scholarly journals Dose–Response Assay for Synthetic Mosquito (Diptera: Culicidae) Attractant Using a High-Throughput Screening System

Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 355
Author(s):  
Dae-Yun Kim ◽  
Theerachart Leepasert ◽  
Michael J. Bangs ◽  
Theeraphap Chareonviriyaphap
Keyword(s):  
High Throughput ◽  
High Throughput Screening ◽  
Egg Production ◽  
Critical Role ◽  
Laboratory Strain ◽  
Screening System ◽  
Significant Difference ◽  
Blood Source ◽  
Parallel Control ◽  
Spatial Repellency

Natural volatile host cues play a critical role for mosquito orientation and locating a blood source for egg production. Similar olfactory activation responses have allowed the use and development of artificial chemical attractants to lure mosquitoes to trapping devices. Using a pre-formulated commercial product mixture of different attractant chemicals, a high-throughput screening system (HITSS) is used to screen varying doses of chemical required to activate behavioral responses. Two strains of Aedes aegypti (L.): permethrin-susceptible (USDA) and -resistant (Pu Teuy) phenotypes and one Culex quinquefasciatus Say. (NIH) laboratory strain were tested. Overall, mosquitoes showed repellency between 1.0 g and to 10.0 g dose of each compound. However, by progressively reducing the dose, Cx. quinquefasciatus showed a greater positive percent attraction (88.9%) at 0.025 g, whereas the USDA and Pu Teuy Ae. aegypti produced optimum attractant activation at 0.005 g (72.6% and 58.9%, respectively) without significant difference within species (p > 0.05). In parallel control assays, Cx. quinquefasciatus was significantly attracted to 1 g of dry ice (carbon dioxide) (76%) more than Ae. aegypti (USDA) (12.2%). The HITSS was originally designed to measure three chemical actions to sublethal concentrations of chemicals by mosquitoes: toxicity and the two primary behavior avoidance responses (contact excitation and spatial repellency). These findings demonstrate that the HITSS assay, with only minor modifications, allows comparison screening of candidate compounds as potential attractants for anemotactic responses under laboratory-controlled conditions. Further investigations will be required to equate measurements obtained from controlled laboratory assays to more varied field conditions for attracting natural mosquito populations.

scholarly journals Evaluation of Mosquito Attractant Candidates Using a High-Throughput Screening System for Aedes aegypti (L.), Culex quinquefasciatus Say. and Anopheles minimus Theobald (Diptera: Culicidae)

Insects ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 528
Author(s):  
Dae-Yun Kim ◽  
Theerachart Leepasert ◽  
Michael J. Bangs ◽  
Theeraphap Chareonviriyaphap
Keyword(s):  
Lactic Acid ◽  
Aedes Aegypti ◽  
High Throughput ◽  
Culex Quinquefasciatus ◽  
High Throughput Screening ◽  
Mosquito Species ◽  
Laboratory Strain ◽  
Screening System ◽  
Anopheles Minimus ◽  
Significant Difference

Several types of olfactometers have been used to evaluate mosquito responses to agents that mimic natural volatiles that repel or attract. The Y-tube olfactometer has been widely used to study repellents and attractants, while the high-throughput screening system assay has only been used to study repellents. Whether the high-throughput screening system assay is suitable for evaluating attractants is unknown. We evaluated the responses to four lactic-acid-based mixtures and two non-lactic-acid-based chemical lure candidates using the high-throughput screening system (HITSS) for three mosquito species (laboratory strains and field populations of both Aedes aegypti (L.) and Culex quinquefasciatus Say.; laboratory strain of Anopheles minimus Theobald) under laboratory-controlled conditions. HITSS assay results showed that KU-lure #1 elicited the greatest percent attraction for pyrethroid-resistant and -susceptible Ae. aegypti. KU-lure #6 elicited the strongest attractive response for pyrethroid-susceptible and -resistant Cx. quinquefasciatus and pyrethroid-susceptible An. minimus. The response to the lures from each species was independent of the pyrethroid susceptibility status (Ae. aegypti, p = 0.825; Cx. quinquefasciatus, p = 0.056). However, a significant difference in attraction to KU-lure #6 was observed between diurnal and nocturnal mosquitoes (Cx. quinquefasciatus vs. Ae. aegypti, p = 0.014; An. minimus vs. Ae. aegypti, p = 0.001). The laboratory-level HITSS assay effectively selects potential lure candidates. Because the host-seeking behavior differs between mosquito species, further studies are needed to develop species-specific attractants. Additional studies in semi-field screen houses using commercial traps are necessary to evaluate the accuracy of these laboratory assay results.

scholarly journals A High-Throughput Screening System Based on Fluorescence-Activated Cell Sorting for the Directed Evolution of Chitinase A

2021 ◽  
Vol 22 (6) ◽  
pp. 3041
Author(s):  
Gheorghita Menghiu ◽  
Vasile Ostafe ◽  
Radivoje Prodanović ◽  
Rainer Fischer ◽  
Raluca Ostafe
Keyword(s):  
High Throughput ◽  
Cell Sorting ◽  
High Throughput Screening ◽  
Screening Method ◽  
Enzymatic Reaction ◽  
Hydrolytic Enzymes ◽  
Screening System ◽  
Fluorescence Activated Cell Sorting ◽  
Fungal Cell ◽  
Chitinase A

Chitinases catalyze the degradation of chitin, a polymer of N-acetylglucosamine found in crustacean shells, insect cuticles, and fungal cell walls. There is great interest in the development of improved chitinases to address the environmental burden of chitin waste from the food processing industry as well as the potential medical, agricultural, and industrial uses of partially deacetylated chitin (chitosan) and its products (chito-oligosaccharides). The depolymerization of chitin can be achieved using chemical and physical treatments, but an enzymatic process would be more environmentally friendly and more sustainable. However, chitinases are slow-acting enzymes, limiting their biotechnological exploitation, although this can be overcome by molecular evolution approaches to enhance the features required for specific applications. The two main goals of this study were the development of a high-throughput screening system for chitinase activity (which could be extrapolated to other hydrolytic enzymes), and the deployment of this new method to select improved chitinase variants. We therefore cloned and expressed the Bacillus licheniformis DSM8785 chitinase A (chiA) gene in Escherichia coli BL21 (DE3) cells and generated a mutant library by error-prone PCR. We then developed a screening method based on fluorescence-activated cell sorting (FACS) using the model substrate 4-methylumbelliferyl β-d-N,N′,N″-triacetyl chitotrioside to identify improved enzymes. We prevented cross-talk between emulsion compartments caused by the hydrophobicity of 4-methylumbelliferone, the fluorescent product of the enzymatic reaction, by incorporating cyclodextrins into the aqueous phases. We also addressed the toxicity of long-term chiA expression in E. coli by limiting the reaction time. We identified 12 mutants containing 2–8 mutations per gene resulting in up to twofold higher activity than wild-type ChiA.

scholarly journals Creation of Novel Protein Transduction Domain (PTD) Mutants by a Phage Display-Based High-Throughput Screening System

2006 ◽  
Vol 29 (8) ◽  
pp. 1570-1574 ◽  
Author(s):  
Yohei Mukai ◽  
Toshiki Sugita ◽  
Tomoko Yamato ◽  
Natsue Yamanada ◽  
Hiroko Shibata ◽  
...  
Keyword(s):  
Phage Display ◽  
High Throughput ◽  
High Throughput Screening ◽  
Protein Transduction ◽  
Protein Transduction Domain ◽  
Screening System ◽  
Novel Protein

scholarly journals A Fully Automated High-Throughput Flow Cytometry Screening System Enabling Phenotypic Drug Discovery

2018 ◽  
Vol 23 (7) ◽  
pp. 697-707 ◽  
Author(s):  
John Joslin ◽  
James Gilligan ◽  
Paul Anderson ◽  
Catherine Garcia ◽  
Orzala Sharif ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Drug Discovery ◽  
High Throughput ◽  
High Throughput Screening ◽  
Screening System ◽  
Preclinical Development ◽  
Drug Identification ◽  
Therapeutic Setting ◽  
Compound Libraries ◽  
Automated Platform

The goal of high-throughput screening is to enable screening of compound libraries in an automated manner to identify quality starting points for optimization. This often involves screening a large diversity of compounds in an assay that preserves a connection to the disease pathology. Phenotypic screening is a powerful tool for drug identification, in that assays can be run without prior understanding of the target and with primary cells that closely mimic the therapeutic setting. Advanced automation and high-content imaging have enabled many complex assays, but these are still relatively slow and low throughput. To address this limitation, we have developed an automated workflow that is dedicated to processing complex phenotypic assays for flow cytometry. The system can achieve a throughput of 50,000 wells per day, resulting in a fully automated platform that enables robust phenotypic drug discovery. Over the past 5 years, this screening system has been used for a variety of drug discovery programs, across many disease areas, with many molecules advancing quickly into preclinical development and into the clinic. This report will highlight a diversity of approaches that automated flow cytometry has enabled for phenotypic drug discovery.

scholarly journals High-throughput screening of high lactic acid-producing Bacillus coagulans by droplet microfluidic based flow cytometry with fluorescence activated cell sorting

RSC Advances ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 4507-4513 ◽  
Author(s):  
Xu-Dong Zhu ◽  
Xiang Shi ◽  
Shu-Wen Wang ◽  
Ju Chu ◽  
Wei-Hong Zhu ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Lactic Acid ◽  
High Throughput ◽  
Cell Sorting ◽  
High Throughput Screening ◽  
Bacillus Coagulans ◽  
Screening System ◽  
Fluorescence Activated Cell Sorting ◽  
Microfluidic Sorting

A high-throughput screening system based on droplet microfluidic sorting was developed and employed for screening of high lactic acid-producing Bacillus coagulans.

A high-throughput screening system for genes extending life-span

2003 ◽  
Vol 38 (10) ◽  
pp. 1051-1063 ◽  
Author(s):  
Cuiying Chen ◽  
Sylviane Dewaele ◽  
Bart Braeckman ◽  
Liesbeth Desmyter ◽  
Jan Verstraelen ◽  
...  
Keyword(s):  
Life Span ◽  
High Throughput ◽  
High Throughput Screening ◽  
Screening System
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