Association between Antimicrobial Consumption and Resistance in Escherichia coli

Abstract

During a 9-year study period from 1997 through 2005, the association between antimicrobial resistance rates in Escherichia coli and outpatient antimicrobial consumption was investigated in 20 hospital districts in Finland. A total of 754,293 E. coli isolates, mainly from urine samples, were tested for antimicrobial resistance in 26 clinical microbiology laboratories. The following antimicrobials were studied: ampicillin, amoxicillin-clavulanate, cephalosporins, fluoroquinolones, trimethoprim, trimethoprim-sulfamethoxazole, pivmecillinam, and nitrofurantoin. We applied a protocol used in earlier studies in which the level of antimicrobial consumption over 1 year was compared with the level of resistance in the next year. Statistically significant associations were found for nitrofurantoin use versus nitrofurantoin resistance (P < 0.0001), cephalosporin use versus nitrofurantoin resistance (P ‫؍‬ 0.0293), amoxicillin use versus fluoroquinolone resistance (P ‫؍‬ 0.0031), and fluoroquinolone use versus ampicillin resistance (P ‫؍‬ 0.0046). Interestingly, we found only a few associations between resistance and antimicrobial consumption. The majority of the associations studied were not significant, including the association between fluoroquinolone use and fluoroquinolone resistance.Urinary tract infection (UTI) is one of the most common indications for antimicrobial treatment. The development of antimicrobial resistance in Escherichia coli has an influence on the successful treatment of UTIs. The rates of resistance to aminopenicillins and fluoroquinolones among E. coli isolates are on the increase, and many isolates already show resistance to two or more classes of antimicrobials (6, 7).According to current Finnish care recommendations, the first-line antimicrobial agents for the treatment of uncomplicated cystitis are trimethoprim, pivmecillinam, nitrofurantoin, or a fluoroquinolone (28). Cephalexin (cefalexin) or cefadroxil, trimethoprim-sulfamethoxazole, and amoxicillin (amoxicilline) are recommended for use as second-line drugs (28). In Finland, 32% of UTIs are treated with trimethoprim, 18% with pivmecillinam, 16% with nitrofurantoin, and 16% with fluoroquinolones (21).Studies describing the relationship between antimicrobial consumption and resistance in E. coli show that there is no clear evidence of how these two factors are linked to each other (13,25). Some reports suggest a positive association between antimicrobial consumption and bacterial resistance (19,26), while others claim that such associations are not evident (1, 4).The aim of the study described here was to investigate the association between the regional rates of antimicrobial resistance among E. coli isolates and antimicrobial consumption in 20 hospital districts in Finland. MATERIALS AND METHODSBacterial isolates and resistance data. A total of 754,293 E. coli isolates were tested for antimicrobial resistance in Finland during a 9-year study period from 1997 through 2005. The number of isolates tested in each central hospital district per yea...

Resistance and utilisation pattern of antibacterial agents in outpatient settings in two Teaching Hospitals in Colombo

“…However, possibility of prescriptions for ciprofloxacin given by doctors to be purchased from outside cannot be ruled out. A significant association has been reported between amoxicillin use and fluoroquinolone resistance [19]. The high utilisation of amoxicillin would have contributed to ciprofloxacin resistance observed in our study.…”

Surveillance and Correlation of Antibiotic Prescription and Resistance of Gram-Negative Bacteria in Singaporean Hospitals

“…Unlike the majority of published studies, there were few significant correlations between antimicrobial prescription and subsequent resistance or vice versa (2,7,10,13,18). Overall carbapenem prescription was correlated with significant but slight changes in imipenem resistance in Acinetobacter blood isolates within the same time period.…”

“…Gram-negative bacterial resistance is of particular importance as there is a dearth of novel antibiotics directed against these organisms (1), which are increasing in prevalence worldwide (8,12,15). Logically, an association should exist between antibiotic consumption and Gram-negative bacterial resistance, and this was demonstrated in multiple studies in both the hospital and community settings (2,7,10,13,18). Causal relationships have been difficult to establish, however, and there are studies that have failed to show any interdependence (1,6).…”

“…Causal relationships have been difficult to establish, however, and there are studies that have failed to show any interdependence (1,6). Even in several supportive studies, the association between antimicrobial consumption and resistance was not universal among all the antibiotics and organisms tested (2,10,18). This has been attributed to various reasons, including failure to control for confounding factors such as infection control measures, study biases, and lack of uniformity in susceptibility testing methods and definitions of resistance (14).…”

Relationship between Antimicrobial Consumption and the Incidence of Antimicrobial Resistance in Escherichia coli and Klebsiella pneumoniae Isolates

“…Interestingly, only a few associations were found between antimicrobial consumption and its resistance. Including the association between consumption of fluoroquinolone and its resistance, the majority of the associations studied were not significant [25]. Most of the research discussed above showed a linear relationship between the rate of antimicrobial use and drug resistance.…”