Pathogen Detector Problem of Pathogen detection Health is the - - PowerPoint PPT Presentation

Mobile Health

Pathogen Detector

Xiaochen Xiaoyi

Identify the pathogen at home thus choose specific medicine? If pathogen in food is conveniently detectable?

Problem of Pathogen detection

• Health is the primary concern in life.
• Limited approaches of pathogen detection

— The outbreak of Escherichia coli in 2011

Picture from Case definition for HUS-cases associated with the outbreak in Germany

Problem of Pathogen detection

• Mobile Health: Make health care accessible at home

The idea of Mobile Health

Test Paper

• Portable Pathogen Detector (PPD)

Pathogen

Two Key Questions

What to target from pathogen

• 1) Detectable

2) Universal 3) Specific

What to use in the test paper?

• 1) Portable

2) Stable 3) Safe

What to target from pathogen

• 1) Detectable

2) Universal 3) Specific

Dry Yeast Food Industry

What to use in the test paper?

• Yeast

Two Key Questions

Dry Yeast Food Industry

What to target from pathogen

• AHL

Two Key Questions

What to use in the test paper?

• Yeast

Module design

— The system is separated into two modules, which are assembled by mating.

· Amplified Signal ·Robustness

Our team

Modules Design

Three novel features

• 1. Quorum sensing system

– Prokaryotic  Eukaryotic

• 2. Diverse combination

– Input & Output; Fast & Easy

• 3. Dry powder

– Safe, stable & portable

Work in E.coli √ Work in yeast ×

• Pol II recruitment
• Nuclear barrier

Quorum sensing-LuxI/R system

Works in yeast √

Modification of sensor module

Three novel features

• 1. Quorum sensing system

– Prokaryotic -> Eukaryotic

• 2. Diverse combination

– Input & Output; Fast & Easy

• 3. Dry powder

– Safe, stable & portable

Design of reporter module

— Interaction between sensor and reporter

Reporter Sensor

Sensor

Reporter

Diverse combination by mating

Fast, easy, automatic

Three novel features

• 1. Quorum sensing system

– Prokaryotic -> Eukaryotic

• 2. Diverse combination

– Input & Output; Fast & Easy

• 3. Dry powder

– Safe, stable & portable

Why make yeast dry powder?

• Easy to store
• Save space
• Can be fixed on test paper
• Recover rapidly

Modeling

Model simulating the process

Model simulating the process

Testing

Modules Testing

Pathogen sensor Pathogen reporter Dry yeast

?

pTF4 Control tVP16-LuxR

Results

— Successful expression of LuxR

sensor

Results

— mCherry fluorescence observed under microscope

Control AHL (24h post-induction)

• Yeast induced with AHL during exponential phase
• Incubation at 30℃, shaking culture

Results

— Quantification of fluorescence by flow cytometry

Modules Testing

Pathogen sensor Pathogen reporter Dry Yeast

? √

Pathogen reporter

?

Results

— Tet system and ADE2 works in yeast

pTF6

Ctrl pTF6

Modules Testing

Pathogen sensor Pathogen reporter Dry yeast Dry yeast

√ ? √ ?

Dry in the vacuum centrifuge 30℃ 45min Centrifuge twice Powder kept under room temperature Reactivate with water, grow on medium Viable after 21+ days

Dry yeast preparation

— Dry yeast viable after three weeks

Modules Testing

Pathogen sensor Pathogen reporter Dry yeast

√ √ √ ?

Future Work

Future work

AHL specificity Non-AHL detection Combination by mating

×

Mating makes it easier

Modifying a pathogen detector

Molecular manipulation

• Switch out the gene
• 1 week or more
• Expensive

Mating

• Choose another reporter
• At least 6 hours
• Inexpensive

GFP RFP

Potential Applications

• Home pathogen detection
• Clinical test
• Environment monitoring
• Many more…

Human Practice

Surveys

Potential problems of Mobile health

Movie Series

• Introducing interesting biological facts
• Emphasizing on interests
• Viewed for more than 6,500 times

Short Story

Human Practice --- Collaboration

• Survey
• Movie Series & Short Story
• Collaboration with other team (OUC, BIT)
• Association of Synthetic Biology in Tsinghua

Acknowledgements

• Prof. Sun Zhirong
• Prof. Chen Guoqiang
• Prof. Dai Junbiao
• Zhao Yu
• Li Teng
• Xie Hengyi
• All team members

Sponsors: Collaboration:

References

• [1] Lazcka O, Campo F, Munoz F X. Pathogen detection: a perspective of traditional methods and

biosensors[J]. Biosensors and Bioelectronics, 2007, 22(7): 1205-1217.

• [2] Nassif X. A revolution in the identification of pathogens in clinical laboratories[J]. Clinical infectious

diseases, 2009, 49(4): 552-553.

• [3] Simon C. Williams et al. Pseudomonas aeruginosa Autoinducer Enters and Functionsin Mammalian
• Cells. 2004, JOURNALOF BACTERIOLOGY, Vol.186,No.8
• [4] F. Sherman et al. Getting Started with Yeast By Fred Sherman, 2003, Methods Enzymol. 350, 3-41.
• Sergi Regot Rodríguez de Mier, Systems and synthetic biology studies in Saccharomyces cerevisiae. 2011,

Barcelona.

• [5] Quorum sensing in biofilms: Why bacteria behave the way they do? 2009, Journal of Food Science.

74(1): R24–R37.

• [6] Avantika Lal, Quorum Sensing : How Bacteria Talk to Each Other, 2009, RESONANCE 866-871.
• [7] Gossen, M. & Bujard, H. Tight control of gene expression in mammalian cells by tetracycline-

responsive promoters. Proc. Natl. Acad. Sci. 89, 5547–5551 (1992).

• [8] Funahashi, A., Morohashi, M., Kitano, H. & Tanimura, N. CellDesigner: a process diagram editor for

gene-regulatory and biochemical networks. BIOSILICO 1, 159–162 (2003).

• [9] Basu, S., Gerchman, Y., Collins, C. H., Arnold, F. H. & Weiss, R. A synthetic multicellular system for

programmed pattern formation. Nature 434, 1130–1134 (2005).

• [10] Goutelle, S. et al. The Hill equation: a review of its capabilities in pharmacological modelling.
• Fundam. Clin. Pharmacol. 22, 633–648 (2008).

Thank you!