Keith studied Medical Microbiology at the University of Leeds, UK, gaining his PhD for work on antibiotic resistance mechanisms in hypermutable bacteria. He completed post-doctoral projects funded by the UK Department of Health, Novartis and the UK Medical Research Council at the University of Leeds on antibiotic resistance mechanisms of linezolid-resistant staphylococci and the development of novel antimicrobial agents against Mur ligases and RNA polymerase. He then joined Sheffield Hallam University in 2008 where his group research the molecular mechanisms of antibiotic resistance and develop novel natural product derived antimicrobials.
Keith is a former council and grant committee member for the British Society for Antimicrobial Chemotherapy and was also an editorial board member for the Journal of Medical Microbiology, published by the Microbiology Society.