Our next #microtwjc session will be on Tuesday 8th July 8pm (BST).

We will be discussing the following paper Fructose-Asparagine Is a Primary Nutrient during Growth of Salmonella in the Inflamed Intestine by Ali et al published in PLoS pathogens in June 2014. The link to the paper is here http://www.plospathogens.org/article/info%3Adoi%2F10.1371%2Fjournal.ppat.1004209

Abstract

Salmonella enterica serovar Typhimurium (Salmonella) is one of the most significant food-borne pathogens affecting both humans and agriculture. We have determined that Salmonella encodes an uptake and utilization pathway specific for a novel nutrient, fructose-asparagine (F-Asn), which is essential for Salmonella fitness in the inflamed intestine (modeled using germ-free, streptomycin-treated, ex-germ-free with human microbiota, and IL10−/− mice). The locus encoding F-Asn utilization, fra, provides an advantage only if Salmonella can initiate inflammation and use tetrathionate as a terminal electron acceptor for anaerobic respiration (the fra phenotype is lost in Salmonella SPI1− SPI2− or ttrA mutants, respectively). The severe fitness defect of a Salmonella fra mutant suggests that F-Asn is the primary nutrient utilized by Salmonella in the inflamed intestine and that this system provides a valuable target for novel therapies.

Author Summary

It has long been thought that the nutrient utilization systems of Salmonella would not make effective drug targets because there are simply too many nutrients available to Salmonella in the intestine. Surprisingly, we have discovered that Salmonella relies heavily on a single nutrient during growth in the inflamed intestine, fructose-asparagine (F-Asn). A mutant of Salmonella that cannot obtain F-Asn is severely attenuated, suggesting that F-Asn is the primary nutrient utilized by Salmonella during inflammation. No other organism has been reported to synthesize or utilize this novel biological compound. The novelty of this nutrient and the apparent lack of utilization systems in mammals and most other bacteria suggest that the F-Asn utilization system represents a specific and potent therapeutic target for Salmonella.

Discussion points
1. Is the paper well written and easy to follow and understand?
2. Are the methods adequate?
3. Do the results further our knowledge?
4. Any other experiments you would do?

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