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Detection of Horizontal Gene Transfer Mediated by Natural Conjugative Plasmids in E. coli
Published on: March 24, 2023
Distribution of horizontally transferred heavy metal resistance operons in recent outbreak bacteria
1Bioinformatics and Computational Biology Unit; Department of Biochemistry; University of Pretoria; Pretoria, South Africa.
Abstract:
Mankind is confronted by the outbreaks of highly virulent and multi-drug resistant pathogens. The outbreak strains often belong to well-known diseases associated species such as Salmonella, Klebsiella and Mycobacterium, but even normally commensal and environmental microorganisms may suddenly acquire properties of virulent bacteria and cause nosocomial infections. The acquired virulence is often associated with lateral exchange of pathogenicity genomic islands containing drug and heavy metal resistance determinants. Metal ions are used by the immune system of macro-organisms against bactericidal agents. The ability to control heavy metal homeostasis is a factor that allows the survival of pathogenic microorganisms in macrophages. In this paper, we investigate the origin of heavy metal resistance operons in the recent outbreak strains and the possible routes which may lead to acquisitions of these genes by potentially new pathogens. We hypothesize that new outbreak microorganisms appear intermittently on an intersection of the non-specialized, genetically naïve strains of potential pathogens and virulence factor comprising vectors (plasmid and/or phages) newly generated in the environmental microflora. Global contamination of the environment and climate change may also have an effect toward the acceleration and appearance of new pathogens.
Insights
New virulent pathogens emerge from genetic exchange, acquiring drug and heavy metal resistance. Environmental factors and climate change may accelerate the rise of these dangerous microbes.
Area of Science:
- Microbiology
- Genetics
- Environmental Science
Background:
- Highly virulent and multi-drug resistant pathogens pose a significant threat to human health.
- Commensal and environmental microorganisms can acquire virulence and cause nosocomial infections.
- Acquired virulence is often linked to horizontal gene transfer of pathogenicity genomic islands.
Purpose of the Study:
- Investigate the origin of heavy metal resistance operons in recent pathogen outbreak strains.
- Explore potential routes for acquiring heavy metal resistance genes in emerging pathogens.
- Understand the role of heavy metal homeostasis in microbial survival against host defenses.
Main Methods:
- Analysis of heavy metal resistance operons in outbreak strains.
- Investigating horizontal gene transfer mechanisms (plasmids, phages).
- Examining the interplay between environmental factors and microbial evolution.
Main Results:
- Heavy metal resistance determinants are frequently found on pathogenicity genomic islands.
- Horizontal gene transfer facilitates the acquisition of virulence and resistance traits.
- Environmental contamination and climate change are potential accelerators for new pathogen emergence.
Conclusions:
- Emerging pathogens likely arise at the interface of genetically naive strains and mobile genetic elements carrying virulence factors.
- Heavy metal resistance is crucial for pathogen survival within host immune systems.
- Environmental factors significantly influence the emergence and spread of infectious diseases.
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