Salmonella causes more than 93 million cases of salmonellosis, resulting in 155,000 deaths annually worldwide. Many severe cases are associated with the production and consumption of pork: salmonella is found in the pig gut and is often multidrug-resistant. The bacteria can be transmitted through the pigs’ oral−fecal route at the farm, the slaughterhouse, and the food processing plant, where it can survive and cross-contaminate equipment or the final food products, leading to human infections.
Salmonella is conventionally dealt with by using antibiotics. However, antimicrobial resistance is on the rise, and it is widely associated with the intensive use of antibiotics in pig farming. This has led to an increased interest in alternatives to antibiotics in the fight against bacterial pathogens.
Dr Alexandros Stratakos, Senior Lecturer in Sustainable Agri-Food Production at UWE Bristol, has led a study on alternatives to antibiotics in pig farming. Alexandros in collaboration with UWE Bristol colleagues Professor Olena Doran and Dr Sotirios Oikonomou, and Dr Dimitrios Lamprou from Queen’s University, Belfast, developed novel nanostructures for the targeted delivery of geraniol, a natural antivirulence compound, in the pig gut.
Geraniol is the primary component of citronella oil but can also be found in many other plant essential oils.
The study has shown that geraniol at specific concentrations inhibits Salmonella colonisation in the pig gut, which can potentially reduce the requirement for antibiotics in pig farming.
For this study, geraniol was also encapsulated in liposomal (spherical fat-like) formulations, which acted as carriers to protect the agent from degradation and increase its effectiveness against the pathogen.
This approach could lead to reduced Salmonella transmission to food, ultimately leading to an increase in the safety of the food supply chain.
The full publication can be accessed on the website of the Journal of Agricultural and Food Chemistry.