Broad Immunity of Acinetobacter baumannii lysogens: Implications for Phage Therapy Strategies

Phage therapy is increasingly considered an alternative treatment for multi-drug-resistant bacteria, including _Acinetobacter baumannii_ (AB), a major nosocomial pathogen. A challenge in phage therapy is the induction of bacterial lysogens, which can become immune to the phage that infects them. In this study, an AB isolate, designated ABU-3, was found to be susceptible to three different AB-phages. Typically, lysogens exhibit immunity to the phage that infects them. However, two of the ABU-3 lysogens also developed resistance to additional AB-phages. This finding highlights a potential complication in phage therapy and underscores the need for strategies to prevent such resistance to ensure its success. The varying immunity of ABU-3 lysogens to AB-phages presents an intriguing topic for further research, particularly in developing strategies to prevent lysogen induction and enhance phage therapy approaches.