Group A Streptococcus: another resistant pathogen.
OBJECTIVE
In Greenville, South Carolina in 1992, erythromycin resistance in GAS was less than 5%, and there were no fully resistant strains. With a large increase in macrolide and azalide usage within the Greenville area, we again examined susceptibility patterns of pharyngeal GAS isolates in 2002 to 2003.


METHODS
Community pediatric offices supplied 106 GAS isolates for study. Screening for macrolide resistance was done via Kirby-Bauer disk diffusion testing. Zones of inhibition from 16 to 20 mm were interpreted as intermediately resistant, and those 15 mm or less were interpreted as resistant per National Committee for Clinical Laboratory Standards guidelines.


RESULTS
A total of 106 GAS isolates were tested; 0.9% of isolates were intermediately resistant to erythromycin and 11% were fully resistant.


CONCLUSIONS
The rate of erythromycin resistance among GAS isolates has increased in the past 10 years in the Greenville community. This pattern has paralleled the increased utilization of macrolides in the same community. Continued monitoring of resistance rates will be needed to alert practitioners of possible treatment failures due to macrolide resistance.
LaCroix
Robin
R
Greenville Hospital System, University Medical Group, Children's Hospital, Greenville, SC 29615, USA. RLaCroix@ghs.org
Rye
Anna Kathryn
AK
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial; D004917:Erythromycin / Q000494:pharmacology*; D006801:Humans; D018942:Macrolides / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D013022:South Carolina; D013290:Streptococcal Infections / Q000382:microbiology; D013297:Streptococcus pyogenes / Q000187:drug effects*
D000900:Anti-Bacterial Agents; D018942:Macrolides; D004917:Erythromycin