Endolysin Kgh3 possesses anti-biofilm activity and affects Klebsiella pneumoniae biofilm formation through peptidoglycan degradation

Abstract

Glycoside hydrolases contribute to both biofilm dispersion and the regulation of bacterial biofilm formation. The discovery of novel anti-biofilm glycoside hydrolases could enhance the understanding of biofilm formation and help to address the problem of chronic infections caused by biofilms. This study aimed to evaluate the potential of the glycoside hydrolase Kgh3 as an anti-biofilm agent. The median effective concentrations of Kgh3 for pre-existing biofilm disruption and the inhibition of biofilm formation in Klebsiella pneumoniae MGH78578 were 19.15 ± 2.47 μg/mL and 40.67 ± 6.16 μg/mL, respectively. Kgh3 showed no toxicity towards mammalian cells in vitro. Kgh3 significantly promoted wound healing and reduced the bacterial load in infected wounds in vivo, using an ICR mouse dorsal-wound biofilm model. Peptidoglycan was identified as a substrate of Kgh3, indicating that its anti-biofilm activity stems from bacterial lysis. Moreover, absence of kgh3 expression enhanced K. pneumoniae MGH78578 biofilm formation. This mechanism involves the degradation of exogenous peptidoglycan by endolysin. These findings indicate that Kgh3 is an endolysin with promising anti-biofilm activity and translational potential.