A novel plasmid carrying bla identified in commensal Escherichia coli from healthy pregnant women in Ibadan, Nigeria.

The aim of this study was to investigate the molecular characteristics of commensal Escherichia coli producing extended-spectrum β-lactamases and showing fluoroquinolone resistance circulating in a healthy population in Ibadan, Nigeria. In total, 101 faecal samples from healthy pregnant women on the day of admission to hospital were collected and plated on eosin-methylene blue agar supplemented with cefotaxime. Genotyping demonstrated the presence of the bla gene in all of the cefotaxime-resistant isolates (n=32), and there was circulation of prevalent clones. The aac(6')-Ib-cr, qnrS1, qepA1 and qnrB1 genes were identified in several strains. A novel plasmid supporting the spread of the bla, bla and qnrS1 genes was identified in these isolates by complete DNA sequencing.