separation of semiochemical lurem tr and entomopathogenic fungi to enhance their compatibility and infectivity in an Autoinoculation system for thrips management
Pest Management Science, 2016Co-Authors: Saliou Niassy, Sevgan Subramanian, Sunday Ekesi, Hannalene Du Plessis, David K Mfuti, Rob W H M Van Tol, G L Wiegers, Willem Jan De Kogel, Nguya K ManianiaAbstract:BACKGROUND The effect of spatial separation of the semiochemical Lurem-TR, which has been found to inhibit conidia of entomopathogenic fungi when put together, on the persistence of conidia of Metarhizium brunneum and M. anisopliae was evaluated in the greenhouse and field in order to develop an autodissemination strategy for the management of Megalurothrips sjostedti on cowpea crop. Influence of spatial separation of the semiochemical on thrips attraction and conidial acquisition by thrips from the Autoinoculation device was also investigated in the field. RESULTS Persistence of conidia of M. brunneum and M. anisopliae increased with distance of separation of Lurem-TR. Direct exposure of fungus without separation from Lurem-TR recorded the lowest conidial germination as compared with the other treatments. Attraction of thrips to the device also varied significantly according to distance between device and semiochemical, with a higher number of thrips attracted when Lurem-TR was placed in a container below the device and at 10 cm distance. There was no significant difference in conidial acquisition between spatial separation treatments of conidia and Lurem-TR. Attraction of other insect pests to the device did not significantly vary between treatments. Positive correlations were found between conidial acquisition and thrips attraction. CONCLUSION This study suggests that spatial separation of fungal conidia from Lurem-TR in an Autoinoculation device could provide a low-cost strategy for effective management of thrips in grain legume cropping systems.
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Performance of a semiochemical-baited Autoinoculation device treated with Metarhizium anisopliae for control of Frankliniella occidentalis on French bean in field cages
Entomologia Experimentalis et Applicata, 2011Co-Authors: Saliou Niassy, Nguya K Maniania, Sevgan Subramanian, L. M. Gitonga, Sunday EkesiAbstract:The performance of an Autoinoculation device was evaluated in field cage experiments for control of Western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), in French bean, Phaseolus vulgaris L. var. Samantha (Fabaceae). Treatments consisted of a fungus-treated device with and without semiochemical (Lurem-TR), and a fungus-free device as control; the fungus used was Metarhizium anisopliae (Metchnikoff) Sorokin (Hypocreales: Clavicipitaceae). The overall mean number of conidia acquired by a single insect was higher in the fungus-treated semiochemical-baited device than in the device without semiochemical: 5.0 ± 0.6 × 104 vs. 2.2 ± 0.4 × 104 conidia per insect. The overall thrips mortality was also higher in the semiochemical-baited device than in the device without the semiochemical: 59.3 ± 3.9 vs. 41.7 ± 3.5%. Conidial viability was not affected in the M. anisopliae-treated device without semiochemicals, 7 days after treatment, whereas it was considerably decreased – from 81.0 ± 1.3 to 6.5 ± 1.1%, 2 and 7 days post-inoculation – in the M. anisopliae-treated semiochemical-baited device. Thrips mortality was positively correlated with M. anisopliae conidial viability, and conidial viability was negatively correlated with conidial acquisition. This suggests that the semiochemical volatiles reduced the conidial viability, which in turn resulted in significant reduction in thrips mortality, despite the highest conidial acquisition in the semiochemical-baited fungus-treated device. Thrips density per plant was significantly reduced in both fungus-treated treatments (with semiochemical: 8.7 ± 1.7 adults per plant; without semiochemical: 6.6 ± 1.4 adults per plant) compared with the fungus-free control (19.8 ± 2.6 adults per plant). These results demonstrate the potential for an Autoinoculation device strategy for the control of thrips, particularly in screenhouses.
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pathogenicity of entomopathogenic fungi metarhizium anisopliae and beauveria bassiana hypocreales clavicipitaceae isolates to the adult pea leafminer diptera agromyzidae and prospects of an Autoinoculation device for infection in the field
Environmental Entomology, 2010Co-Authors: L N Migiro, A Chabiolaye, Nguya K Maniania, Jacob VandenbergAbstract:ABSTRACT Seventeen isolates of Metarhizium anisopliae (Metschnikoff) Sorokin and three isolates of Beauveria bassiana (Balsamo) Vuillemin (Hypocreales: Clavicipitaceae) were evaluated for their pathogenicity to the adult pea leafminer, Liriomyza huidobrensis (Blanchard) (Diptera: Agromyzidae), in the laboratory. Flies were contaminated with dry conidia through a velvet material wrapped around the inner side of a cylindrical plastic tube. All the isolates were pathogenic to the pea leafminer, causing mortality between 40 and 100% at 5 d after exposure. The lethal time for 50% mortality (LT50) ranged from 2.6 to 5.4 d, whereas the LT90 values varied between 3.2 and 9.1 d depending on the isolate. An Autoinoculation device was evaluated in cage field experiments using only one of the virulent isolates, M. anisopliae ICIPE 20. The device was loaded with 2–3 g of dry conidia. Mortality of up to 100% was observed in flies captured from fungus-treated cages held under laboratory conditions. The average number of...
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pathogenicity of entomopathogenic fungi metarhizium anisopliae and beauveria bassiana hypocreales clavicipitaceae isolates to the adult pea leafminer diptera agromyzidae and prospects of an Autoinoculation device for infection in the field
Environmental Entomology, 2010Co-Authors: L N Migiro, A Chabiolaye, Nguya K Maniania, Jacob VandenbergAbstract:Seventeen isolates of Metarhizium anisopliae (Metschnikoff) Sorokin and three isolates of Beauveria bassiana (Balsamo) Vuillemin (Hypocreales: Clavicipitaceae) were evaluated for their pathogenicity to the adult pea leafminer, Liriomyza huidobrensis (Blanchard) (Diptera: Agromyzidae), in the laboratory. Flies were contaminated with dry conidia through a velvet material wrapped around the inner side of a cylindrical plastic tube. All the isolates were pathogenic to the pea leafminer, causing mortality between 40 and 100% at 5 d after exposure. The lethal time for 50% mortality (LT(50)) ranged from 2.6 to 5.4 d, whereas the LT(90) values varied between 3.2 and 9.1 d depending on the isolate. An Autoinoculation device was evaluated in cage field experiments using only one of the virulent isolates, M. anisopliae ICIPE 20. The device was loaded with 2-3 g of dry conidia. Mortality of up to 100% was observed in flies captured from fungus-treated cages held under laboratory conditions. The average number of spores picked up by a single fly visiting the device increased with days after inoculation. One day after the inoculation, adults picked up an average of 4.1 +/- 0.7 x 10(5) conidia and 39.6 +/- 4.0 x 10(5) conidia 5 d after inoculation. Depending on the sampling date, the LT(50) varied between 1.8 and 3.4 d. Results indicate that some isolates of B. bassiana and M. anisopliae are highly pathogenic to L. huidobrensis, suggesting a potential for their use in the control of this pest. They also suggest the possibility of L. huidobrensis suppression with fungi using an Autoinoculation device.
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the use of a semiochemical bait to enhance exposure of amblyomma variegatum acari ixodidae to metarhizium anisopliae ascomycota hypocreales
Veterinary Parasitology, 2009Co-Authors: Nguya K Maniania, Felix Nchu, A Toure, Ahmed Hassanali, J N EloffAbstract:Experiments were conducted to explore the use of a semiochemical bait to enhance exposure of Amblyomma variegatum Fabricius (Acari: Ixodidae) to different formulations of the entomopathogenic fungus Metarhizium anisopliae (Metsch.) Sorok. (Ascomycota: Hypocreales). Initially, the relative efficacies of attraction-aggregation-attachment pheromone (AAAP), made up of o-nitrophenol, methyl salicylate and nonanoic acid in the ratio 2:1:8, 1-octen-3-ol and butyric acid, were evaluated in an olfactometer. Only AAAP and 1-octen-3-ol were found to elicit attractive responses to the tick. Simultaneous release of 1-octen-3-ol and AAAP together with CO2 from a trap in semifield plots attracted up to 94.0 ± 6% of adult ticks from a distance of 6 m, and up to 24.0 ± 5.1% from 8 m. Formulations of M. anisopliae (dry powder, oil, and emulsifiable) applied within the trap baited with AAAP, 1-octen-3-ol and CO2 resulted in high levels of contamination of the ticks attracted to the traps. However, 48 h after Autoinoculation, 89.1 and 33.3% of conidia were lost in dry powder and oil formulations, respectively. Emulsifiable formulation showed least loss of propagules (17.1%). Samples of ticks attracted to the baited traps were transferred to plastic basins containing grass and maintained for 5 weeks. The experiment was conducted in rainy and dry seasons. Emulsifiable formulation gave the highest relative tick reduction in both seasons: 54.7 and 46.5% in rainy and dry seasons, respectively, followed by oil formulation (32.0 and 23.8%) and powder formulation (38.0 and 24.4%).
Laxmi Yeruva - One of the best experts on this subject based on the ideXlab platform.
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is it time to switch to doxycycline from azithromycin for treating genital chlamydial infections in women modelling the impact of Autoinoculation from the gastrointestinal tract to the genital tract
BMC Infectious Diseases, 2015Co-Authors: Andrew P Craig, Roger G Rank, Laxmi Yeruva, Fabian Y S Kong, Jane S Hocking, David Wilson, Basil DonovanAbstract:Single-dose azithromycin is recommended over multi-dose doxycycline as treatment for chlamydial infection. However, even with imperfect adherence, doxycycline is more effective in treating genital and rectal infection. Recently, it has been suggested that Autoinoculation from the rectum to the genitals may be a source of persistent chlamydial infection in women. We estimated the impact Autoinoculation may have on azithromycin and doxycycline effectiveness. We estimate treatment effectiveness using a simple mathematical model, incorporating data on azithromycin and doxycycline efficacy from recent meta-analyses, and data on prevalence of rectal infection in women with genital chlamydial infection. When the possibility of Autoinoculation is taken into account, we calculate that doxycycline effectiveness may be 97% compared to just 82% for azithromycin. Consideration should be given to re-evaluating azithromycin as the standard treatment for genital chlamydia in women.
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hidden in plain sight chlamydial gastrointestinal infection and its relevance to persistence in human genital infection
Infection and Immunity, 2014Co-Authors: Roger G Rank, Laxmi YeruvaAbstract:Although the concept of persistence in chlamydial infections has been recognized for about 80 years, there is still very little known about the mechanism by which this occurs. In this review, we revisit an old paradigm, long known to chlamydiologists and veterinarians, that in virtually all hosts of chlamydiae, including mammals and birds, chlamydiae reside in the gastrointestinal tract for long periods of time in the absence of clinical disease. Thus, if gastrointestinal infection occurs in most hosts, then it is very likely that gastrointestinal infection occurs in humans as well. We demonstrate that gastrointestinal infection does indeed occur in humans and propose that this anatomical site is the source of persistent infection in humans. The data in ruminants and animal models demonstrate that the immune system is unable to clear chlamydiae from the gut, so they can remain indefinitely, with continual shedding in feces. Clearly, many women become reinfected from an untreated partner; however, we propose that women, cured of genital infection, remain at risk for Autoinoculation from the lower gastrointestinal tract. Moreover, there are substantial data demonstrating treatment failure of chlamydial infections, particularly with azithromycin. New data in the mouse model have shown that azithromycin is far less effective against chlamydial gastrointestinal infection than against genital infections. Therefore, it is possible that women cured of genital infection by antibiotics remain infected in the gastrointestinal tract and can become reinfected by Autoinoculation from that site.
Roger G Rank - One of the best experts on this subject based on the ideXlab platform.
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Hidden in plain sight: chlamydial gastrointestinal infection and its relevance to persistence in human genital infection. Infect Immun 82:1362–1371
2016Co-Authors: Roger G Rank, Laxmi A YeruvabAbstract:Although the concept of persistence in chlamydial infections has been recognized for about 80 years, there is still very little known about the mechanism by which this occurs. In this review, we revisit an old paradigm, long known to chlamydiologists and veterinarians, that in virtually all hosts of chlamydiae, including mammals and birds, chlamydiae reside in the gastrointesti-nal tract for long periods of time in the absence of clinical disease. Thus, if gastrointestinal infection occurs in most hosts, then it is very likely that gastrointestinal infection occurs in humans as well. We demonstrate that gastrointestinal infection does indeed occur in humans and propose that this anatomical site is the source of persistent infection in humans. The data in ruminants and animal models demonstrate that the immune system is unable to clear chlamydiae from the gut, so they can remain indefinitely, with continual shedding in feces. Clearly, many women become reinfected from an untreated partner; however, we propose that women, cured of genital infection, remain at risk for Autoinoculation from the lower gastrointestinal tract. Moreover, there are substantial data demonstrating treatment failure of chlamydial infections, particularly with azithromycin. New data in the mouse model have shown that azithromycin is far less effective against chlamydial gastrointestinal infection than against genital infections. Therefore, it is possible that women cured of genital infection by antibiotics remain infected in the gastrointestinal tract and can become reinfected by Autoinoculation from that site. Perhaps the most recognized biological property of chlamydialspecies is their ability to remain associatedwith their host over long periods of time, often in an apparent quiescent or latent stat
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is it time to switch to doxycycline from azithromycin for treating genital chlamydial infections in women modelling the impact of Autoinoculation from the gastrointestinal tract to the genital tract
BMC Infectious Diseases, 2015Co-Authors: Andrew P Craig, Roger G Rank, Laxmi Yeruva, Fabian Y S Kong, Jane S Hocking, David Wilson, Basil DonovanAbstract:Single-dose azithromycin is recommended over multi-dose doxycycline as treatment for chlamydial infection. However, even with imperfect adherence, doxycycline is more effective in treating genital and rectal infection. Recently, it has been suggested that Autoinoculation from the rectum to the genitals may be a source of persistent chlamydial infection in women. We estimated the impact Autoinoculation may have on azithromycin and doxycycline effectiveness. We estimate treatment effectiveness using a simple mathematical model, incorporating data on azithromycin and doxycycline efficacy from recent meta-analyses, and data on prevalence of rectal infection in women with genital chlamydial infection. When the possibility of Autoinoculation is taken into account, we calculate that doxycycline effectiveness may be 97% compared to just 82% for azithromycin. Consideration should be given to re-evaluating azithromycin as the standard treatment for genital chlamydia in women.
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hidden in plain sight chlamydial gastrointestinal infection and its relevance to persistence in human genital infection
Infection and Immunity, 2014Co-Authors: Roger G Rank, Laxmi YeruvaAbstract:Although the concept of persistence in chlamydial infections has been recognized for about 80 years, there is still very little known about the mechanism by which this occurs. In this review, we revisit an old paradigm, long known to chlamydiologists and veterinarians, that in virtually all hosts of chlamydiae, including mammals and birds, chlamydiae reside in the gastrointestinal tract for long periods of time in the absence of clinical disease. Thus, if gastrointestinal infection occurs in most hosts, then it is very likely that gastrointestinal infection occurs in humans as well. We demonstrate that gastrointestinal infection does indeed occur in humans and propose that this anatomical site is the source of persistent infection in humans. The data in ruminants and animal models demonstrate that the immune system is unable to clear chlamydiae from the gut, so they can remain indefinitely, with continual shedding in feces. Clearly, many women become reinfected from an untreated partner; however, we propose that women, cured of genital infection, remain at risk for Autoinoculation from the lower gastrointestinal tract. Moreover, there are substantial data demonstrating treatment failure of chlamydial infections, particularly with azithromycin. New data in the mouse model have shown that azithromycin is far less effective against chlamydial gastrointestinal infection than against genital infections. Therefore, it is possible that women cured of genital infection by antibiotics remain infected in the gastrointestinal tract and can become reinfected by Autoinoculation from that site.
Basil Donovan - One of the best experts on this subject based on the ideXlab platform.
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is it time to switch to doxycycline from azithromycin for treating genital chlamydial infections in women modelling the impact of Autoinoculation from the gastrointestinal tract to the genital tract
BMC Infectious Diseases, 2015Co-Authors: Andrew P Craig, Roger G Rank, Laxmi Yeruva, Fabian Y S Kong, Jane S Hocking, David Wilson, Basil DonovanAbstract:Single-dose azithromycin is recommended over multi-dose doxycycline as treatment for chlamydial infection. However, even with imperfect adherence, doxycycline is more effective in treating genital and rectal infection. Recently, it has been suggested that Autoinoculation from the rectum to the genitals may be a source of persistent chlamydial infection in women. We estimated the impact Autoinoculation may have on azithromycin and doxycycline effectiveness. We estimate treatment effectiveness using a simple mathematical model, incorporating data on azithromycin and doxycycline efficacy from recent meta-analyses, and data on prevalence of rectal infection in women with genital chlamydial infection. When the possibility of Autoinoculation is taken into account, we calculate that doxycycline effectiveness may be 97% compared to just 82% for azithromycin. Consideration should be given to re-evaluating azithromycin as the standard treatment for genital chlamydia in women.
L N Migiro - One of the best experts on this subject based on the ideXlab platform.
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pathogenicity of entomopathogenic fungi metarhizium anisopliae and beauveria bassiana hypocreales clavicipitaceae isolates to the adult pea leafminer diptera agromyzidae and prospects of an Autoinoculation device for infection in the field
Environmental Entomology, 2010Co-Authors: L N Migiro, A Chabiolaye, Nguya K Maniania, Jacob VandenbergAbstract:ABSTRACT Seventeen isolates of Metarhizium anisopliae (Metschnikoff) Sorokin and three isolates of Beauveria bassiana (Balsamo) Vuillemin (Hypocreales: Clavicipitaceae) were evaluated for their pathogenicity to the adult pea leafminer, Liriomyza huidobrensis (Blanchard) (Diptera: Agromyzidae), in the laboratory. Flies were contaminated with dry conidia through a velvet material wrapped around the inner side of a cylindrical plastic tube. All the isolates were pathogenic to the pea leafminer, causing mortality between 40 and 100% at 5 d after exposure. The lethal time for 50% mortality (LT50) ranged from 2.6 to 5.4 d, whereas the LT90 values varied between 3.2 and 9.1 d depending on the isolate. An Autoinoculation device was evaluated in cage field experiments using only one of the virulent isolates, M. anisopliae ICIPE 20. The device was loaded with 2–3 g of dry conidia. Mortality of up to 100% was observed in flies captured from fungus-treated cages held under laboratory conditions. The average number of...
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pathogenicity of entomopathogenic fungi metarhizium anisopliae and beauveria bassiana hypocreales clavicipitaceae isolates to the adult pea leafminer diptera agromyzidae and prospects of an Autoinoculation device for infection in the field
Environmental Entomology, 2010Co-Authors: L N Migiro, A Chabiolaye, Nguya K Maniania, Jacob VandenbergAbstract:Seventeen isolates of Metarhizium anisopliae (Metschnikoff) Sorokin and three isolates of Beauveria bassiana (Balsamo) Vuillemin (Hypocreales: Clavicipitaceae) were evaluated for their pathogenicity to the adult pea leafminer, Liriomyza huidobrensis (Blanchard) (Diptera: Agromyzidae), in the laboratory. Flies were contaminated with dry conidia through a velvet material wrapped around the inner side of a cylindrical plastic tube. All the isolates were pathogenic to the pea leafminer, causing mortality between 40 and 100% at 5 d after exposure. The lethal time for 50% mortality (LT(50)) ranged from 2.6 to 5.4 d, whereas the LT(90) values varied between 3.2 and 9.1 d depending on the isolate. An Autoinoculation device was evaluated in cage field experiments using only one of the virulent isolates, M. anisopliae ICIPE 20. The device was loaded with 2-3 g of dry conidia. Mortality of up to 100% was observed in flies captured from fungus-treated cages held under laboratory conditions. The average number of spores picked up by a single fly visiting the device increased with days after inoculation. One day after the inoculation, adults picked up an average of 4.1 +/- 0.7 x 10(5) conidia and 39.6 +/- 4.0 x 10(5) conidia 5 d after inoculation. Depending on the sampling date, the LT(50) varied between 1.8 and 3.4 d. Results indicate that some isolates of B. bassiana and M. anisopliae are highly pathogenic to L. huidobrensis, suggesting a potential for their use in the control of this pest. They also suggest the possibility of L. huidobrensis suppression with fungi using an Autoinoculation device.
