Rev Esp Quimioter 2008;21(3):157-165

Distribution of patterns of sensitivity and associated phenotypes of resistance in nosocomial and community acquired Escherichia coli during 2005

M. V. García López ,  M. M. Gallardo García ,  R. Rodríguez-Ortega ,  F. Ropero Pinto ,  E. Granados Martín ,  M. I. Viciana Ramos ,  A. Gutiérrez-Cobos ,  A. Pinedo Sánchez


Introduction. The increase of resistances to Escherichia coli over recent years has made it necessary to know the patterns of sensitivity in a certain area in order to be able to orient adequate empirical treatment with this knowledge.

Method. Prospective longitudinal study using E. coli isolations obtained during year 2005 in the University Hospital Virgen de la Victoria was performed. Sensitivity identification and study were made according to standardized laboratory protocols.

Results. A total of 2,612 strains of E. coli were isolated from 2,098 patients with an average age of 52 years who had urinary infection as the most frequent sign. E. coli sensitivity was: ampicillin (AMP) (35.4%), ciprofloxacin (QUIN) (67.3 %), trimethoprim-sulfametoxazole (SXT) (63.4 %), phosphomycin (97.2 %) and amoxicillin-clavulanic acid (89%). The percentage of E. coli extended-spectrum β-lactamase (ESBL) producers was 8.2%. In general, nosocomial isolations were more resistant, this difference being significant for third generation cephalosporins, gentamicin and piperacillin/tazobactam (p < 0.005). Resistance in men was greater than in women and also in adults compared to children, with significant differences to ciprofloxacin and gentamicin (p < 0.005). A total of 27.5% of the strains were multiresistant, the most frequent phenotype being the one to AMP/SXT (11.9%), followed by AMP/QUIN/SXT (10.9%).

Conclusions. Resistances to E. coli are very elevated in out setting, above all, in quinolones, that even appear in children, so that up to half of the multiresistant phenotypes present resistance to this family. Furthermore, during the last year, an increase in the isolations of E. coli ESBL producers has been observed.

Key words: Escherichia coli. Phenotype of resistance. Antibiotic sensitivity. ESBL.

Rev Esp Quimioter 2008;21(3):157-165 [pdf]