Genetic Characterization of Plasmid-Borne in Distinct Acinetobacter Species.

We characterize by whole-plasmid-sequence (WPS) two-plasmid-borne obtained from (Asp-1069) and (Acb-45063) clinical strains recovered 17 years apart from distinct Brazilian regions. Multilocus sequence type (MLST) analysis showed that the Asp-1069 and Acb-45063 strains belong to ST551 and ST15/CC15, respectively. WPS analysis demonstrated that was located in two distinct plasmids named pAs1069_a (24,672 bp/44 open reading frames [ORFs]) and pAb45063_b (19,808 bp/24 ORFs), which belong to the GR8/GR23 () and GR4 () incompatibility groups, respectively. The genetic environments surrounding revealed that it was flanked by two intact IS copies on pAb45063_b, which differed from pAs1069_a. In the latter, the upstream IS copy was truncated by insertion of IS element. Although Re27-specific recombination sites were found adjacent to IS-IS arrangement on pAb45063_b, such structures were absent on pAs1069_a. The conserved IS-- arrangement was disrupted by Tn harboring the aminoglycosides resistance gene on pAs1069_a, while an IS--3-IS genetic structure was found upstream from IS-IS on pAb45063_b. Other two plasmids, pAb45063_a (183,767 bp/209 ORFs) and pAs1069_b (13,129 bp/14 ORFs), were also found in the OXA-58-producing species strains, harboring the and genes and the gene, which confer resistance to streptomycin and sulfonamides, respectively. The plasmid-mediated virulence factors corresponding to genes , , , , , and were found in both strains, as well distinct toxin-antitoxin system-encoding genes and (pAs1069_a), and (pAb45063_b), and (pAb45063_a). Although infrequently reported in Brazil, plasmid-borne showed a complex and diverse genetic backbone that confers stability in different species that have been isolated from nosocomial settings over time. Although the gene has been infrequently described in Brazil, contrasting with other bordering South American countries, we verified the maintenance of this resistance determinant over time among carbapenem-resistant species isolates, not only in nosocomial settings but also in the environment. In addition, to the best of our knowledge, this is the first study to have used WPS analysis to evaluate the genetic surroundings of in Brazil. Moreover, the and clinical strains evaluated in this study were recovered 17 years apart in hospitals located in distinct Brazilian geographic regions.