During my PhD at the University of Antwerp and the Institute of Tropical Medicine in Antwerp, I studied a serovar of Salmonella named 'Concord'. It was of particular interest as it was rarely reported yet notorious for its antimicrobial resistance (AMR) and global spread via Ethiopian adoptees. The findings of our study, published in Nature Communications (https://www.nature.com/articles/s41467-023-38902-x ), shed light on the complexity and alarming characteristics of this pathogen, and the global and pressing issue of AMR in general.
The study findings
This collaborative effort has laid the groundwork for comprehensive molecular surveillance of Salmonella Concord. By collecting and analysing genomes from 284 historical and contemporary Salmonella Concord isolates spanning nearly 80 years and multiple countries, we discovered that Salmonella Concord is polyphyletic, indicating diverse evolutionary lineages.
Of particular concern are the highly resistant lineages identified in Ethiopia. Some strains showed such high levels of AMR, that, if they would infect a patient, the infections would be almost untreatable with the resources at hand in low-and middle-income countries. These lineages spread globally due to an adoption program.
Using advanced techniques such as nanopore sequencing, we uncovered that Salmonella Concord acquired its AMR through various types of plasmids and chromosomal integrations. This genetic insight provides valuable information to better understand the mechanisms driving the spread of resistance and guides future surveillance efforts.
The implications of this research extend far beyond the scientific community. Antimicrobial resistance is a pressing global issue, threatening our ability to treat infections effectively. The emergence of highly resistant Salmonella Concord lineages could pose a significant risk to public health and calls for urgent action. Due to the lack of recent data from Ethiopia, it is not known whether highly resistant Salmonella Concord still circulates. Much like the ongoing Salmonella Typhimurium epidemic in sub-Saharan Africa, the origin of the infections remains enigmatic.
Personal Outlook and Call to Action
My core belief is that in the context of monitoring pathogens and AMR, we have to think more in terms of global, interdisciplinary partnerships. It cannot be overstated how important it is for clinicians, microbiologists, and bioinformaticians to work together across borders.
Support for research efforts in regions where pathogens like Salmonella Concord are widespread is crucial in our shared mission to safeguard public health. I'm grateful to be working on a project in the Adrem Data Lab at the University of Antwerp, where I will be the catalyst for such collaborations. We aim to enhance genomic monitoring of pathogens in low-and middle-income countries using nanopore sequencing.