146 research outputs found

    Effect of carbofuran on the diversity and mean abundance of ground spiders

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    The effect of carbofuran on the diversity, richness, evenness and abundance of ground spiders is documented in the present study. Two fields (control and treated) were selected in district Kasur during 2008 and 2009. Pitfall traps were used to collect ground spiders. A total of 1629 specimens of spiders, belonging to 8 families, 16 genera and 24 species were recoded from control field while 1173 specimens belonging to 8 families, 14 genera and 20 species were recorded from the treated field. The most dominant family and species in both the fields were Lycosidae and Lycosa terrestris, respectively. Family Lycosidae accounted more than 90% of the total spider sample. Diversity, richness and evenness of ground spiders in the treated and untreated field did not differ. However, the abundance of dominat spiders declined significantly in the carbofuran treated field. It is concluded that the use of carbofuran is a serious threat to the ground spiders, the important group of biological control agents. So, the use of carbofuran should be minimized in the fields.Key words: Ground spiders, carbofuran, natural predators, pest reduction

    Ovarian Cancer in the Sudan - Identifying the Social and Clinical Factors that Prevent an Early Diagnosis

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    Ovarian cancer, because it often presents with vague symptoms, is a difficult disease to diagnose at the early stages, especially in developing countries. In Sudan, diagnosis is further complicated by additional factors and challenges. First, as in any developing country, access to treatment, facilities and medical staff is generally lacking. Secondly, Sudan is the second largest country in Africa: its very size presents difficulties for the implementation of a centralized health system. The two tertiary hospitals in or near the capital have long patient waiting lists.The lack of female education in sub-Saharan Africa, together with social and economic issues affecting women, is a further obstacle to disease diagnosis and management. Misdiagnosis, leading to inappropriate treatment, may result from the presence of comorbid diseases such as Tuberculosis (TB), which can mimic ovarian cancer and obstruct early detection. Most patients are identified at the later stages when the complications associated with invasive procedures and conventional chemotherapy make treatment much less effective. The early detection of biomarkers may prove to be a vital tool to indicate targets for immunotherapy treatment.Financial aid may help improve the outcomes for patients with ovarian cancer in the Sudan, assisting with diagnosing and management procedures including training medical staff. Research and development, documentation and updating the statistical register for the whole country are also important requirements for future improvements.Finally, there is a need to promote interdisciplinary work between surgeons and clinical oncologists to optimize international guidelines and protocols in accordance with the facilities available

    Safety and immunogenicity of an autoclaved Leishmania major vaccine

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    Objective: To test the safety and immunogenicity of two doses of autoclaved L.major (ALM) vaccine mixed with BCG.Setting: Kala-azar endemic area of eastern Sudan.Design: This was a randomised, double blind and BCG controlled phase I/II study.Subjects: Eighty healthy volunteers (forty children and forty adults) with no past history of kala-azar, no reactivity to leishmanin antigen and with a reciprocal direct agglutination test (DAT) titre o

    Heterologous expression screens in Nicotiana benthamiana identify a candidate effector of the wheat Yellow Rust Pathogen that associates with processing bodies

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    Rust fungal pathogens of wheat (Triticum spp.) affect crop yields worldwide. The molecular mechanisms underlying the virulence of these pathogens remain elusive, due to the limited availability of suitable molecular genetic research tools. Notably, the inability to perform high-throughput analyses of candidate virulence proteins (also known as effectors) impairs progress. We previously established a pipeline for the fast-forward screens of rust fungal candidate effectors in the model plant Nicotiana benthamiana. This pipeline involves selecting candidate effectors in silico and performing cell biology and protein-protein interaction assays in planta to gain insight into the putative functions of candidate effectors. In this study, we used this pipeline to identify and characterize sixteen candidate effectors from the wheat yellow rust fungal pathogen Puccinia striiformis f sp tritici. Nine candidate effectors targeted a specific plant subcellular compartment or protein complex, providing valuable information on their putative functions in plant cells. One candidate effector, PST02549, accumulated in processing bodies (P-bodies), protein complexes involved in mRNA decapping, degradation, and storage. PST02549 also associates with the P-body-resident ENHANCER OF mRNA DECAPPING PROTEIN 4 (EDC4) from N. benthamiana and wheat. We propose that P-bodies are a novel plant cell compartment targeted by pathogen effectors

    Molecular drivers of insecticide resistance in the Sahelo-Sudanian populations of a major malaria vector Anopheles coluzzii.

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    BACKGROUND: Information on common markers of metabolic resistance in malaria vectors from countries sharing similar eco-climatic characteristics can facilitate coordination of malaria control. Here, we characterized populations of the major malaria vector Anopheles coluzzii from Sahel region, spanning four sub-Saharan African countries: Nigeria, Niger, Chad and Cameroon. RESULTS: Genome-wide transcriptional analysis identified major genes previously implicated in pyrethroid and/or cross-resistance to other insecticides, overexpressed across the Sahel, including CYP450s, glutathione S-transferases, carboxylesterases and cuticular proteins. Several, well-known markers of insecticide resistance were found in high frequencies-including in the voltage-gated sodium channel (V402L, I940T, L995F, I1527T and N1570Y), the acetylcholinesterase-1 gene (G280S) and the CYP4J5-L43F (which is fixed). High frequencies of the epidemiologically important chromosomal inversion polymorphisms, 2La, 2Rb and 2Rc, were observed (~80% for 2Rb and 2Rc). The 2La alternative arrangement is fixed across the Sahel. Low frequencies of these inversions (C), between Forkhead box L1 and c-EST putative binding sites, were responsible for the high overexpression of GSTe2 in the resistant mosquitoes. Transgenic flies expressing CYP6Z2 exhibited marginal resistance towards 3-phenoxybenzylalcohol (a primary product of pyrethroid hydrolysis by carboxylesterases) and a type II pyrethroid, α-cypermethrin. However, significantly higher mortalities were observed in CYP6Z2 transgenic flies compared with controls, on exposure to the neonicotinoid, clothianidin. This suggests a possible bioactivation of clothianidin into a toxic intermediate, which may make it an ideal insecticide against populations of An. coluzzii overexpressing this P450. CONCLUSIONS: These findings will facilitate regional collaborations within the Sahel region and refine implementation strategies through re-focusing interventions, improving evidence-based, cross-border policies towards local and regional malaria pre-elimination

    Insecticide resistance in the sand fly, Phlebotomus papatasi from Khartoum State, Sudan

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    <p>Abstract</p> <p>Background</p> <p><it>Phlebotomus papatasi </it>the vector of cutaneous leishmaniasis (CL) is the most widely spread sand fly in Sudan. No data has previously been collected on insecticide susceptibility and/or resistance of this vector, and a first study to establish a baseline data is reported here.</p> <p>Methods</p> <p>Sand flies were collected from Surogia village, (Khartoum State), Rahad Game Reserve (eastern Sudan) and White Nile area (Central Sudan) using light traps. Sand flies were reared in the Tropical Medicine Research Institute laboratory. The insecticide susceptibility status of first progeny (F1) of <it>P. papatasi </it>of each population was tested using WHO insecticide kits. Also, <it>P. papatasi </it>specimens from Surogia village and Rahad Game Reserve were assayed for activities of enzyme systems involved in insecticide resistance (acetylcholinesterase (AChE), non-specific carboxylesterases (EST), glutathione-S-transferases (GSTs) and cytochrome p450 monooxygenases (Cyt p450).</p> <p>Results</p> <p>Populations of <it>P. papatasi </it>from White Nile and Rahad Game Reserve were sensitive to dichlorodiphenyltrichloroethane (DDT), permethrin, malathion, and propoxur. However, the <it>P. papatasi </it>population from Surogia village was sensitive to DDT and permethrin but highly resistant to malathion and propoxur. Furthermore, <it>P. papatasi </it>of Surogia village had significantly higher insecticide detoxification enzyme activity than of those of Rahad Game Reserve. The sand fly population in Surogia displayed high AChE activity and only three specimens had elevated levels for EST and GST.</p> <p>Conclusions</p> <p>The study provided evidence for malathion and propoxur resistance in the sand fly population of Surogia village, which probably resulted from anti-malarial control activities carried out in the area during the past 50 years.</p

    Risk factors of visceral leishmaniasis: a case control study in north-western Ethiopia

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    Background Visceral leishmaniasis (VL, also called “kala-azar”), is a life threatening neglected tropical infectious disease which mainly affects the poorest of the poor. VL is prevalent in Ethiopia particularly in the northwest of the country. Understanding the risk factors of VL infection helps in its prevention and control. The aim of the present study was to identify the factors associated with VL. Methods A case–control study was carried out during the period of January-July 2013 in northwest Ethiopia. Cases and controls were diagnosed using clinical presentation, the rk39 rapid diagnostic test and Direct Agglutination Test (DAT). A total of 283 (84.8% males versus 15.2% females) participants were interviewed. 90 cases and 193 controls were involved, matched by age, sex and geographical location with a ratio of 1:2 (case: controls). Univariate and backward multivariate conditional logistic regression were used to identify risk factors of VL. Results Elevated odds of VL was associated with goat ownership (OR = 6.4; 95%: confidence interval [Cl]: 1.5-28.4), living in houses with cracked wall (OR = 6.4; 95% Cl: 1.6-25.6), increased family size (OR = 1.3; 95% Cl: 1.0-1.8) and the number of days spent in the farm field (OR = 1.1; 95% Cl: 1.0-1.2). However, daily individual activities around the home and farm fields, mainly sleeping on a bed (OR = 0.2; 95%: Cl 0.03-0.9), sleeping outside the house under a bed net (OR = 0.1; 95% Cl: 0.02-0.36)] and smoking plant parts in the house during the night time (OR = 0.1; 95% Cl: 0.01-0.6) were associated with decreased odds of being VL case. Conclusion Our findings showed that use of bed net and smoke could be helpful for the prevention of VL in the area particularly among individuals who spend most of their time in the farm. VL control effort could be focused on improving housing conditions, such as sealing cracks and crevices inside and outside houses. Further research is warranted to elucidate the role of goats in the transmission of L. donovani, assess the impact of bed nets and the role of the traditional practice of smoking plants

    Spatial Distribution and Risk Factors of Highly Pathogenic Avian Influenza (HPAI) H5N1 in China

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    Highly pathogenic avian influenza (HPAI) H5N1 was first encountered in 1996 in Guangdong province (China) and started spreading throughout Asia and the western Palearctic in 2004–2006. Compared to several other countries where the HPAI H5N1 distribution has been studied in some detail, little is known about the environmental correlates of the HPAI H5N1 distribution in China. HPAI H5N1 clinical disease outbreaks, and HPAI virus (HPAIV) H5N1 isolated from active risk-based surveillance sampling of domestic poultry (referred to as HPAIV H5N1 surveillance positives in this manuscript) were modeled separately using seven risk variables: chicken, domestic waterfowl population density, proportion of land covered by rice or surface water, cropping intensity, elevation, and human population density. We used bootstrapped logistic regression and boosted regression trees (BRT) with cross-validation to identify the weight of each variable, to assess the predictive power of the models, and to map the distribution of HPAI H5N1 risk. HPAI H5N1 clinical disease outbreak occurrence in domestic poultry was mainly associated with chicken density, human population density, and elevation. In contrast, HPAIV H5N1 infection identified by risk-based surveillance was associated with domestic waterfowl density, human population density, and the proportion of land covered by surface water. Both models had a high explanatory power (mean AUC ranging from 0.864 to 0.967). The map of HPAIV H5N1 risk distribution based on active surveillance data emphasized areas south of the Yangtze River, while the distribution of reported outbreak risk extended further North, where the density of poultry and humans is higher. We quantified the statistical association between HPAI H5N1 outbreak, HPAIV distribution and post-vaccination levels of seropositivity (percentage of effective post-vaccination seroconversion in vaccinated birds) and found that provinces with either outbreaks or HPAIV H5N1 surveillance positives in 2007–2009 appeared to have had lower antibody response to vaccination. The distribution of HPAI H5N1 risk in China appears more limited geographically than previously assessed, offering prospects for better targeted surveillance and control interventions
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