Exploring the Genetic Diversity, Virulence, and Antimicrobial Resistance
of Diarrheagenic Escherichia coli from Southern Africa Using Whole
Genome Data
Abstract
Introduction: Previous studies, including our research, provide
critical insights into the contamination of food and water consumed by
children under five in the Southern African Development Community (SADC)
with Diarrheagenic Escherichia coli (DEC). Methods: This
study uncovered the transmission dynamics of eleven DEC isolates from
food, children under five and water from Maputo, Mozambique, with 125
others from the SADC region previously collected from food, animals and
environment but available in the EnteroBase database
([http://enterobase.warwick.ac.uk](http://enterobase.warwick.ac.uk/)).
The assemblies of the DEC isolates were analysed using pipelines at the
Center for Genomic Epidemiology, Denmark. At the same time, statistical
analysis and visualization were done using R-statistics. Results:
Clustering based on Single Nucleotide Polymorphism (SNP) and core genome
Multilocus sequence typing (cgMLST) alleles revealed associations based
on geographic locations, sample niche, pathovar, and O:H antigen,
pointing to evolutionary relatedness between the clades with Principal
Coordinate Analysis uncovering this accounted for 27.55% of the genetic
diversity. Virulence genes eae (63.97%), LT (25.00%), and Stx1
(15.44%) were most abundant, with an inverse association between the
presence of LT and eae genes. Resistance to folate pathway antagonists
(sulfamethoxazole– 55.9%), beta-lactamases (amoxicillin, ampicillin
and piperacillin– all 54.4%), and aminoglycoside (streptomycin–
55.1%) were most abundant. Conclusions: The study provides
insightful evidence on horizontal gene transfer and the risk associated
with antibiotic and detergent resistance and virulent genes. We also
provide a framework to facilitate a proactive response in the regional
effort to protect human and animal health.