The following are true for Escherichia coli (E. coli) uropathogenesis, EXCEPT:A. Represents 80% of uncomplicated UTI
The spectrum of aetiological agents is similar in uncomplicated upper and lower UTIs, with E. coli the causative pathogen in 70%–95% of cases and Staphylococcus saprophyticus in 5%–10%. Occasionally, other Enterobacteriaceae, such as Proteus mirabilis and Klebsiella species are isolated. Virulence factors prevent E. coli from immune recognition or even actively reduce an immune response. They include adhesins, toxins, iron acquisition systems and immune evasion mechanisms.
Pathogen recognition receptors Toll-like receptor (TLR) 4 and TLR5 appear the most important receptors for endotoxins, with TLR4 recognising lipopolysaccharide (LPS), as the major component of the cell wall in Gram-negative bacteria.