Copper Stress-Induced Transcriptional Regulatory Protein CusR also Regulates Silver Efflux in Klebsiella pneumoniae KW

ABSTRACT Silver and silver containing compounds have had been in medicinal use since centuries. The antimicrobial properties of silver depend on its accumulation in bacterial cells. Klebsiella pneumoniae remains a major health concern around the globe due to its associated infections, such as, pneumonia, meningitis and bloodstream, surgical site and wound infections. The present study reports a locally isolated K. pneumoniae strain exhibiting high resistance (MIC=90mM) against Ag+ and its accumulation potential. Transcription of Cus (Cu sensing) determinants is found to be upregulated in the presence of Ag+. The transcriptional regulator CusR bound effectively with bidirectional cus promoter. STRING database analysis revealed that CusR possesses strong interactions and linkages with other Cus determinants and via ZraS with lead and zinc resistant genes. This regulator also possesses weak associations with Cue and Cut regulons and starvation sensing system.