Scientific Frontline: "At a Glance" Summary
- Main Discovery: Escherichia coli found in diabetic foot infections is not a uniform pathogen but constitutes a highly diverse array of genetic groups, with distinct lineages independently adapting to the diabetic wound environment.
- Methodology: Researchers conducted the first comprehensive whole-genome sequencing analysis of 42 E. coli strains isolated from diabetic foot ulcers across diverse global populations, including the UK, Nigeria, Brazil, and the USA.
- Key Statistic: Approximately 8% of the analyzed strains were classified as multidrug-resistant or extensively drug-resistant, possessing mechanisms to withstand multiple or nearly all available antibiotic classes.
- Specific Mechanism: The genomic data identified critical virulence factors—specifically genes enabling tissue attachment and immune evasion—that explain the rapid progression and severity of these infections.
- Significance: This genomic characterization provides a foundation for developing precision diagnostics and targeted therapies, directly addressing the urgent need to reduce treatment failure and lower-limb amputations in diabetic patients.
Second-year doctoral researcher at the University of Westminster and King’s College London, Victor Ajumobi, was the first author of a recently published paper revealing the hidden diversity of E. coli in diabetic foot infections. The findings will enable clinicians to choose therapies that are more likely to work, reducing prolonged infection, hospitalization, and the risk of amputation.
Published in Microbiology Spectrum, the research provides the first comprehensive genomic characterization of E. coli strains isolated directly from diabetic foot ulcers across multiple continents. The findings could help to explain why some infections become particularly difficult to treat and why they can lead to severe, sometimes life-threatening, outcomes.
Diabetic foot infections remain one of the most serious complications of diabetes and are a leading cause of lower-limb amputation worldwide. Although clinicians have recognized that these chronic wound infections are often complex, little is known about the specific pathogens involved, particularly E. coli, despite its frequent detection in clinical samples.
Researchers analyzed whole-genome sequences from 42 E. coli strains isolated from infected diabetic foot ulcers in patients across Nigeria, the UK, Ghana, Sweden, Malaysia, China, South Korea, Brazil, India and the USA. By sequencing the complete DNA of each bacterial strain, the team was able to examine global patterns in the biology of E. coli associated with diabetic foot disease. This approach enabled the researchers to compare genetic differences between strains, identify genes linked to antibiotic resistance, and pinpoint factors that contribute to disease severity.
The genomic analysis showed that the E. coli strains were highly diverse. The bacteria belonged to many different genetic groups and carried a wide range of genes linked to antibiotic resistance and disease. This demonstrates that there is no single type of E. coli responsible for diabetic foot infections, and distinct lineages were independently capable of adapting to the diabetic foot environment.
By analyzing how the strains are related and identifying the resistance mechanisms and virulence traits (the features or tools that make a microbe more harmful) they carry, the research helps explain why some diabetic foot infections are particularly difficult to treat or can progress rapidly to severe illness.
Notably, around 8% of the strains were classified as multidrug-resistant or extensively drug-resistant, meaning they are resistant to multiple or nearly all available antibiotics.
The team’s future research will focus on understanding how specific virulence factors identified in the study contribute to disease progression. Many of the isolates carry genes that enable E. coli to attach to host tissues or evade the immune system. Investigating how these traits operate within the diabetic foot environment could reveal new therapeutic targets and support the development of improved treatment strategies.
About the study Victor Ajumobi said: “This information will be particularly valuable in low-resource settings, where E. coli infections of diabetic foot ulcers are more common and where rapid diagnostic tools for antimicrobial resistance are not always readily available.”
Dr Vincenzo Torraca, Lecturer in Infectious Disease at King’s College London and senior author of the paper, added: “Understanding these bacteria at a genomic level is a crucial step towards improving diagnosis and enabling more targeted treatments for people with diabetes. By identifying which E. coli strains are most common and which antibiotics they are likely to resist, clinicians can choose therapies that are more likely to work, helping to reduce prolonged infection, hospitalization and the risk of amputation.”
Additional information: This research directly contributes to the United Nations Sustainable Development Goals (SDGs) 3: Good Health and Wellbeing and 17: Partnerships for the Goals. Since 2019, the University of Westminster has used the SDGs holistically to frame strategic decisions to help students and colleagues fulfil their potential and contribute to a more sustainable, equitable, and healthier society.
Published in journal: Microbiology Spectrum
Authors: Victor Ajumobi, Zaid Tahir, Polly Hayes, Adele McCormick, and Vincenzo Torraca
Source/Credit: University of Westminster
Reference Number: bmed011326_02
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