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January 09, 2023
Updates in the Management of AmpC-producing Enterobacterales: AmpC β-lactamase-producing Enterobacterales (AmpC-E) are gram-negative enteric bacteria commonly implicated in urinary tract and intra-abdominal infections. Recently published Infectious Diseases Society of America guidance deemphasized certain bacteria (e.g., Serratia spp., Morganella spp., etc.) historically considered clinically relevant AmpC-E, and highlighted three species (Enterobacter cloacae complex, Citrobacter freundii, and Klebsiella aerogenes) as being at moderate-high risk of inducible AmpC production. Authors addressed roles in therapy of workhorse β-lactams including ceftriaxone, cefepime, piperacillin-tazobactam, and carbapenems – as well as the role of non-β-lactam antibiotics. Recommendations which may constitute significant changes to the practice of some clinicians include consideration of third-generation cephalosporins for treatment of organisms at lower risk of AmpC production, preferential use of carbapenems for AmpC-E with susceptible-dose-dependent cefepime minimum inhibitor concentrations (MICs) of 4-8 mcg/mL, and suggestion against use of piperacillin-tazobactam for most AmpC-E infections.
Upon completion of the chapter, the reader will be able to:
Determine the diagnostic criteria for significant bacteriuria, urinary tract infections (UTIs), and catheter-associated UTIs.
Recognize the signs and symptoms of UTIs, and differentiate asympotomatic bacteriuria from acute cystitis and pyelonephritis and acute prostatitis from chronic prostatitis.
Identify the pathogenic organisms most commonly implicated in different UTIs.
Assess the laboratory tests used in the diagnosis of UTIs.
Based on clinical signs, symptoms, and laboratory parameters, recommend appropriate empiric and targeted pharmacotherapy for the treatment of acute cystitis, pyelonephritis, and prostatitis, including drug, dose, and duration of therapy.
Formulate appropriate monitoring and education information for patients with UTIs.
A urinary tract infection (UTI) is defined as the presence of pathogenic microorganisms in the genitourinary tract with associated signs and symptoms of infection. UTIs represent a diverse array of syndromes based on location within the urinary tract, including acute cystitis, pyelonephtritis, and prostatitis.1-3 UTIs are one of the most common reasons for the receipt of antimicrobial therapy.4
EPIDEMIOLOGY AND ETIOLOGY
The prevalence and type of UTIs generally vary according to age and gender.5,6 In adults, bacteriuria is more common in young, nonpregnant women (range, 1%–3%) but uncommon in men (up to 0.1%).7 Symptomatic UTIs occur most frequently in women of childbearing age. It is estimated that the lifetime risk of UTIs in women is as high as 60%, with 25% of those patients experiencing a recurrence within 1 year.8 UTIs are much more common in women than men due to their inherently shorter urethra and proximity to the perineal area. However, older men may experience UTIs due to immunoscenesence and concomitant disease states, such as benign prostatic hypertrophy (BPH).
UTIs are classified as either uncomplicated or complicated. Uncomplicated infections usually occur in women ...