Klebsiella pneumonia is an opportunistic human pathogen that can cause acute ,life threatening infections.Part of the virulence repertoire of this microorganism includes the ability to sequeater iron from the host during infection by synthesis and secretion of siderophores..The aim of study was to determine the effect of Petroleum ether, chloroform, methanol and water extracts of eight traditional Indian medicinal plants Biophytum sensitivum, Leucus aspera, Aegle marmlos, Plectranthus amboinicus, Vettiveria zizanoides, Cynodon dactylon, Emilia sonchifolia, Terminalia catappa on the siderophore production in Klebsiella pneumoniae. .A highthroughput two step screening assay was done to spectrophotometrically analyse growth of the organism and siderophore production. If an extract inhibited growth only in iron limited medium(primary screening) its effect on siderophore production was determined(secondary screening)using Chrome Azurol Sulphonate assay. Chloroform extracts of Vettiveria zizanoides, methanol extracts of Cynodon dactylon and methanol extracts of Terminalia catappa showed 57,45,25 % of siderophore production in clinical strainand chloroform extracts of Emilia sonchifolia showed 66 % reduction.Apart from showing antimicrobial activity ,this study has shown that these plants can also act as antivirulence agent.The apparent multifaceted action of these plant extracts therefore make them both versatile and effective as an antimicrobial agent which is paramount in an age where antibiotics are becoming increasingly inadequate.
