Signs, Symptoms and Treatment of Common UTIs: Cystitis & Pyelonephritis. The symptoms for kindey infection (pyelonephritis) typically include high fever and flank pain, as well as urinary symptoms similar to bladder infection (cystitis). Recommended empiric treatment is based upon current susceptibility patterns for common pathogens such as E. coli or ESBL-producing Klebsiella observed at Tulane University Hospital and elsewhere (Hooton, 2011b).

Approximately 75-95% of UTIs in women are caused by Escherichia coli. Other less common pathogens are listed below (Gupta et al., 2011).

• E. coli (75-95% of cases)
• Proteus mirabilis
• Klebsiella pneumoniae
• Enterobacter
• Staph b (less common)

• Acute cystitis: an infection of the bladder (a specific type of lower urinary tract infection).
• More common in women than men due to males having a longer urethral length, drier periurethral environment & the presence of antibacterial compounds in prostatic fluid (Hooton 2011)
• The incidence of symptomatic UTI is relatively high in sexually active young women (e.g. 0.5-0.7 UTIs per person-year).
• Risk factors include recent intercourse, spermicide use, and a history of UTI (Hooton, 2011b).
• Clinical Manifestations:
  • dysuria (painful urination)
  • frequency & urgency (frequent urination, the sudden urge to urinate)
  • suprapubic pain (pain in the lower central abdomen)
  • hematuria (RBCs in the urine) may or may not be present
• Nitrofurantoin is a good choice for initial empiric therapy because it exerts antibacterial activity in the urine, but has little systemic antibacterial effect, and bacterial resistance is uncommon.
  • Alternative treatments include sulfamethoxazole + trimethoprim (Bactrim ®) if resistance is not common, or fosfomycin, for which resistance is uncommon, but which is typically less efficacious (Gupta et al., 2011; Gupta 2023b).

• Pyelonephritis: infection of the kidney (a type of upper urinary tract infection)
• Clinical Manifestations:
  • symptoms for cystitis (listed above), and
  • high fever
  • flank pain
• IV ceftriaxone (a 3rd Generation Cephalosporin) is a good drug of choice for initial empiric treatment because of its spectrum of activity and ability to penetrate tissue (unlike nitrofurantoin, which is localized to urine). An alternative drug of choice is piperacillin/tazobactam (Zosyn ®).

Urinary tract infections by Extended-Spectrum Beta-lactamase-producing bacteria such as Klebsiella pneumoniae requires a different drug therapy because the beta-lactamases produced by these pathogens confer resistance to most beta-lactam antibiotics (including penicillins, cephalosporins & monobactams). Infection by ESBL-producing bacteria has been associated with poor outcomes. Failure to treat with an antibiotic with in vitro activity against cultured isolates during the first 5 days after obtaining culture results has been associated with an increased mortality (64 vs 14%) (Munoz-Price & Jacoby, 2011).

Treatment with a carbapenem has produced the best outcomes in terms of survival. Recommended options include (Munoz-Price & Jacoby, 2011):

• Meropenem
• Ertapenem

• Gupta K (2023a): Acute complicated urinary tract infection (including pyelonephritis) in adults. In: UpToDate, Harris A, Edwards MS, Baron EL (Ed); accessed on 9/19/2023.
• Gupta K (2023b): Acute simple cystitis in females. In: UpToDate, Harris A, Edwards MS, Baron EL (Ed); accessed on 9/19/2023.
• Gupta K, Hooton TM et al. (2011): International clinical practical guidelines for the treatment of acute uncomplicated cystitis and pyelonephritis in women: A 2010 update by the Infectious Diseases Society of America and the European Society for Microbiology and Infectious Diseases. Clinical Infectious Diseases 52(5): e103-e120
• Hooton TM (2011): Acute uncomplicated cystitis, pyelonephritis, and asymptomatic bacteriuria in men. In: UpToDate, Harris A, Edwards MS, Baron EL (Ed); accessed on 12-1-11; Last literature review version 19.3: September 2011
• Hooton TM (2011b): Acute uncomplicated cystitis and pyelonephritis in women. In: UpToDate, Harris A, Edwards MS, Baron EL (Ed); accessed on 12-1-11; Last literature review version 19.3: September 2011
• Munoz-Price LS, Jacoby GA (2011): Extended-spectrum beta-lactamases. In: UpToDate, Harris A, Edwards MS, Baron EL (Ed); accessed on 12-1-11; Last literature review version 19.3: September 2011