Urinary Tract Infections due to Multidrug-Resistant Enterobacteriaceae: Prevalence and Risk Factors in a Chicago Emergency Department

Abstract

Background. Selection of empiric antibiotics for urinary tract infections (UTIs) has become more challenging because of the increasing rates of multidrug-resistant Enterobacteriaceae (MDRE) infections. Methods. This retrospective study was conducted to determine antibiotic resistance patterns, risk factors, and appropriate empiric antibiotic selection for MDRE UTIs. Adult patients seen in the Emergency Department (ED) with Enterobacteriaceae UTIs during 2008-2009 were identified from review of microbiology records. MDRE were defined as organisms resistant to at least 3 categories of antibiotics. Results. There were 431 eligible patients; 83 (19%) had MDRE UTIs. Resistance rates for individual antibiotics among MDRE UTIs were significantly greater than non-MDRE UTIs: levofloxacin, 72% versus 14%; TMP-SMX, 77% versus 12%; amoxicillin-clavulanate, 35% versus 4%; nitrofurantoin, 21% versus 12%, and ceftriaxone, 20% versus 0%. All Enterobacteriaceae isolates were susceptible to ertapenem (MIC ≤ 2 mg/L). Independent risk factors for MDRE UTI were prior fluoroquinolone use within 3 months (adjusted odds ratio (aOR) 3.64; P = 0.001), healthcare-associated risks (aOR 2.32; P = 0.009), and obstructive uropathy (aOR 2.22; P = 0.04). Conclusion. Our study suggests that once-daily intravenous or intramuscular ertapenem may be appropriate for outpatient treatment of ED patients with MDRE UTI.

Multidrug resistant Escherichia coli strains isolated from urine sample, University of Gondar Hospital, Northwest Ethiopia

“…Specifically, it showed that high prevalence of MDR E. coli isolates identified from patients with UTI was 92.9% (95% confidence interval: 87.3%-97.7%). The rate of MDR E. coli demonstrated in this study was much higher than findings from developed countries [8][9][10], but comparable to published data from low income countries [4,5,11,12]. However, few reports from developing countries documented lower prevalence of MDR E. coli as compared to this study [13][14][15][16].…”

Clinical Management of an Increasing Threat: Outpatient Urinary Tract Infections Due to Multidrug-Resistant Uropathogens: Table 1.

“…Recent studies have demonstrated that use of antimicrobials in the 4 weeks to 1 year preceding the index infection increases the probability of MDR in the index infection. Use of fluoroquinolones and antipseudomonal penicillins, as well as more cumulative days of treatment with any antimicrobial prior to UTI presentation, were most strongly associated with resistance [3,11,12].…”

“…Men who present with acute cystitis in the outpatient setting may have an uncomplicated infection, though predisposing anatomical and functional risk factors for infection should be considered, particularly related to the prostate. The likelihood of resistance can be higher among men, and a urine culture is warranted to help adjust whatever empiric therapy is chosen and to help inform management of future infections [3]. Any patient (regardless of sex) considered to be at risk of having a UTI due to a multidrug-resistant (MDR) uropathogen (generally considered nonsusceptible to ≥1 agent in ≥3 antibiotic classes, though definitions may vary by institution) should have a urine culture performed as part of the initial assessment in order to tailor the empiric therapy and inform empiric antimicrobial selection in the case of future occurrences [4].…”

Two Simple Rules for Improving the Accuracy of Empiric Treatment of Multidrug-Resistant Urinary Tract Infections

“…As urinary sources are one of the most common sources of bacteremia caused by Gram-negative bacteria and treatment for UTIs is usually initiated prior to the availability of microbiologic data, it is important to optimize decision making for the initial choice of antimicrobial therapy. Although previous studies have examined the rates of inaccurate therapy for MDR UTIs, few have evaluated strategies for improving accuracy (9)(10)(11).…”