Dr Stapleton started his research career under the direction of Professor Barry Cookson, initially at St. Thomas’s Hospital and then at the Central Public Health Laboratory, Colindale London, where he conducted investigations into the molecular epidemiology of staphylococci and mupirocin and triclosan resistance.After his PhD studies, he continued with his interests in beta-lactamases discovering the mobile genetic element, ISEcp1, responsible for the mobilisation of several important beta-lactamase genes.