Molecular analysis of Streptococcus pyogenes macrolide resistance of paediatric isolates during a 7 year period (2007-13)

• Published in: Journal of antimicrobial chemotherapy Vol. 71; no. 8; pp. 2113 - 2117
• Main Authors: Michos, Athanasios, Koutouzi, Foteini I, Tsakris, Athanasios, Chatzichristou, Panagiota, Koutouzis, Emmanouil I, Daikos, George L, Stathi, Angeliki, Syriopoulou, Vassiliki P
• Format: Journal Article
• Language: English
• Published: England 01.08.2016
• Subjects: Anti-Bacterial Agents - pharmacology; Antigens, Bacterial - genetics; Bacterial Outer Membrane Proteins - genetics; Carrier Proteins - genetics; Child; Child, Preschool; Drug Resistance, Bacterial; Female; Genes, Bacterial; Genotype; Greece - epidemiology; Humans; Macrolides - pharmacology; Male; Microbial Sensitivity Tests; Prevalence; Streptococcal Infections - epidemiology; Streptococcal Infections - microbiology; Streptococcus pyogenes - classification; Streptococcus pyogenes - drug effects; Streptococcus pyogenes - genetics; Streptococcus pyogenes - isolation & purification
• ISSN: 0305-7453; 1460-2091
• DOI: 10.1093/jac/dkw116

The molecular characterization of paediatric group A Streptococcus (GAS) isolates regarding macrolide resistance and relevant emm types in Athens, Greece. Pharyngeal and non-pharyngeal GAS isolates were collected during a 7 year period (2007-13) and examined for antibiotic susceptibility, macrolide resistance genes [mef(A), erm(A) and erm(B)] and relevant emm types. Overall, 20.4% (270/1324) of GAS isolates were resistant to macrolides. The macrolide resistance rate varied during the study period with a maximum rate observed in 2008 (29.57%) and a minimum rate observed in 2013 (10.95%) (P value for trend = 0.007). During the same period, consumption of macrolides was gradually reduced by 56.6%. No difference was observed in macrolide resistance between pharyngeal and non-pharyngeal isolates (P = 0.7). Among macrolide-resistant isolates, mef(A) was detected in 87 (32.2%), erm(A) in 136 (50.4%), erm(B) in 44 (16.3%) and both mef(A) and erm(A) in 3 (1.1%) isolates. The most prevalent emm types among macrolide-resistant isolates were emm77 (31.5%), emm4 (18.1%) and emm12 (10.7%). Ten emm types (77, 4, 12, 28, 1, 22, 11, 2, 44 and 89) accounted for 90.3% of macrolide-resistant isolates. emm types 4, 22, 44 and 77 were more prevalent in macrolide-resistant compared with macrolide-susceptible isolates, whereas emm types 1, 3, 5, 6, 75 and 89 were more prevalent in macrolide-susceptible compared with macrolide-resistant isolates. GAS macrolide resistance remained significant in our area during the study period. A substantial decline in the resistance rate was observed in the last year of the study, which may be related to reduced consumption of macrolides.