Investigation of Antimicrobial Resistance Genes in Listeria monocytogenes from 2010 through to 2021 Original paper
Researched by:
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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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Microbes
Microbes
Microbes are microscopic organisms living in and on the human body, shaping health through digestion, vitamin production, and immune protection. When microbial balance is disrupted, disease can occur. This guide explains key microbe types—bacteria, viruses, fungi, protozoa, and archaea—plus major pathogenic and beneficial examples.
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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?
This study investigated antimicrobial resistance (AMR) genes in Listeria monocytogenes isolates over a period from 2010 to 2021. The research analyzed the frequency and trends of AMR genes within Listeria monocytogenes samples sourced from multiple regions using data from the National Pathogen Detection Isolate Browser (NPDIB).
Who was studied?
The study focused on Listeria monocytogenes, a pathogenic bacterium responsible for listeriosis, affecting the immunocompromised, elderly, and pregnant women. Isolates were drawn from clinical and environmental sources across different regions, including North America, Europe, Australia/New Zealand, Asia, South Africa, and the UK/Ireland.
What were the most important findings?
The study identified the most frequently occurring AMR genes in Listeria monocytogenes, including fosX, lin, abc-f, and tet(M). The genes fosX and lin were found in nearly all samples, while abc-f and tet(M) were also notably frequent. The analysis revealed no significant increase in AMR genes over the 2010-2021 period, indicating stability in the prevalence of resistance within the bacterium. Interestingly, certain resistance genes, such as those related to vancomycin (vanC, vanR, vanS, vanT, and vanXY-C), spiked in 2014 and 2016 but were not observed in recent years. The study also highlighted that Listeria monocytogenes isolates in clinical settings predominantly contained fosX, lin, and abc-f, while environmental isolates had a broader diversity of AMR genes. The research confirmed that Listeria monocytogenes strains resistant to ampicillin and gentamicin were not common, suggesting the continued effectiveness of current treatment regimens.
What are the greatest implications of this study?
This study provides critical insight into the ongoing monitoring of AMR in Listeria monocytogenes, especially in foodborne infections. Despite the widespread presence of certain AMR genes, the stability of resistance levels in recent years suggests that the threat to first-line treatment antibiotics, like ampicillin and gentamicin, remains low. However, the presence of specific resistance genes, especially in environmental sources, signals the importance of continued surveillance to track emerging resistance patterns. Additionally, the identification of frequently occurring AMR genes lays the groundwork for developing targeted strategies to prevent the spread of resistance and ensure effective treatment in clinical and food safety settings.
Listeria monocytogenes
Listeria monocytogenes is an opportunistic pathogen capable of surviving in diverse environments, including soil, water, and decaying vegetation. L. monocytogenes has the unique ability to evade the immune system by moving directly from cell to cell within the host. This intracellular lifestyle allows the bacterium to avoid extracellular immune detection, contributing to its ability to cause invasive diseases like meningitis and septicemia, particularly in the elderly and immunocompromised.