Participating Centres
Centres have contributed data for different periods, and new laboratories join the study each year.
The centres which have contributed data, together with the earliest and latest months for which full data are available, are as follows:
| Participating Centre |  | Date started | | Latest month for which data available |
| Ashford: William Harvey Hospital | | January 2002 | | March 2010 |
| Birmingham: West Midlands HPA Laboratory, Heartlands Hospital | | January 2002 | | March 2010 |
| Bristol: Bristol HPA Laboratory | | April 2006 | | March 2010 |
| Cambridge: Cambridge HPA Laboratory, Addenbrooke's Hospital | | January 2002 | | March 2010 |
| Chester: Chester HPA Laboratory (via Manchester) | | January 2002 | | March 2010 |
| Grimsby: Diana Princess of Wales Hospital | | April 2004 | | March 2010 |
| Hull: Castle Hill Hospital | | April 2002 | | April 2007 |
| Leeds: Leeds General Infirmary & St James' Hospital | | September 2004 | | March 2010 |
| Leeds: Leeds HPA Laboratory (No longer active) | | January 2002 | | July 2005 |
| Liverpool: Liverpool HPA Laboratory (via Manchester) | | January 2002 | | March 2010 |
| Liverpool: Royal Liverpool University Hospital | | January 2002 | | March 2010 |
| London: Centre for Infections | | January 2002 | | March 2010 |
| London: Chelsea and Westminster Hospital | | January 2008 | | December 2009 |
| London: Ealing Hospital (No longer active) | | November 2002 | | October 2003 |
| London: North Middlesex Hospital | | July 2002 | | March 2010 |
| London: Northwick Park Hospital | | May 2008 | | December 2009 |
| London: St Bartholomew's Hospital | | August 2004 | | March 2010 |
| London: St George's Hospital | | January 2002 | | March 2010 |
| London: University College Hospital | | September 2004 | | March 2010 |
| Manchester: Manchester Medical Microbiology Partnership, Manchester Royal Infirmary | | January 2002 | | March 2010 |
| Newcastle: Newcastle HPA Laboratory | | January 2002 | | March 2010 |
| Nottingham: Queen's Medical Centre | | September 2002 | | March 2010 |
| Portsmouth: St Mary's Hospital | | January 2002 | | March 2010 |
| Preston: Preston HPA Laboratory (via Manchester) | | January 2002 | | March 2010 |