Widespread fungal–bacterial competition for magnesium lowers bacterial susceptibility to polymyxin antibiotics Original paper
Researched by:
-
Divine Aleru
ID
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.
-
Metals
Metals
Heavy metals influence microbial pathogenicity in two ways: they can be toxic to microbes by disrupting cellular functions and inducing oxidative stress, and they can be exploited by pathogens to enhance survival, resist treatment, and evade immunity. Understanding metal–microbe interactions supports better antimicrobial and public health strategies.
-
Divine Aleru
Read More
Researched by:
-
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?
The study focused on understanding the interactions between the fungus Candida albicans and the bacterium Pseudomonas aeruginosa, specifically how C. albicans sequesters magnesium (Mg²⁺) from P. aeruginosa and the impact this has on bacterial fitness and resistance to polymyxin antibiotics, such as colistin.
Who was studied?
The study involved P. aeruginosa (specifically the PAO1 strain) and C. albicans (strain SC5314), exploring their interaction in polymicrobial environments, such as in co-culture settings.
What were the most important findings?
The study revealed that C. albicans sequesters Mg²⁺ from P. aeruginosa, impairing the latter’s fitness in co-culture conditions. This was observed through competitive fitness assays and RNA sequencing, which showed that magnesium transporter MgtA in P. aeruginosa plays a crucial role in overcoming Mg²⁺ depletion during co-culture. Mg²⁺ sequestration by C. albicans also led to enhanced survival of P. aeruginosa when exposed to polymyxin antibiotics like colistin. This magnesium-mediated resistance was independent of the canonical mechanisms of resistance, highlighting how fungi influence antibiotic susceptibility in bacteria. Interestingly, this increased resistance could be disrupted by removing C. albicans or adding Mg²⁺. Moreover, the evolution of P. aeruginosa in the presence of C. albicans led to mutations that provided resistance to colistin, demonstrating the role of fungal competition in the evolution of antibiotic resistance.
What are the greatest implications of this study?
This study emphasizes the complex dynamics of microbial competition in polymicrobial infections, particularly the role of nutritional competition for Mg²⁺ between fungi and bacteria. The findings suggest that fungal-mediated Mg²⁺ sequestration not only impairs bacterial fitness but also enhances bacterial resistance to last-resort antibiotics like colistin. This insight could have significant implications for the treatment of polymicrobial infections, suggesting that disrupting fungal–bacterial competition or supplementing Mg²⁺ may improve the efficacy of polymyxin antibiotics, potentially mitigating resistance in clinical settings. Moreover, understanding these interactions could influence strategies for combating antibiotic resistance in diverse environments, including clinical infections and chronic conditions such as cystic fibrosis.
Magnesium (Mg)
Magnesium (Mg) is a vital metal that not only supports critical cellular functions in both humans and microbes but also plays a significant role in shaping microbial pathogenesis. By regulating microbial growth, virulence factor expression, and competition for nutrients, magnesium directly influences infection outcomes. Understanding how magnesium interacts with microbial communities and the host immune system provides novel insights into therapeutic strategies that modulate microbial behavior, potentially improving infection management and microbiome health.