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Category: CTEGD Blog

Kitchen utensils can spread bacteria between foods, UGA study finds

Griffin, Ga. – In a recent study funded by the U.S. Food and Drug Administration, University of Georgia researchers found that produce that contained bacteria would contaminate other produce items through the continued use of knives or graters—the bacteria would latch on to the utensils commonly found in consumers’ homes and spread to the next item.

Unfortunately, many consumers are unaware that utensils and other surfaces at home can contribute to the spread of bacteria, said the study’s lead author Marilyn Erickson, an associate professor in the College of Agricultural and Environmental Sciences’ department of food science and technology.

“Just knowing that utensils may lead to cross-contamination is important,” Erickson said. “With that knowledge, consumers are then more likely to make sure they wash them in between uses.”

Erickson has been researching produce for the past 10 years. Her past work has mainly focused on the fate of bacteria on produce when it’s introduced to plants in the field during farming.

In 2013, she was co-author on a study looking at the transfer of norovirus and hepatitis A between produce and common kitchen utensils—finding that cutting and grating increased the number of contaminated produce items when that utensil had first been used to process a contaminated item.

This study, published in Food Microbiology, is similar in that it considers the influence that knives and graters have on the transfer of pathogenic bacteria to and from produce items. She urges consumers to realize that these germs can spread in their kitchens as well.

Researchers have known that poor hygiene and improper food preparation practices in a consumer’s home can lead to foodborne illnesses, but considering what practices in the kitchen are more likely to lead to contamination has not been examined extensively.

“The FDA was interested in getting more accurate numbers as to what level of cross-contamination could occur in the kitchen using standard practices,” Erickson said.

In her recent study, Erickson contaminated many types of fruits and vegetables in her lab—adding certain pathogens that often can be found on these foods, such as salmonella and E. coli.

Using a knife, Erickson would cut into things like tomatoes or cantaloupe and other types of produce to see how easily the bacteria could spread when the knife was continuously used without being cleaned. Because they “were looking at what would be the worst-case scenario,” she said, Erickson and study co-authors did not wash between cutting these different produce items.

Researchers also grated produce, like carrots, to see how easily the pathogens spread to graters. They found that both knives and graters can cause additional cross-contamination in the kitchen and that the pathogens were spread from produce to produce if they hadn’t washed the utensils.

“A lot of the broken up material and particles from the contaminated produce remained on the graters,” said Erickson, who conducts her research at the UGA Center for Food Safety in Griffin. “Then if you were to shred another carrot or something else immediately after that, it gets contaminated, too.”

The study also found that certain fruits and vegetables spread pathogens to knives to different degrees.

“For items like tomatoes, we tended to have a higher contamination of the knives than when we cut strawberries,” Erickson said. “We don’t have a specific answer as to why there are differences between the different produce groups. But we do know that once a pathogen gets on the food, it’s difficult to remove.”

Knives and graters aren’t the only utensils in the kitchen consumers should be worried about. Erickson has also helped study the role brushes and peelers have on the transfer of dangerous kitchen bacteria.

In concurrent studies, Erickson found that scrubbing or peeling produce items—like melons, carrots and celery—did not eliminate contamination on the produce item but led to contamination of the brush or peeler. Even when placed under running water, the utensils still became contaminated; however, the ability to cross-contaminate later produce items depended on the brush type and the pathogenic agent.

These studies combined give researchers a better idea as to how common cross-contamination is in the kitchen—even when just using standard practices.

Erickson explained there is a small chance of buying fruits and vegetables contaminated with bacteria, but the problem can occur-whether the product is store-bought or locally grown.

Additional study co-authors were Qing Wang, a doctoral student at the University of Delaware, and Jean Liao, a research professional; and associate professors Jennifer Cannon and Ynes Ortega with UGA’s Center for Food Safety and the Center for Tropical and Emerging Global Diseases.

The study, “Contamination of knives and graters by bacterial foodborne pathogens during slicing and grating of produce,” is available at

Writer: Sydney Devine
Contact:Marilyn Erickson

UGA researcher receives $1 million for cryptosporidium research

Boris Striepen

Athens, Ga. – Researchers at the University of Georgia have received $1 million from the Wellcome Trust and the Bill & Melinda Gates Foundation to speed the development of new drugs for the treatment of cryptosporidiosis, a major cause of diarrheal disease and mortality in young children around the world.

Cryptosporidiosis is caused by cryptosporidium, a microscopic parasite commonly spread through tainted drinking or recreational water. There is currently no vaccine and only a single drug of modest efficacy available to treat cryptosporidiosis.

“Cryptosporidiosis is a tremendous public health challenge,” said Boris Striepen, Distinguished Research Professor in Cellular Biology in the Franklin College of Arts and Sciences and a member of UGA’s Center for Tropical and Emerging Global Diseases. “We are extremely grateful to the Trust and the Foundation for providing generous support and leadership to drive a global research agenda to face this challenge.”

Cryptosporidium is notoriously difficult to study in the laboratory, and this has stalled the development of better treatments. But earlier this year, Striepen and his research group created new tools to genetically manipulate the parasite, and his team will use funds from the Wellcome Trust and Gates Foundation to leverage this new technology and speed drug discovery.

The Wellcome Trust’s Pathfinder Award of $244,000 will support a collaboration between UGA and the Novartis Institute for Tropical Diseases, a public-private partnership between the pharmaceutical company Novartis and the Singapore Economic Development Board.

The Novartis Institute for Tropical Diseases “has been at the forefront of discovery of new treatments for malaria, tuberculosis and sleeping sickness,” Striepen said. “Engaging a group with this track record to the problem of cryptosporidiosis will be game changing.”

The primary goal of the joint project is to develop better assays to evaluate the effectiveness of drugs in cell cultures and mice. These assays will be used to discover novel candidate drugs using the Novartis Institute for Tropical Diseases’ large collection of candidates.

A $775,000 grant from the Bill & Melinda Gates Foundation will support the development of genetic technology to discover specific drug targets within the parasite, which will ultimately help enhance drug potency and reduce side effects.

Initially, the project will validate targets for drugs for which predictions for likely candidates can be made from prior experience-in particular from the related malaria parasite. In a second phase the project will discover the yet unknown targets of novel drugs.

“The need for effective treatment of cryptosporidiosis is critical, both nationally and internationally. This highly welcome initiative is a major step for those millions of children who globally suffer from this devastating disease,” said Dan Colley, director of CTEGD and former director of the CDC’s Division of Parasitic Diseases.

For more information on the UGA Center for Tropical and Emerging Global Diseases, visit

The Wellcome Trust is a global charitable foundation dedicated to improving health. For more information, visit

Writer: Donna Huber
Contact:Boris Striepen

Faculty Position Search

The Department of Cellular Biology at The University of Georgia is searching for an Assistant/Associate Professor Biology of Parasitism. The successful candidate will also join the faculty of the Center for Tropical and Emerging Global Diseases.

UGA receives $1.25 million for training of tropical, emerging global diseases researchers

trainee Charles Rosenberg

Athens, Ga. – The University of Georgia’s Center for Tropical and Emerging Global Diseases was awarded $1.25 million by the National Institutes of Health to continue training graduate and postdoctoral students over the next five years who can help address the growing threats of parasitic diseases.

Every year, diseases caused by protozoan and helminth parasites are responsible for more than a million deaths and cause hundreds of millions more cases of severe or subtle morbidity due to chronic infections lasting years.

“The University of Georgia is uniquely positioned as a training ground for the next generation of parasitology and tropical diseases researchers,” said Silvia Moreno, a professor of cellular biology in the Franklin College of Arts and Sciences and co-director of the center’s T32 trainee program.

The internationally recognized research center brings together the largest number of laboratories in the U.S. that collectively conduct research on the full gamut of parasite diseases. These diseases are highly prevalent in sub-Saharan Africa, South America and Asia. Often they are the consequence and cause of poverty. They also are increasingly emerging or re-emerging in the U.S. and other industrialized nations.

The CTEGD training program is currently in its 10th year. Past trainees have gone on to successful careers as staff scientists at the Centers for Disease Control and Prevention and as faculty, postdoctoral scholars or medical and veterinary scientists at leading universities and research institutes.

“The breadth and culture of our program instills trainees with the ability to not only translate basic scientific findings into tool development and the implementation of interventions, but also to identify and formulate fundamental research questions beyond the context of parasitic disease itself,” Moreno said.

“This program is very attractive to students,” said Boris Striepen, Distinguished Research Professor of Cellular Biology in the Franklin College and co-director of the training grant. “We have had many more strong candidates than training slots.”

To address this issue, the new NIH award will double the number of postdoctoral trainees from one to two each year, and matching funding from UGA’s Office of the Vice President for Research will support two predoctoral trainees in addition to the three graduate students supported by the training grant each year.
“This institutional matching support is tremendously important when competing for NIH training grants,” said Dan Colley, CTEGD director, who was the T32 training grant program director for its first 10 years.

Trainees in the program build upon their background in biomedical sciences through specialized courses and research mentored by one or more CTEGD faculty. The program is unique in that students can also broaden their perspective on the global aspects of parasitic diseases through a capstone experience, which typically takes students away from the UGA campus for four to eight weeks. Many of the previous trainees have conducted field studies in a disease-endemic country.

“My capstone experience in Kenya provided an exceptional opportunity to gain experience both working in the field and in a laboratory in a developing setting,” said Briana Flaherty, a doctoral student in the CTEGD and the department of infectious diseases. “This short time has had a profound impact on my future interests and career goals.”

The many international collaborations of the center’s faculty provide a wide variety of opportunities to the trainees. Over the last nine years, graduate students have worked in Haiti, Tanzania, Argentina, Thailand and Kenya. The Office of the Vice President for Research also has committed funds over the next five years to assist in the provision of these experiences on the T32 training grant.

“We in CTEGD are extremely pleased that NIH has seen fit to fund this T32 training grant for an additional five years,” Colley said. “It is an investment in our new program directors, Drs. Striepen and Moreno, and in CTEGD’s commitment to high-quality training of the next generation in this important area of parasitic disease-related research.”

The grant funding is provided under NIH award number 3T32AI060546.

UGA Center for Tropical and Emerging Global Diseases
The University of Georgia Center for Tropical and Emerging Global Diseases draws on a strong foundation of parasitology, immunology, cellular and molecular biology, biochemistry and genetics to develop medical and public health interventions. Established in 1998, the center promotes international biomedical research and educational programs at UGA and throughout Georgia to address the parasitic and other tropical diseases that continue to threaten the health of people throughout the world. For more information, see

Writer: Donna Huber
Contact:Boris Striepen

SCORE: Moving towards schistosomiasis elimination

As a consortium tasked with operational research, SCORE is finding out what current and future NTD program managers need to do to make mass drug administration (MDA) for schistosomiasis a better intervention in terms of alternative approaches. SCORE is also working to evaluate and develop tools needed by national program managers for mapping and diagnostics.