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Luisa Cheng   Dr.  Research or Laboratory Scientist 
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Luisa Cheng published an article in December 2018.
Top co-authors See all
Michel R. Popoff

172 shared publications

Bacterial Toxins, Institut Pasteur, 75015 Paris, France

Vicky Avery

151 shared publications

Discovery Biology, Griffith Institute for Drug Discovery, Griffith University, Nathan, Queensland, 4111, Australia

Peter J. Sadler

134 shared publications

Department of Chemistry

Hannu J. Korkeala

121 shared publications

Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki 00014, Finland.

Miia Lindström

85 shared publications

Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland

55
Publications
70
Reads
23
Downloads
237
Citations
Publication Record
Distribution of Articles published per year 
(2007 - 2018)
Total number of journals
published in
 
24
 
Publications See all
Article 0 Reads 0 Citations Influence of Food Matrices on the Stability and Bioavailability of Abrin Christina C. Tam, Thomas D. Henderson, Larry H. Stanker, Lui... Published: 01 December 2018
Toxins, doi: 10.3390/toxins10120502
DOI See at publisher website ABS Show/hide abstract
Abrin, a highly toxic plant toxin, is a potential bioterror weapon. Work from our laboratory and others have shown that abrin is highly resistant to both thermal and pH inactivation methods. We sought to evaluate the effectiveness of selected food processing thermal inactivation conditions against abrin in economically important food matrices (whole milk, non-fat milk, liquid egg, and ground beef). The effectiveness of toxin inactivation was measured via three different assays: (1) In vitro cell free translation (CFT) assay, (2) Vero cell culture cytotoxicity; and the in vivo mouse intraperitoneal (ip) bioassay. For both whole and non-fat milk, complete inactivation was achieved at temperatures of ≥80 °C for 3 min or 134 °C for 60 s, which were higher than the normal vat/batch pasteurization or the high temperature short time pasteurization (HTST). Toxin inactivation in liquid egg required temperatures of ≥74 °C for 3 min higher than suggested temperatures for scrambled eggs (22% solids) and plain whole egg. Additionally, the ground beef (80:20%) matrix was found to be inhibitory for full toxin activity in the mouse bioassay while retaining some activity in both the cell free translation assay and Vero cell culture cytotoxicity assay.
Article 0 Reads 0 Citations A Rapid, Sensitive, and Portable Biosensor Assay for the Detection of Botulinum Neurotoxin Serotype A in Complex Food Ma... Christina C. Tam, Andrew R. Flannery, Luisa W. Cheng Published: 15 November 2018
Toxins, doi: 10.3390/toxins10110476
DOI See at publisher website ABS Show/hide abstract
Botulinum neurotoxin (BoNT) intoxication can lead to the disease botulism, characterized by flaccid muscle paralysis that can cause respiratory failure and death. Due to the significant morbidity and mortality costs associated with BoNTs high toxicity, developing highly sensitive, rapid, and field-deployable assays are critically important to protect the nation’s food supply against either accidental or intentional contamination. We report here that the B-cell based biosensor assay CANARY® (Cellular Analysis and Notification of Antigen Risks and Yields) Zephyr detects BoNT/A holotoxin at limits of detection (LOD) of 10.0 ± 2.5 ng/mL in assay buffer. Milk matrices (whole milk, 2% milk and non-fat milk) with BoNT/A holotoxin were detected at similar levels (7.4–7.9 ng/mL). BoNT/A complex was positive in carrot, orange, and apple juices at LODs of 32.5–75.0 ng/mL. The detection of BoNT/A complex in solid complex foods (ground beef, smoked salmon, green bean baby puree) ranged from 14.8 ng/mL to 62.5 ng/mL. Detection of BoNT/A complex in the viscous liquid egg matrix required dilution in assay buffer and gave a LOD of 171.9 ± 64.7 ng/mL. These results show that the CANARY® Zephyr assay can be a highly useful qualitative tool in environmental and food safety surveillance programs.
Article 0 Reads 0 Citations Highly Potent 1H-1,2,3-Triazole-Tethered Isatin-Metronidazole Conjugates Against Anaerobic Foodborne, Waterborne, and Se... Sumit Kumar, Trpta Bains, Ashley Sae Won Kim, Christina Tam,... Published: 30 October 2018
Frontiers in Microbiology, doi: 10.3389/fcimb.2018.00380
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Parasitic infections like amebiasis, trichomoniasis, and giardiasis are major health threats in tropical and subtropical regions of the world. Metronidazole (MTZ) is the current drug of choice for amebiasis, giardiasis, and trichomoniasis but it has several adverse effects and potential resistance is a concern. In order to develop alternative antimicrobials, a library of 1H-1,2,3-triazole-tethered metronidazole-isatin conjugates was synthesized using Huisgen's azide-alkyne cycloaddition reaction and evaluated for their amebicidal, anti-trichomonal, and anti-giardial potential. Most of the synthesized conjugates exhibited activities against Trichomonas vaginalis, Tritrichomonas foetus, Entamoeba histolytica, and Giardia lamblia. While activities against T. vaginalis and T. foetus were comparable to that of the standard drug MTZ, better activities were observed against E. histolytica and G. lamblia. Conjugates 9d and 10a were found to be 2–3-folds more potent than MTZ against E. histolytica and 8–16-folds more potent than MTZ against G. lamblia. Further analysis of these compounds on fungi and bacteria did not show inhibitory activity, demonstrating their specific anti-protozoal properties.
PREPRINT 0 Reads 0 Citations A Rapid, Sensitive, and Portable Biosensor Assay for the Detection of Botulinum Neurotoxin Serotype A in Complex Food Ma... Christina C. Tam, Andrew R. Flannery, Luisa W. Cheng Published: 22 August 2018
doi: 10.20944/preprints201808.0390.v1
DOI See at publisher website ABS Show/hide abstract
Botulinum neurotoxin (BoNT) intoxication can lead to the disease botulism, characterized by flaccid muscle paralysis that can cause respiratory failure and death.  Due to the significant morbidity and mortality costs associated with BoNTs high toxicity, developing highly sensitive, rapid, and field-deployable assays are critically important to protect the nation’s food supply against either accidental or intentional contamination. We report here that the B-cell based biosensor assay (CANARY® Zephyr) detects BoNT/A in buffer and various food matrices rapidly in ≤ 40 min, in small volumes ≈ 50 μL, with minimal processing of samples, and is extremely portable (suitcase-sized equipment). BoNT/A was detected at limits of detection (LOD) < 0.075 ng ± 0.02 in assay buffer while milk matrices (non-fat, 2 %, whole milk) increased the LOD to < 0.175 – 0.314 ng. Limits of detection for the assay in complex foods were < 1 ng ± 0.0 (neutralized acidic juices-carrot, orange and apple); < 16.7 ng ± 7.7 (liquid egg); and varied from < 0. 39 – 3.125 ng for solid complex foods (ground beef, green bean baby puree, smoked salmon). These results show that the CANARY® Zephyr assay can be a highly useful tool in clinical, environmental, and food safety surveillance programs.
Article 0 Reads 0 Citations Cinnamoyl-Oxaborole Amides: Synthesis and Their in Vitro Biological Activity Maureen Gumbo, Richard M. Beteck, Tawanda Mandizvo, Ronnett ... Published: 15 August 2018
Molecules, doi: 10.3390/molecules23082038
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Due to the increased interest in their application in the treatment of infectious diseases, boron-containing compounds have received a significant coverage in the literature. Herein, a small set of novel cinnamoly-oxaborole amides were synthesized and screened against nagana Trypanosoma brucei brucei for antitrypanosomal activity. Compound 5g emerged as a new hit with an in vitro IC50 value of 0.086 μM against T. b. brucei without obvious inhibitory activity against HeLa cell lines. The same series was also screened against other human pathogens, including Mycobacterium tuberculosis, the causative agent of tuberculosis (TB), for which moderate to weak activity (10 to >125 μM) was observed. Similarly, these compounds exhibited moderate activity against the human protozoal pathogen Trichomonas vaginalis with no observed effect on common microbiome bacterial species. The cross-species inhibitory activity presents the possibility of these compounds serving as broad-spectrum antibiotics for these prevalent three human pathogens.
Article 0 Reads 0 Citations Potato Peels and Their Bioactive Glycoalkaloids and Phenolic Compounds Inhibit the Growth of Pathogenic Trichomonads Mendel Friedman, Vincent Huang, Quincel Quiambao, Sabrina No... Published: 24 July 2018
Journal of Agricultural and Food Chemistry, doi: 10.1021/acs.jafc.8b01726
DOI See at publisher website
Conference papers
CONFERENCE-ARTICLE 36 Reads 0 Citations High Efficiency Drug Repurposing for New Antifungal Agents Jong H. Kim, Kathleen L. Chan, Luisa W. Cheng, Lisa A. Tell,... Published: 03 November 2018
doi: 10.3390/ecmc-4-05620
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There has been a persistent effort to improve efficacy of conventional antimycotic drugs. However, current antimycotic interventions have often limited efficiency in treating fungal pathogens, especially those resistant to drugs. Considering development of entirely new antimycotic drugs is a capital-intensive and time-consuming process, we investigated an alternative approach termed drug repurposing whereby new utility of various marketed, non-antifungal drugs could be repositioned as novel antimycotic agents. As a proof of concept, we applied chemosensitization as a new screening strategy, where combined application of a second compound, viz., chemosensitizer, with a conventional drug could enhance antifungal efficacy of the drug co-applied. Unlike the conventional combination therapy, a chemosensitizer itself does not necessarily have to possess an antifungal activity, but the chemosensitizer significantly debilitates defense systems of pathogens to drugs, enabling improved identification of antifungal activity of off-patent drugs. Of note, inclusion of fungal mutants, such as antioxidant mutants, could facilitate drug repurposing process by enhancing the sensitivity of antifungal screening. Altogether, our strategy could lead to high efficiency drug repurposing, which enhances the drug susceptibility of targeted fungal pathogens.

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