Lots of work is being done to recognise and control infections such as community acquired MRSA and the UK is learning from situations in community and healthcare settings both here and abroad to stay ahead of the game, scientists will be told at the Society for General Microbiology's 162nd meeting being held this week at the Edinburgh International Conference Centre.
Some strains of Staphylococcus aureus produce a potent toxin called Panton-Valentine leukocidin (PVL). PVL-Staphylococcus aureus (PVL-SA) usually causes skin and soft tissue infections, including boils and abcesses. More rarely it can cause serious diseases such as necrotising haemorrhagic pneumonia, which has been associated with a high mortality rate.
“Although several other countries have encountered widespread problems with PVL-related disease, infections caused by PVL S. aureus (including PVL MRSA) remain uncommon in the UK. Nonetheless we need to keep the situation under constant review,” says Dr Angela Kearns from the Health Protection Agency. Tests carried out at the Health Protection Agency's Staphylococcus Reference Laboratory show that around 2% of all Staphylococcus aureus strains produce the PVL toxin.
“The HPA, working with other healthcare professionals, is in the process of updating guidance on PVL Staphylococcus aureus infection in the UK,” says Dr Kearns. “This will provide healthcare professionals with advice to assist the recognition, investigation and management of PVL-SA cases.”
To date, most strains of S. aureus that produce the PVL toxin in the UK have been sensitive to a range of antibiotics, including methicillin. These strains are called methicillin sensitive S. aureus (MSSA). In North America, strains of PVL Staphylococcus aureus, most notably the USA300 clone, have been spreading in the community and are resistant to methicillin. USA300 has become endemic in some US hospitals. In contrast, this strain has rarely been seen in England and Wales: 40 cases were identified during a two year study carried out in 2004/5 and most occurred in the community.