Macrolide-resistance mechanisms in Streptococcus pneumoniae isolates from Belgium.
Of 233 erythromycin-resistant pneumococcal isolates collected in Belgium in 1999-2000, 89.7% carried the erm(B) gene, 6% the mef(A) gene, and 3.5%erm(B) plus mef(A). Two isolates contained neither erm(B) nor mef(A); one contained an erm(A) subclass erm(TR) gene, while the other contained an A2058G mutation in domain V of the 23S rRNA gene. Of 209 erm(B)-positive isolates, 191 had clindamycin MICs > 16 mg/L and 18 had MICs < or = 16 mg/L. Mef(A)-positive isolates all displayed the M resistance phenotype. Telithromycin remained active against erythromycin-resistant isolates, with the highest telithromycin MIC50 being found in mef(A)-positive isolates. No difference in the prevalence of different resistance mechanisms was observed compared to isolates collected in 1995-1997.
Van Eldere
J
J
Department of Microbiology and Immunology, Katholieke Universiteit Leuven, Leuven, Belgium. johan.vaneldere@uz.kuleuven.ac.be
Meekers
E
E
Lagrou
K
K
Massonet
C
C
Canu
A
A
Devenyns
I
I
Verhaegen
J
J
Syrogiannopoulos
G
G
Leclercq
R
R
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics; D001530:Belgium; D002981:Clindamycin / Q000494:pharmacology; D024881:Drug Resistance, Bacterial / Q000235:genetics; D004917:Erythromycin / Q000494:pharmacology; D005798:Genes, Bacterial; D006801:Humans; D048628:Ketolides / Q000494:pharmacology; D018942:Macrolides / Q000494:pharmacology*; D008565:Membrane Proteins / Q000235:genetics; D008780:Methyltransferases / Q000235:genetics; D008826:Microbial Sensitivity Tests; D009154:Mutation; D012338:RNA, Ribosomal, 23S / Q000235:genetics; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D048628:Ketolides; D018942:Macrolides; C117866:MefA protein, Streptococcus; D008565:Membrane Proteins; D012338:RNA, Ribosomal, 23S; D002981:Clindamycin; D004917:Erythromycin; D008780:Methyltransferases; C431709:ErmA protein, Bacteria; C106791:telithromycin