Open AccessChanges in epidemiologic characteristics and antimicrobial resistance of Streptococcus pyogenes isolated over 10 years from Japanese children with pharyngotonsillitis
Author(s) -
Kimiko Ubukata,
Takeaki Wajima,
Miyuki Morozumi,
Megumi Sakuma,
Tsuyoshi Tajima,
Keita Matsubara,
Koju Itahashi,
Satoshi Iwata
Publication year - 2020
Publication title -
journal of medical microbiology/journal of medical microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.91
H-Index - 117
eISSN - 1473-5644
pISSN - 0022-2615
DOI - 10.1099/jmm.0.001158
Subject(s) - streptococcus pyogenes , multilocus sequence typing , antibiotics , microbiology and biotechnology , cephalosporin , biology , streptococcus pneumoniae , antibiotic resistance , streptococcus , antimicrobial , typing , medicine , bacteria , genotype , gene , staphylococcus aureus , genetics
. Pharyngotonsillitis caused by Streptococcus pyogenes (group A streptococci, or GAS) is among the most common infections treated with antibiotics in pediatric patients. Aim. This study aimed to analyse changes in molecular epidemiology and antibiotic susceptibility among GAS isolates in three study periods spanning 10 years. Methodology . GAS isolated from paediatric patients with pharyngotonsillitis during Period I (mid-2007 to 2008, n =235), Period II (2012, n =210), and Period III (2018, n =189) were analysed for emm type, multilocus sequence type (MLST), antibiotic susceptibility, and macrolide (ML)- and quinolone (QL)-resistance genes. Results. Over 20 % of isolates represented emm 1 and emm 12 types, remaining common in all three periods. Among other emm types, emm 4 was common in Period I, emm 28 and emm 89 in Period II, and emm 3 and emm 89 in Period III. All isolates remained highly susceptible to penicillins and cephalosporins. Isolates possessing mefA, ermA, or ermB genes mediating ML resistance increased from 34.9 % in Period I to 60.9 % in Period II, but fell to 27.5 % in Period III. QL-resistant isolates with amino acid substitutions affecting ParC and/or GyrA gradually increased from 11.5 to 14.3 %. Specific sequence types identified by MLST and emm typing were associated closely with ML or QL resistance. Conclusion. Our findings indicate that even in ambulatory care, antibiotic choice for these infections should be based on rapid identification and characterization of causative pathogens.