Headlines out of the European Union this week warned that superbug versions of foodborne pathogens have become more resistant to antibiotics than was previously thought. Campylobacter is the most commonly reported cause of food poisoning in the EU and is increasingly able to survive ciprofloxacin, an antibiotic commonly used against foodborne pathogens, according to a report from the European Food Safety Authority (EFSA) and the European Centre for Disease Prevention and Control (ECDC). Salmonella’s resistance is also strengthening, according to the report, with the bug showing resistance to multiple antibiotics in 26 percent of human isolates. That number pales in comparison to the Campylobacter, though. Cipro resistance hit 60 percent in Campylobacter isolates from people. It’s a serious situation, but not insurmountable. Here are a couple of encouraging news nuggets. Genes identified that indicate levels of immunity to E. coli A study published in the Jan. 19 edition of the Journal of Infectious Diseases reports details of a study that showed some individuals have a natural resistance to E. coli bacteria. Researchers from Duke University, Durham VA Medical Center and Johns Hopkins University collaborated on the study. They exposed 30 healthy people to enterotoxigenic E. coli and found that six developed severe symptoms while six others had no symptoms at all. Out of thousands of genes that differentiated the two groups, researchers identified 29 genes that are predictors of who will succumb to the pathogen. “We have found a set of immune-related genes to focus on,” senior author Ephraim Tsalik said. “Now if we can understand how the expression of these genes imparts this resistance and susceptibility, we might be able to offer new ways to boost your immune system to protect against prevalent infections such as E. coli or better predict who is at greatest risk of getting an infection.” Clinical trials of panel test seek faster, more accurate diagnosis One of the problems public health officials often cite during foodborne illness outbreak investigations is the lack of quick, easy-to-use pathogen tests to decrease the frequency of misdiagnosis. Illnesses from foodborne pathogens often include sets of symptoms that fit other causes, according to the Centers for Disease Control and Prevention, sometimes resulting in ineffective treatment and unnecessary surgeries. Clinical trials by four entities are showing encouraging results from a new panel test developed to diagnosis gastrointestinal diseases. Three hospitals — University of Nebraska Medical Center in Omaha, Nationwide Children’s Hospital in Columbus, Ohio, and Lifespan Academic Medical Center, Providence in Rhode Island — joined Hawaii-based Diagnostic Laboratory Services Inc. to perform the trials. The panel can identify 23 pathogens, including Salmonella, norovirus and Campylobacter, simultaneously in about an hour. “This is a significant breakthrough for physicians and patients,” Dr. Matthew Bankowski, vice president and technical director of Diagnostic Laboratory Services told the Pacific Business Times. “Prior to this test, it took days to get results, and the tests could have missed up to 30 percent of the pathogens, simply because they are extremely difficult and time-consuming to culture.” But some bugs are smarter than we thought Just when you think the medical researchers are making progress, other scientists find out more about what we’re up against. No one is saying the foodborne pathogens are self aware or free-thinking individuals, but studies in Lin Chao’s lab at the University of California-San Diego are revealing reproductive strategies of E. coli colonies. In the process of replication, E. coli bacteria play favorites in a kind of twisted microscopic version of “Sophie’s Choice.” Chao’s ongoing study has found the E. coli distribute accumulated damage unevenly among offspring, violating the traditional equal division rule. Instead of an E. coli bacterium dividing equally to create two so-called daughters, who then each divide and create two daughters, and so on, Chao’s work has shown mother bacterium divide unevenly. The daughters are not identical, equal halves. Rather, one is stronger and more likely to succeed. That’s bad news for us humans. And then there are the bugs that use GPS Researchers at the University of Virginia School of Medicine were in the news recently with a new discovery about Salmonella. Turns out the foodborne bacteria uses food as a sort of GPS system to keep track of where it is in our bodies. The Salmonella isn’t concerned about keeping an accurate travelogue as it meanders through our bodies, it needs to keep track of its location so it knows whether to go into defense mode against our immune system or pig out on our cell membranes and reproduce. Salmonella must know where it is in a body to survive, reported graduate student Christopher J. Anderson in a discussion of the research in the journal PLOS Pathogens. “What’s really unique about salmonella is that it’s able to not only survive in our immune cells but also replicate. It actually highjacks these immune cells, sort of like a taxicab, to get from the intestinal tract to systemic sites like our liver and spleen,” he said. “Normally these immune cells are quite good at killing bacteria they encounter, but salmonella possesses the machinery and capability to stop this killing process and instead turn these immune cells into a hospitable niche that allows disease progression.” If scientists can better understand the behavior of Salmonella they theorize that they will be able to confuse the bacteria into thinking it is not in a human host, which could mean it would pass through a person’s body harmlessly. Bugs are smart and strong, but we’ve got Bemidji Middle School So, times are pretty desperate. Salmonella has GPS. E. coli moms make Sophie choices to perpetuate their species. Superbugs are standing up to antibiotics all over the world. Enter the next generation of scientists just when you need them. The annual Science Fair at Bemidji (Minnesota) Middle School this month included an experiment by 11-year-old Seth Lindgren who sought to determine if shining ultraviolet light on water would kill coliform and E. coli in it, according to the Bemidji Pioneer. It reminded me of my fifth-grade science project, which was a joint venture with my friend Karen Smith. We examined what happened when you exposed a substance to freezing, battery acid and fire. The substance was, of course, coral. Who knows if it was our expert observations or my goofy name connection with the project, but we got a blue ribbon at the school level and in the citywide fair. Karen and I didn’t really learn much about the properties of a coral reef from our vantage point in Kansas City, KS, but we did learn how to record our observations. A useful skill I tend to use quite a bit as a journalist. The feature story in the Bemidji Pioneer newspaper tactfully did not report how the judges ruled in the middle school science fair, but we do know two key things about Seth’s experiment thanks to the hometown report:
- Ultraviolet light does kill coliform and E. coli in water; and
- Seth decided to examine bacteria because his dad works for the Minnesota Department of Health.
Congratulations to Seth and his dad for pushing the envelope — one bacterium and one young mind at a time. (To sign up for a free subscription to Food Safety News, click here.)