| prevalence of clinical isolates of escherichia coli and klebsiella spp. producing multiple extended-spectrum beta-lactamases. | eleven thousand two hundred seventy-two escherichia coli, 1109 klebsiella pneumoniae, 1124 salmonella enterica, and 602 klebsiella oxytoca unrelated clinical isolates were obtained between 2001 and 2004 in a university hospital in salamanca, spain. one hundred thirteen e. coli (1%), 32 k. pneumoniae (2.9%), 4 k. oxytoca (0.66%), and 5 s. enterica (0.44%) isolates produced extended-spectrum beta-lactamases (esbls). we obtained 42.2% of the esbl-producing isolates from outpatients and 57.8% from i ... | 2007 | 17913435 |