aureus strains. Results Characterisation of rep families check details A total of 21 rep families were assigned. 8 families (rep 5 rep 7 rep 10 rep 10b rep 13 rep 15 rep 16 and rep 19) match those previously characterised by Jensen et al.[11]. 13 rep families are newly characterised in this study. 6 orphan rep sequences were also identified; in plasmids pAVX (repA_N domain), pWBG746 (repA_N

domain), pWBG745 (repA_N domain), pKKS825 (rep_1 domain), pRJ6 (rep_3 domain), SAP099B (rep_2 domain). Plasmid groups possess unique combinations of rep genes A total of 39 plasmid groups of Staphylococcus aureus (pGSA) were assigned (Figure 1) based on the Anlotinib research buy combination of rep genes each plasmid possessed. Each plasmid group had a unique combination of rep gene sequences. 6 of the 243 sequenced plasmids contain orphan rep sequences and were not assigned to a plasmid group. 18 plasmid groups carried 1 rep sequence, 17

plasmid groups carried 2 rep sequences and 4 plasmid groups carried 3 rep sequences. The large number of plasmid groups with more than 1 rep gene indicates high levels of recombination between S. aureus plasmids. We note that in the majority of cases there was no difference in the length of a rep gene that appeared on single rep plasmids or multi-rep plasmids. The https://www.selleckchem.com/products/dihydrotestosterone.html number of plasmids belonging to each plasmid group varied considerably (ranging from 1–32). The average length of plasmids belonging to plasmid groups varied (Figure 1). Nine plasmid groups have small genomes

(<5Kb) and carried few genes. 28 plasmid groups have large genomes (>15Kb) and carried a diverse range of genes. 21 of these 28 large plasmid groups possessed more than 1 rep gene sequence. Many of these large plasmids carried rep genes found in small plasmids indicating recombination and integration of smaller plasmids. 13/243 plasmids carried plasmid conjugation transfer (tra) A-M genes. All plasmids GNA12 from groups pGSA 6, pGSA 28 and pGSA 39 possessed traA-M genes, whilst plasmids from group pGSA 10 possess homologs of traE, traG and traI. Conjugation ability is therefore tightly linked with the replication machinery and rep sequences of rep 15 and rep 21, respectively. Figure 1 The distribution of rep genes and resistance genes in S. aureus plasmids. Sequenced plasmids may carry a single rep gene or a combination of rep genes. Each unique rep gene combination forms a plasmid group of S. aureus (pGSA). The number (n) and average length (nucleotides) of plasmids in each plasmid group is shown. Plasmid conjugation transfer (tra) genes are present in single-rep plasmid groups that possess rep 15 and rep 21 genes. The number (nR) of resistance gene profiles carried by members of each plasmid group is shown. Core resistance genes are found in all plasmids of a plasmid group, variable resistance genes are found in only some plasmids of the group.