Data from: Combining in vivo and in vitro approaches to better understand host-pathogen nutritional interactions
Data files
Dec 20, 2024 version files 46.72 KB
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BacGro4_archive.csv
11.93 KB
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BFdata_archive.csv
30.87 KB
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README.md
3.92 KB
Abstract
Nutrition often shapes the outcome of host-parasite interactions, however understanding the mechanisms by which this occurs is often confounded by the intimate nature of the association and by the fact that the host and parasite may compete for the same limiting nutrients. One way of disentangling this interaction is to combine in vivo and in vitro approaches. Here, we explore the role of host nutrition in determining the outcome of infections using a model insect-bacterium system: the cotton leafworm Spodoptera littoralis and the blood-borne bacterium Xenorhabdus nematophila. S. littoralis larvae were reared on one of a series of 20 chemically-defined diets ranging in their protein:carbohydrate (P:C) ratio and caloric density. They were then challenged with either a fixed dose of X. nematophila cells (live or dead) or were sham-injected. Survivorship of larvae challenged with live bacterial cells was strongly dependent on the protein levels of the diet, with mortality being highest on low-protein diets. This trend was reflected in the bacterial growth rate in vivo, which peaked in larvae fed low-protein diets. To determine whether in vivo bacterial growth rates were driven by the direct effects of blood nutrients or by the indirect effects of the host immune response, we used 20 synthetic haemolymphs (‘nutribloods’) that mimicked the nutritional content of host blood. In vitro bacterial growth rate was negatively impacted by the protein content of the nutribloods, replicating the patterns seen in vivo and suggesting that nutrient availability and not host immunity was driving the interaction. By comparing standardized bacterial growth rates in vivo and in vitro, we conclude that the outcome of this host-parasite interaction is largely driven by ‘bottom-up’ effects of nutrients on bacterial growth, rather than by ‘top-down’ effects of nutrients on host-mediated immune responses. The outcome of host-parasite interactions is typically assumed to be strongly determined by the host immune response. The direct effects of nutrition have been underexplored and may have broad consequences for host-parasite interactions across taxa.
README: Combining in vivo and in vitro approaches to better understand host-pathogen nutritional interactions
https://doi.org/10.5061/dryad.pzgmsbcxv
Description of the data and file structure
This was a lab-based study. The data were analysed using R. The datasets compare growth of Xenorhabdus bacteria in vivo (Spodoptera littoralis larvae) and in vitro (synthetic insect blood).
Files and variables
File: BacGro4_archive.csv
Description: This file contains the data required to compare bacteriall growth in vitro versus in vivo (see Figure 4 of the paper)
Variables
- Diet.no: Diet number: 1-20
- Plate: Microtitre plate number
- Max.OD: Maximum optical density at 600 nm
- P2C: Protein : Carbohydate (g)
- P2C.ratio: Protein : Carbohydate (1:5 to 5:1)
- Conc: Concentration of the digestible diet
- prop.Prot.x: Proportion of protein in diet (P/P+C)
- pc.Prot: Percentage of protein in diet (P/P+C) (%)
- pc.Carb: Percentage of carbohydrate in diet (P/P+C) (%)
- pc.cellulose: Percentage of indigesticle cellulose in diet (%)
- Total.prot.g: Absolute amount of protein in the diet (g/100g)
- Total.carb.g: Absolute amount of carbohydrate in the diet (g/100g)
- cellulose.g: Absolute amount of cellulose in the diet (g/100g)
- Total.g.per.diet: Total g of diet per 100g
- Protein: Amount of protein in the nutriblood (mg/mL)
- Sum.carbs: Amount of carbohydrate in the nutribloood (mg/mL)
- Lipids: Amount of lipids in the nutribloood (mg/mL)
- stvitroP: Standardized protein in the nutriblood
- stvitroC: Standardized carbohydrate in the nutriblood
- stvitrogro: Standardized bacterial growth in the nutriblood
- stvivoP: Standardized protein in the diet
- stvivoC: Standardized carbohydrate in the diet
- stvivoMaxOD: Standardized bacterial growth in vivo
- stvitrovivoP: Standardized difference in protein in vitro versus in vivo
- stvitrovivoC: Standardized difference in carbohydrate in vitro versus in vivo
- stDIFF: Standardized difference in bacterial growth in vitro versus in vivo
File: BFdata_archive.csv
Description: This file contains the data to compare speed of death and bacterial growth rate in relation to dietary attributes (see Figures 1- 3 of paper).
Variables
- Diet.no: Diet number: 1-20
- ID: Arbitrary Caterpilar number
- Treat: Treatment: Dead, sham or live challenged
- DState: Stage at death (caterpillar, pupae, moth)
- F1D3.ml.mean: Mean number of Xenorhabdus F1D3 colony forming units/ml
- P2C: Protein : Carbohydrate (g)
- P2C.ratio: Protein : Carbohydate (g)
- Conc: Concentration of the digestible diet
- prop.Prot: Proportion of protein in diet (P/P+C)
- pc.Prot: Percentage of protein in diet (P/P+C) (%)
- pc.Carb: Percentage of carbohydrate in diet (P/P+C) (%)
- pc.cellulose: Percentage of indigesticle cellulose in diet (%)
- Total.prot.g: Absolute amount of protein in the diet (g/100g)
- Total.carb.g: Absolute amount of carbohydrate in the diet (g/100g)
- cellulose.g: Absolute amount of cellulose in the diet (g/100g)
- Total.g.per.diet: Total g of diet per 100g
- Died: Died during larval stage (0=no, 1=yes)
- DSpeed: Time taken to die (h)
- logF1D3mean: log10(mean number of Xenorhabdus F1D3 colony forming units+1)
- Outcome: Outcome (Sham-injected, Dead bacteria-injected, Live-bacteria-injected survived, Live bacteria-injected died)
- st.DSpeedALL: Standardized speed of death (all larvae)
- st.F1D3mean: Standardized mean number of Xenorhabdus F1D3 colony forming units
- st.DSpeed: Stadardized time taken to die
- st.logF1D3mean: Standardized log10(mean number of Xenorhabdus F1D3 colony forming units+1)
Code/software
All files are .csv and can be read using Excel
Access information
Other publicly accessible locations of the data:
- not applicable
Data was derived from the following sources:
- not applicable