Prevalence, distribution and transfer of small β-lactamase-containing plasmids in Swedish Haemophilus influenzae.

The β-lactamase genes of Haemophilus influenzae are commonly positioned on large integrative and conjugative elements, but a group of blaTEM-carrying small plasmids (4000-6000 bp) with a common structural backbone have recently been characterized. In this study we investigated the epidemiological significance and potential for transfer of this group of small plasmids