Research traces bacteria in salmonella outbreaks

By Krishna Ramanujan
The photo shows human cells poisoned with salmonella toxins. The blue in the center of the cells shows the nucleus, while the green color represents "actin stress fibers" that formed as a result of toxins. Lorraine Rodriguez-Rivera (Wiedmann lab) and Rasika Jinadasa (Duhamel lab)

(Medical Xpress) -- During such mass food-poisoning outbreaks as the recent contamination of ground turkey, speedy identification of the bacteria involved can save lives and reduce illness. New research co-authored by a Cornell food scientist will accelerate the process of identifying strains of salmonella bacteria behind food poisonings -- and reduce the time it takes to track the culprit from farm to fork.

The paper, published in the Aug. 24 issue of the journal , offers a comparative study of the sequences of 47 different , including 16 that were sequenced for the first time. One of the genomes analyzed was for salmonella Heidelberg, the strain that was recently involved in the ground turkey outbreak in more than 30 states.

Also, four of the serovars (a group of closely related microorganisms distinguished by a characteristic set of antigens) sequenced have been implicated in outbreaks in the last four years: Serovar Wandsworth caused an outbreak with 65 reported cases in 20 states in 2007; serovar Montevideo caused an outbreak with 272 reported cases in 2009-10 in 44 states; serovar Hvittingfoss caused an outbreak with 90 reported cases in Illinois in 2010; and serovar Baildon was involved in an outbreak with 80 reported cases in 15 states, also in 2010.

"The data generated by this paper can be used to rapidly identify strains by their ," said Martin Wiedmann, professor and director of graduate studies in food science and technology at Cornell and the paper's senior author.

The research by Wiedmann and his co-authors may also help health officials predict strain-specific characteristics, such as risk groups and the diseases caused by such strains.

The found that the salmonella pathogen can be divided into two main groups, called clade A and clade B, with each clade differing in genes that potentially affect the way these pathogens disperse and the kind of infection they cause, according to the study.

The two groups differ in the carbon resources they use, which can make them more adapted to certain hosts. Preliminary data show that while both strains can cause disease in humans, clade A is more abundant in mammals, and clade B is more common in reptiles.

In the United States, an estimated 11 percent of the food-borne illnesses are caused by salmonella, making it the most prevalent non-viral foodborne pathogen.

The work was done in collaboration with Life Technologies, a global biotechnology tools company. Lead authors include postdoctoral associate Henk den Bakker and graduate student Andrea Morena Switt, both in Wiedmann's lab.

Related Stories

Salmonella survives better in stomach due to altered DNA

Jan 29, 2007

Since 1995 there has been a considerable increase in the number of infections with a specific type of Salmonella bacteria transmitted via food. This type, Salmonella serovar Typhimurium DT104, is resistant to at least five ...

Scientists advance understanding of food pathogen

Jan 12, 2011

Listeria is an opportunistic pathogen that causes brain infection, blood poisoning, abortion and death for about 500 Americans and a number of farm animals each year. But while its harmful strains can be more lethal than ...

83 Britons report rare food poisoning

Jul 09, 2006

At least 83 people in England, Scotland and Wales have a rare Salmonella food poisoning, more than 10 times the normal level for an entire year.

Salmonella in garden birds responsive to antibiotics

Jun 02, 2008

Scientists at the University of Liverpool have found that Salmonella bacteria found in garden birds are sensitive to antibiotics, suggesting that the infection is unlike the bacteria found in livestock and humans.

Recommended for you

Can robots help stop the Ebola outbreak?

1 hour ago

The US military has enlisted a new germ-killing weapon in the fight against Ebola—a four-wheeled robot that can disinfect a room in minutes with pulses of ultraviolet light.

New bird flu case in Germany

1 hour ago

A worrying new strain of bird flu has been observed for the first time in a wild bird in northern Germany, the agriculture ministry said Saturday.

Mali announces new Ebola case

Nov 22, 2014

Mali announced Saturday a new case of Ebola in a man who is fighting for his life in an intensive care unit in the capital Bamako.

Plague outbreak kills 40 in Madagascar: WHO

Nov 22, 2014

An outbreak of plague has killed 40 people in Madagascar, the World Health Organization said, warning that the disease could spread rapidly in the country's densely populated capital Antananarivo.

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.