Charting the evolutionary trajectories of bacterial pathogens allows us to understand the history of acquisition of virulence traits. Scientists are increasingly implementing phylogenetic approaches to classify bacterial strains, understand the evolution of antibiotic resistance and monitor outbreaks. Writing in this issue of Nature Microbiology, Pulford et al. reconstruct the evolutionary history of Salmonella Typhimurium in Africa and uncover the recent emergence of a highly invasive lineage in Malawi1.
Salmonella species are capable of causing disease with varying degrees of severity. Most often, humans that become infected with Salmonella develop uncomplicated symptoms associated with food poisoning. However, Salmonella can also produce severe bloodstream infections that require antibiotic treatment2. Salmonella-associated bloodstream infections are particularly problematic in Africa, where case fatality rates range from approximately 25% in children to 50% in adults, resulting in almost 50,000 deaths each year.
Click here to read the article, published in Nature Microbiology.