scholarly journals Lack of Resistance in Aedes vexans Field Populations After 36 Years of Bacillus thuringiensis subsp. Israelensis Applications in the Upper Rhine Valley, Germany

2018 ◽  
Vol 34 (2) ◽  
pp. 154-157 ◽  
Author(s):  
Norbert Becker ◽  
Mario Ludwig ◽  
Tianyun Su

ABSTRACT Bacillus thuringiensis subsp. israelensis (Bti) has been widely and solely used against floodwater mosquitoes, mostly Aedes vexans, for 36 years in the Upper Rhine Valley by the German Mosquito Control Association. During this period, almost 5,000 tons of Bti formulations were applied to an area of approximately 400,000 ha. To investigate a possible resistance development after such a long-term and widespread application of Bti, the susceptibility of Ae. vexans larvae to Bti in 3 untreated (Lake Constance) and 6 treated areas on both sides of the Rhine within the Upper Rhine Valley was assessed by bioassays following World Health Organization guidelines. Comparing log-probit analyses, it was shown that neither the median lethal concentration (LC50 values) nor slopes of the probit lines of bioassays of the larvae deriving from treated and untreated areas showed significant differences. These results have been confirmed by resistance ratios, which varied from 0.80 to 1.12 in all tests. The results provided the evidence that no restistance in the target species Ae. vexans has developed in the areas of the Upper Rhine Valley, despite the large-scale use of Bti for 36 years.

Author(s):  
Vikas Sharma ◽  
Chandana Majee ◽  
Rahul Kaushik ◽  
Shivani Saxena ◽  
Salahuddin Salahuddin ◽  
...  

Herbal digestive tablets are meant for treating indigestion problems. The indigestion problem is one of the major problems of all (the) ages of human beings. As trends for eating fast foods is increasing, simultaneously the improper digestion also tends to increase. There are a number of digestive tablets in the market but in attempt to improve their taste the actual motto behind their use is masked. To combat the indigestion problems, in the present study an attempt has been made to formulate, develop and evaluate herbal digestive tablets. The formula of the digestive tablet has been decided after deep review of Ayurvedic formulary of India. The ingredients of this formulation have been procured from authentic sources. The wet granulation method was used to prepare the granules for punching the tablets. After preparation, the herbal digestive tablets were subjected to various pharmaceutical evaluations and quality control evaluations as per the guidelines from World Health Organization (WHO). The formulation was also subjected to antioxidant screening using Phosphomolybdenum method. The digestive tablets are obtained as light brown-colored round tablets with pleasant odour and spicy taste with an average size of 8mm and smooth edges. Maximum extractive value was observed as 34% in methanol with a total ash value of 10.16%. Other parameters reported as bitterness value- 0.69 units, volatile oil content-8%, loss on drying- 12.3%, swelling and foaming index of 0.27 and less than 100 respectively. The tablets showed a total antioxidant potential of 0.51mg/mg as Ascorbic acid equivalent. Tablets also pass various pharmaceutical evaluation parameters like hardness, friability, weight variation, and disintegration test. Herbal digestive tablets have very excellent taste due to less bitter drugs. The tablet formula can be applied to prepare large scale production of digestive tablets.


2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Kauara Brito Campos ◽  
Ademir Jesus Martins ◽  
Cynara de Melo Rodovalho ◽  
Diogo Fernandes Bellinato ◽  
Luciana dos Santos Dias ◽  
...  

Abstract Background Chemical mosquito control using malathion has been applied in Brazil since 1985. To obtain chemical control effectiveness, vector susceptibility insecticide monitoring is required. This study aimed to describe bioassay standardizations and determine the susceptibility profile of Ae. aegypti populations to malathion and pyriproxyfen, used on a national scale in Brazil between 2017 and 2018, and discuss the observed impacts in arbovirus control. Methods The diagnostic-doses (DD) of pyriproxyfen and malathion were determined as the double of adult emergence inhibition (EI) and lethal doses for 99% of the Rockefeller reference strain, respectively. To monitor natural populations, sampling was performed in 132 Brazilian cities, using egg traps. Colonies were raised in the laboratory for one or two generations (F1 or F2) and submitted to susceptibility tests, where larvae were exposed to the pyriproxyfen DD (0.03 µg/l) and adults, to the malathion DD determined in the present study (20 µg), in addition to the one established by the World Health Organization (WHO) DD (50 µg) in a bottle assay. Dose-response (DR) bioassays with pyriproxyfen were performed on populations that did not achieve 98% EI in the DD assays. Results Susceptibility alterations to pyriproxyfen were recorded in six (4.5%) Ae. aegypti populations from the states of Bahia and Ceará, with Resistance Ratios (RR95) ranging from 1.51 to 3.58. Concerning malathion, 73 (55.3%) populations distributed throughout the country were resistant when exposed to the local DD 20 µg/bottle. On the other hand, no population was resistant, and only 10 (7.6%) populations in eight states were considered as exhibiting decreased susceptibility (mortality ratios between 90 and 98%) when exposed to the WHO DD (50 µg/bottle). Conclusions The feasibility of conducting an insecticide resistance monitoring action on a nation-wide scale was confirmed herein, employing standardized and strongly coordinated sampling methods and laboratory bioassays. Brazilian Ae. aegypti populations exhibiting decreased susceptibility to pyriproxyfen were identified. The local DD for malathion was more sensitive than the WHO DD for early decreased susceptibility detection.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ole Lagatie ◽  
Ann Verheyen ◽  
Stijn Van Asten ◽  
Maurice R. Odiere ◽  
Yenny Djuardi ◽  
...  

Abstract Infections with intestinal worms, such as Ascaris lumbricoides, affect hundreds of millions of people in all tropical and subtropical regions of the world. Through large-scale deworming programs, World Health Organization aims to reduce moderate-to-heavy intensity infections below 1%. Current diagnosis and monitoring of these control programs are solely based on the detection of worm eggs in stool. Here we describe how metabolome analysis was used to identify the A. lumbricoides-specific urine biomarker 2-methyl pentanoyl carnitine (2-MPC). This biomarker was found to be 85.7% accurate in determining infection and 90.5% accurate in determining a moderate-to-heavy infection. Our results also demonstrate that there is a correlation between 2-MPC levels in urine and A. lumbricoides DNA detected in stool. Furthermore, the levels of 2-MPC in urine were shown to rapidly and strongly decrease upon administration of a standard treatment (single oral dose of 400 mg albendazole). In an Ascaris suum infection model in pigs, it was found that, although 2-MPC levels were much lower compared to humans, there was a significant association between urinary 2-MPC levels and both worm counts (p = 0.023) and the number of eggs per gram (epg) counts (p < 0.001). This report demonstrates that urinary 2-MPC can be considered an A. lumbricoides-specific biomarker that can be used to monitor infection intensity.


2020 ◽  
Vol 8 ◽  
Author(s):  
Lee Smith ◽  
Nicola Veronese ◽  
Vincenzo Racalbuto ◽  
Damiano Pizzol

The COVID-19 outbreak was declared by the World Health Organization (WHO) as global pandemic in March 2020. Considering the necessity to implement rapid response to control the pandemic and the fragility and the state of need of low income countries, it will be mandatory to develop a global approach in order to reduce the spread of infection and the creation of community viral reservoirs. So far, we could hypothesize a worst case scenario in which when the COVID-19 outbreak hits a peak in Africa and in low-income countries, the majority of such countries will be unprepared, with low resources allocated for affording the viral emergency and the consequences will be catastrophic with no lesson learnt. In the best case scenario, the COVID-19 will not affect Africa or South America on a large scale and, if the prevention measures will be implemented, we could register a lower incidence of hygiene linked diseases that still represent leading causes of death.


2019 ◽  
Vol 220 (Supplement_4) ◽  
pp. S148-S154 ◽  
Author(s):  
Jaymin C Patel ◽  
Heidi M Soeters ◽  
Alpha Oumar Diallo ◽  
Brice W Bicaba ◽  
Goumbi Kadadé ◽  
...  

Abstract Meningococcal meningitis remains a significant public health threat, especially in the African meningitis belt where Neisseria meningitidis serogroup A historically caused large-scale epidemics. With the rollout of a novel meningococcal serogroup A conjugate vaccine (MACV) in the belt, the World Health Organization recommended case-based meningitis surveillance to monitor MACV impact and meningitis epidemiology. In 2014, the MenAfriNet consortium was established to support strategic implementation of case-based meningitis surveillance in 5 key countries: Burkina Faso, Chad, Mali, Niger, and Togo. MenAfriNet aimed to develop a high-quality surveillance network using standardized laboratory and data collection protocols, develop sustainable systems for data management and analysis to monitor MACV impact, and leverage the surveillance platform to perform special studies. We describe the MenAfriNet consortium, its history, strategy, implementation, accomplishments, and challenges.


2014 ◽  
Vol 147 (1) ◽  
pp. 118-123 ◽  
Author(s):  
Elin C. Maki ◽  
Lee W. Cohnstaedt

AbstractSampling a cosmopolitan mosquito (Diptera: Culicidae) species throughout its range is logistically challenging and extremely resource intensive. Mosquito control programmes and regional networks operate at the local level and often conduct sampling activities across much of North America. A method for large-scale sampling of two mosquito species using crowdsourcing to network with these local and regional programmes is described. A total of 961 mosquito vector and control districts, health departments, and individual collectors across the United States of America and Canada were contacted in 2011 and 2012 of which 9% positively responded by sending mosquitoes. In total, 1101 unique population samples of Aedes vexans (Meigen) and Culex tarsalis Coquillett were collected throughout their range in these two countries. Aedes vexans outgroup samples were also submitted from Europe and Asia. This is the largest crowd-sourced collection of samples to date.


Author(s):  
Suryani Suryani ◽  
Loly Subhiaty Idrus ◽  
Ruslin Ruslin ◽  
Rini Hamsidi

Background: Transmission of COVID-19 developed rapidly until the World Health Organization (WHO) established a pandemic status on COVID-19 since March 11, 2020. Various of government efforts in the context of prevention and treatment have been carried out including lockdowns decisision, social distancing and new normal was currently carried out. Objective: This community service activity aims as an effort to increase the knowledge and awareness of South Konawe communities to prevent and fight covid-19 by clean and healthy living behaviors. Method: The implementation of this activity using socialization and persuasive communication online methods via social media instagram and youtube and offline method performed in two categories, small-scale and large-scale at South Konawe. These community service activities are outlined in 4 main programs, GERMAS (Healthy Living Community Movement), GEMAS (Community Movement Using Masks), socialization about TOGA (Family Medicinal Plants), antiseptics and disinfectants. Results: The result of this program is increasing public knowledges about how to improve the immune system, such as consuming nutritious food, consuming herbs which can be processed into an infusion or decocta preparations as well as understand the importance of implementing about prevention of covid-19 in daily life, such wearing masks, antiseptics, and disinfectants and washing hand correctly. Conclusion: This community service activity really helped increase the knowledge and awareness of the community of South Konawe to prevent and fight the corona virus.


Author(s):  
Mohammad Rubayet Hasan ◽  
Sathyavathi Sundararaju ◽  
Chidambaram Manickam ◽  
Faheem Mirza ◽  
Hamad Al-Hail ◽  
...  

Since the beginning of the coronavirus disease 2019 (COVID-19) pandemic, laboratory testing to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by real-time reverse transcription PCR (RT-qPCR) has played a central role in mitigating the spread of the virus (1). Soon after the viral genome sequences were available, several RT-qPCR assays were developed and made available by World Health Organization (WHO) for public use (https://www.who.int/docs/default-source/coronaviruse/whoinhouseassays.pdf). The primer and probe sequences for these assays were chosen from multiple target genes within the viral genome such as the E gene, RdRp gene, ORF1ab and N gene. Many commercial and laboratory-developed assays were developed for SARS-CoV-2 detection based on these primer and probe sequences. The large-scale sustained person-to-person transmission of SARS-CoV-2 has led to many mutational events, some of which may affect the sensitivity and specificity of available PCR assays (2). Recently, mutations in the E gene (C26340T) and N gene (C29200T) were reported affecting the detection of target genes by two commercial assays in 8 and 1 patients, respectively. Interestingly, both mutations are of C>T type, a common single nucleotide polymorphism (SNP) that may be associated with strong host cell mRNA editing mechanisms known as APOBEC cytidine deaminase (3, 4). Another study found a G to U substitution in position 29140 that affected the sensitivity of detection of N gene-based assays (5). Here we report a novel N gene mutation (C29200A) seen in 3 patients, which affected the detection of SARS-CoV-2 N gene by a commercial assay.


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