Determining PCR performance for detection of Staphylococcus aureus Small Colony Variants

Background: Staphylococcus aureus (SA) is a bacterium that can cause a wide range of infections, from minor skin conditions to severe, life-threatening disease. Small Colony Variants (SCVs) of Staphylococcus aureus are often associated with chronic and recurrent infections. Their altered metabolism and slow growth makes it difficult to perform conventional antimicrobial susceptibility testing.

Objective: To compare capabilities of two PCR methods (GeneXpert with the Hologic Panther System) in identifying methicillin resistance in SCVs.

Methods: Previously identified SCVs were cultured. The samples of bacteria where then processed to be analysed GeneXpert and Panther PCR systems to determine the presence or absence of the methicillin resistance gene. Their results will be compared with each other.

Results: Currently the GeneXpert has been shown to have a sensitivity of 91.9% and a specificity of 92.3% in identifying MRSA from SCVs when compared to traditional method. Results of the Panther system are yet to be determined.

Conclusions: Our data shows, that molecular methods is a viable alternative to traditional culture methods, and greatly improves the turn around time for the result.

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