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Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria
14:04

Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria

Published on: May 8, 2013

Linezolid-resistant Staphylococcus aureus isolated from 2006 through 2008 at six hospitals in Japan

Yurika Ikeda-Dantsuji1, Hideaki Hanaki, Fuminori Sakai

  • 1Research Center for Anti-Infectious Drugs, Kitasato Institute for Life Sciences, Kitasato University, Tokyo, Japan.

Journal of Infection and Chemotherapy : Official Journal of the Japan Society of Chemotherapy
|July 8, 2010
PubMed

Insights

Linezolid resistance in methicillin-resistant Staphylococcus aureus (MRSA) emerged in Japan. Mutations in 23S ribosomal RNA genes correlated with resistance levels, suggesting potential nosocomial spread.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Genetics

Background:

  • Linezolid is an important antibiotic for treating infections caused by Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA).
  • Limited use of linezolid for MRSA infections was approved in Japan in 2006.
  • Monitoring the emergence of antibiotic resistance is crucial for effective treatment strategies.

Purpose of the Study:

  • To investigate the status and genetic basis of linezolid-resistant MRSA in Japan.
  • To determine the correlation between specific mutations and the level of linezolid resistance.
  • To assess the clonal diversity and potential transmission routes of linezolid-resistant MRSA.

Main Methods:

  • Collection and characterization of 11 linezolid-resistant MRSA clinical isolates from Japanese hospitals (2006-2008).
  • Determination of minimal inhibitory concentrations (MICs) for linezolid.
  • Analysis of mutations in the 23S ribosomal RNA (rRNA) genes using polymerase chain reaction (PCR).
  • Pulsed-field gel electrophoresis (PFGE) for clonal typing.

Main Results:

  • All 11 strains exhibited linezolid resistance with MICs ranging from 8 to 64 μg/ml.
  • A G2576T mutation in the 23S rRNA genes was present in all resistant strains.
  • The level of linezolid resistance correlated with the number of mutated 23S rRNA gene copies.
  • Seven distinct clones were identified among the 11 isolates, indicating potential transmission.
  • Some resistant strains were found in patients with no prior linezolid exposure, suggesting possible nosocomial spread.

Conclusions:

  • The emergence of linezolid-resistant MRSA in Japan is confirmed.
  • The G2576T mutation in 23S rRNA genes is a key mechanism conferring linezolid resistance.
  • The number of mutated rRNA genes influences the degree of resistance.
  • Linezolid-resistant MRSA may spread within healthcare settings, necessitating vigilant surveillance and infection control measures.

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