Nanotechnology May Be Used For Food Safety

A microscopic biological sensor that detects Salmonella bacteria in lab tests has been developed by an Agricultural Research Service (ARS) scientist and university colleagues. The sensor could be adapted to detect other foodborne pathogens as well.

The sensor is part of an evolving science known as nanotechnology—the study and manipulation of materials on a molecular or even atomic level, measured in billionths of a meter, which is about 10 to100 times thinner than a human hair.

A microscopic biological sensor that can detect Salmonella bacteria--shown here in a petri dish--in lab tests has been developed by an Agricultural Research Service scientist and university colleagues.

There are examples of biosensors in nature. Insects detect tiny amounts of sex pheromones in the environment and use them as a beacon to find mates. And fish use natural biosensors to detect barely perceptible vibrations in the surrounding water.

ARS engineer Bosoon Park at the Quality and Safety Assessment Research Unit in Athens, Ga., and cooperators at the University of Georgia used nanotechnology to develop the biosensor. The detection method may have great potential for food safety and security, according to Park.

The biosensors that Park and his university colleagues developed include fluorescent organic dye particles attached to Salmonella antibodies. The antibodies hook onto Salmonella bacteria and the dye lights up like a beacon, making the bacteria easier to see.

People who eat Salmonella-infected food products can get salmonellosis, a disease characterized by nausea, vomiting, severe diarrhea, and sometimes death.

Source: Sciencedaily

Anti-virulence Factor In Salmonella

Researchers at the University of British Columbia have discovered an anti-virulence factor in Salmonella, knowledge that could be used to design improved Salmonella vaccines. Virulence factors allow a pathogen to thrive in the host and cause disease. An anti-virulence factor controls the degree of infectiveness.

Salmonella are bacteria that infect a variety of vertebrae hosts. Salmonellosis, infection from Salmonella, can lead to gastroenteritis or typhoid fever -- a severe life-threatening systemic disease.

The finding, published in Public Library of Science, suggests that there is a distinct pathway in Salmonella that acts as an anti-virulence factor during salmonellosis. This pathway is also involved in fine-tuning the host-pathogen balance during salmonellosis.

The research demonstrates that the pathway is activated prior to ingestion and entry into the intestine and then shut off once Salmonella penetrates the intestine.

“When the anti-virulence factor is knocked out Salmonella becomes up to 10 times more virulent,” says Brett Finlay, Peter Wall Prof. of Microbiology and Biochemistry at UBC and senior investigator at the Michael Smith Laboratories. “The research also demonstrates that Salmonella has the ability to control its virulence even before it enters the host.”

“The pathway is designed to initially control the level of virulence and not kill the host immediately,” says Finlay. “Tapering the level of infectiveness allows Salmonella to establish itself in the host and then become more virulent.”

“This research will allow us to design improved salmonella vaccines,” says Finlay. “We will be able to better tailor the vaccine strain with the appropriate level of virulence.”Adapted from materials provided by University of British Columbia.

Souces: ScienceDaily