Resistance Genes and Genetic Elements Associated with Antibiotic Resistance in Clinical and Commensal Isolates of Streptococcus salivarius.
Appl Environ Microbiol
; 81(12): 4155-63, 2015 Jun 15.
Article
em En
| MEDLINE
| ID: mdl-25862227
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.
Texto completo:
1
Bases de dados:
MEDLINE
Assunto principal:
Infecções Estreptocócicas
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Streptococcus
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Sequências Repetitivas Dispersas
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Farmacorresistência Bacteriana
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Fezes
Tipo de estudo:
Risk_factors_studies
Limite:
Adult
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Child, preschool
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Humans
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Infant
Idioma:
En
Revista:
Appl Environ Microbiol
Ano de publicação:
2015
Tipo de documento:
Article
País de afiliação:
França