Fluoroquinolone Resistance among<i>Streptococcus pneumoniae</i>in Hong Kong Linked to the Spanish 23F Clone

Abstract

Serotypes 6A/B, 19F, and 23F accounted for 73% of 140 mucosal isolates of Streptococcus pneumoniae from Hong Kong. In pulsed-field gel electrophoresis analysis, a group of related patterns was shared by 14 of 15 ciprofloxacin-resistant and 12 of 16 ciprofloxacin-susceptible isolates. These strains exhibited capsular switching and were highly similar to the Spanish 23F clone.