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Published on: October 13, 2015
In vivo and in vitro effects of lactoferrin on Yersinia pseudotuberculosis
1Botany and Microbiology Department, College of Science, King Saud University, Riyadh, Saudi Arabia.
Abstract:
Iron is a growth requirement for virtually all microbes. In the human body, extracellular iron is sequestered from microbes by binding to proteins such as lactoferrin. In this study the effect of lactoferrin and human milk on Yersinia pseudotuberculosis was investigated. Its growth in vitro was inhibited by iron-free, but not iron saturated, pure lactoferrin or human milk. Iron-free human milk and to a less extent normal human milk were bactericidal for Y. pseudotuberculosis cells that were suspended in deionized water. The in vivo studies also show that iron-saturated lactoferrin enhanced growth, whereas, the viable count was reduced by iron-free pure lactoferrin and EDDA. Nine envelope proteins were decreased or disappeared upon growth in iron-deficient medium, whereas one new high molecular weight protein appeared under the same conditions.
Insights
Iron restriction by lactoferrin and human milk inhibits Yersinia pseudotuberculosis growth. Iron-free conditions were bactericidal, while iron-saturated lactoferrin enhanced bacterial growth in vivo.
Area of Science:
- Microbiology
- Immunology
- Nutritional Biochemistry
Background:
- Iron is essential for microbial growth.
- The human body sequesters extracellular iron using proteins like lactoferrin to limit microbial access.
- Yersinia pseudotuberculosis is a pathogen that requires iron for survival.
Purpose of the Study:
- To investigate the impact of lactoferrin and human milk on Yersinia pseudotuberculosis growth.
- To determine the role of iron availability in these interactions.
- To analyze changes in bacterial envelope proteins under iron-deficient conditions.
Main Methods:
- In vitro growth inhibition assays using pure lactoferrin and human milk under varying iron saturation levels.
- In vivo studies assessing bacterial viability with different lactoferrin preparations and EDDA.
- Analysis of bacterial envelope protein expression via gel electrophoresis under iron-deficient conditions.
Main Results:
- Iron-free lactoferrin and human milk inhibited Yersinia pseudotuberculosis growth in vitro.
- Iron-free human milk and normal human milk demonstrated bactericidal effects.
- Iron-saturated lactoferrin promoted growth in vivo, whereas iron-free lactoferrin and EDDA reduced bacterial counts.
- Iron deficiency led to the disappearance of nine envelope proteins and the appearance of one new high molecular weight protein.
Conclusions:
- Iron availability is a critical factor in the interaction between Yersinia pseudotuberculosis and host defense factors like lactoferrin.
- Lactoferrin and human milk can restrict iron, thereby inhibiting bacterial growth and potentially acting as antimicrobial agents.
- Modulation of bacterial envelope proteins under iron-deficient conditions suggests adaptive strategies for survival.
