Long-term dissemination of acquired AmpC β-lactamases among Klebsiella spp. and Escherichia coli in Portuguese clinical settings

article

Freitas, Francisco
Machado, Elisabete
Ribeiro, Teresa
Novais, Ângela
Peixe, Luísa

Springer-Verlag

FREITAS, Francisco [et al.] (2014) - Long-term dissemination of acquired AmpC β-lactamases among Klebsiella spp. and Escherichia coli in portuguese clinical settings. European Journal of Clinical Microbiology & Infectious Diseases. ISSN1435-4373. vol. 33, nº 4, p. 551-558

1435-4373

10.1007/s10096-013-1983-9

Long-term dissemination of acquired AmpC β-lactamases among Klebsiella spp. and Escherichia coli in Portuguese clinical settings

Acquired AmpC-betalactamases
Antimicrobial resistance

The present work was funded by Fundação para a Ciência e Tecnologia (FCT), which belongs to the Ministry of Science, Technology and Innovation of Portugal (through grant nos. PEst-C/EQB/LA0006/ 2011, EXPL/DTP-EPI/0196/2012 and FCOMP-01-0124-FEDER- 027745), and Fundação Ensino e Cultura Fernando Pessoa. T.G.R. was supported by a fellowship from the FCT (SFRH/BD/75752/2011) and Â.N. by a Marie Curie Intra European Fellowship within the European Commission’s 7th Framework Programme (PIEF-GA-2009-255512).

2015-05-19T14:30:09Z
2015-05-19T14:30:09Z
2014-04-01

We investigated the occurrence, diversity and molecular epidemiology of genes coding for acquired AmpC β-lactamases (qAmpC) among clinical isolates of Enterobacteriaceae lacking inducible chromosomal AmpCs in Portugal. A total of 675 isolates non-susceptible to broad-spectrum cephalosporins obtained from four hospitals and three community laboratories during a 7-year period (2002-2008) were analysed. The presence of genes coding for qAmpC was investigated by phenotypic criteria, polymerase chain reaction (PCR) and sequencing. Bacterial identification, antibiotic susceptibility testing, conjugation assays and clonal analysis were performed by standard procedures. The presence of bla qAmpC genes was detected in 50 % (50/100; 41 Klebsiella pneumoniae, 5 Escherichia coli, 4 Klebsiella oxytoca) of the presumptive qAmpC producers. DHA-1, detected in those species, was the most prevalent qAmpC (94 %, 47/50), being identified since 2003 and throughout the studied period in different institutions. Despite the high clonal diversity observed, three DHA-1-producing Klebsiella spp. clones were more frequently identified. CMY-2 (6 %, 3/50) was observed in B1-E. coli clones. Conjugative transfer was only observed in one (2 %) CMY-2-producing isolate. Most qAmpC producers (94 %, 47/50) co-expressed SHV-type and/or OXA-1 or CTX-M-32 extended-spectrum β-lactamases (ESBLs). To the authors' knowledge, this is the first description of the molecular epidemiology and the long-term dissemination of qAmpC-producing Enterobacteriaceae in Portuguese clinical settings, highlighting an evolution towards a more complex epidemiological situation regarding cephalosporin resistance in Portugal.

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