Two Zinc Uptake Systems Contribute to the Full Virulence of Listeria monocytogenes during Growth In Vitro and In Vivo Original paper
Researched by:
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Divine Aleru
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Divine Aleru
Read MoreI am a biochemist with a deep curiosity for the human microbiome and how it shapes human health, and I enjoy making microbiome science more accessible through research and writing. With 2 years experience in microbiome research, I have curated microbiome studies, analyzed microbial signatures, and now focus on interventions as a Microbiome Signatures and Interventions Research Coordinator.
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Microbes
Microbes
Microbes are microscopic organisms living in and on the human body, shaping health through digestion, vitamin production, and immune protection. When microbial balance is disrupted, disease can occur. This guide explains key microbe types—bacteria, viruses, fungi, protozoa, and archaea—plus major pathogenic and beneficial examples.
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Divine Aleru
Read More
Researched by:
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Divine Aleru
ID
Divine Aleru
Read More
Microbiome Signatures identifies and validates condition-specific microbiome shifts and interventions to accelerate clinical translation. Our multidisciplinary team supports clinicians, researchers, and innovators in turning microbiome science into actionable medicine.
Divine Aleru
What was studied?
This study focused on the role of two zinc uptake systems, ZurAM and ZinABC, in the virulence of Listeria monocytogenes. The researchers investigated how these systems contribute to the bacterium’s ability to grow both in vitro and in vivo, particularly under zinc-limited conditions, which are commonly encountered within the host during infection. The study explored the impact of these zinc transport systems on Listeria’s growth in defined media, its ability to survive inside host cells, and its virulence in a mouse model.
Who was studied?
The study investigated Listeria monocytogenes and its two major zinc uptake systems: ZurAM and ZinABC. The research involved using wild-type Listeria strains as well as mutants lacking either or both zinc uptake systems. Additionally, the study assessed the bacterial strains in various growth conditions, including those with limited zinc availability, and during infection in a mouse model and in HeLa cells.
What were the most important findings?
The study revealed that both the ZurAM and ZinABC zinc uptake systems play critical roles in the virulence of Listeria monocytogenes. Although deletion of either the zurAM or zinA gene had minimal effect on bacterial growth in zinc-supplemented media, the double mutant (lacking both systems) was unable to grow in the absence of zinc. This growth defect was complemented by zinc supplementation. Moreover, the ZurAM system was found to be essential for Listeria‘s ability to grow inside host cells, especially HeLa cells, while ZinABC contributed less significantly under these conditions. In vivo, both systems were required for full virulence in an oral mouse model, where the Listeria strains with disrupted zinc uptake systems showed reduced survival rates. Furthermore, the double mutant strain was defective in actin-based motility and failed to spread from cell to cell, indicating that zinc acquisition is vital for the bacterium’s ability to replicate intracellularly and spread within tissues.
What are the greatest implications of this study?
The findings highlight the crucial role of zinc acquisition in Listeria monocytogenes pathogenesis and its survival in zinc-limited environments within the host. Targeting the ZurAM and ZinABC zinc uptake systems could offer a novel therapeutic approach to control Listeria infections, particularly in immunocompromised individuals or pregnant women, who are most vulnerable to listeriosis. The identification of these systems also suggests that disrupting bacterial zinc acquisition could be a strategy to prevent Listeria‘s ability to replicate within host cells and to halt its spread. Moreover, the study underscores the broader concept of nutritional immunity, where pathogens and hosts compete for essential nutrients, and targeting such systems could shift the balance in favor of the host.
Listeria monocytogenes
Listeria monocytogenes is an opportunistic pathogen capable of surviving in diverse environments, including soil, water, and decaying vegetation. L. monocytogenes has the unique ability to evade the immune system by moving directly from cell to cell within the host. This intracellular lifestyle allows the bacterium to avoid extracellular immune detection, contributing to its ability to cause invasive diseases like meningitis and septicemia, particularly in the elderly and immunocompromised.