Characterisation of a novel integrative and conjugative element ICESsD9 carrying erm(B) and tet(O) resistance determinants in Streptococcus suis, and the distribution of ICESsD9-like elements in clinical isolates

Chromosomal Conjugative and Mobilizable Elements in Streptococcus suis: Major Actors in the Spreading of Antimicrobial Resistance and Bacteriocin Synthesis Genes

“…Most of the IMEs carrying AMR genes are integrated into SNF2 or PPI. They are also carried by ICEs as previously described, but were not recognized as IMEs by the authors of these works [12,14]. These IMEs are related to the tet(O) fragment integrated into ICESp2905 described in Streptococcus pyogenes [37].…”

“…Most of them carry tet(O) (that confers resistance to tetracycline) (n = 89) or tet(O) and erm(B) (that confers resistance to macrolides-lincosamides-streptogramin B) (n = 62) ( Figure 8) and are themselves carried by ICEs of the Tn5252 family. They are integrated into SNF2 (for example, in ICE_SsuNSUI002_rplL, Figure 7) or into PPI (for example, in ICE_SsuNSUI086_rplL and the previously described ICE_SsD9 [14], Figure 7).…”

“…In the context of the rising threat of antimicrobial resistance [7,8] requiring a One Health approach, S. suis is receiving growing attention due to its extended drug resistance [9]. Numerous resistance determinants (in particular tetracycline, macrolide, aminoglycoside, and chloramphenicol resistance genes) have been described in this bacterial species, many of them being carried by Integrative Conjugative Elements (ICEs) [10][11][12][13][14][15][16]. ICEs are mobile genetic elements that excise from the chromosome and transfer autonomously by conjugation [17].…”

“…After cleavage at a site called oriT, DNA is addressed to a type IV secretion system by a relaxase, thanks to its interactions with a coupling protein [18]. The main families of ICEs carrying antimicrobial resistance (AMR) genes described in S. suis are Tn916, Tn5252, and Tn1549 families [11][12][13][14][15]19,20]. Mosaic or composite elements resulting from tandem accretions of ICEs or internal insertions of ICEs within another ICE were reported [11][12][13][14][15]19,20].…”

ICESsuHN105, a Novel Multiple Antibiotic Resistant ICE in Streptococcus suis Serotype 5 Strain HN105

“…For mating experiments, the mutant strain P1/7 (Cm R , Tet S , and Ery S ) was used as a recipient and the multi-drug resistant strain HN105 as the donor. The filter mating assays were performed as previously described (Huang J. et al, 2016;Huang K. et al, 2016). The cultured donor and recipient strains, at an OD 600 of 0.4–0.6, were mixed at a ratio of 1:5.…”