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Volume 05
Journal of Clinical Nutrition & Dietetics
ISSN: 2472-1921
Page 8
June 17-18, 2019 London, UK
&
JOINT EVENT
26
th
World Nutrition Congress
15
th
Euro Obesity and Endocrinology Congress
Nutrition World 2019
Euro Obesity 2019
June 17-18, 2019
Richard Y Kao, J Clin Nutr Diet 2019, Volume 05
Richard Y Kao
The University of Hong Kong, Hong Kong
Food ingredients modulating the expression of virulence factors in bacteria
Statement of the Problem:
Disease-causing properties (virulence) of microbial pathogens are greatly influenced by
environmental factors such as temperature, pH, and food ingredients like carbohydrates. As human bodies are inhabited
by a number of opportunistic pathogens, factors modulating the virulence of these potential disease-causing bacteria
may have important health consequences. We have developed reporter systems in bacteria for evaluating the virulence
modulating properties of various agents including common food ingredients.
Methodology & Theoretical Orientation:
We have constructed
gfp-luxABCDE
dual-reporter plasmids with selected
promoters from bacterial virulence-associated genes. The plasmids were introduced into bacteria to establish a
gfp-lux
based multiplex promoter reporter platform for monitoring bacterial virulence gene expressions in real time to identify
factors that may modulate virulence factors expression. We have selected a number of common food ingredients and
tested these ingredients in our multiplex promoter reporter platform to evaluate their virulence modulating properties.
Virulence gene expression in bacteria was monitored by luminescence signals detected with an IVIS Spectrum
In Vivo
Imaging System (PerkinElmer).
Findings:
We have profiled the virulence modulating activities of common food ingredients on 9 bacterial virulence gene
promoters, namely promoters from genes involved in the production of α-toxin, Panton-Valentine leukotoxin, phenol-
soluble modulins, Protein A, Extracellular Adhesion Protein, fibronectin binding protein A, fibronectin binding protein
B, clumping factors A, and capsular polysaccharide. The tested virulence factors are important for the establishment of
bacterial infections in humans.
Conclusion & Significance:
Microbial virulence is an overlooked factor while considering food ingredients and
nutritional supplements for healthy individuals or patients with special needs. Our study has provided an evidence-based
scientific platform for the effective evaluation of various food substances that may modulate the virulence of opportunistic
pathogens residing in humans.
Recent Publications
1.
Woo P C Y, Lau S K P, Lau C C Y, Tung E T K, Au-Yeung R K H, Cai J P, Chong K T K, Sze K H, Kao RY, Hao
Q and Yuen K Y (2018) Mp1p homologues as virulence factors in
Aspergillus fumigatus
. Med Mycol. 56(3):350-
360.
2.
Gao P, Ho P L, Yan B, Sze K H, Davies J and Kao R Y T (2018) Suppression of
Staphylococcus aureus
virulence by
a small-molecule compound. Proc Natl Acad Sci U S A. 115(31):8003-8008.