Newswise — A recent study conducted by Chalmers University of Technology and the University of Gothenburg in Sweden has revealed that genes responsible for antibiotic resistance in bacteria are more prevalent in our environment than previously understood. The research demonstrates that bacteria in nearly all environments contain these resistance genes, increasing the risk of their spread and exacerbating the problem of bacterial infections that cannot be effectively treated with antibiotics. This highlights the urgent need to address the issue of antibiotic resistance to prevent the emergence of untreatable bacterial infections.
Erik Kristiansson, a professor in the Department of Mathematical Sciences, emphasizes the significance of the study's findings by stating, "We have discovered previously unidentified resistance genes in locations that have gone unnoticed until now. These genes could pose a hidden danger to human health." This statement underscores the potential risks associated with the presence of undiscovered antibiotic resistance genes and highlights the need for further research and action to address this threat to human well-being.
The World Health Organization (WHO) recognizes antibiotic resistance as a major global health concern. When bacteria develop resistance to antibiotics, it becomes challenging or even impossible to effectively treat various illnesses, including pneumonia, wound infections, tuberculosis, and urinary tract infections. According to the UN Interagency Coordination Group on Antimicrobial Resistance (IACG), approximately 700,000 people lose their lives annually due to infections caused by antibiotic-resistant bacteria. These statistics highlight the severe impact of antibiotic resistance on public health and underscore the urgent need for effective strategies to address this issue.
Looking for resistance genes in new environments
Traditionally, research on antibiotic resistance genes has primarily concentrated on identifying those genes already present in pathogenic bacteria. However, the recent study from Sweden took a different approach by examining extensive DNA sequences from various bacteria. The objective was to analyze new variations of resistance genes and determine their prevalence. The researchers investigated thousands of bacterial samples obtained from diverse environments, including the human body, soil, and sewage treatment plants. The study involved an analysis of an enormous total of 630 billion DNA sequences. This comprehensive analysis allowed for a broader understanding of the occurrence and distribution of novel forms of resistance genes across different bacterial populations.
Juan Inda Díaz, the lead author of the article and a doctoral student in the Department of Mathematical Sciences, explains that processing the extensive amount of data obtained from the study required substantial effort. The researchers employed a methodology called metagenomics, which enabled the analysis of massive volumes of data. Metagenomics involves studying genetic material directly extracted from environmental samples, allowing for a comprehensive examination of genetic diversity and functions within microbial communities. This approach proved instrumental in handling and analyzing the vast quantities of data generated in the study.
The study revealed that the newly discovered antibiotic resistance genes are widely distributed among bacteria in nearly all types of environments. This includes the microbiomes of humans, which refers to the genes of bacteria residing inside and on our bodies. Alarmingly, these resistance genes were also detected in pathogenic bacteria, which can cause infections that are challenging to treat. The researchers found that the abundance of resistance genes in bacteria from human microbiomes and the environment was ten times greater than previously known. Furthermore, an astonishing 75 percent of the resistance genes identified in the human microbiome were previously unknown. These findings underscore the extent of antibiotic resistance gene prevalence and highlight the urgent need for comprehensive strategies to combat this global health threat.
The researchers stress the need for more knowledge about the problem of antibiotic resistance.
According to Kristiansson, prior to this study, there was a complete lack of knowledge regarding the occurrence of these newly discovered resistance genes. Antibiotic resistance is a multifaceted issue, and this research demonstrates the necessity of expanding our comprehension of bacterial resistance development and the potential threat posed by these resistance genes in the future. The study underscores the importance of continuous research and vigilance in addressing antibiotic resistance to stay ahead of emerging challenges and potential health risks.
Hoping to prevent bacterial outbreaks in the healthcare sector
The research team is actively collaborating with the international EMBARK project (Establishing a Monitoring Baseline for Antibiotic Resistance in Key environments) to incorporate their new data. Led by Johan Bengtsson-Palme, an assistant professor in the Department of Life Sciences at Chalmers University, the project focuses on collecting samples from various sources like wastewater, soil, and animals. The objective is to gain insights into the transmission and spread of antibiotic resistance between humans and the environment. By integrating their findings, the team aims to contribute valuable information to the broader understanding of antibiotic resistance dynamics and aid in the development of effective monitoring and control strategies.
Bengtsson-Palme emphasizes the importance of considering the newly discovered forms of resistance genes in risk assessments associated with antibiotic resistance. The techniques developed by the research team offer a means to monitor these novel resistance genes in the environment. By proactively detecting these genes in pathogenic bacteria, there is a greater likelihood of preventing outbreaks in healthcare settings. This proactive approach aims to enhance surveillance efforts and improve preparedness to mitigate the spread of antibiotic resistance and its associated health risks.
More about the study
The researchers used DNA from two public databases. The first database, ResFinder, contains a couple of thousand previously known antibiotic resistance genes in bacteria. The researchers expanded these with a large number of new resistance genes that they had found through an analysis of bacterial DNA. The known and new resistance genes amounted to 20,000 in total.
The second database, MGnify, contains large quantities of bacterial DNA from different sources such as bacteria living on and in people, in sewage treatment plants and from the soil and water. These were analysed to investigate how common the various resistance genes were in bacterial DNA. The study analysed 630 billion DNA sequences in total and the results showed that the resistance genes are present in almost all environments. Prior to this study, there was no knowledge about the incidence of these new resistance genes.
The method used by the researchers is called metagenomics, and is not new, but so far has not been used to analyse new types of antibiotic resistance genes in such large quantities. Metagenomics is a method of studying the metagenome, which is the complete gene set of all different organisms in a given sample or within a given environment. Using the method, it is also possible to study microorganisms that cannot be grown in a lab.
The study Latent antibiotic resistance genes are abundant, diverse, and mobile in human, animal, and environmental microbiomes has been published in the journal Microbiome.
This study has been carried out by Juan Salvador Inda-Díaz, David Lund, Marcos Parras-Moltó, Anna Johnning, Johan Bengtsson-Palme and Erik Kristiansson. The researchers work at Chalmers University of Technology, the University of Gothenburg and Fraunhofer-Chalmers Centre in Sweden.
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