title: Emergence of a novel macrolide-resistant Streptococcus pyogenes emm53 strain.
abstract: An unusual emm53, T-28/T-non-typeable, iMLS(B) phenotype clone represented a substantial proportion (28.6%) of invasive erythromycin-resistant group A streptococcus (GAS) isolates in the Czech Republic during 2003. Clonal analysis of emm53 isolates between 2001 and 2004 revealed four pulsed-field gel electrophoresis (PFGE) patterns and two emm subtypes. Isolates produced identical PFGE patterns regardless of their invasiveness and/or tetracycline resistance. Multilocus sequence typing classified all isolates as ST340. An ST5 (emm83) isolate, a potential ancestor of ST340, was isolated in the Czech Republic from an impetigo patient in 1988. The Czech emm53/ST340 isolates shared only three of seven alleles with the original Lancefield emm53/ST11 isolate.
authors.affiliation: National Reference Laboratory (NRL) for Streptococci and Enterococci, National Institute of Public Health, Prague, Czech Republic. lenka.strakova@szu.cz
authors.forename: L
authors.initials: L
authors.lastname: Strakova
authors.forename: J
authors.initials: J
authors.lastname: Motlova
authors.forename: V
authors.initials: V
authors.lastname: Jakubu
authors.forename: P
authors.initials: P
authors.lastname: Urbaskova
authors.forename: P
authors.initials: P
authors.lastname: Kriz
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002648:Child; D002675:Child, Preschool; D024881:Drug Resistance, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D004917:Erythromycin / Q000494:pharmacology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008875:Middle Aged; D013297:Streptococcus pyogenes / Q000145:classification / Q000187:drug effects* / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D004917:Erythromycin