Transposition of Tn 552-II (a Tn 552 derivative) to the conjugative pCtra plasmid family in pediatric multidrug-resistant community-associated MRSA

We report the transposition of a 9,045-bp transposon (Tn 552-II ) carrying the tnpABC /target-gene-like( tgl )/ blaZ-R1-I array to a conjugative plasmid (pCtra) in pediatric multidrug-resistant community-associated methicillin-resistant Staphylococcus aureus . Tn 552-II contained a 7-bp target site ( att ) on the left; an internal i-att on the right, apparently “brought-in” through a circular intermediate; and i-att2 and i-att3 in the tgl gene and its neighboring gene, respectively. This transposition enhanced ampicillin resistance and facilitated Tn 552-II spread at a frequency of 10 −3 .