The ARESC study: an international survey on the antimicrobial resistance of pathogens involved in uncomplicated urinary tract infections

https://doi.org/10.1016/j.ijantimicag.2009.04.012Get rights and content

Abstract

The ARESC (Antimicrobial Resistance Epidemiological Survey on Cystitis) study is an international survey to investigate the prevalence and susceptibility of pathogens causing cystitis. Female patients (n = 4264) aged 18–65 years with symptoms of uncomplicated cystitis were consecutively enrolled in nine European countries as well as Brazil during 2003–2006. Pathogens were identified and their susceptibility to nine antimicrobials was determined. Escherichia coli accounted for 76.7% of isolates. Among E. coli, 10.3% of the isolates were resistant to at last three different classes of antimicrobial agents. Resistance was most common to ampicillin (48.3%), trimethoprim/sulfamethoxazole (29.4%) and nalidixic acid (18.6%). Fosfomycin, mecillinam and nitrofurantoin were the most active drugs (98.1%, 95.8% and 95.2% susceptible strains, respectively) followed by ciprofloxacin, amoxicillin/clavulanic acid and cefuroxime (91.7%, 82.5% and 82.4%, respectively). Resistance to ciprofloxacin was >10% in Brazil, Spain, Italy and Russia. Overall, Proteus mirabilis were more susceptible to β-lactams and less susceptible to non-β-lactams than E. coli, whereas Klebsiella pneumoniae strains, which are intrinsically resistant to ampicillin, were less susceptible to mecillinam (88.8%), fosfomycin (87.9%), cefuroxime (78.6%) and nitrofurantoin (17.7%). Resistance was rare in Staphylococcus saprophyticus, with the exception of ampicillin (36.4%) and trimethoprim/sulfamethoxazole (10.2%). In Italy, Spain, Brazil and Russia, the countries most affected by antimicrobial resistance, extended-spectrum β-lactamase (ESBL) enzymes (mainly CTX-M type) were detected in 48 strains (39 E. coli, 6 K. pneumoniae and 3 P. mirabilis). Despite wide intercountry variability in bacterial susceptibility rates to the other antimicrobials tested, fosfomycin and mecillinam have preserved their in vitro activity in all countries investigated against the most common uropathogens.

Introduction

Uncomplicated urinary tract infections (UTIs) are among the most prevalent infectious diseases and affect mainly women. Between one-quarter and one-half of all women experience a UTI during their lifetime [1].

The overall aetiology has not changed in recent years and Escherichia coli remains by far the most common uropathogen, accounting for >80% of all positive cultures [2]. However, the management of these infections, generally treated empirically, is becoming complicated due to the emergence of resistance to several first-line antimicrobial agents in this primary pathogen [3].

Because there is a close correlation between resistance to antibiotics and the persistence of E. coli in UTIs as well as wide local variations in the susceptibility of uropathogens to these drugs, recommendation of first-line treatment agents should be supported by updated epidemiological data [4], [5].

The ARESC (Antimicrobial Resistance Epidemiological Survey on Cystitis) study was conducted in nine countries in Europe as well as Brazil from September 2003 to June 2006 to determine the susceptibility of the major uropathogens circulating in the community of these geographic areas.

Part of the ARESC data focusing on E. coli, with emphasis on the clinical implications of the study for empirical antimicrobial therapy, has recently been published [5]. In the present paper we report the complete set of microbiological results involving all bacterial pathogens isolated from uncomplicated cystitis.

Section snippets

Collaborating centres

Seventy centres were enrolled over a 3-year period (2003–2006) in nine European countries and Brazil. Sixty-two centres (3 Austria, 6 Brazil, 10 France, 7 Germany, 4 Hungary, 5 Italy, 6 Poland, 10 Russia, 9 Spain and 2 The Netherlands) provided valuable strains. All participating laboratories adopted the same protocol for classifying urine samples as positive and negative in accordance with the Infectious Diseases Society of America (IDSA) guidelines [6].

Each local site forwarded the strains

Results

Between September 2003 and June 2006, 4264 eligible patients aged 18–65 years with symptoms of acute uncomplicated UTI were enrolled in the survey. Uropathogens with colony counts of >104/mL were cultured from 3181 patients (74.6%). In 3060 patients (96.2%) the infection was monomicrobial and a mixed infection was found in 121 patients (3.8%).

Of the 3181 patients with bacteriuria, causative agents (n = 3018) from 2927 patients were sent to the central laboratory for further evaluation.

Among the

Discussion

Uncomplicated cystitis in females is among the most frequent infections in the community. The ARESC study has assessed the epidemiology and susceptibility patterns of common uropathogens to standard antimicrobials used in the treatment of uncomplicated lower UTI (cystitis). The clinical implications for empirical antimicrobial therapy in nine European countries and Brazil have been published elsewhere [5].

Adoption of the same strict criteria to enrol patients and to classify microbiological

Acknowledgments

This study was performed under the auspices of the European Society for Infection in Urology (ESIU) (Chairman: Truls E. Bjerklund-Johansen) affiliated to the European Association of Urology (EAU). The authors are grateful to Antonio Colantoni for statistical evaluation as well as the investigators of the ARESC Study Group who contributed their findings to the study: Austria: Andreas Sommerhuber (Linz), Daniela Ullisch (Wien), Andreas Szalay (Wien); Brazil: Sergio Cimerman (Sao Paulo), Juvencio

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