An efficient Pulsed-Field Gel Electrophoresis (PFGE) method for typing autolytic Lacticaseibacillus rhamnosus strains

Species of lactic acid bacteria, due to their versatile metabolism, are commonly used in food and feed products, both as technological starters and as health- and welfare-promoting agents. Correct strain identification in microbe-containing products is vital, and the Pulsed-Field Gel Electrophoresis (PFGE) typing method is considered the ‘gold standard’ for this purpose. This typing technique is widely used in molecular epidemiology, especially for the early detection of emerging isolates with food-safety implications, for outbreak surveillance, and for infection control. The autolytic behavior that we encountered when typing Lacticaseibacillus rhamnosus strains using the PFGE technique led us to modify the current method used for typing lactic acid bacteria. This study describes a PFGE method for the molecular typing of autolytic members of the lactic acid bacteria.•An efficient method for overcoming DNA degradation during PFGE analysis for typing Lacticaseibacillus rhamnosus strains is described.•The method described herein could be considered for typing autolytic lactic acid bacteria.