Expanding their scope of study on the mechanisms of bacterial infection, researchers at Worcester Polytechnic Institute (WPI) have reported the surprise finding from a small clinical study that cranberry juice cocktail blocked a strain of Staphylococcus aureus (S. aureus) from beginning the process of infection.
The data was reported in a poster presentation at the American Chemical Society's national meeting in Boston on August 23, 2010, by Terri Camesano, professor of chemical engineering at WPI. "Most of our work with cranberry juice has been with E. coli and urinary tract infections, but we included Staphylococcus aureus in this study because it is a very serious health threat," Camesano said. "This is early data, but the results are surprising."
The virulent form of E. coli that Camesano studies is the primary cause of most urinary tract infections. Strains of S. aureus can cause a range of "staph infections" from minor skin rashes to serious bloodstream infections. One particular strain, known as Methicillin-resistant Staphylococcus aureus, or MRSA, is a growing public health problem in hospitals, nursing homes, and other institutions because it doesn't respond to most antibiotics.
To cause an infection, bacteria must first adhere to a host, then gather together in colonies to form a biofilm. In the current study, Camesano recruited healthy female students at WPI to drink either cranberry juice cocktail or a placebo fluid that looked and tasted like cranberry juice. The subjects provides urine samples at prescribed intervals after drinking the juice or placebo, and those samples were incubated in petri dishes with several strains of E. coli and a single strain of S. aureus. Camesano's team stained the bacteria with a special dye, then used a spectrophotometer to measure the density of the bacterial colonies in the dishes over time. Their analysis showed that the urine samples from subjects who had recently consumed cranberry juice cocktail significantly reduced the ability of E. coli and S. aureus to form biofilms on the surface of the dishes.
"What was surprising is that Staphylococcus aureus showed the most significant results in this study," Camesano said. "We saw essentially no biofilm in the staph samples, which is very surprising because Staph aureus is usually very good at forming biofilms. That's what makes it such a health problem."
With E. coli, Camesano's focal point is the small hair-like projections known as fimbriae, which act like hooks and help the bacteria latch onto cells that line the urinary tract. Camesano has shown that exposure to cranberry juice causes the fimbriae on E. coli to curl up, blunting their ability to attach to cells. S. aureous, however, doesn't have fimbirae, so there must be other reasons why the cranberry juice affected its biofilm formation in the study. "These results do create more questions than answers," Camesano said. "We believe this is an important new area to explore, and we are now thinking about how best to proceed."
Since bacterial adhesion is required for infection, Camesano hopes that better understanding of the specific mechanisms and forces involved in biofilm formation will help inform future studies aimed at identifying potential drug targets for new antibiotics. The data may also be useful in studies aimed at engineering the surfaces of invasive medical devices like catheters to make them more resistant to bacterial adhesion.
The research detailed in the current study was supported by grants from the Cranberry Institute and the Wisconsin Cranberry Board.
About Worcester Polytechnic Institute
Founded in 1865 in Worcester, Mass., WPI was one of the nation's first engineering and technology universities. Its14 academic departments offer more than 50 undergraduate and graduate degree programs in science, engineering, technology, management, the social sciences, and the humanities and arts, leading to bachelor's, master's and PhD degrees. WPI's world-class faculty work with students in a number of cutting-edge research areas, leading to breakthroughs and innovations in such fields as biotechnology, fuel cells, information security, materials processing, and nanotechnology. Students also have the opportunity to make a difference to communities and organizations around the world through the university's innovative Global Perspective Program. There are more than 25 WPI project centers throughout North America and Central America, Africa, Australia, Asia, and Europe.
Michael Cohen | EurekAlert!
Finnish research group discovers a new immune system regulator
23.02.2018 | University of Turku
Minimising risks of transplants
22.02.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg
A newly developed laser technology has enabled physicists in the Laboratory for Attosecond Physics (jointly run by LMU Munich and the Max Planck Institute of Quantum Optics) to generate attosecond bursts of high-energy photons of unprecedented intensity. This has made it possible to observe the interaction of multiple photons in a single such pulse with electrons in the inner orbital shell of an atom.
In order to observe the ultrafast electron motion in the inner shells of atoms with short light pulses, the pulses must not only be ultrashort, but very...
A group of researchers led by Andrea Cavalleri at the Max Planck Institute for Structure and Dynamics of Matter (MPSD) in Hamburg has demonstrated a new method enabling precise measurements of the interatomic forces that hold crystalline solids together. The paper Probing the Interatomic Potential of Solids by Strong-Field Nonlinear Phononics, published online in Nature, explains how a terahertz-frequency laser pulse can drive very large deformations of the crystal.
By measuring the highly unusual atomic trajectories under extreme electromagnetic transients, the MPSD group could reconstruct how rigid the atomic bonds are...
Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...
For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.
In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
23.02.2018 | Physics and Astronomy
23.02.2018 | Health and Medicine
23.02.2018 | Physics and Astronomy