From Shadow to Threat: Uncovering Klebsiella oxytoca's Power

الملخص

Klebsiella oxytoca, a gram-negative bacillus of the Enterobacteriaceae family, is an opportunistic pathogen increasingly implicated in a spectrum of human diseases, ranging from urinary tract infections to life-threatening sepsis. While historically overshadowed by Klebsiella pneumoniae, its clinical significance has grown due to its association with nosocomial infections and antibiotic-associated hemorrhagic colitis (AAHC). This review synthesizes current knowledge on the pathogenicity, virulence factors, and clinical manifestations of K. oxytoca, emphasizing its role as an emerging multidrug-resistant (MDR) pathogen. The bacterium's polysaccharide capsule, cytotoxin production (e.g., tilivalline and tilimycin), and siderophores contribute to its virulence, enabling it to evade host defenses and cause tissue damage. Clinically, K. oxytoca is linked to infections in immunocompromised patients, neonates, and those exposed to invasive medical procedures, with resistance to β-lactams, carbapenems, and other antibiotics complicating treatment. Genetic studies reveal a diverse array of resistance genes, underscoring the bacterium's adaptability. Epidemiologically, healthcare settings remain the primary reservoir, though community-acquired cases are emerging. Diagnosis relies on culture and molecular techniques, while treatment requires tailored antibiotic regimens based on susceptibility profiles. This review also explores future research directions, including genomic sequencing to uncover novel virulence mechanisms and the development of targeted therapies to combat MDR strains.