Denise O’Sullivan at LGC in the Molecular and Cell Biology Team is investigating the application of metrology (the science of measurement) in the areas of metagenomics, infectious diseases and antimicrobial resistance. Previous work at UCL and LSHTM has been in area of diagnosis of Mycobacterium tuberculosis and investigating drug resistance.
Methicillin resistant Staphylococcus aureus (MRSA) is a major pathogen associated with complicating hospital and community medicine. Drug resistance increases the risk of complications and can challenge routine procedures such as surgery. As different species, such as Staphylococcus epidermidis, can also carry resistance, this can further increase the challenge of diagnosis using culture and/or molecular methods. We describe a digital PCR approach that uses a three colour detection platform (Naica Crystal Digital™ PCR System, Stilla Technologies) to count the number of genes that confer resistance and compare this with the number of genes from S. aureus and S. epidermidis within a sample. This method may be useful to determine which organism is carrying the resistance gene.