Malnutrition and maternal vaccination against typhoid toxin

Abstract

Children are particularly susceptible to typhoid fever caused by the bacterial pathogen Salmonella Typhi. Typhoid fever is prevalent in developing countries where diets can be less well-balanced. Here, using a murine model, we investigated the role of the macronutrient composition of the diet in maternal vaccination efficacies of two subunit vaccines targeting typhoid toxin: ToxoidVac and PltBVac. We found that maternal vaccinations protected all offspring against a lethal-dose typhoid toxin challenge in a balanced, normal diet (ND) condition, but the declined protection in a malnourished diet (MD) condition was observed in the PltBVac group. Despite the comparable antibody titers in both MD and ND mothers, MD offspring had a significantly lower level of typhoid toxin neutralizing antibodies than their ND counterparts. We observed a lower expression of the neonatal Fc receptor on the yolk sac of MD mothers than in ND mothers, agreeing with the observed lower antibody titers in MD offspring. Protein supplementation to MD diets, but not fat supplementation, increased FcRn expression and protected all MD offspring from the toxin challenge. Similarly, providing additional typhoid toxin-neutralizing antibodies to MD offspring was sufficient to protect all MD offspring from the toxin challenge. These results emphasize the significance of balanced/normal diets for a more effective maternal vaccination transfer to their offspring.

Single missense mutations in Vi capsule synthesis genes confer hypervirulence to Salmonella Typhi

“…Cmah-null mice expressing the human-type glycan receptor (Jackson Laboratory, RRID: IMSR_JAX:017588) 47,57,59,60,63,[83][84][85] were infected intraperitoneally with 8 × 10 5 S. Typhi WT, tviE K266N, or tviE P263S strain in 100 µl of PBS. Both males and females aged 6-to 12weeks were used, and no sex-dependent phenotypic differences with regards to S. Typhi susceptibility were observed.…”

Antimicrobial properties of tomato juice and peptides against typhoidal Salmonella

“…Despite the availability of typhoid vaccines, numerous developing countries continue to face substantial obstacles in accessing these vital resources. Additionally, the issue of antibiotic resistance poses a significant risk, particularly among malnourished children ( 22 – 27 ).…”

“…It is worth noting that in 2018, approximately 65% of children in the country did not consume an adequate amount of vegetables or fruits, which was the highest across Asian countries, with India following closely ( 28 ). This correlation may be attributed to the association between the consumption of fruits and vegetables and the enhancement of immunity and antibacterial activity ( 26 – 28 ).…”