Cloning and sequencing of the class A β-lactamase gene (blaTEM-15) located on a chromosomal Tn801 transposon

Escherichia coli CA0210 was identified in a stool culture of a 03-mounth-newonate in Tunisia. This strain was resistant to β-lactams, including ureidopenicillins, ticarcillin–clavulanic acid, cefpirome, ceftazidime, and cefotaxime, but it remained susceptible to imipenem and cefoxitin. The β-lactam–hydrolyzing β-lactamase gene of E. coli CA0210 and the upstream and downstream regions were cloned, sequenced, and expressed in E. coli DH5α. These resistances were carried by a 1080-bp chromosomal gene that encoded a β-lactamase with a pI of 6.3. Cloning and sequencing experiments showed that the corresponding blaTEM-15 gene was part of a chromosomally located Tn801 transposon.