title: Characterisation of fluoroquinolone-resistant clinical isolates of Streptococcus pyogenes in Barcelona, Spain.
abstract: Resistance mechanisms and clonal relationships were determined for six Streptococcus pyogenes isolates with low- or high-level ciprofloxacin resistance. Four isolates displayed reduced susceptibility to ciprofloxacin and levofloxacin and had alterations in ParC: Ser80-->Pro (isolate emm3.1); Ser79-->Ala (two isolates emm6.0); and a double substitution Ser79-->Phe and Ala121-->Val (isolate emm12.27). Two isolates (emm12.26) displayed high-level resistance to ciprofloxacin and levofloxacin, as well as to other quinolones. These isolates had the same double substitution in ParC as isolate emm12.27, and an additional substitution (Ser81-->Tyr) in GyrA. Resistance patterns, emm typing and sequencing of the quinolone resistance-determining regions defined two clusters containing three and two isolates, respectively.
authors.affiliation: Servei de Microbiologia, Hospital de la Santa Creu i Sant Pau, and Unitat de Microbiologia, Departament de Genètica i Microbiologia, Universitat Autònoma de Barcelona, Barcelona, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Rivera
authors.forename: M
authors.initials: M
authors.lastname: Rebollo
authors.forename: F
authors.initials: F
authors.lastname: Sánchez
authors.forename: F
authors.initials: F
authors.lastname: Navarro
authors.forename: E
authors.initials: E
authors.lastname: Miró
authors.forename: B
authors.initials: B
authors.lastname: Mirelis
authors.forename: P
authors.initials: P
authors.lastname: Coll
mesh_terms: D019943:Amino Acid Substitution; D000890:Anti-Infective Agents / Q000494:pharmacology*; D000942:Antigens, Bacterial / Q000235:genetics; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics; D002352:Carrier Proteins / Q000235:genetics; D002939:Ciprofloxacin / Q000494:pharmacology*; D027101:DNA Topoisomerase IV / Q000235:genetics; D024901:Drug Resistance, Multiple, Bacterial; D006801:Humans; D064704:Levofloxacin; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D015242:Ofloxacin / Q000494:pharmacology*; D013030:Spain / Q000453:epidemiology; D013290:Streptococcal Infections / Q000453:epidemiology*; D013297:Streptococcus pyogenes / Q000187:drug effects / Q000235:genetics*
chemical_list: D000890:Anti-Infective Agents; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D002352:Carrier Proteins; C014689:streptococcal M protein; D002939:Ciprofloxacin; D064704:Levofloxacin; D015242:Ofloxacin; D027101:DNA Topoisomerase IV