Full Length Research Paper

The effect of mutations in the AmpC promoter region on β-lactam resistance from an Escherichia coli clinical isolate in a public sector hospital in KwaZulu-Natal, South Africa

Chunderika Mocktar¹*, Usha Govinden¹, A. Willem Sturm² and Sabiha Essack¹

¹School of Pharmacy and Pharmacology, Faculty of Health Sciences, University of KwaZulu-Natal, South Africa.

²Department of Medical Microbiology, Nelson R Mandela Medical School, University of KwaZulu-Natal, South Africa.

*Corresponding author: E-mail: mocktarc@ukzn.ac.za. Tel: +27 31 260 7358; Fax: +27 31 260 7792

Accepted 16 June, 2008

The ampC promoter and attenuator regions of an Escherichia coli clinical isolate from a public hospital in KwaZulu-Natal was investigated to detect the presence of mutations in these regions. The isolate was subjected to MIC determinations, IEF analysis, PCR for the presence of β-lactamases and sequencing of the ampC gene. Analysis of the ampC promoter and attenuator regions of the isolate showed that the isolate had mutations in the promoter region and this included insertions of nucleotides in the spacer region between the -10 and -35 Pribnow boxes. The insertion of an extra nucleotide in the spacer region between the -10 and -35 boxes affects the resistance of bacteria to β-lactam antibiotics.

Key words: Escherichia coli, promoter, pribnow box.