Antibiotic resistance in 1962 invasive isolates of Escherichia coli in 27 Spanish hospitals participating in the European Antimicrobial Resistance Surveillance System (2001)

In Europe, antimicrobial resistance of invasive pathogens has been monitored since 1998 by the European Antimicrobial Resistance Surveillance System (EARSS). The goal of this study is to analyse the susceptibility data of invasive Escherichia coli collected by 27 Spanish laboratories in 2001. Each laboratory identified strains and tested their susceptibility using its own methods. To assess the comparability of susceptibility test results, a quality assurance exercise was performed. We report data from 1962 invasive isolates of E. coli: 1959 from blood and three from cerebrospinal fluid, corresponding to the same number of patients. Resistance to ampicillin, co-trimoxazole, ciprofloxacin and gentamicin was found in 58.46%, 32.91%, 17.19% and 6.39% of isolates, respectively. Extended-spectrum beta-lactamase (ESBL) production was detected in 30 strains (1.55%). Ciprofloxacin resistance was higher in isolates from men and in-patients than in those from women and out-patients (P < 0.001). Resistance to ampicillin and co-trimoxazole was more widespread in children than in adults: 70.37% versus 57.87% (P = 0.01) and 41.84% versus 32.53% (P = 0.05). Non-significant differences in resistance to fluoroquinolones were observed between isolates from children (11.1%) and adults (17.54%), despite the fact that fluoroquinolones are not administered to children. Significantly, resistance to non-beta-lactam antibiotics (co-trimoxazole, ciprofloxacin and gentamicin) was more prevalent in ampicillin-resistant strains and ESBL-producing strains than in ampicillin-susceptible strains and non-ESBL-producing strains. Multidrug resistance was present in 13.92% of isolates; the most prevalent phenotype was resistance to ampicillin, co-trimoxazole and ciprofloxacin, which was detected in 59.36% of multiresistant strains and in 8.22% of strains overall.