RESUMO
Mobile drug-resistance genes with identical nucleic acid sequences carried by multidrug-resistant Escherichia coli strains that cause community-acquired infections are becomingly increasingly dispersed worldwide. Over a 2-year period, we analysed gram-negative bacterial (GNB) pathogens from the blood of inpatients at an urban public hospital to determine what proportion of these isolates carried such globally dispersed drug-resistance genes. Of 376 GNB isolates, 167 (44â%) were Escherichia coli, 50 (13â%) were Klebsiella pneumoniae, 25 (7â%) were Pseudomonas aeruginosa, 25 (7â%) were Proteus mirabilis and 20 (5â%) were Enterobacter cloacae; the remainder (24â%) comprised 26 different GNB species. Among E. coli isolates, class 1 integrons were detected in 64 (38â%). The most common integron gene cassette configuration was dfrA17-aadA5, found in 30 (25â%) of 119 drug-resistant E. coli isolates and in one isolate of Moraxella morganii. Extended-spectrum ß-lactamase (ESBL) genes were found in 16 E. coli isolates (10â%). These genes with identical sequences were found in nearly 40â% of bloodstream E. coli isolates in the study hospital, as well as in a variety of bacterial species from clinical and non-clinical sources worldwide. Thus, a substantial proportion of bloodstream infections among hospitalized patients were caused by E. coli strains carrying drug-resistance genes that are dispersed globally in a wide variety of bacterial species.