BMC Microbiology (Jan 2012)

Dominance of multidrug resistant CC271 clones in macrolide-resistant <it>streptococcus pneumoniae </it>in Arizona

  • Bowers Jolene R,
  • Driebe Elizabeth M,
  • Nibecker Jennifer L,
  • Wojack Bette R,
  • Sarovich Derek S,
  • Wong Ada H,
  • Brzoska Pius M,
  • Hubert Nathaniel,
  • Knadler Andrew,
  • Watson Lindsey M,
  • Wagner David M,
  • Furtado Manohar R,
  • Saubolle Michael,
  • Engelthaler David M,
  • Keim Paul S

DOI
https://doi.org/10.1186/1471-2180-12-12
Journal volume & issue
Vol. 12, no. 1
p. 12

Abstract

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Abstract Background Rates of resistance to macrolide antibiotics in Streptococcus pneumoniae are rising around the world due to the spread of mobile genetic elements harboring mef(E) and erm(B) genes and post-vaccine clonal expansion of strains that carry them. Results Characterization of 592 clinical isolates collected in Arizona over a 10 year period shows 23.6% are macrolide resistant. The largest portion of the macrolide-resistant population, 52%, is dual mef(E)/erm(B)-positive. All dual-positive isolates are multidrug-resistant clonal lineages of Taiwan19F-14, mostly multilocus sequence type 320, carrying the recently described transposon Tn2010. The remainder of the macrolide resistant S. pneumoniae collection includes 31% mef(E)-positive, and 9% erm(B)-positive strains. Conclusions The dual-positive, multidrug-resistant S. pneumoniae clones have likely expanded by switching to non-vaccine serotypes after the heptavalent pneumococcal conjugate vaccine release, and their success limits therapy options. This upsurge could have a considerable clinical impact in Arizona.