Diarrhoeagenic Escherichia coli: Virulence Genes and Other Markers for Detection and Typing
Stefano Morabito and Rosangela Tozzoli
from: Pathogenic Escherichia coli: Evolution, Omics, Detection and Control (Edited by: Pina M. Fratamico, Yanhong Liu and Christopher H. Sommers). Caister Academic Press, U.K. (2018) Pages: 29-46.
Escherichia coli are usually commensal bacteria, harmlessly colonizing the gastrointestinal tract of mammals, where they exert an advantageous effect on the host. Nonetheless, some strains have evolved the ability to induce disease in humans in many anatomical sites. Among these, diarrhoeagenic E. coli (DEC) cause enteric/diarrhoeal illness, sometimes with systemic complications. DEC are subdivided into pathotypes on the basis of the colonization mechanism and the toxins elaborated, which determine the clinical, pathological, and epidemiological features of the disease induced. DEC pathotypes include enterotoxigenic (ETEC), enteroinvasive (EIEC), enteropathogenic (EPEC), enteroaggregative (EAEC), and Shiga toxin producing E. coli (STEC). In order to discriminate pathogenic E. coli strains from commensal E. coli, pathotype-specific genetic markers are generally employed for the diagnosis of the infections and strain characterization. This chapter describes the different DEC pathotypes, in order to provide a general picture of their virulence mechanisms and the associated genetic determinants, with the aim of illustrating the molecular targets used for their identification and typing read more ...