The genetic environment of the antiseptic resistance genes qacE Delta 1 and cepA in Klebsiella pneumoniae

The genetic environment of two antiseptic resistance genes (qacE Delta 1 and cepA) was examined in Klebsiella pneumoniae isolates obtained from the Royal Infirmary of Edinburgh between 2006 and 2008. In 4 of 34 isolates, which carried the qacED1 gene, the sul1 gene was located immediately downstream. In two of these, the orf5 gene of unknown function was found immediately downstream of the sul1 gene. In one case, this was substituted by the chrA gene. The cepA gene was carried by 56 (87.5%) isolates, and the pfkA gene was found directly downstream in 45 (70.3%) isolates, and in 40 (62.5%) of these isolates, the menG gene was found directly downstream. The cpxP gene was found in 47 (73.4%) isolates upstream of the cepA, and in 35 of these isolates, the cpxR gene was identified. These latter genes are transcription regulators, and reverse transcription polymerase chain reaction (RT-PCR) revealed that their presence was associated with cepA expression.