Severe lower limb infection by Kerstersia gyiorum: clinical and genomic insights into an underestimated pathogen

Since <i>Kerstersia gyiorum</i> was first described and named in 2003, reports of human infections caused by this organism have gradually increased. Here, we present a detailed report of a severe case of lower right limb infection caused by <i>K. gyiorum</i> that was characterized by rapid disease progression and multidrug resistance. We also present the complete genome sequence of the isolate, WCHKG1. A systematic analysis of the clinical features of our case patient and previous <i>K. gyiorum</i>-infected patients revealed that the most common site of infection was the lungs (48%), and that the organism showed the lowest sensitivity to commonly used quinolones among the major antibiotic classes. Clinical infections caused by <i>K. gyiorum</i> may be underestimated, thus the use of quinolones in treating such infections should be avoided. Genomic and phylogenetic analyses of <i>K. gyiorum</i> identified conservation of antibiotic efflux pump systems and virulence factors, which may play critical roles in its antibiotic resistance and pathogenicity. Furthermore, evidence of clonal transmission in animals suggests a need for vigilance regarding potential clonal spread in clinical settings. Our study contributes to the current understanding of <i>K. gyiorum</i> and offers useful insights to support its clinical management and infection control.