Editorial: Emerging Approaches for Typing, Detection, Characterization, and Traceback of Escherichia coli

Commensal E. coli inhabit the large intestines of humans and animals and are important in maintaining normal intestinal homeostasis. There are also many groups of disease-causing E. coli, including diarrheagenic and extra-intestinal pathogenic E. coli (ExPEC). E. coli strains have been identified primarily based on their O-and H-antigens, defining the E. coli serotype. There are approximately 188 somatic O-antigens, 74 capsular K-antigens, 53 flagellar H-antigens, and greater than 60 fimbrial F-antigens in E. coli identified based on antigens that produce an immune response in animals. This research topic consists of articles based on the subject of an international workshop on " Emerging approaches for typing, detection and characterization of Escherichia coli " held at the Pennsylvania State University in 2015. This workshop brought together well-known scientists from throughout the world to provide a forum for the exchange of ideas with regard to examining the current serotype classification and nomenclature for E. coli, emerging pathotypes, and new technologies and whole genome sequencing (WGS) for detection, characterization, and outbreak investigation. Scientists who presented papers at the conference were affiliated with public health laboratories, regulatory agencies, academic institutions, and industry groups from the U. and Japan, as well as industry groups working on technologies for characterization, detection, identification, and subtyping E. coli. This workshop provided a forum to discuss different concepts and practices for typing E. coli based on O-and H-antigens and for characterization of pathotypes. Furthermore, there were discussions on the progress made in the area of WGS as a tool for E. coli typing, subtyping, characterization, diagnostics, and outbreak investigation, as well as on the evolution and emergence of highly pathogenic strains (Franz et al., 2014). A mini review, providing an overview on this research topic is " Advances in molecular serotyping and subtyping of Escherichia coli " (Fratamico et al.). Phenotypic methods, such as serotyping for O-and H-antigen determination, biotyping based on biochemical characteristics, or bacteriophage typing have been used for differentiating and characterizing E. coli for many years; however, these methods are labor intensive, time consuming, and not always accurate. Recent advances in molecular techniques and DNA sequencing technologies have led to the development of typing and subtyping methods for E. coli that are more accurate and have better discriminatory power than phenotypic typing methods. WGS of E. coli is allowing more rapid and accurate identification of pathogenic strains and is replacing pulsed-field gel electrophoresis (PFGE), a gold standard …