We describe the first outbreak of Klebsiella pneumoniae carbapenemase-producing K. pneumoniae (KPC-KP), the infection control measures adopted and the shift in resistance patterns of isolates during antibiotic treatment. The ST258 KPC-KP strain exhibited a multiresistant antibiotic phenotype including co-resistance to gentamycin, colistin and tigecycline intermediate susceptibility. Isolates before and after treatment had different behaviour concerning their antibiotic susceptibility and the population analysis profile study. A progressive increase in the aminoglycosides (acquiring amicacin resistance) and β-lactam MICs, and a decreased susceptibility to fosfomycin was observed throughout the administration of combined antimicrobial regimens including meropenem. A high meropenem resistance KPC-KP homogeneous population (MIC 256 Jg/mL), could arise from the meropenem heterogeneous low-level resistance KPC-KP population (MIC 8 Jg/mL), by the selective pressure of the prolonged meropenem therapy. The kpc gene was inserted in a Tn4401 isoform a, and no transconjugants were detected. The core measures adopted were successful to prevent evolution towards resistance dissemination.

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TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractThe objective of this paper is to highlight the results and

e26014th International Congress on Infectious Diseases (ICID) Abstracts four percent (12/49) of patients received inappropriate initial antibiotics and 83% (10/12) of these were patients who had RGN. Mortality trended higher in patients with RGN infection compared to other GN bacilli (3/10, 30% vs. 3/39, 7.7%; p = 0.06).Conclusion: Most patients diagnosed with GN-CRBSI did not meet our strict criteria for diagnosis, a fact that suggests that GN-CRBSI is misdiagnosed. However, the true diagnosis of GN-CRBSI does not clearly impact mortality or median length of stay. There was a nonsignificant trend towards increased mortality in patients with RGN infection. Antibiotics active against RGN should be considered as part of initial empiric coverage.