The genus 'streptococcus' is huge and encompasses a large variety of human and animal pathogenic and commensal bacteria. It is not known why some species are virulent and others not, and why even within one species, the virulence potential varies. These and other key questions are addressed in this timely book which draws on the recent advances in streptococcal genomics to provide an up-to-date coherent picture of the molecular and cellular biology of streptococci. With contributions from internationally renowned streptococcal researchers, this comprehensive book reviews all of the important topics. The book is divided into three sections: Streptococcus pneumoniae, Streptococcus spp. (group A and B streptococci, oral streptococci and others), and Methods. Topics include: genetic transformation in S. pneumoniae, biologically active S. pneumoniae peptides, the pneumococcal cell wall, the capsular polysaccharides, virulence factors and adhesion proteins, genetics regulation of virulence, genome-wide screening for essential S. pneumoniae genes, molecular epidemiology, penicillin resistance, and much more. An important and useful feature of this book is the methods section. This contains information on a number of key streptococcal molecular genetic techniques which will be invaluable to the reader.