It has been estimated that there are more microbial cells inhabiting the human body than there are eukaryotic cells of which it is made up. This normal microflora usually co-exists relatively peacefully with the host and does not cause infection. The mechanisms by which this co-existence is achieved are still not properly understood and the interaction between the normal microflora and the host is far from simple. For a variety of reasons, however, this interaction can be disturbed and often results in the microflora becoming pathogens. The study of the diseases then caused is important both in terms of treatment and in terms of contributing to our understanding of the mechanisms by which the normal microflora usually interacts with the host. This title brings together an international list of contributors, all of whom have active research interests in the normal microflora. Each of the chapters reviews current knowledge about a specific group or organism within the microflora and the diseases they can cause. Microflora of the skin, respiratory tract, oral cavity, gastrointestinal system and genital tract are all discussed and the impact of molecular methods on our understanding of the normal microflora is emphasised throughout the book. Medical microbiologists, dental specialists, infectious disease specialists, nutritionists and gastroenterologists will all find this book of immense interest and value, as will epidemiologists, dermatologists and general microbiologists.