DNA adenine methylation modulates pathogenicity of Klebsiella pneumoniae genotype K1

BACKGROUND/PURPOSE: Klebsiella pneumoniae genotype K1 is a highly virulent pathogen that causes liver abscess and metastatic endophthalmitis/meningitis. Whether its pathogenicity is controlled by DNA adenine methylase (Dam), an epigenetic regulator of bacterial virulence gene expression, is yet unknown. We aimed to study the role of DNA adenine methylation in the pathogenicity of K. pneumoniae genotype K1. METHODS: mutant and compared it with the wild type, in terms of in vitro serum resistance and in vivo BALB/cByl mice inoculation. RESULTS: CFUs). Attenuation of the dam mutant was not attributable to its growth rate, which was similar to that of the wild type. CONCLUSION: Our results support the view that DNA adenine methylation plays an important role in modulating the pathogenicity of K. pneumoniae genotype K1. The incomplete attenuation indicates the existence of other regulatory factors.