Functional characterization of a cadmium resistance operon in Staphylococcus aureus ATCC12600: CadC does not function as a repressor Original paper
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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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Metals
Metals
OverviewHeavy metals play a significant and multifaceted role in the pathogenicity of microbial species. Their involvement can be viewed from two primary perspectives: the toxicity of heavy metals to microbes and the exploitation of heavy metals by microbial pathogens to establish infections and evade the host immune response. Understanding these aspects is critical for both […]
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Microbes
Microbes
Microbes, short for microorganisms, are tiny living organisms that are ubiquitous in the environment, including on and inside the human body. They play a crucial role in human health and disease, functioning within complex ecosystems in various parts of the body, such as the skin, mouth, gut, and respiratory tract. The human microbiome, which is […]
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Divine Aleru
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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 functional characterization of a cadmium resistance operon in Staphylococcus aureus ATCC12600. The operon, which consists of two key genes, cadC and cadA, was identified in a transposon mutagenesis library. The research aimed to investigate the role of these genes in cadmium and zinc resistance and explore the genetic and functional mechanisms behind the resistance, particularly focusing on the efflux mechanism.
Who was studied?
The study involved Staphylococcus aureus ATCC12600, a non-methicillin-resistant strain. The operon was compared to similar operons found in methicillin-resistant strains (MRSA), particularly S. aureus MRSA252, and examined the gene expression and resistance properties. The research also involved mutant strains, including those with transposon disruptions in cadC, to better understand the functional impact of each gene within the operon.
Most important findings
The S. aureus ATCC12600 strain containing the cadC-positive plasmid showed high levels of resistance to cadmium sulfate, with minimal growth reduction even in the presence of 250 mg/ml cadmium sulfate. In contrast, the cadC-mutant strains exhibited significantly lower resistance. This suggested that cadC plays a crucial role in cadmium efflux, although the absence of CadC did not completely block cadmium efflux, as the cadA gene, even in the absence of cadC, still contributed to a lower level of resistance. Additionally, the study found that the CadC protein from S. aureus ATCC12600 did not function as a transcriptional repressor, unlike the CadC protein from pI258, which had been previously identified as a repressor.
Key implications
The findings demonstrate that the cadC gene in S. aureus ATCC12600 is integral to cadmium resistance, specifically through its involvement in cadmium efflux, but it does not operate as a repressor as seen in other strains. This research provides new insights into cadmium resistance mechanisms in S. aureus and highlights the differences between resistance mechanisms in non-MRSA and MRSA strains. Understanding these resistance pathways may aid in developing strategies for tackling cadmium toxicity, particularly in environments contaminated with heavy metals.
Cadmiun (Cd)
Cadmium (Cd) is a highly toxic heavy metal commonly found in industrial, agricultural, and environmental settings. Exposure to cadmium can occur through contaminated water, food, soil, and air, and it has been linked to a variety of health issues, including kidney damage, osteoporosis, and cancer. In agriculture, cadmium is often present in phosphate fertilizers and can accumulate in plants, entering the food chain. Its toxicity to living organisms makes cadmium a subject of regulatory concern worldwide, particularly in industrial waste disposal and environmental monitoring.
Staphylococcus aureus (S. Aureus)
Staphylococcus aureus is a versatile skin and mucosal commensal that can transition into a highly virulent pathobiont. Known for its immune-evasive strategies, toxin production, and antibiotic resistance, it plays a significant role in chronic infections and microbiome imbalance.