Antimicrobial resistance in uncomplicated urinary tract infections in 3 California EDs

Department of Emergency Medicine, Alameda County Medical Center-Highland Campus, Oakland, CA 94602, USA.
The American journal of emergency medicine (Impact Factor: 1.27). 07/2011; 30(6):942-9. DOI: 10.1016/j.ajem.2011.05.008
Source: PubMed


Increased trimethoprim/sulfamethoxazole (TMP/SMX) resistance has led to changes in empiric treatment of female urinary tract infections (UTI) in the emergency department (ED), particularly increased use of fluoroquinolones (Acad Emerg Med.2009;16(6):500-507). Whether prescribing changes have affected susceptibility in uropathogens is unclear. Using narrow-spectrum agents and therapy tailored to local susceptibilities remain important goals.
The primary goal of this study is to characterize the susceptibility patterns of uropathogens among ambulatory female ED patients with UTI. Its secondary goal is to identify demographic or clinical factors predictive of resistance to narrow-spectrum agents.
This was a cross-sectional study of women with suspected UTI referred to a trial of computer kiosk-aided treatment of UTI in 3 Northern California EDs. Demographic and clinical data were gathered from the kiosk and chart, and features associated with resistance were identified by bivariate and multivariable regression analysis.
Two hundred eighty-three participants, aged 15 to 84 years, were diagnosed with UTI and cultured. One hundred thirty-five (48%) of cultures were positive, with full susceptibilities reported (81% Escherichia coli). Only 2 isolates (1.5%) were fluoroquinolone resistant. Resistance to TMP/SMX was 18%, to nitrofurantoin 5%, and to cefazolin 4%. Seventy-four percent were sensitive to all 3 narrow-spectrum agents. Resistance to narrow-spectrum agents did not vary significantly by diagnosis, age, recent UTI, or any clinical or demographic factors; but overall, there was a trend toward lower resistance rates in our population than in our hospitals' published antibiograms.
In our population of ambulatory female ED patients, resistance to TMP/SMX is just below the 20% threshold that the Infectious Disease Society of America recommends for continued empiric use (Clin Infect Dis.1999;29(4):745-758, Clin Infect Dis.2011;52(5):e103-120), whereas resistance to other narrow-spectrum agents, such as nitrofurantoin and cephalexin, may be lower than published antibiograms for our sites. Fluoroquinolone resistance remains very low.

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    • "Similar to other investigations [3], E. coli constituted a lower percentage of isolates in inpatients than outpatients. However, the pattern of isolates in an ambulatory setting may be quite variable, with E. coli being the most common organism, followed by Staphylococcus saprophyticus, Proteus mirabilis, and Enteric gram-negative rods in one study [8]. Another observational study on microbiologic patterns of UTI in general practice also revealed E. coli as the most common culprit followed by typical uropathogens and Enterococcus faecalis [9]. "
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    ABSTRACT: Aim. To demonstrate the prevalence of isolated organisms in urinary/respiratory tract infections and their antibiotic susceptibilities in a tertiary care center. Methods and Material. Between January 2008 and January 2010, patients referring to the clinic of cardiology or those admitted to the cardiac wards were enrolled in this cross-sectional descriptive study. Urine and sputum sampling was done for all the patients and the specimens underwent microbiologic examination and, in case of isolation of microorganism, antibiotic disk diffusion test was performed. Results. Escherichia coli (E. coli) was the most prevalent isolated organism in-hospital and community-acquired UTIs and was highly resistant to cephalothin in all the samples followed by cotrimoxazole, and ceftriaxone. It revealed high sensitivity to imipenem, amikacin, and nitrofurantoin. Acinetobacter constituted the most prevalent organism isolated from respiratory secretions and represented the highest resistance to ceftriaxone and the greatest sensitivity to imipenem. Conclusions. E. coli and Acinetobacter remain the most common uropathogenic and respiratory organisms, respectively. However, their increasing resistance to wide-spectrum imipenem, meropenem, and vancomycin is a major concern.
    Full-text · Article · Jun 2014 · International Journal of Microbiology
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    • "Variance has also been seen when comparing E coli resistance rates of the ED to those of the hospital antibiogram. Moffett et al [11] found no significant difference between resistance rates in the ED and the cumulative hospital population (represented by the antibiogram), whereas Khawcharoenporn et al [12] demonstrated significantly lower rates of E coli resistance in ED patients when compared with the hospital-wide antibiogram. "
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    ABSTRACT: Purpose: The purpose of this study is to provide resistance data for Escherichia coli isolates causing urinary tract infections in emergency department (ED) patients not requiring admission and explore if differences between this subpopulation and the hospital antibiogram exist. Differences between community-acquired urinary tract infection (CA-UTI) and health care-associated (HA-UTI) subgroups were also investigated. Methods: Patients with a positive urine culture treated and discharged from the ED of a 200-bed community hospital were reviewed. Patients with urinary isolates of more than 100000 colony-forming unit/mL and documented intention to treat were included. Patients who required admission, were pregnant, less than the age of 18 years, or who had a positive culture but without any evidence of intention to treat were excluded. Only the initial visit was included for patients who returned to the ED within 7 days. Results: Overall, 308 visits were screened, and 217 were included. Of these, 78.3% were CA-UTI, and 21.7% were HA-UTI. Females comprised 88.5% of all patients. E coli was the most common pathogen overall and in both subgroups. E coli resistance to levofloxacin was 13.5% overall, 9.2% for CA-UTI, and 38.5% for HA-UTI compared with 27% on the hospital antibiogram. E coli resistance to sulfamethoxazole/trimethoprim was 26.9% overall, 25.2% for CA-UTI, and 34.6% for HA-UTI vs 26% on the antibiogram. Conclusions: E coli susceptibility for ED patients not requiring admission may not be accurately represented by hospital antibiograms that contain culture data from various patient types, sites of infection, or patients with varying illness severity. Separation of the ED population into CA-UTI and HA-UTI subgroups may be helpful when selecting empiric antibiotic therapy.
    Full-text · Article · Apr 2014 · American Journal of Emergency Medicine
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    ABSTRACT: Introduction: This review summarizes data on the fluoroquinolone resistance epidemiology published in the previous 5 years. Materials and methods: The data reviewed are stratified according to the different prescription patterns by either primary- or tertiary-care givers and by indication. Global surveillance studies demonstrate that fluoroquinoloneresistance rates increased in the past several years in almost all bacterial species except Staphylococcus pneumoniae and Haemophilus influenzae causing community-acquired respiratory tract infections (CARTIs), as well as Enterobacteriaceae causing community-acquired urinary tract infections. Geographically and quantitatively varying fluoroquinolone resistance rates were recorded among Gram-positive and Gram-negative pathogens causing healthcare-associated respiratory tract infections. One- to two-thirds of Enterobacteriaceae producing extendedspectrum b-lactamases (ESBLs) were fluoroquinolone resistant too, thus, limiting the fluoroquinolone use in the treatment of community- as well as healthcare-acquired urinary tract and intra-abdominal infections. The remaining ESBL-producing or plasmid-mediated quinolone resistance mechanisms harboring Enterobacteriaceae were low-level quinolone resistant. Furthermore, 10-30 % of H. influenzae and S. pneumoniae causing CARTIs harbored first-step quinolone resistance determining region (QRDR) mutations. These mutants pass susceptibility testing unnoticed and are primed to acquire high-level fluoroquinolone regulatory authorities, and the pharmaceutical industry have diverse interests, which, however, are not addressed by different designs of a surveillance study. Tools should be developed to provide customer-specific datasets. Conclusion: Consequently, most surveillance studies suffer from well recognized but uncorrected biases or inaccuracies. Nevertheless, they provide important information that allows the identification of trends in pathogen incidence and antimicrobial resistance.
    Full-text · Article · Mar 2012 · Infection
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