Survey of extended-spectrum β-lactamases in Escherichia coli isolates from a Portuguese hospital and characterisation of a novel class 1 integron (In60A) carrying the blaCTX-M-9 gene

Between November 2001 and November 2004, 231 Escherichia coli isolates resistant to β-lactam antibiotics were identified. In 14 isolates, blaTEM-24 (2 isolates), blaTEM-52 (5 isolates) and blaTEM-26 (7 isolates) were identified. In 145 E. coli isolates with the same M13 fingerprinting profile and the same resistance phenotype, the blaCTX-M-15 gene was found in association with an insertion sequence ISEcp1. The blaCTX-M-2 gene was identified in one E. coli isolate (290HSM), and in other E. coli isolate (246HSM) the blaCTX-M-9 gene was contained in a new complex sul1-type class 1 integron (named In60A). This is the first report of three cefotaximases (CTX-M-15, CTX-M-2 and CTX-M-9) in E. coli isolates from a Portuguese hospital.