Circulation of international clones of levofloxacin non-susceptible Streptococcus pneumoniae in Taiwan

Y. C. Hsieh, L. Y. Chang, Y. C. Huang, H. C. Lin, L. M. Huang, P. R. Hsueh*

*Corresponding author for this work

Research output: Contribution to journalJournal Article peer-review

16 Scopus citations


Levofloxacin susceptibility testing was carried out for a total of 2539 Streptococcus pneumoniae isolates obtained from January 2001 to February 2008 at the National Taiwan University Hospital (NTUH) and a further 228 pneumococcal isolates obtained from January 2004 to December 2006 at three other hospitals in different geographical areas in Taiwan. Levofloxacin non-susceptible S. pneumoniae isolates were subsequently analysed for serotype and molecular epidemiology. Rates of levofloxacin non-susceptibility of S. pneumoniae increased significantly from 1.2% in 2001 to 4.2% in 2007 at NTUH. A total of 30 isolates of levofloxacin non-susceptible S. pneumoniae isolates (MIC ≥ 4 mg/L) were available for evaluation of serotype, antimicrobial susceptibility, nucleotide sequence of the quinolone resistance-determining regions of parC, gyrA, parE and gyrB, reserpine effect on quinolone susceptibility and multilocus sequence type. Among these isolates, seven (23.3%) were from children, and two (6.7%; one from a 3- and one from a 93-year-old patient) were from blood. One levofloxacin-resistant isolate (MIC = 8 mg/L) was recovered from a previously healthy child with bacteraemic necrotizing pneumonia complicated by empyema and a haemolytic-uraemic syndrome. All isolates except two had Ser79 and/or Asp83 changes in ParC, and/or Ser81 or Glu85 changes in GyrA. An efflux phenotype concerning levofloxacin was detected in only one (3.3%) isolate. A novel clone (ST3642), genetically related to Spain9V-3 and belonging to serotype 11A, was identified. Dissemination of clonal complexes related to Spain23F-1, Taiwan19F-14, Spain9V-3 and Taiwan23F-15 has contributed to levofloxacin non-susceptibility among these S. pneumoniae isolates from Taiwan.

Original languageEnglish
Pages (from-to)973-978
Number of pages6
JournalClinical Microbiology and Infection
Issue number7
StatePublished - 07 2010
Externally publishedYes


  • Clonal spread
  • Levofloxacin-non-susceptible
  • Streptococcus pneumoniae
  • Taiwan


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