citri GII3. The signs on the right indicate the ability (+) and inability (−) to replicate in a given species. ND: not determined. A: plasmid integration in the Mmc chromosome. B: spiralin expression in Mcc was detected by immunoblot. Electrotransformation of S. citri was carried out as previously described [43] with 1–5 μg of DNA. Polyethylene glycol-mediated transformation of mycoplasmas was performed as described previously [44] with 5–10 μg of plasmid and transformants were selected by plating on medium containing 5–15 μg.ml−1 of tetracycline. Results and

discussion Detection and initial characterization of plasmids from ruminant mycoplasmas A total of 194 ruminant AZD8931 manufacturer mycoplasma strains were selected from our collection on the basis that there was no apparent epidemiological link between them. Their distribution amongst taxa is summarized in Table 2. No plasmid was detected in species belonging to the Hominis phylogenetic group, i.e. in the M. bovis and M. agalactiae species. In contrast, several plasmids were detected in strains belonging to the M. mycoides cluster or to closely related species of the Spiroplasma phylogenetic group (Table 2). Indeed, 37 out of the 112 strains screened (33%) were found to carry plasmids.

Although plasmids have already been described for strains belonging to the Mmc, M. yeatsii and M. leachii species, this is the first report of plasmids in M. cottewii and Mcc. While nearly all strains carried a single plasmid, the M. yeatsii (GIH) type strain contained selleckchem two plasmids. Except for the larger plasmid of M. yeatsii GIH TS (3.4 kbp),

all other plasmids had apparent sizes of 1.0 to 2.0 kbp. Also, no correlation between PLEKHB2 the presence of plasmid and the history of the strains such as the year and/or place of isolation, and the host species (bovine versus caprine), could be established (Additional file 2: Table S2). Table 2 Detection of plasmids from ruminant mycoplasmas Phylogenetic group Taxon nb of screened strains a strains with plasmidb Hominis M. agalactiae 40 0   M. bovis 42 0   Subtotal 82 0 Spiroplasma M. mycoides subsp. capri 43 12   M. capricolum subsp. capricolum 41 15   M. leachii 10 1   M. yeatsii 16 7   M. cottewii 2 2   Subtotal 112 37   Total 194 37 (a) including the species type strain. (b) as visualized on agarose gel after total DNA extraction by phenol/chloroform. Twenty one plasmids, at least one per taxon, were randomly chosen and fully sequenced. Plasmid sizes ranged from 1,041 bp to 1,865 bp. To assess the diversity and genetic variability of mycoplasma plasmids, the 21 sequences were compared to each other and to those of the five mycoplasma plasmids available in GenBank: pADB201, pKMK1, and pMmc95010 from Mmc, pBG7AU from M. leachii, and pMyBK1 from M. yeatsii (Table 1). The overall nucleotide identity was calculated after a global alignment for each plasmid-pair.