Murine Models of <i>Klebsiella pneumoniae</i> Gastrointestinal Infection

Klebsiella pneumoniae (Kpn) is a Gram-negative opportunistic pathogen and a leading cause of hospital-acquired infections. The gastrointestinal (GI) tract serves as a critical site for Kpn colonization and a reservoir for host-to-host spread that primarily occurs through the fecal-oral route. The emergence of multidrug-resistant strains, coupled with virulence factors such as enhanced capsule production, presents significant challenges for clinical management and public health. Animal models-particularly murine models of GI colonization-are essential for advancing our understanding of Kpn pathogenesis, host-pathogen interactions, and for identifying therapeutic strategies. In this manuscript, we describe standardized protocols for studying Kpn GI colonization and systemic dissemination. These methods are designed to facilitate reproducibility and consistency across laboratories investigating Kpn colonization dynamics, dissemination routes, and immune evasion mechanisms. © 2025 The Author(s). Current Protocols published by Wiley Periodicals LLC. By providing detailed and optimized experimental approaches, this work aims to support the development of uniform methodologies for Kpn GI colonization and host response studies Basic Protocol 1: Murine model of Kpn gastrointestinal colonization via oral feeding Basic Protocol 2: Murine model of Kpn gastrointestinal colonization via gavage Basic Protocol 3: Murine model of Kpn intraperitoneal challenge Basic Protocol 4: Murine model of systemic Kpn infection via intravenous injection Basic Protocol 5: Kpn transmission studies following gastrointestinal colonization with intact microbiota Basic Protocol 6: Transmission studies of Kpn gastrointestinal colonization in antibiotic-pretreated mice Support Protocol 1: Preparation of Kpn inoculum Support Protocol 2: Preparation of mixed Kpn inoculum for competitive infection Support Protocol 3: Assessment of Kpn bacterial burden Support Protocol 4: Preparation of cecal filtrate.