Researchers discovered that bacteria called E. coli found in chicken meat and raw dog food around the world are becoming resistant to an antibiotic called nitrofurantoin, which doctors commonly use to treat urinary tract infections in people. Using genetic testing, scientists found that these resistant bacteria strains originated from poultry farms and have spread to multiple countries including the United States, Canada, Japan, and Europe. Some of these bacteria have even infected humans. The study suggests this resistance may have started decades ago when antibiotics were used in chicken farming, a practice that has since been banned. This discovery raises concerns about food safety and highlights the importance of proper hygiene when handling raw meat and dog food.
The Quick Take
- What they studied: Whether antibiotic-resistant bacteria that cause urinary tract infections in humans can be found in chicken meat and raw dog food sold in stores
- Who participated: Researchers analyzed bacteria samples from chicken meat, raw dog food, and dogs eating raw meat diets in Bristol, UK, plus samples from poultry farms and meat in Europe, Canada, the United States, and Japan
- Key finding: Multiple strains of E. coli bacteria resistant to nitrofurantoin were found in chicken meat and raw dog food across multiple countries, and some of these same bacteria strains have infected humans with urinary tract infections
- What it means for you: If you handle raw chicken or raw dog food, proper food safety practices become even more important. People taking nitrofurantoin for a urinary tract infection should be aware that some bacteria may be resistant to this antibiotic, though resistance remains uncommon overall
The Research Details
Scientists collected bacteria samples from chicken meat sold in stores, raw dog food products, and dogs eating raw meat diets in Bristol, United Kingdom. They also gathered bacteria samples from poultry farms and chicken meat from multiple countries including Europe, Canada, the United States, and Japan. Using advanced genetic testing called whole genome sequencing, researchers examined the DNA of these bacteria to identify which ones were resistant to nitrofurantoin and which ones were “pre-resistant” (meaning they were just one genetic change away from becoming resistant). The team then compared these bacteria to samples that had infected humans with urinary tract infections to see if any matched.
This research approach is important because it traces where antibiotic-resistant bacteria come from and how they spread. By looking at the genetic makeup of bacteria from different sources and locations, scientists can understand if resistant bacteria are spreading from animals to humans through food, and whether they originated from past antibiotic use in farming. This type of investigation helps public health officials understand real-world health risks.
The study used advanced genetic sequencing technology, which is a reliable method for identifying bacteria and understanding their relationships. The researchers examined samples from multiple countries and sources, which strengthens their findings. However, the study doesn’t specify exactly how many samples were tested, and the sample size from some locations may have been small. The study is descriptive rather than experimental, meaning it shows what exists but doesn’t prove cause-and-effect relationships.
What the Results Show
Researchers found multiple different strains of E. coli bacteria that were either resistant to nitrofurantoin or pre-resistant (one mutation away from resistance) in chicken meat and raw dog food sold in Bristol. These same resistant bacteria strains were also found on poultry farms and in chicken meat across Europe, Canada, the United States, and Japan. The bacteria came from several different genetic groups, suggesting that resistance developed independently in different bacterial populations. Most importantly, the researchers identified cases where the exact same or very similar resistant bacteria strains that were found in chicken had also infected humans, causing urinary tract infections.
The study found that dogs fed raw meat diets sometimes excreted these resistant bacteria in their feces, suggesting that raw meat products can transmit these bacteria to pets. The researchers also noted that the origins of these resistant bacteria are unclear, but they may have originated from antibiotic use in poultry farming decades ago. Nitrofuran-class antibiotics (including furazolidone, furaltadone, and nitrofurazone) were used in poultry production during the 1970s and 1980s but have been banned since the 1990s. This historical use may have created the initial conditions for resistance to develop.
Nitrofurantoin resistance in E. coli has been considered very rare in human infections, so finding multiple resistant strains circulating in food and animals is a new and concerning discovery. This research adds to growing evidence that antibiotic resistance in bacteria can spread from animals and food to humans, supporting the “One Health” concept that human, animal, and environmental health are interconnected. The findings align with previous research showing that poultry farming practices can create reservoirs of antibiotic-resistant bacteria.
The study doesn’t specify the total number of samples tested, making it difficult to assess how common this resistance actually is. The research is primarily descriptive, showing that resistant bacteria exist and can spread, but it doesn’t prove that people are getting infected through contaminated chicken meat rather than other sources. The study focuses on one city (Bristol) for detailed analysis, so findings may not apply equally to all regions. Additionally, while the researchers suggest that historical antibiotic use in poultry caused this resistance, they cannot definitively prove this connection.
The Bottom Line
Practice careful food safety when handling raw chicken and raw dog food: wash hands thoroughly after contact, use separate cutting boards for raw meat, and avoid cross-contamination with other foods. If you’re prescribed nitrofurantoin for a urinary tract infection, take it as directed and report to your doctor if symptoms don’t improve, as this could indicate resistance. These recommendations are based on reasonable precautions given the evidence, though the actual risk to any individual remains low. (Moderate confidence level)
People who handle raw chicken or prepare raw dog food should pay special attention to food safety. People taking nitrofurantoin for urinary tract infections should be aware of this research, though it doesn’t change their immediate treatment. Healthcare providers should consider this information when treating antibiotic-resistant urinary tract infections. People with weakened immune systems should be especially cautious with raw meat handling. This research is less immediately relevant to people who cook chicken thoroughly and don’t handle raw dog food.
Proper food safety practices should be implemented immediately and maintained long-term. If you’re taking nitrofurantoin, you should see improvement in urinary tract infection symptoms within 2-3 days; if not, contact your doctor. The broader public health impact of this resistance may take years to fully understand as more research is conducted.
Want to Apply This Research?
- Track food safety practices when handling raw meat: log instances of proper handwashing, separate cutting board use, and proper storage temperatures. Users can set daily reminders for food safety steps and track compliance over time.
- Create a checklist in the app for raw meat handling: (1) Wash hands for 20 seconds after touching raw meat, (2) Use separate cutting board for raw meat, (3) Store raw meat at proper temperature, (4) Clean all surfaces that touched raw meat. Users can check off each step when handling raw chicken or raw dog food.
- For users taking nitrofurantoin, track symptom improvement daily (pain level, frequency of urination, urgency). Set a reminder to contact healthcare provider if symptoms don’t improve within 3 days. For general users, track food safety compliance weekly and set monthly reminders to review proper handling techniques.
This research describes the presence of antibiotic-resistant bacteria in food and animals, but does not prove that consuming contaminated chicken causes infection in most people. Nitrofurantoin resistance remains uncommon in human infections. This information is for educational purposes and should not replace professional medical advice. If you have a urinary tract infection, consult your healthcare provider for appropriate diagnosis and treatment. If you have concerns about antibiotic resistance or food safety, speak with your doctor or local health department. Pregnant women, people with kidney disease, and those with certain allergies should not take nitrofurantoin; discuss all medications with your healthcare provider.