contain tetM and are tetracycline-resistant [10]. Further evidence of genome integrated transposons were some of the site-specific recombinases found in the genomes: TnpX, required for the excision of Tn4451 [10]

Daporinad clinical trial and TndX, which was the first member of the large-resolvase subgroup of the resolvase/invertase family of site-specific recombinase shown to be able to mediate the insertion and excision of a conjugative transposon, more specifically Tn5397 [30]. A TraG/D family protein was recognized in serovars 9 and 13 (UUR9_0186 [GenBank: ZP_03079565] and UUR13_0031 [GenBank: ZP_02932006]). The TraG/D (transport) family genes aid the transfer of DNA from the plasmid into the host bacterial chromosome [31, 32], mediate the interactions between the DNA processing (Dtr) and mating pair formation (Mpf) systems during conjugation. Another suggestion for the capacity of horizontal gene transfer in at least some serovars is the presence of relaxases/mobilization proteins (UUR9_0148 [GenBank: ZP_03079581] and UUR13_0045 [GenBank: ZP_02696018]). Such proteins SRT1720 in vitro are required for the horizontal transfer of genetic information

contained on plasmids that occurs during bacterial conjugation [33]. Aligning the genomes of the 14 ATCC ureaplasma genomes made evident two major insertion events. The first one was consistent with a transposon insertion, due to the repeat of some host sequence on both sides of the inserted region. At the time of insertion a short part of the 3′ end of the ruvB was duplicated, so that the insertion was located between the full length ruvB gene and its short

duplication. The insertion has been inherited by UPA1, 3, and 14 from a common ancestor. Some of the genes present in this insertion had orthologs in UUR serovars. The inserted DNA fragment was 11,822 bp long in UPA3 and 14, and 12293 bp in UPA1. It contained 8 genes, which encoded 6 hypothetical Vitamin B12 proteins, one hypothetical protein containing a subtilase domain, and one Type I specificity subunit restriction protein. The second insertion was present in 9 of the 14 serovars (UPA3, and 6, UUR4, 5, 7, 8, 10, 11, and 12) and had a size of about 20 Kb. Based on the fact that there were three phage genes in the insert, we believe that this event is due to a phage insertion into the genomes. The first gene of the insertion encodes an integrase-recombinase protein that contains a phage integrase domain (UPA3_0153 [GenBank: YP_001752228]). A phage recombination protein Bet (UPA3_0162 [GenBank: YP_001752237] is located further downstream of the integrase and the final gene in the insert is a phage terminase, large subunit, of the pbsx family (UPA3_0176 [GenBank: YP_001752251]. The rest of the genes are hypothetical proteins, however some of them have one or more transmembrane domains and/or signal peptides, suggesting that they may play a role on the surface of the ureaplasma cell.