The prevalence of erythromycin resistance in group B streptococcal isolates at a University Hospital in Taiwan.
Due to reduced antibiotic consumption in Taiwan, erythromycin resistance rate had decreased in Streptococcus pyogenes, but it increased in Streptococcus pneumoniae. The objectives of the present study were (1) to determine the erythromycin and clindamycin resistance rate and minimum inhibitory concentration (MIC) of the group B streptococcus (GBS) clinical isolates, and (2) to investigate the mechanism responsible for the macrolide, lincosamide, and group B streptogramin (MLS(B)) resistance. A total of 1,395 GBS isolates were collected from June 2001 to April 2007. Forty-four percent of the GBS isolates were resistant to erythromycin, and 39% were resistant to clindamycin. The annual erythromycin resistance rate increased from 32% in 2001 to 51% in 2004; a significant decrease was observed in 2005 (47%), 2006 (42%), and 2007 (38%). Percentage of erythromycin-resistant isolates with erm(B) gene significantly increased from 72% in 2001 to 90% in 2007. We found that the plasmid encoded zeta gene was present in 13% of the resistant isolates, along with erm(B). When compared to our previous study (1991 to May 2001), the overall erythromycin resistance rate increased from 30% to 44%. erm(B) was the major resistant determinant, and zeta toxin encoding plasmid has a limited role in mediating erythromycin resistance unlike in GAS isolates as reported earlier.
Janapatla
Rajendra Prasad
RP
Department of Medical Laboratory Science and Biotechnology, National Cheng Kung University, Tainan, Taiwan.
Ho
Yueh-Ren
YR
Yan
Jing-Jou
JJ
Wu
Hsiu-Mei
HM
Wu
Jiunn-Jong
JJ
D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics; D002981:Clindamycin / Q000494:pharmacology; D024881:Drug Resistance, Bacterial / Q000235:genetics; D004917:Erythromycin / Q000494:pharmacology*; D006785:Hospitals, University; D006801:Humans; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D015995:Prevalence; D013290:Streptococcal Infections / Q000453:epidemiology* / Q000382:microbiology; D013292:Streptococcus agalactiae / Q000187:drug effects* / Q000235:genetics; D013624:Taiwan / Q000453:epidemiology
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D002981:Clindamycin; D004917:Erythromycin