Alonso Rodrigo, Mateo Estibaliz, Ezpeleta Guillermo, Cisterna Ramón
Departamento de Inmunología, Microbiología y Parasitología, Facultad de Farmacia, Universidad del País Vasco, Paseo de la Universidad 7, 01006 Vitoria-Gasteiz, Spain.
Int J Antimicrob Agents. 2007 Aug;30(2):183-5. doi: 10.1016/j.ijantimicag.2007.04.001. Epub 2007 May 31.
The resistance mechanisms and clonal relationship were determined for two Streptococcus pyogenes isolates with high-level resistance to levofloxacin as well as to other fluoroquinolones. DNA amplification and sequencing revealed a serine-81-->phenylalanine substitution in GyrA and a double substitution in ParC of serine-79-->phenylalanine and aspartic acid-91-->asparagine. Pulsed-field gel electrophoresis analysis and emm typing determined that both isolates were emm type 28 and were genetically indistinguishable.