1. Figure 1 Infection and resistance in urological practice
Figure 1 | Infection and resistance in urological practice. a | Antibiotic resistance mechanisms in Gram-negative bacteria. These include antibiotic hydrolysis by β-lactamase enzymes (including carbapenemases) or other antibiotic-modifying enzymes (for example, against aminoglycosides). Porin loss or mutation can reduce antibiotic permeability; increased expression or activity of efflux pumps can prevent an antibiotic reaching its target site; a modified drug target can stop antibiotics (for example, quinolones) binding to the active site; mutation in lipopolysaccharide can render the bacteria resistant to the polymyxin group of antibiotics. b | UPEC pathogenesis. UPEC attach to and invade uroepithelial cells and form intracellular bacterial communities. These aid evasion of the host immune system and provide some protection against antibiotic exposure. The formation of a quiescent reservoir within the transitional cell layer might contribute to relapsing or persistent infection. c | Biofilm formation enables the organism to avoid host defences, resist antibiotic therapy and provides a reservoir for ongoing infection if the catheter is not removed. d | Transrectal prostate biopsy allows direct transfer of bacteria from the rectum to the prostate, including a potential reservoir of resistance that can be enhanced by prior antibiotic exposure. Abbreviation: UPEC, uropathogenic E. coli.
Zowawi, H. M. et al. (2015) The emerging threat of multidrug-resistant Gram-negative bacteria in urology
Nat. Rev. Urol. doi: /nrurol