Posts tagged with "pathogens"

Rapidly detecting invisible dangers to food

When food is recalled due to contamination from bacteria such as salmonella, one may wonder how a tainted product ended up on store shelves. New technology being developed at the University of Missouri could give retailers and regulators an earlier warning on dangers in food, improving public health and giving consumers peace of mind.

The biosensor provides a rapid way for producers to know if this invisible danger is present in both raw and ready-to-eat food before it reaches the store. Annually, more than 48 million people get sick from foodborne illnesses in America, such as salmonella, according to the Centers for Disease Control and Prevention.

“Current tests used to determine positive cases of salmonella — for instance culturing samples and extracting DNA to detect pathogens — are accurate but may take anywhere from one to five days to produce results,” said Mahmoud Almasri, associate professor of electrical engineering and computer science at the MU College of Engineering. “With this new device, we can produce results in just a few hours.”

In this study, researchers focused on poultry products, such as chicken and turkey. The biosensor uses a specific fluid that is mixed with the food to detect the presence of bacteria, such as salmonella, along a food production line in both raw and ready-to-eat food. That way, producers can know within a few hours — typically the length of a worker’s shift — if their products are safe to send out for sale to consumers. The researchers believe their device will enhance a food production plant’s operational efficiency and decrease cost.

“Raw and processed food could potentially contain various levels of bacteria,” said Shuping Zhang, professor and director of the Veterinary Medical Diagnostic Laboratory at the MU College of Veterinary Medicine. “Our device will help control and verify that food products are safe for consumers to eat and hopefully decrease the amount of food recalls that happen.”

Researchers said the next step would be testing the biosensor in a commercial setting. Almasri said he believes people in the food processing industry would welcome this device to help make food safer.

The study, “A microfluidic based biosensor for rapid detection of Salmonella in food products,” was published in PLOS ONE, one of the world’s leading peer-reviewed journals focused on science and medicine. Other authors include Ibrahem Jasim, Zhenyu Shen, Lu Zhao at MU; and Majed Dweik at Lincoln University. Funding was provided by a partnership between MU, the Coulter Foundation and the U.S. Department of Agriculture. The content is solely the responsibility of the authors and does not necessarily represent the official views of the funding agencies.

This study details the latest findings for this interdisciplinary team of researchers who have developed multiple biosensors and published results of their previous findings in Scientific Reports, Biosensors and Bioelectronics and Electrophoresis.

Fighting Antibiotic Resistance

To combat the rise of drug-resistant bacteria, researchers are examining how one superbug adapts to fight an antibiotic of last resort, hoping to find clues that can prolong the drug’s effectiveness.

At Rice University and the University of Texas Health Science Center at Houston ran experiments to track the biochemical changes that vancomycin-resistant Enterococci (VRE) underwent as they adapted to fight another antibiotic, daptomycin. “We need to get to a stage where we can anticipate how these pathogens will become resistant to antibiotics so we can stay one step ahead of them,” said Rice biochemist Yousif Shamoo, co-author of a study in the journal Antimicrobial Agents and Chemotherapy that found VRE can develop resistance to daptomycin in more than one way. The stakes are high. In 2014, the World Health Organization reported that antibiotic-resistant infections were on pace to kill 10 million people per year worldwide by 2050.

According to the U.S. Centers for Disease Control, VRE is one of the nation’s leading antibiotic resistance threats. The CDC estimated VRE will infect some 20,000 people in the U.S. this year and kill 1,300 of them. Daptomycin, an antibiotic that first became available in 2003, is one of the last drugs doctors can use to fight multidrug-resistant superbugs like VRE, methicillin-resistant Staphylococcus aureus (MRSA) and glycopeptide resistant enterococci (GRE). Unfortunately, health officials documented cases of daptomycin resistance as early as 2005, and the number of cases is on the rise worldwide.

Shamoo said one of the principle findings of the study was that a specific strain of VRE, Enterococcus faecium, has an unusually diverse set of strategies for resisting antibiotics like daptomycin, and that diversity can make treatment of infections even more difficult. “By understanding how these pathogens acquire resistance, we can develop new treatment strategies or new ‘co-drugs’ that target their ability to become resistant,” Shamoo said. Co-drugs that target the evolution of resistance could be administered with antibiotics like daptomycin to both help patients fight off infection and stem the spread of increasingly resistant strains of bacteria in hospitals, he said.

Study lead author Amy Prater, a Ph.D. student who graduated from Rice in July, showed that the same strain of VRE could activate different biochemical pathways to activate up to three strategies, depending upon its environment. Shamoo said the multipronged strategy will make it more difficult for health officials to fight growing daptomycin resistance in VRE, but he said the results help clear up previously confusing experimental findings about VRE resistance, which is a step in the right direction. “If we understand how a pathogen acquires resistance, we can anticipate its next move, and hopefully act beforehand to cut it off,” Shamoo said. “Predictability is the key.”

Shamoo is Rice’s vice provost for research and a professor of biochemistry and cell biology in the Department of BioSciences. Additional co-authors include Heer Mehta and Abigael Kosgei of Rice and William Miller, Truc Tran and Cesar Arias of the UTHealth McGovern Medical School.