High prevalence of erythromycin resistance of Streptococcus pyogenes in Greek children.
BACKGROUND
Macrolide resistance among Streptococcus pyogenes strains is increasing in many European countries. Greece was not considered a country with high prevalence of macrolide-resistant S. pyogenes strains, and until now the genetic mechanism of resistance was unknown.


METHODS
During the 25-month period from December, 1998, to December, 2000, pharyngeal cultures for S. pyogenes were performed on 743 Greek children with the clinical diagnosis of pharyngitis. The children were 1 to 16 years old (median age, 7 years) and were living in Central and Southern Greece. S. pyogenes isolates were tested for their susceptibility to erythromycin, clarithromycin, azithromycin, clindamycin, penicillin G, amoxicillin/clavulanate and cefprozil. The erythromycin-resistant isolates were further studied for their genetic mechanism of resistance by means of PCR.


RESULTS
Of a total of 275 S. pyogenes isolates recovered, 105 (38%) were erythromycin-resistant (MIC > or = 1 microgram/ml) [corrected], with 54, 45 and 1% of them carrying mef(A), erm(A) [subclass erm(TR)] and erm(B) gene, respectively. The prevalence of erythromycin-resistant strains was 29 and 42% during the time periods December, 1998, to December, 1999, and January, 2000, to December, 2000, respectively. All erythromycin-resistant isolates were also resistant to clarithromycin and azithromycin. The isolates carrying the erm(A) gene were inducibly resistant to clindamycin. The 275 S. pyogenes isolates had ceprozil MICs < or = 0.032 microgram/ml.


CONCLUSIONS
The current high (38%) prevalence of erythromycin-resistant S. pyogenes in Central and Southern Greece requires continuous surveillance and careful antibiotic policy.
Syrogiannopoulos
G A
GA
Department of Pediatrics, Division of Infectious Disease, University of Patras, School of Medicine, 265 00 Rion, Patras, Greece. syrogian@med.upatras.gr
Grivea
I N
IN
Fitoussi
F
F
Doit
C
C
Katopodis
G D
GD
Bingen
E
E
Beratis
N G
NG
D000293:Adolescent; D017677:Age Distribution; D016009:Chi-Square Distribution; D002648:Child; D002675:Child, Preschool; D024881:Drug Resistance, Bacterial; D004917:Erythromycin / Q000494:pharmacology*; D005260:Female; D006115:Greece / Q000453:epidemiology; D006801:Humans; D007223:Infant; D008297:Male; D008826:Microbial Sensitivity Tests; D010612:Pharyngitis / Q000453:epidemiology* / Q000382:microbiology; D015995:Prevalence; D011336:Probability; D012189:Retrospective Studies; D012307:Risk Factors; D017678:Sex Distribution; D013290:Streptococcal Infections / Q000175:diagnosis / Q000453:epidemiology*; D013297:Streptococcus pyogenes / Q000187:drug effects* / Q000302:isolation & purification
D004917:Erythromycin