Mechanisms of Increased Susceptibility to Salmonella enterica Serovar Typhimurium Bacteremia in the Context of Malaria in African Children
Salmonella enterica serovar Typhimurium bacteremia is known to be associated with malaria in African children. To understand the immunological basis of this association, Nyirenda et al. (e00057-17) investigated bactericidal immunity to S. Typhimurium in children with acute and convalescent uncomplicated malaria and in controls. They found that Plasmodium falciparum infection reduced serum bactericidal activity to S. Typhimurium and was associated with reduced complement C3, irrespective of preexisting specific-IgG antibody titers. P. falciparum infection also reduced whole-blood bactericidal activity to S. Typhimurium and was associated with reduction of neutrophil respiratory burst. These findings provide new insights into the increase in susceptibility to S. Typhimurium bacteremia in children from settings of malaria endemicity.
P. falciparum infection compromises bactericidal immunity to S. Typhimurium (STm).
Virus-Like Particle Vaccine Platform That Mimics the Immature Form of Alphavirus
Urakami et al. (e00090-17) developed a novel vaccine platform, which is composed of an alphavirus virus-like particle (VLP) and any inserted epitope of choice. Robust immunogenicity against a target protein or pathogen was achieved through the dense and symmetrical display of 480 copies of the epitope. Furthermore, modification of the VLP by mimicking the immature form of an alphavirus enhanced immunogenicity. As proof of concept, effective immunogenicity and protection were achieved by employing the malaria circumsporozoite protein as the epitope inserted into the alphavirus VLP. This study supports the use of this novel platform as a blueprint for vaccine development against other pathogens and diseases.
Malaria epitope NANP-inserted VLPs.
Accurate and Rapid Distinction between Acute Infections Caused by Bacteria or Virus
Human neutrophil lipocalin (HNL) is released from blood neutrophils upon stimulation. The release is highly increased by blood neutrophils obtained from patients with bacterial infections as opposed to neutrophils obtained from patients with viral causes of their infection. Venge et al. (e00064-17) have invented a whole-blood format of activation of neutrophils that results in the accurate distinction between the causes of infections within a few minutes. The diagnostic accuracy of the HNL assay was shown to be superior to any other known biomarker, such as C-reactive protein (CRP), procalcitonin (PCT), and white blood cell counts, and the format lends itself to the development of rapid point-of-care assays.
Diagnostic accuracy of CRP and the HNL assay in the distinction between bacterial or viral causes in patients with infectious symptoms of the respiratory tract.
- Copyright © 2017 American Society for Microbiology.
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- Mechanisms of Increased Susceptibility to Salmonella enterica Serovar Typhimurium Bacteremia in the Context of Malaria in African Children
- Virus-Like Particle Vaccine Platform That Mimics the Immature Form of Alphavirus
- Accurate and Rapid Distinction between Acute Infections Caused by Bacteria or Virus
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