# Dissemination of Enterococcuscal Genetic Lineages: A One Health Perspective
## 4 Enterococcal Genetic Traits: Dissemination in the One Health Continuum
### Human Healthcare-Associated Genetic Traits
For instance, CC2 is characterized by the presence of the _aac (6')-aph(2'')_ gene for high-level gentamicin resistance, encoded by _Tn5281_[62; 74], _vanB_-type resistance or vancomycin-susceptibility, high-level resistance to \(\beta\)-lactams due to \(\beta\)-lactamase production (conferred by the _blaZ_ gene), and resistance to erythromycinycin by the occurrence of the _ermB_ gene [59; 61; 75]. Additionally, some studies [62; 76; 77] in Asia detected at least two virulence genes in CC2 and CC87, including _esp_, _gelE_, _cyLA_, _asal_, _ace_, and _hyl_. Although _E. faecalis_ CC87 from Poland is not distributed worldwide, as is also the case for CC2 or CC9, these three complexes share several virulence and antibiotic resistance determinants, as illustrated in Table 2. However, a remarkable characteristic of CC87 is the exclusive dissemination of certain MGEs, such as repUS1 pVEF1 plasmids, which carry _vanA_ resistance in Polish hospitals [78]. Compared with CC2, the other globally disseminated _E. faecalis_ healthcare-associated complex, CC9, has not been so well described in the literature, in terms of phenotypic and genotypic features. However, virulence and antimicrobial resistance traits, in common with CC2, have been identified [29; 61; 64]. Furthermore, in _E. faecalis_ a wide range of plasmids and transposons are involved in the genetic transmission of resistance and virulence, which may promote the prevalence and dissemination of CC2 and CC9 in healthcare settings [29; 79]. Nonetheless, these healthcare-associated clones are not only disseminated in hospitals, but also in the community and in animals, especially CC2 [56]. Regarding _E. facetum_, some specific clones have rapidly developed multiple AMR since the 1990s, which allowed adaptation and spread in healthcare environments [65]. Clinical-derived _E. facetum_ forms a polyclonal subpopulation of different CCs assembled in clade A, which have separately developed from several ancestral clones, namely MLST sequence type 17 (ST17), ST18, ST78, ST192, and ST203 [17; 37; 80]. _E. facetum_ CC17 or clade A1 have been found in at least five continents, carrying ampicillin, vancomycin, high-level quinolone resistance, and the presence of an accessory genome that contains putative virulence genes, namely _esp_ and _hyl_ genes [60; 68; 81; 82]. Moreover, _fms_ genes are also present in CC17 isolates (e.g., _fms8_, _fms9_, and _fms21_), coding for virulence factors such as MSCRAMM-like proteins [69]. For instance, _fms8_ or _acm_ seem \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Species**} & \multirow{2}{*}{**Source**} & \multirow{2}{*}{**Location (Date)**} & \multirow{2}{*}{**Clade**} & \multicolumn{3}{c}{**Clonal lineages**} & \multirow{2}{*}{**Virulence**} & \multirow{2}{*}{**Antimicrobial Resistance Genes**} & \multirow{2}{*}{**Ref.**} \\ \cline{5-5} \cline{7-10}  & & & & **MIST Sequence Type** & & & **Clonal Complex** & \\ \hline \multirow{6}{*}{_E. facetum_} & Healthcare-associated infections & Worldwide (first in the USA) & \multirow{6}{*}{Clade A} & ST17 & \multirow{6}{*}{CC17} & _acm, esp,hyl, fts_ & _unrA, umbB, dfG, trtM, msrC, cmB, aacC-aph2”_ & [37; 65; 66; 67; 68; 69] \\ \cline{5-5} \cline{8-10}  & & & ST18 & & _acm, esp,hyl_ & - & [65; 66; 67; 68; 69] \\ \cline{5-5} \cline{8-10}  & & & ST78 & & _-_ & - & [65; 68] \\ \cline{5-5} \cline{8-10}  & & & ST203 & & _acm, esp_ & _unrA_ & [65; 66; 67; 68; 69] \\ \cline{5-5} \cline{8-10}  & & & ST796 & & _acm, esp_ & _unrA_, umbB, dfG, trtM, msrC, cmB, aacC-aph2”_ & [65; 66; 67; 68; 69] \\ \cline{5-5} \cline{8-10}  & & & ST1421 & & - & _unrA_ & [71] \\ \hline \hline \end{tabular}  
NA—Non-applicable. Information on virulence or antimicrobial resistance genes, associated with each ST, was recovered from the cited reference source, which does not imply that the indicated STs may not harbor other genetic traits.  
\end{table} 
Table 2: _Cont._to contribute to the success of healthcare-associated infections, being related to a higher prevalence of CC17 in hospitals [59].