Development of strain-level microbial detection method with monoclonal antibody and identification of strain unique characteristics

To maintain human health and treat infectious diseases, it is essential to analyze individual gut bacterial strains simply and accurately. The inefficiency of existing cultivation methods, particularly in terms of selectivity, has led to the need for a method that can efficiently detect, isolate, and cultivate target bacterial strains specifically. Therefore, this study developed a novel method using Secondary Lymphoid Organ Transplantation for the specific detection, isolation, and cultivation of bacterial strains. Using this method, we produced a monoclonal antibody against human-derived Bifidobacterium longum Jih1 (Jih1). It was demonstrated that this anti-Jih1 specific monoclonal antibody could isolate and re-culture Jih1 from a defined microbial consortium. Interestingly, it was discovered that Jih1 expressed the intracellular enzyme glutamine synthetase on their surface, and these antibodies specifically recognize this enzyme. Taken together, in this study, we developed an efficient bacterial strain-specific isolation and cultivation method using antibody against molecules with unique characteristics.