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Molecular characterization of methicillin-resistant Staphylococcus aureus isolated in Tunisia

Mouna Ben Nejma1, Maha Mastouri, Sonia Frih

  • 1Institut Supérieur de Biotechnologie, 5000 Monastir, Tunisia.

Diagnostic Microbiology and Infectious Disease
|February 28, 2006
PubMed

Insights

Community-acquired methicillin-resistant Staphylococcus aureus (MRSA) is a growing concern due to toxin production. This study characterized 72 Tunisian MRSA strains, finding them multiresistant and often carrying specific toxin genes like Panton-Valentine leukocidin.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Genetics

Background:

  • Community-acquired methicillin-resistant Staphylococcus aureus (MRSA) presents a significant and increasing public health challenge.
  • Staphylococcal toxin production is a key factor in the virulence and spread of MRSA infections.

Purpose of the Study:

  • To investigate the phenotypic and genotypic characteristics of 72 community-acquired MRSA strains from Tunisia.
  • To identify specific toxin genes and staphylococcal cassette chromosome mec (SCCmec) types present in these MRSA isolates.

Main Methods:

  • Multiplex polymerase chain reaction (PCR) was employed to detect SCCmec types and specific toxin genes.
  • Phenotypic characterization of multiresistance was assessed.
  • Accessory gene regulator (agr) group typing was performed.

Main Results:

  • All 72 Tunisian MRSA strains exhibited multidrug resistance.
  • SCCmec type IV and IVA were prevalent (66 isolates), with IVA strains being Panton-Valentine leukocidin positive.
  • Leukotoxin genes (lukE-lukD) were detected in 92.4% of strains; gamma-hemolysin and exfoliatin A genes were rare.

Conclusions:

  • Tunisian community-acquired MRSA strains are multiresistant and harbor specific virulence factors, including leukotoxin genes.
  • SCCmec typing is crucial, but comprehensive characterization necessitates integration with other molecular methods like PFGE, MLST, and spa typing.

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