A novel plasmid from Staphylococcus epidermidis specifying resistance to kanamycin, neomycin and tetracycline

Abstract

The naturally occurring plasmid pSTS7 from Staphylococcus epidermidis mediated resistance to tetracycline via a tetL gene and to kanamycin and neomycin via an aadD gene. Plasmid pSTS7 showed partial restriction map and sequence homology to the previously described tetracycline resistance plasmid pNSl981 from Bacillus subtilis and to the kanamycin/neomycin/bleomycin resistance plasmid PUB1 10 from S. aureus. Sequence analysis of the regions flanking the two resistance genes in pSTS7 led to the identification of a novel site for interplasmid recombination which could explain the derivation of pSTS7 from the incompatible pNS1981-and pUBl1O-like parental plasmids under tetracycline-selective pressure.

Antimicrobial resistance in staphylococci from animals with particular reference to bovine Staphylococcus aureus, porcine Staphylococcus hyicus, and canine Staphylococcus intermedius

“…Their presence in staphylococci seems to be limited to a few staphylococcal species of animal origin, such as S. aureus, S. hyicus, S. lentus, S. sciuri, and S. xylosus [91]. The tet(L) genes were mainly found on plasmids that varied in size between 4.3 and 11.5 kbp [78,87,89]. As a consequence of co-integrate formation and recombination events with other resistance plasmids [89], but also due to the integration of small transposons [87], some of these tet(L)-carrying plasmids harbour additional antibiotic resistance genes.…”

“…The tet(L) genes were mainly found on plasmids that varied in size between 4.3 and 11.5 kbp [78,87,89]. As a consequence of co-integrate formation and recombination events with other resistance plasmids [89], but also due to the integration of small transposons [87], some of these tet(L)-carrying plasmids harbour additional antibiotic resistance genes. Such genes include the kanamycin/neomycin resistance gene aadD or the Tn917-borne macrolide-lincosamide-streptogramin B (MLS B ) resistance gene erm(B) [78].…”

“…It is located on the 4.5 kbp plasmid pUB110 [45]. The 5.5 kbp plasmid pSTS7 obtained from a porcine isolate of S. epidermidis carried a pUB110-analogous aadD gene in addition to a tet(L) tetracycline resistance gene [89]. Sequence analysis of the flanking regions of both resistance genes led to the development of a model according to which plasmid pSTS7 arose from the interplasmidic recombination between two incompatible aadD-and tet(L)-carrying plasmids [89].…”

“…The 5.5 kbp plasmid pSTS7 obtained from a porcine isolate of S. epidermidis carried a pUB110-analogous aadD gene in addition to a tet(L) tetracycline resistance gene [89]. Sequence analysis of the flanking regions of both resistance genes led to the development of a model according to which plasmid pSTS7 arose from the interplasmidic recombination between two incompatible aadD-and tet(L)-carrying plasmids [89]. A plasmid indistinguishable from pSTS7 in its restriction map and also mediating resistances to kanamycin, neomycin and tetracycline has subsequently been detected in a porcine S. hyicus isolate as well [Schwarz, unpublished data].…”

Evolution of multi-resistance plasmids in Australian clinical isolates of Escherichia coli

“…Where two incompatible plasmids are simultaneously selected for, he argues that new plasmids will arise by transposition and predicts that the position of resistance genes in otherwise identical plasmids will be highly variable. Where selection for the co-transfer of compatible resistance plasmids is involved, he argues that new multi-resistance plasmids will arise through cointegration and predicts the occurrence of resistance genes in plasmids with multiple replicons that can be identified as the co-integrates of other plasmids.Both co-integration and transposition have been implicated in empirical studies of plasmid evolution (Berg et al, 1998; Bradley et al, 1986;Guessouss et al, 1996;Mitsuhashi et al, 1977;Schwarz et al, 1996;Sohail & Dyke, 1995;Venkatesan et al, 2001;Woodward et al, 1990). However, a range of other mechanisms, including recombination and the acquisition of integron cassettes, have also been observed (Boerlin, 1999;Boyd et al, 1996;Brown et al, 2000;Lindler et al, 1998;Prentice et al, 2001;Radstrom et al, 1991;Venkatesan et al, 2001).…”