A Novel Plasmid, pSx1, Harboring a New Tn <i>1696</i> Derivative from Extensively Drug-Resistant <i>Shewanella xiamenensis</i> Encoding OXA-416

The whole genome sequencing of extensively drug-resistant Shewanella xiamenensis T17 isolated from hospital effluents in Algeria revealed the presence of a novel 268.4 kb plasmid designated pSx1, which carries several antibiotic-resistance genes in the novel Tn 1696 derivative (Tn 6297 ), in addition to the chromosomal bla OXA-48 -like gene ( bla OXA-416 ). The presence of the plasmid was confirmed by nuclease S1-PFGE analysis and transformation by electroporation into Escherichia coli DH10B. Tn 6297 contains an In27 class 1 integron harboring the dfrA12-orfF-aadA2 array, msr(E) and mph(E) associated with IS 26 ; a new efflux pump multidrug resistance composite transposon delimited by two IS Ec29 s; Tn-tet harboring tetR and tetA (C); a class 1 integron with the qacG gene cassette ; qnrVC6 and dfrA23 associated with IS CR1 ; and a complex class 1 integron In4-like containing aacC1, aadA1, bla VEB-16 , catA2 , sul1Δ , cmlA9 , tetR , tetA (G), aac(6′)-II , and bla PSE-1 . Its mer operon carries merB , but lacks merC , in contrast to Tn 1696 and Tn 21 . This study represents the first characterization of a multidrug-resistant transposon and multidrug resistance plasmid in Shewanella and is the first report of bla OXA-416 in Algeria, providing evidence that Shewanella spp. could be an important reservoir and vehicle for drug resistance genes.