Skip directly to site content Skip directly to page options Skip directly to A-Z link Skip directly to A-Z link Skip directly to A-Z link
Volume 18, Number 9—September 2012

Antimicrobial Drug Use and Macrolide-Resistant Streptococcus pyogenes, Belgium

Liesbet Van Heirstraeten, Samuel Coenen, Christine Lammens, Niel Hens, Herman Goossens, and Surbhi Malhotra-KumarComments to Author 
Author affiliations: University of Antwerp, Antwerp, Belgium (L. Van Heirstraeten, S. Coenen, C. Lammens, N. Hens, H. Goossens, S. Malhotra-Kumar); and University of Hasselt, Hasselt, Belgium (N. Hens)

Main Article


Characteristics of macrolide-resistant Streptococcus pyogenes used in competition experiments and relative fitness* of the erm(A)-emm77 geno-emm-type against competitor strains, Belgium, 1999–2009

Geno-emm-type Macrolide MIC, mg/L
Relative fitness (SD)†
p value, t test
Erythromycin Clindamycin erm(A)-emm77 Competitor
erm(A)-emm77 2 0.125 ND ND ND
erm(B)-emm28 >512 >512 1.03 (0.09) 0.98 (0.09) 0.662
erm(B)-emm22 >512 >512 1.27 (0.15) 0.79 (0.09) 0.080
erm(B)-emm11 >512 256 2.12 (0.28) 0.48 (0.06) 0.013
mef(A)-emm12 8 0.125 1.29 (0.18) 0.78 (0.11) 0.105
mef(A)-emm4 8 <0.03 1.55 (0.15) 0.65 (0.06) 0.047
mef(A)-emm1 16 0.5 1.01 (0.05) 1.00 (0.06) 0.934

*The ability of the bacteria to survive and reproduce. ND, no data.
†Average of duplicate experiments.

Main Article

Page created: August 17, 2012
Page updated: August 17, 2012
Page reviewed: August 17, 2012
The conclusions, findings, and opinions expressed by authors contributing to this journal do not necessarily reflect the official position of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions. Use of trade names is for identification only and does not imply endorsement by any of the groups named above.