ABSTRACT
Macrolide-resistance was assessed in 216 consecutive Streptococcus pyogenes isolates from throat infections in the region of Aachen, Germany. Seventeen isolates were resistant to erythromycin: 12 isolates revealed a macrolide (M) phenotype and harbored mefA, and five strains expressed an inducible macrolide-lincosamide-streptogramin B (MLSB) phenotype of which four strains harbored ermA(TR) and one strain contained ermB(AM). Telithromycin (HMR 3647) and quinupristin/dalfopristin remained active particularly against the ermA(TR)-containing S. pyogenes isolates studied. Random amplified polymorphic DNA analysis identified multiple clones among erythromycin-resistant strains, but did not discriminate beyond the emm-type. mefA was present in three isolates either with emm2, emm12, or emm75, and in nine isolates with emm4. All four strains with ermA(TR) contained emm77, and the single strain with ermB(AM) harbored emm1. Despite the relative low rate of macrolide-resistance, these data suggest that at least three different macrolide-resistance determinants are prevalent in Germany and that mefA has spread rapidly into multiple clones of S. pyogenes.
Subject(s)
Anti-Bacterial Agents/pharmacology , Ketolides , Macrolides , Pharynx/microbiology , Respiratory Tract Infections/epidemiology , Respiratory Tract Infections/microbiology , Streptococcal Infections/epidemiology , Streptococcal Infections/microbiology , Streptococcus pyogenes/drug effects , Virginiamycin/analogs & derivatives , Drug Resistance , Erythromycin/pharmacology , Genotype , Germany/epidemiology , Microbial Sensitivity Tests , Phenotype , Polymorphism, Restriction Fragment Length , Regulon/genetics , Reverse Transcriptase Polymerase Chain Reaction , Streptococcus pyogenes/isolation & purification , Streptogramins/pharmacology , Virginiamycin/pharmacologyABSTRACT
BACKGROUND: Changes in the epidemiology of Streptococcus pyogenes infections may be associated with the introduction and reappearance of individual serotypes within a population. MATERIALS AND METHODS: Typing of 216 consecutive isolates of S. pyogenes from patients with pharyngitis in the region of Aachen, Germany, was performed by sequencing the emm gene, slide-agglutination of the T-antigen and determining the serum opacity reaction (SOR). RESULTS: All 216 isolates were unequivocally emm-typable. emm1 was most common (18.5%), foLlowed by emm12 (15.7%), emm3 (14.4%) and emm28 (13.9%). Only four isolates contained newly validated emm types: emm89 or emm94 were harbored by two isolates each. In one isolate, the sequence type s104 was found. CONCLUSION: Despite an anticipated selective pressure, the prevalence of emm1 among isolates from throat infections in northwestern Germany remains high, but does not reflect the predominance of emm1 among invasive isolates in Germany.
