Urosepsis is a dreaded complication of UTI with mortality rates as high as 40%.

Gram-negative bacilli account for majority of the cases of urosepsis. These include Escherichia coli (50%), Proteus spp. (15%), Enterobacter and Klebsiella spp. (15%), and Pseudomonas aeruginosa (5%) which dominate the bacterial spectrum in urosepsis, while Gram-positive organisms are involved less frequently (15%).