A new integrative conjugative element occurs in Mycoplasma agalactiae as chromosomal and free circular forms

it occurs as multiple chromosomal copies and as a free circular form. The distribution of ICEA sequences in M. agalactiae strains and their occurrence in Mycoplasma bovis suggest the spreading of the element within or between species. Integrative conjugative elements (ICEs) are mobile, modu-lar sequences that are present in many bacterial species and that spread from donor to recipient by conjugation (4, 19). In mollicutes, such an element has not been thoroughly described except for the ICEF of the human-infecting Mycoplasma fer-mentans strain PG18, in which it occurs in two versions, ICEF-I (1 copy) and ICEF-II (3 copies), and produces a circular form after excision from its locus (6). This mycoplasma belongs to the hominis phylogenic group, along with Mycoplasma agalac