Vol.64 No.1 January 2016
Annual change in antibiotic resistance and penicillin-binding-protein genotype of Streptococcus pneumoniae and Haemophilus influenzae isolated from children with respiratory infection between 2001 and 2015
Department of Pediatrics, Asahikawa Kosei Hospital, 1-24, Asahikawa, Hokkaido, Japan
Abstract
We investigated the detection rates of resistant strains of Streptococcus pneumoniae and Haemophilus influenzae among 20 to 35 strains of each species isolated from clinical materials obtained from children with respiratory tract infections who were examined at our hospital during a 1- to 2-month period around every February, spanning the 15 years from 2001 through 2015. The survey was divided into 3 periods, early, middle, and late, and changes were examined. The strains were classified according to their penicillin-binding-protein (PBP) resistance mutation; in addition, S. pneumoniae and H. influenzae strains were classified according to susceptibility to penicillin G and ampicillin, respectively. Among S. pneumoniae strains, penicillin-susceptible S. pneumoniae (PSSP) strains increased (p< 0.001) from the early to the middle period according to the susceptibility classification. There were very few changes according to the resistant gene classification; the PSSP strain which increased according to the susceptibility classification was gPISP with the pbp2x mutation. With regard to H. influenzae strains, beta-lactamase nonproducing ABPC-susceptible strains (BLNAS) decreased (p< 0.001) from the early to the middle period, whereas beta-lactamase-producing ABPC-resistant strains (BLPAR) significantly increased (p< 0.05) from the early to the late period. According to the resistant gene classification, gBLNAS also decreased (p< 0.001) from the early to the middle period, whereas gBLNAR increased (p< 0.001) from the early to the middle period. The BLPAR which increased according to the susceptibility classification was gBLPACR-2.
Our investigation of resistant strains according to drug susceptibility and resistant gene mutation identified major changes in the types and frequencies of resistant strains of S. pneumoniae and H. influenzae during a period of 15 years. Antibiotic susceptibility according to genotype of penicillin-binding-protein and macrolide resistance genes, and serotype of S. pneumoniae isolates from community-acquired pneumonia in children.
Key word
Streptococcus pneumoniae, Haemophilus influenzae, drug-resistance, penicillin-binding-protein, respiratory infection
Received
August 21, 2015
Accepted
October 16, 2015
Jpn. J. Chemother. 64 (1): 76-81, 2016
