Professor Mark Nicol is a clinical microbiologist based in the Division of Infection and Immunity within the School of Biomedical Sciences at the University of Western Australia. He also holds an honorary appointment at the University of Cape Town. He studied medicine and medical microbiology at the University of the Witwatersrand and completed his PhD in childhood tuberculosis in Cape Town. His current work explores the role of the early life microbiota in young children in the pathogenesis of acute and chronic illnesses, particularly of the respiratory system. He also has an active research programme involved in the development and evaluation of better diagnostic tests for tuberculosis and pneumonia; this has spanned working with test developers on assay development, early pilot evaluation, formal assessment of test accuracy and implementation research.