Virulence Profiles of Diarrheagenic Escherichia coli Isolated from the Western Region of Ghana

Diarrhea is one of the most common health complaints, especially in young children, with nearly 1.7 billion cases of childhood diarrheal diseases occur every year (1). Children younger than 5 years of age are especially vulnerable, with those from sub-Saharan Africa and South Asia recording the highest mortality burden (2). In Ghana, the mortality rate is 25% in children under the age of 5 years, with more than 9 million episodes of diarrhea every year (3). Because of its fecal-oral transmission, poor hygiene and unsanitary conditions that prevail in resource-limited areas contribute to their vulnerability to infectious diarrhea (4). The introduction of rotavirus vaccines has been helpful in reducing the burden of rotavirus-induced diarrhea. However, this reduction has caused a proportional increase in the burden of non-viral pathogens (5): enterotoxigenic E. coli (ETEC), a diarrhoeagenic Escherichia coli (DEC), and Shigella spp. are the major bacteria causing childhood diarrhea in sub-Saharan Africa and South Asia (5). Other DEC subtypes include enteropathogenic E. coli (EPEC), enterohemorrhagic E. coli (EHEC)/Shiga toxin-producing E. coli (STEC), enteroaggregative E. coli (EAEC), and enteroinvasive E. coli (EIEC), classified according to their virulence factors (6) and are associated with intestinal disease. These pathotypes also differ in their mechanisms of infection, clinical presentation, and colonization sites (7,8). Interestingly, the distribution and genetic diversity of DEC isolates vary even within the same country (9–11). Strains of DEC are constantly evolving through horizontal transfer of mobile genetic elements (12), and have emerged as a significant cause of outbreak infections, necessitating regular surveillance. Although some studies have described the distribution of DEC pathotypes in some parts of Ghana, there have been no such reports from its Western region (13–15). Specifically, there is a dearth of data on DEC genotypes, their associated virulence factors, and serotypes in Ghana partly because these pathogens are not routinely Original Article