The foodborne illness Salmonella causes an alarming number of infections each year.
The recent development of an intracellular autolytic vaccine has shown promising results in preventing Salmonella contamination of poultry hosts, making them and the resulting food safer for human consumption.
This unique vaccine design offers a sustainable approach to controlling Salmonella contamination without the use of synthetic compounds.
By integrating genes 13 and 19 of bacteriophage P22 into the bacterial chromosome, scientists have successfully developed an intracellular autolytic vaccine against SE serovar Typhimurium.
This vaccine not only targets the direct source of contamination, but also does not require synthetic compounds that can harm both humans and animals. Vaccinating poultry against SE could play a critical role in reducing contamination and preventing future cases of salmonellosis.
The authors Mengfei Peng, Jungsoo Joo, Zabdiel Alvarado-Martinez, Zajeba Tabashsum, Arpita Aditya, and Debabrata Biswas published their findings in the article Intracellular autolytic whole cell Salmonella vaccine prevents colonization of pathogenic Salmonella Typhimurium in chicken, dated October 2022.
- Salmonella enterica (SE) is an important bacterial pathogen that is commonly found in the normal flora of various animals.
- Poultry play an important role in the spread of SE through direct contact with live animals and consumption of contaminated products.
- Vaccination of poultry against SE is a sustainable approach that can reduce the spread of SE in the host and thus prevent future infections in humans.
- An intracellular autolytic vaccine against SE serovar Typhimurium (STLT2+P13+19) was developed by integrating bacteriophage P22 genes 13 (holin) and 19 (lysozyme) into the bacterial chromosome.
- This study provides insight into a novel vaccine design that could make food products safer without the use of synthetic compounds.
Salmonella enterica (SE) is a major foodborne bacterial pathogen, commonly found as the normal flora of various animals that is attributed to causing at least 1.2 million infections annually.
Poultry plays a major role in disseminating SE through direct contact with live animals and consumption of contaminated products. Vaccinating poultry against SE is a sustainable approach that can reduce SE in the host, preventing future infections in humans.
An intracellular autolytic SE serovar Typhimurium vaccine (STLT2+P13+19) was developed by integrating genes 13 (holin) and 19 (lysozyme) of bacteriophage P22 into the bacterial chromosome. These were inserted downstream of sseA, an SPI-2 chaperone in SE that expresses during the intracellular phase of SE.
Intracellular viability of STLT2+P13+19 reduced by 94.42% at 24 hr compared to the wild type in chicken macrophage cells (HD-11), whereas growth rate and adhesion ability remained unchanged. Inoculating STLT2+P13+19 in HD-11 significantly enhanced the relative log fold expression of genes associated to production of pro-inflammatory cytokines (IL-1β, IL-6, IL-8, IL-10, IL-12 p40, IL-18, and GM-CSF) and Toll-like-receptors (TRL-3 and 7). Vaccination of an in vivo chicken model demonstrated significant changes in secretion of iNOS, IL-6, IL-8, IL-12, and TNF-α, as well as a reduction in the intestinal colonization of SE serovar Typhimurium. Microbiome analysis of cecal fluid using 16S rRNA gene sequencing also showed modulation of intestinal microbial composition, specifically a decrease in relative abundance of Proteobacteria and increasing Firmicutes.
This study provides insight into a novel vaccine design that could make food products safer without the use of synthetic compounds.
Keywords: Bacteriophage P22; Colonization; Gut microbiota; Immunity; Intracellular autolysis; Poultry; Salmonella; Vaccine.
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