title: Resistance Genes and Genetic Elements Associated with Antibiotic Resistance in Clinical and Commensal Isolates of Streptococcus salivarius.
abstract: The diversity of clinical (n = 92) and oral and digestive commensal (n = 120) isolates of Streptococcus salivarius was analyzed by multilocus sequence typing (MLST). No clustering of clinical or commensal strains can be observed in the phylogenetic tree. Selected strains (92 clinical and 46 commensal strains) were then examined for their susceptibilities to tetracyclines, macrolides, lincosamides, aminoglycosides, and phenicol antibiotics. The presence of resistance genes tet(M), tet(O), erm(A), erm(B), mef(A/E), and catQ and associated genetic elements was investigated by PCR, as was the genetic linkage of resistance genes. High rates of erythromycin and tetracycline resistance were observed among the strains. Clinical strains displayed either the erm(B) (macrolide-lincosamide-streptogramin B [MLSB] phenotype) or mef(A/E) (M phenotype) resistance determinant, whereas almost all the commensal strains harbored the mef(A/E) resistance gene, carried by a macrolide efflux genetic assembly (MEGA) element. A genetic linkage between a macrolide resistance gene and genes of Tn916 was detected in 23 clinical strains and 5 commensal strains, with a predominance of Tn3872 elements (n = 13), followed by Tn6002 (n = 11) and Tn2009 (n = 4) elements. Four strains harboring a mef(A/E) gene were also resistant to chloramphenicol and carried a catQ gene. Sequencing of the genome of one of these strains revealed that these genes colocalized on an IQ-like element, as already described for other viridans group streptococci. ICESt3-related elements were also detected in half of the isolates. This work highlights the potential role of S. salivarius in the spread of antibiotic resistance genes both in the oral sphere and in the gut.
authors: INRA, UMR1128 DynAMic, Faculté des Sciences et Technologies, Vandœuvre-lès-Nancy, France; Université de Lorraine, UMR1128 DynAMic, Faculté des Sciences et Technologies, Vandœuvre-lès-Nancy, France.
authors: Fanny
authors: F
authors: Chaffanel
authors: INRA, UMR1128 DynAMic, Faculté des Sciences et Technologies, Vandœuvre-lès-Nancy, France; Université de Lorraine, UMR1128 DynAMic, Faculté des Sciences et Technologies, Vandœuvre-lès-Nancy, France.
authors: Florence
authors: F
authors: Charron-Bourgoin
authors: INRA, UMR1128 DynAMic, Faculté des Sciences et Technologies, Vandœuvre-lès-Nancy, France; Université de Lorraine, UMR1128 DynAMic, Faculté des Sciences et Technologies, Vandœuvre-lès-Nancy, France.
authors: Virginie
authors: V
authors: Libante
authors: INRA, UMR1128 DynAMic, Faculté des Sciences et Technologies, Vandœuvre-lès-Nancy, France; Université de Lorraine, UMR1128 DynAMic, Faculté des Sciences et Technologies, Vandœuvre-lès-Nancy, France.
authors: Nathalie
authors: N
authors: Leblond-Bourget
authors: INRA, UMR1128 DynAMic, Faculté des Sciences et Technologies, Vandœuvre-lès-Nancy, France; Université de Lorraine, UMR1128 DynAMic, Faculté des Sciences et Technologies, Vandœuvre-lès-Nancy, France payot@nancy.inra.fr.
authors: Sophie
authors: S
authors: Payot
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002675:Child, Preschool; D002874:Chromosome Mapping; D024881:Drug Resistance, Bacterial / Q000235:genetics; D005243:Feces / Q000382:microbiology*; D008040:Genetic Linkage; D064368:Healthy Volunteers; D006801:Humans; D007223:Infant; D020071:Interspersed Repetitive Sequences / Q000187:drug effects; D055231:Lincosamides / Q000494:pharmacology; D018942:Macrolides / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D058885:Multilocus Sequence Typing; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012463:Saliva / Q000382:microbiology; D013290:Streptococcal Infections / Q000382:microbiology*; D013291:Streptococcus / Q000145:classification / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D013559:Symbiosis
chemical_list: D000900:Anti-Bacterial Agents; D055231:Lincosamides; D018942:Macrolides