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Revista do Instituto de Medicina Tropical de São Paulo
On-line version ISSN 1678-9946
DROPA, Milena et al. Extended-spectrum beta-lactamases among Enterobacteriaceae isolated in a public hospital in Brazil. Rev. Inst. Med. trop. S. Paulo [online]. 2009, vol.51, n.4, pp.203-209. ISSN 1678-9946. http://dx.doi.org/10.1590/S0036-46652009000400005.
Extended-spectrum β-lactamases (ESBL) in enterobacteria are recognized worldwide as a great hospital problem. In this study, 127 ESBL-producing Enterobacteriaceae isolated in one year from inpatients and outpatients at a public teaching hospital at São Paulo, Brazil, were submitted to analysis by PCR with specific primers for blaSHV, blaTEM and blaCTX-M genes. From the 127 isolates, 96 (75.6%) Klebsiella pneumoniae, 12 (9.3%) Escherichia coli, 8 (6.2%) Morganella morganii, 3 (2.3%) Proteus mirabilis, 2 (1.6%) Klebsiella oxytoca, 2 (1.6%) Providencia rettgeri, 2 (1.6%) Providencia stuartti, 1 (0.8%) Enterobacter aerogenes and 1 (0.8%) Enterobacter cloacae were identified as ESBL producers. BlaSHV, blaTEM and blaCTX-M were detected in 63%, 17.3% and 33.9% strains, respectively. Pulsed field gel eletrophoresis genotyping of K. pneumoniae revealed four main molecular patterns and 29 unrelated profiles. PCR results showed a high variety of ESBL groups among strains, in nine different species. The results suggest the spread of resistance genes among genetically different strains of ESBL-producing K. pneumoniae in some hospital wards, and also that some strongly related strains were identified in different hospital wards, suggesting clonal spread in the institutional environment.
Keywords : ESBL; Enterobacteriaceae; Klebsiella pneumoniae; Pulsed Field Gel Electrophoresis; Antimicrobial resistance.