mef(A), mef(E) and a new mef allele in macrolide-resistant Streptococcus spp. isolates from Norway

• Published in: Journal of antimicrobial chemotherapy Vol. 56; no. 5; pp. 841 - 846
• Main Authors: Sangvik, Maria, Littauer, Pia, Simonsen, Gunnar Skov, Sundsfjord, Arnfinn, Dahl, Kristin Hegstad
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01-11-2005; Oxford Publishing Limited (England)
• Subjects: Amino Acid Sequence; Anti-Bacterial Agents - pharmacology; Antibiotics. Antiinfectious agents. Antiparasitic agents; Bacterial Proteins - genetics; Biological and medical sciences; Carrier State - microbiology; Deoxyribonuclease BamHI - metabolism; DNA, Bacterial - genetics; DNA, Bacterial - metabolism; Drug Resistance, Bacterial - genetics; erythromycin; Humans; Hydrophobic and Hydrophilic Interactions; M-type resistance; macrolide efflux; Macrolides - pharmacology; Major Facilitator Superfamily; Medical sciences; Membrane Proteins - genetics; Microbial Sensitivity Tests; Molecular Epidemiology; Molecular Sequence Data; Norway; Pharmacology. Drug treatments; Polymerase Chain Reaction; Sequence Analysis, DNA; Sequence Homology, Amino Acid; Streptococcal Infections - microbiology; Streptococcus - drug effects; Streptococcus - genetics; Streptococcus - isolation & purification; Streptococcus pneumoniae; Streptococcus pneumoniae - drug effects; Streptococcus pneumoniae - genetics; Streptococcus pneumoniae - isolation & purification; Streptococcus pyogenes; Streptococcus pyogenes - drug effects; Streptococcus pyogenes - genetics; Streptococcus pyogenes - isolation & purification; Viridans Streptococci - drug effects; Viridans Streptococci - genetics; Viridans Streptococci - isolation & purification; Norway; Europe; Erythromycin; Macrolide; M-type resistance; Infection; Resistance; Major Facilitator Superfamily; Streptococcaceae; Allele; Antibiotic; Streptococcus; Streptococcal infection; Bacteriosis; Bacteria; Micrococcales; Genetics; Isolate; Antibacterial agent; macrolide efflux
• ISSN: 0305-7453; 1460-2091
• DOI: 10.1093/jac/dki327

Objectives: To type mef genes in a nationwide collection of clinical isolates of Streptococcus pneumoniae and Streptococcus pyogenes as well as pharyngeal carrier strains of viridans streptococci in Norway. Methods: Erythromycin-resistant mef-positive multilocus sequence-typed (MLST) clinical isolates of S. pneumoniae (n = 36) and S. pyogenes (n = 12) from the National Surveillance Program for Antimicrobial Resistance (NORM) as well as viridans streptococci (n = 20) from healthy adults were included. PCR-amplified mef genes were initially discriminated by BamHI digestion. Selected mef genes from representatives of different sequence types (STs) of S. pneumoniae (n = 11) and S. pyogenes (n = 4), and viridans group streptococcal species (n = 8) were typed by sequencing and their strains examined for co-resistances. Hydropathy plots of different mef-encoded proteins were performed. Results: A predominance of mef(A) was detected in S. pneumoniae (23/36) and S. pyogenes (9/12) due to the clonal spread of ST9 and ST39, respectively. mef(E) was the most widely distributed mef determinant occurring in nine different STs of S. pneumoniae and in four different viridans species. A new mef allele was identified in two STs of S. pyogenes. Conclusions: mef(E) is the most widely distributed mef determinant in Norwegian clinical strains of S. pneumoniae and pharyngeal carrier strains of various viridans streptococci. However, mef(A) is more prevalent in S. pneumoniae and S. pyogenes due to clonal spread. A new mef allele was found in two different STs of S. pyogenes.