title: Identification and characterization of plasmid-borne erm(T) macrolide resistance in group B and group A Streptococcus.
abstract: One hundred and seven group B Streptococcus (GBS) isolates and 344 group A Streptococcus (GAS) isolates were collected between 2005 and 2009 from 2 area hospitals and studied for resistance to erythromycin (ERY) and clindamycin (CLI) and the presence of the erm(T) macrolide resistance gene. The erm(T) gene was found in 5 (8%) of 61 erythromycin nonsusceptible GBS isolates and in 22 (55%) of 40 erythromycin nonsusceptible GAS isolates. The erm(T) gene in all 27 GBS/GAS erm(T) gene-positive isolates was located on a plasmid. Three erm(T) gene-positive plasmids were DNA sequenced. Two plasmids (1 each from GBS and GAS isolates) were both 4967 bp in size, contained the erm(T) gene, and differed by only 2 base pairs, suggesting interspecies horizontal transfer of the erm(T) gene containing plasmid. The third (GBS) plasmid was 6825 bp in size and contained GBSi1, a group II bacterial intron, as well as the erm(T) gene. Pulsed-field gel electrophoresis of all 27 erm(T) gene containing isolates and a selection of erm(T) gene-negative isolates indicated possible clonal expansion among erm(T) gene containing GAS isolates, but not among the 5 erm(T) gene-positive GBS isolates.
authors: Department of Pathology and Laboratory Medicine, Summa Health System, Akron, OH 44304, USA. dipersil@summahealth.org
authors: Linda P
authors: LP
authors: DiPersio
authors: Joseph R
authors: JR
authors: DiPersio
authors: Jacqueline A
authors: JA
authors: Beach
authors: Andrew M
authors: AM
authors: Loudon
authors: Ashley M
authors: AM
authors: Fuchs
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D024881:Drug Resistance, Bacterial / Q000235:genetics; D023061:Gene Order; D006801:Humans; D018942:Macrolides / Q000494:pharmacology*; D008780:Methyltransferases / Q000235:genetics*; D008826:Microbial Sensitivity Tests; D010957:Plasmids; D013290:Streptococcal Infections / Q000382:microbiology; D013292:Streptococcus agalactiae / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D013297:Streptococcus pyogenes / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D018942:Macrolides; C111078:ErmTR protein, bacteria; D008780:Methyltransferases