Macrolide-resistant Streptococcus pneumoniae clinical isolates that occur in Hokkaido prefecture, Japan.
We examined the macrolide susceptibility and the presence of macrolide-resistance genes in 780 Streptococcus pneumoniae strains that were isolated and collected at trunk hospitals and commercial clinical laboratories in Hokkaido prefecture, Japan, between 1999 and 2003. Of the 780 strains, 57.0% and 49.6% were found to bear the macrolide-resistance genes erm(B) and mef(A), respectively, while 87.9% had either or both of these genes. The mef(A)-positive strains were more frequently found in patients who were younger than 10 years (43.4%) compared to patients who were 10 years or older (30.3%), whereas the erm(B)-positive strains were similarly frequent in both groups (57.2% vs 54.9%). Strains that were extremely resistant to erythromycin (> or = 256 microg/ml) were frequently found in strains isolated at trunk hospitals but were rarely found in strains that had been collected at commercial clinical laboratories. In conclusion, the high frequency of emergence of macrolide resistance in S. pneumoniae strains was similar to reports from other areas of Japan and other east Asian countries. However, the distribution of resistant genes to macrolides and the distribution of the minimum inhibitory concentrations (MICs) differed depending on patients' ages and depending on whether the strains were isolated at trunk hospitals or commercial clinical laboratories.
Yokota
Shin-ichi
S
Department of Microbiology, Sapporo Medical University School of Medicine, Chuo-ku, Sapporo, 060-8556, Japan.
Sato
Kiyoshi
K
Yoshida
Shigeru
S
Hayashi
Tasuku
T
Matsuda
Keiko
K
Kuwahara
Osamu
O
Habadera
Satoshi
S
Kobayashi
Kazuhiko
K
Ueno
Ryo
R
Akizawa
Hirotsugu
H
Fujii
Nobuhiro
N
D000293:Adolescent; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007564:Japan / Q000453:epidemiology; D018942:Macrolides / Q000494:pharmacology*; D008565:Membrane Proteins / Q000235:genetics; D008780:Methyltransferases / Q000235:genetics; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D011008:Pneumococcal Infections / Q000453:epidemiology / Q000382:microbiology; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D018942:Macrolides; C117866:MefA protein, Streptococcus; D008565:Membrane Proteins; D008780:Methyltransferases; C035181:rRNA (adenosine-O-2'-)methyltransferase