The global burden and epidemiology of invasive non-typhoidal Salmonella infections

Abstract

Invasive non-typhoidal Salmonella (iNTS) disease has emerged as a major public health concern. Yet, understanding of the global burden is incomplete, limited particularly by the breadth of blood culture-based surveillance systems that are able to accurately diagnose the etiology of bacteremia. The accessibility of whole genome sequencing has allowed for genetic characterization of pathogens, shedding light on its evolutionary history and sounding alerts for its future progression. iNTS disease is observed to be a particular threat in sub-Saharan Africa, with a case fatality rate greatly exceeding that of typhoid fever, and commonly affecting infants, young children and immunocompromised adults. While iNTS disease might also be a threat in Asia and Latin America, its burden is not well characterized, primarily owing to the lack of comprehensive reporting in these regions. Drug-resistant Salmonella enterica (S. enterica) serovars (e.g. Typhimurium sequence type 313 (ST313)) have emerged as a potential consequence of sustained antibiotic pressure. Genetic analyses have identified distinguished iNTS disease-causing strains that are particularly virulent in certain human host populations. Effective treatment strategies, including vaccination, are necessary; iNTS vaccines targeting the most common S. enterica serovars, Typhimurium, Enteritidis and Dublin, are currently in early developmental stages. Funding and political support is needed to promote vaccine development and implementation programs to ultimately reduce the threat of iNTS disease in high risk areas.

Salmonella Virulence and Immune Escape

“…Typhoidal serovars causing typhoid fever include Salmonella enterica serovar Typhi (S. Typhi), Paratyphi (S. Paratyphi), and Sendai (S. Sendai) [6,7]. The most common NTS are serovars Typhimurium (S. Typhimurium), Enteritidis (S. Enteritidis), and Dublin (S. Dublin) [8]. Infection with NTS ordinarily results in gastroenteritis, diarrhea, and fever (almost always present), with a low case fatality [9,10].…”

Bacteriophage ZCSE2 is a Potent Antimicrobial against Salmonella enterica Serovars: Ultrastructure, Genomics and Efficacy

“…In the developed world, Salmonella infection usually presents as a self-limiting gastrointestinal infection, although antibiotic treatments may be required. Non-typhoidal Salmonella (NTS) can be attributed to 93 million cases of gastrointestinal disease annually, of which 155,000 infections result in death [1]. Furthermore, invasive non-typhoidal Salmonella (iNTS) is associated with enhanced pathogenicity towards specific demographics in the developing world.…”

RpoS-regulated SEN1538 gene promotes resistance to stress and influences Salmonella enterica serovar enteritidis virulence

“…Although Salmonella pathogenesis has been extensively studied in Salmonella enterica subspecies I serovar Typhimurium (S. Typhimurium), they have not been studied in Salmonella enterica subspecies I serovar Enteritidis (S. Enteritidis) [3]. Of the two serovars, S. Enteritidis has emerged as the more prevalent serovar and is a major contaminant in the poultry and meat industry [4,5].…”