Original Article

Group A Streptococcus: Another Resistant Pathogen

Authors: Robin LaCroix, MD, Anna Kathryn Rye, MD

Abstract

Objectives: 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.


Key Points


Streptococcus pyogenes has increasing resistance to macrolides.


* Use of azalides and macrolides may be a factor in increasing resistance.


* Geographic variations of Streptococcus pyogenes resistance have been well described in the medical literature.

This content is limited to qualifying members.

Existing members, please login first.

If you have an existing account please login now to access this article or view your purchase options.

Purchase only this article ($15)

Create a free account, then purchase this article to download or access it online for 24 hours.

Purchase an SMJ online subscription ($75)

Create a free account, then purchase a subscription to get complete access to all articles for a full year.

Purchase a membership plan (fees vary)

Premium members can access all articles plus recieve many more benefits. View all membership plans and benefit packages.

References

1. Casey JR, Pichichero ME. Meta-analysis of cephalosporin versus penicillin treatment of Group A streptococcal tonsillopharyngitis in children. Pediatrics 2004;113:866–882.
 
2. Syrogiannopopoulos GA, Grivea IN, Fitoussi F, et al. High prevalence of erythromycin resistance of Streptococcus pyogenes in Greek children. Pediatr Infect Dis J 2001;20:863–868.
 
3. Seppala H, Nissinen A, Jarvinen H, et al. Resistance to erythromycin in Group A streptococci. N Engl J Med 1992;326:292–297.
 
4. De Azavedo JC, Yeung RH, Bast DJ, et al. Prevalence and mechanisms of macrolide resistance in clinical isolates of Group A streptococci from Ontario, Canada. Antimicrob Agents Chemother 1999;43:2144–2147.
 
5. Cizman M, Pokorn M, Seme K, et al. The relationship between trends in macrolide use and resistance to macrolides of common respiratory pathogens. J Antimicrob Chemother 2001;47:475–477.
 
6. Martin JM, Green M, Barbadora KA, et al. Erythromycin-resistant group A streptococci in school children in Pittsburgh. N Engl J Med 2002;346:1200–1206.
 
7. Fujita K, Murono K, Yoshikawa M, et al. Decline of erythromycin resistance of Group A streptococci in Japan. Pediatr Infect Dis J 1994;13:1075–1078.
 
8. Seppala H, Klaukka T, Lehtonin R, et al. Outpatient use of erythromycin: link to increased erythromycin resistance in Group A streptococci. Clin Infect Dis 1995;21:1378–1385.
 
9. Seppala H, Klaukka T, Vuopio-Varkila J, et al. The effects of changes in the consumption of macrolide antibiotics on erythromycin resistance in Group A streptococci in Finland: a Finnish study group for antimicrobial resistance. N Engl J Med 1997;337:441–446.