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Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria
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Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria

Published on: May 8, 2013

Molecular analysis of methicillin-resistant Staphylococcus aureus reveals an absence of plasmid DNA in

Jonathan M Caddick1, Anthony C Hilton, Jessica Rollason

  • 1Department of Molecular Biosciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK.

FEMS Immunology and Medical Microbiology
|May 24, 2005
PubMed

Insights

Multidrug resistance in hospital-acquired methicillin-resistant Staphylococcus aureus (MR-HA-MRSA) is not linked to increased plasmid DNA. However, plasmids do contribute to antibiotic resistance in non-multidrug-resistant HA-MRSA and community-acquired MRSA.

Area of Science:

  • Microbiology
  • Genetics
  • Infectious Diseases

Background:

  • Methicillin-resistant Staphylococcus aureus (MRSA) is a significant public health concern.
  • Understanding the genetic basis of antibiotic resistance in MRSA is crucial for effective treatment and control.
  • Hospital-acquired (HA-MRSA) and community-acquired (CA-MRSA) strains exhibit varying resistance mechanisms.

Purpose of the Study:

  • To compare plasmid carriage and diversity in different MRSA subtypes.
  • To investigate the relationship between plasmid DNA and multidrug resistance phenotypes.
  • To determine the role of plasmids in antibiotic resistance in HA-MRSA and CA-MRSA isolates.

Main Methods:

  • Analysis of plasmid DNA, SCCmec types, and pulsed-field gel electrophoresis (PFGE) patterns in 164 MRSA isolates.
  • Categorization of isolates into multidrug-resistant hospital-acquired (MR-HA-MRSA), multidrug-resistant community-acquired (MR-CA-MRSA), HA-MRSA, and CA-MRSA groups.
  • Comparison of plasmid carriage and antibiotic resistance profiles across different MRSA classifications.

Main Results:

  • MR-HA-MRSA and MR-CA-MRSA isolates predominantly carried type II SCCmec, lacked plasmid DNA, and showed limited PFGE diversity.
  • HA-MRSA and CA-MRSA isolates mostly possessed type IV SCCmec, with many harboring one or two plasmids.
  • Non-multidrug-resistant isolates without plasmids were only resistant to methicillin, while those with plasmids showed resistance to additional antibiotics.

Conclusions:

  • Multidrug resistance in HA-MRSA is characterized by an absence of plasmid DNA, contrary to expectations.
  • Plasmid carriage plays a significant role in conferring antibiotic resistance, particularly in non-multidrug-resistant HA-MRSA and CA-MRSA.
  • The genetic determinants of multidrug resistance differ between MRSA subtypes, with plasmids being key in some but not others.

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