Snapshot A 55-year-old woman presents to the emergency department with fatigue and abdominal pain. Her symptoms are associated with dysuria, hematuria, and increased urinary frequency. Physical examination is remarkable for bilateral flank pain, suprapubic tenderness, and costovertebral angle tenderness. Urine studies are obtained and she is started on empiric antibiotics. Urine cultures grows Pseudomonas aeruginosa. (Pyelonephritis secondary to Pseudomonas infection) Introduction Aerobic, non-lactose fermenting, oxidase-positive, gram-negative bacillus Pathogenesis phospholipase C produced to degrade cell membranes endotoxin, which leads to fever hypotension disseminated intravascular coagulation exotoxin A this inactivates elongation factor 2 (EF-2), which stops protein synthesis via ADP ribosylation pyoverdine and pyocyanin pigment leads to a blue-green pigment Associated Conditions Conditions Comments Pneumonia - Sepsis - Ecythma gangrenosum Seen in severely ill and immunocompromised patients Urinary tract infections - Diabetes - Osteomyelitis Can be seen in patients with puncture wounds Nosocomial infections Such as catheter-associated and ventilator-associated infections Skin infections Hot tub folliculitis Wound infections in burn victims Cystic fibrosis (CF) Its mucoid polysaccharide capsule may play a role in chronic pneumonia seen in CF patients most common microbe isolated in adults with cystic fibrosis Treatment Prompt antibiotic administration is associated with improved mortality In addition to antibiotic treatment, source control is important (e.g., abscess drainage and removal of the catheter) Treatment options include carbapenems aminoglycosides monobactams polymyxins fluoroquinolones third and fourth generation cephalosporins piperacillin