Functional analysis of ETEC adaptation to survival in water and in vivo colonisation

Enterotoxigeneic Escherichia coli (ETEC) is a leading cause of diarrhoeal infections in young children living in endemic regions in low- and middle-income countries as well as adults travelling to these destinations. CFA/I fimbriae have been identified as the predominant colonisation factor associated with human ETEC infections. Here we used Transposon-directed insertion-site sequencing (TraDIS) and transcriptomic analysis to identify the essential genome of the prototypical CFA/I expressing ETEC strain H10407 and uncover the survival mechanisms that enhance persistence of ETEC isolates in water and within mammalian hosts. The research work, including the construction of transposon library consisting of 1x106 mutants; screening of mutant library in water and mouse gut; bioinformatics and statistical analyses; development of defined knock-outs of H10407 for validation; confirmation of essential genes and phenotypes associated with the survival of H10407 in water and in vivo persistence (colonization), were executed at the Wellcome Trust Sanger Institute (WTSI) and the Westmead Institute for Medical Research (WIMR), the University of Sydney. The sequencing data was generated in the Bioscience Core Laboratory at King Abdullah University of Science and Technology.