A new serotype of Salmonella has been discovered by a researcher at Texas Tech University in Lubbock, Texas. The new serotype, found by Marie Bugarel, a research assistant professor at Texas Tech’s Department of Animal and Food Sciences in the College of Agricultural Sciences and Natural Resources, was confirmed by the Pasteur Institute in Paris, the international reference center for Salmonella.
Because convention calls for a new serotype to be named after the city in which it is discovered, this one will be called Salmonella Lubbock.
Bugarel came to the university with an extensive background in Salmonella research, and has worked on developing new tools to detect Salmonella, new approaches to distinguish serotypes and ways to understand Salmonella’s biology.
In Bugarel’s research for Salmonella Lubbock, the impetus was to reduce Salmonella in food and improve public health. She focused on providing solutions to control Salmonella in cattle population, which led to a better understanding of the biological makeup of Salmonella itself, including its genetic makeup. Through this approach, Bugarel discovered the new strain never before described.
The long-held standard way of distinguishing one strain of Salmonella from another is called serotyping and is based on the molecules on the surface of the bacterium. Each serotype has its own pattern of molecules, called antigens, and the collection of molecules provides a unique molecular appearance. These antigens interact with certain antibodies found in specifically prepared serum, thus providing the serotype. It is similar to how blood typing is performed.
“This discovery reinforces my feeling that the microbiological flora present in cattle in the United States harbors a singularity, which is an additional justification of the research we are doing in the International Center for Food Industry Excellence (ICFIE) laboratories at Texas Tech,” Bugarel said. “Additional research will be performed to better describe the characteristics of this atypical bacterial flora and, more specifically, of the Lubbock serotype.”
Guy Loneragan, a professor of food safety and public health and one Bugarel’s mentors at Texas Tech, believes that between 20 and 30 percent of two current strains, Salmonella Montevideo and Salmonella Mbandaka, will be reclassified as Salmonella Lubbock. The algorithm used in serotyping has some stopping points, but Bugarel discovered a need to go a step further to get the correct strain name. Therefore some of those strains called Montevideo and Mbandaka are now Salmonella Lubbock.
Some of the strains of Salmonella Lubbock fall into the category of serotype patterns that are more broadly resistant to many families of antibiotics, furthering the need for more research on the subject. Human susceptibility to the Lubbock strains remains unknown.
“We will continue to develop methods to detect, identify and control the presence of pathogenic microorganisms in food products in order to improve food safety and public health,” Bugarel said.
Loneragan added: “This discovery illustrates there is more that needs to be discovered about Salmonella and how it interacts with cattle populations. With this understanding will come awareness of how to intervene to break the ecological cycle and reduce Salmonella in animals and in beef, pork and chicken products.”