The genetic relatedness of levofloxacin less susceptible isolates was determined by pulsed field gel electrophoresis (PFGE), QRDR profile and resistance pattern.

• 同时对左氧氟沙星敏感性下降菌株染色体进行PFGE（Pulsed Field Gel Electrophoresis，脉冲场电泳）分型，并结合其耐药谱、QRDR突变模式分析氟喹诺酮类敏感性下降肺炎链球菌的同源性。