High prevalence of antimicrobial resistance in rapidly growing mycobacteria in Taiwan.
An increasing number of clinical isolations of rapidly growing mycobacteria (RGM) at the National Taiwan University Hospital were noted from 1992 to 2001. Broth microdilution MICs of 15 antimicrobial agents were determined for 200 clinical isolates of RGM, including the Mycobacterium fortuitum group (69 isolates), M. chelonae (39 isolates), and M. abscessus (92 isolates). Our results showed that the resistance rates of these isolates to the currently available agents were remarkably high. Amikacin was active against nearly all RGM isolates. Clarithromycin was usually active against M. abscessus (79% susceptibility) and the M. fortuitum group (65% susceptibility). The majority of M. fortuitum group isolates were susceptible to ciprofloxacin (62%) and imipenem (61%). The susceptibilities to other conventional anti-RGM agents of these isolates were poor but differed markedly by species. The newer fluoroquinolones (levofloxacin, moxifloxacin, and gatifloxacin) and meropenem showed better in vitro activities against the M. fortuitum group isolates than against the other two species of RGM. Linezolid had fairly good activity against these RGM isolates, particularly against M. chelonae isolates (82% susceptible). Telithromycin had poor activity against these RGM isolates (the MICs at which 50% of the isolates tested are inhibited [MIC(50)s] were 32 to 64 microg/ml, and the MIC(90)s were >64 microg/ml).
Yang
Shun-Cheng
SC
Department of Laboratory Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan.
Hsueh
Po-Ren
PR
Lai
Hsin-Chih
HC
Teng
Lee-Jene
LJ
Huang
Li-Min
LM
Chen
Jong-Min
JM
Wang
Shu-Kuan
SK
Shie
Der-Chuen
DC
Ho
Shen-Wu
SW
Luh
Kwen-Tay
KT
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004269:DNA, Bacterial / Q000235:genetics; D024881:Drug Resistance, Bacterial; D006801:Humans; D008826:Microbial Sensitivity Tests; D009164:Mycobacterium Infections / Q000382:microbiology; D016926:Mycobacterium chelonae / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D019907:Mycobacterium fortuitum / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D013624:Taiwan
D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S