Animal models of Klebsiella pneumoniae mucosal infections are essential for understanding the pathogenesis of this opportunistic pathogen, which causes severe infections in various mucosal sites, including the respiratory, gastrointestinal, and urinary tracts. K. pneumoniae is a major cause of hospital-acquired infections and is increasingly resistant to antibiotics. Animal models help in evaluating the efficacy of therapeutic agents and vaccines, as well as in understanding the host immune response and bacterial virulence factors. However, the choice of model depends on the specific research question, as different models have varying levels of immunological complexity and ability to mimic human infections. Mice are the most commonly used animal models for K. pneumoniae infections, but they have limitations such as natural resistance to the pathogen and difficulty in reproducing human mucosal infection processes. Other models, such as Drosophila melanogaster, Caenorhabditis elegans, Galleria mellonella, and Danio rerio, provide insights into specific aspects of infection, such as bacterial lethality and innate immune responses, but lack the immunological complexity of mammals. The study reviews various models used to investigate K. pneumoniae infections, including respiratory, gastrointestinal, and urinary tract infections, and discusses their advantages, limitations, and applications. The models used for respiratory infections include direct bacterial instillation, tracheal inoculation, and gavage, while for gastrointestinal infections, models involve oral administration, gavage, and contamination of drinking water. For urinary tract infections, models include catheterization and transurethral inoculation. Each model has its own strengths and weaknesses, and the choice of model depends on the research objectives. The study highlights the importance of using appropriate models to understand the disease process and develop effective preventive and therapeutic strategies against K. pneumoniae infections.Animal models of Klebsiella pneumoniae mucosal infections are essential for understanding the pathogenesis of this opportunistic pathogen, which causes severe infections in various mucosal sites, including the respiratory, gastrointestinal, and urinary tracts. K. pneumoniae is a major cause of hospital-acquired infections and is increasingly resistant to antibiotics. Animal models help in evaluating the efficacy of therapeutic agents and vaccines, as well as in understanding the host immune response and bacterial virulence factors. However, the choice of model depends on the specific research question, as different models have varying levels of immunological complexity and ability to mimic human infections. Mice are the most commonly used animal models for K. pneumoniae infections, but they have limitations such as natural resistance to the pathogen and difficulty in reproducing human mucosal infection processes. Other models, such as Drosophila melanogaster, Caenorhabditis elegans, Galleria mellonella, and Danio rerio, provide insights into specific aspects of infection, such as bacterial lethality and innate immune responses, but lack the immunological complexity of mammals. The study reviews various models used to investigate K. pneumoniae infections, including respiratory, gastrointestinal, and urinary tract infections, and discusses their advantages, limitations, and applications. The models used for respiratory infections include direct bacterial instillation, tracheal inoculation, and gavage, while for gastrointestinal infections, models involve oral administration, gavage, and contamination of drinking water. For urinary tract infections, models include catheterization and transurethral inoculation. Each model has its own strengths and weaknesses, and the choice of model depends on the research objectives. The study highlights the importance of using appropriate models to understand the disease process and develop effective preventive and therapeutic strategies against K. pneumoniae infections.