Relieving antibiotic resistance: Researchers take steps toward new treatment for E. coli

August 8, 2017 by Tiffany Roney, Kansas State University
Philip Hardwidge, professor of diagnostic medicine and pathobiology in Kansas State University's College of Veterinary Medicine, right, and Samir El Qaidi, postdoctoral researcher, are researching new ways to treat E. coli. Credit: Kansas State University

By understanding the functional differences between proteins expressed by two E. coli strains, researchers at Kansas State University are exploring new opportunities to inhibit their impacts to human health.

The scientists are using findings from their study, "NleB/SseK effectors from Citrobacter rodentium, Escherichia coli, and Salmonella enterica display distinct differences in host substrate specificity," published in the Journal of Biological Chemistry, to start researching new ways to treat two types of E. coli: enterohemorrhagic E. coli and enteropathogenic E. coli.

Enterohemorrhagic E. coli outbreaks are traced to improperly cooked meats, unpasteurized dairy products and unwashed vegetables. Enteropathogenic E. coli is a common cause of diarrhea in developing countries, especially in children younger than 2, according to Philip Hardwidge, professor of diagnostic medicine and pathobiology in the College of Veterinary Medicine.

Both forms cause abdominal pain and severe diarrhea, and in some cases, enterohemorrhagic E. coli infections progress to , which is a potentially fatal kidney illness, especially for children.

Hardwidge and postdoctoral researcher Samir El Qaidi suggest that strategies to inhibit the activity of NleB, a expressed by both forms of E. coli, may be effective in reducing E. coli's virulence, or its ability to cause disease in people. Thus, their work could lead to new antivirulence treatments, which are important alternatives to antibiotics that are less prone to antibacterial resistance, Hardwidge said.

This method of combating E. coli would not kill the bacteria because the bacteria do not need this protein to replicate. Rather, it would inhibit the bacteria's ability to cause disease in the body.

The Kansas State University scientists are working with researchers at the University of Kansas to screen for inhibitors of the NleB protein that could potentially be developed for antivirulence treatment of E. coli and other bacteria that have the protein, including salmonella.

"If we could block this protein from functioning, we might reduce bacterial burdens and let the immune system have a chance to do its job in clearing the infection," Hardwidge said. "Pathogen-specific therapies are expected to be less disruptive to the safe, normal bacteria in the intestine, many of which perform beneficial functions for humans. This strategy also could be used to supplement existing therapies to increase their effectiveness in treating infections."

Additionally, their study resolves an important debate regarding proteins found in enterohemorrhagic E. coli and enteropathogenic E. coli.

NleB appears to have a nearly identical genetic sequence in both forms of the E. coli, Hardwidge said. Scientists had thought NleB performed similar functions in each type of E. coli, but previous studies from other institutions came to different conclusions about its function.

"When scientists conduct similar experiments but reach different conclusions, people wonder who is right," Hardwidge said. "In this particular case, the answer depends on which form of E. coli is being examined. We devoted our research to answering that question, because as the field moves forward, it will be critical to specify which form is being studied."

Hardwidge and El Qaidi determined that the forms of NleB, despite appearing to be nearly identical at the genetic level, perform distinctly different activities in the different types of E. coli.

Hardwidge and El Qaidi partnered with scientists in Denmark, Germany and Spain, as well as others in the U.S., for this project. The National Institutes of Health funded the research at Kansas State University.

Explore further: Immunology research sheds new light on cell function, response

More information: Samir El Qaidi et al, NleB/SseK effectors fromCitrobacter rodentium,Escherichia coli, andSalmonella entericadisplay distinct differences in host substrate specificity, Journal of Biological Chemistry (2017). DOI: 10.1074/jbc.M117.790675

Related Stories

Immunology research sheds new light on cell function, response

January 16, 2013

A Kansas State University-led study has uncovered new information that helps scientists better understand the complex workings of cells in the innate immune system. The findings may also lead to new avenues in disease control ...

Dangerous bacteria a true survivor

June 14, 2017

Infectious bacteria E. coli can defend itself and grow in acidic and copper-rich human environments a new University of Queensland study suggests.

Disease-causing gut bacteria common in children

October 4, 2016

A type of bacteria, which can cause diarrhea and inhibit growth in children in developing countries, has been found in 14% of a sample of children in an industrialized country. However, the children had only mild gastrointestinal ...

Recommended for you

A way to make cleaner metal-free perovskites at low cost

July 13, 2018

A team of researchers at Southeast University in China has found a way to make metal-free perovskites in a useable form. In their paper published in the journal Science, the group describes their technique and how well it ...

The secret sulfate code that lets the bad Tau in

July 13, 2018

Vampires can turn humans into vampires, but to enter a human's house, they must be invited in. Researchers at the UT Southwestern Medical Center, writing in the Journal of Biological Chemistry, have uncovered details of how ...


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.