On the 5th and 6th of October this year, I will be taking part in a relatively small, but very interesting conference on veterinary and environmental AMR, held in Amsterdam. The theme of the event will be “Optimal practices to protect human health care from antimicrobial resistance selected in the veterinary domain”.
The aim of the conference is to discuss innovative additional measures to prevent development of resistance in animals. In addition, the participants will explore possibilities to prevent transfer to human health care after selection has taken place. The conference program will consist of both lectures and break-out sessions and is intended for researchers as well as for policy makers involved in the battle against antimicrobial resistance. The results of the break-out sessions are to be published in an open access journal, and I will be charing one of these break-out sessions. Please see the conference web site for the entire program: https://www.nvwa.nl/amrconference
There is an upper cap of 120 participants for the event, so if you’re interested make sure to register soon! The conference will be held on October 5 and 6 2023 in the Park Inn by Radisson in Amsterdam, The Netherlands. The hotel is easy to reach by a 12 minutes train ride from Schiphol airport and a 5 minutes train ride from the city center.
I look forward to seeing you in Amsterdam!
The first (or technically the second, but the other order makes more sense when explaining this…) is the first paper involving most of the people who have been working in the EMBARK consortium for an extended period of time. It’s an overview paper titled “Towards monitoring of antimicrobial resistance in the environment: For what reasons, how to implement Itit, and what are the data needs?” (1) and I think the title describes the topic pretty well. Basically, we go through why it would be interesting to monitor for antibiotic resistance in the environments, how that could be implemented and what we would need to know to get there.
The very condensed story is that if one is considering implementing monitoring for environmental resistance, these are a few things that should be considered:
- The purpose of monitoring: What is the motivation? What should be achieved? What type of risk should be assessed? What type of action would monitoring enable?
- Choice of methods: Which methods are economically feasible? Which methods would deliver results within a useful timeframe for taking appropriate actions?
- Targeted environments: In what type of environment would monitoring for a given purpose be worthwhile?
- Intended users: Who would be able to use, implement and act upon this strategy?
- Integration potential: How does this monitoring integrate with other monitoring efforts? How can the resulting data be communicated?
We then dive into the knowledge gaps we are currently facing, and particularly highlight the following areas:
- Establish how different existing methods for monitoring resistance compare to each other
- Extend pathogen-centric databases for resistance genes with latent resistance genes (2)
- Determine the locations and type of environments relevant for resistance monitoring
To reduce costs, utilizing already existing environmental monitoring should be prioritized, as should locations integrated into operating or planned surveillance programs. More efforts should also be made to identify additional pathways for resistance transmission through the environment.
- Study the environment as a source and transmission route for antibiotic resistance
Stratify risks associated with resistance genes found in the environment. Define typical levels of antibiotic resistance in different environments (3), and define how these levels change over time.
- Identify settings where the relationship between fecal bacteria and antibiotic resistance is absent
Usually, these levels follow each other, but the environments where they don’t are important as they deviate from the expected baseline of resistance. This knowledge can aid in identifying situations in which it would be helpful to investigate a microbial community for resistance to specific antibiotics.
- Identify the origins for more antibiotic resistance genes (4)
This knowledge will be instrumental in preventing the emergence of new forms of resistance in pathogens in the future.
An important outcome of this paper is that we realise that we are still not at a level of understanding where routine monitoring for resistance in the environment can be easily justified or implemented. Still, there is a need for monitoring data in natural environments to even get started, and therefore we support the implementation of national, regional and global of initiatives without having all the scientific answers. The lack of comprehensive understanding should not be an obstacle to starting environmental monitoring for AMR, nor for action against environmental development and spread of AMR.
The second paper is very much related to the first, in that it actually tries to address one of these knowledge gaps: the need for normal background levels of antibiotic resistance in different environments. In this paper, Anna Abramova did an herculean effort collecting (we hope) all qPCR data on antibiotic resistance gene abundances in the environment for the past two decades. All in all, she collected data for more than 1500 samples across 150 studies and integrated these into an analys of what we could consider normal levels of resistance in different environments.
For an ‘average’ resistance gene, we found that the normal relative abundance range was form 10-5 to 10-3 copies per bacterial 16S rRNA, or that around one in 1,000 bacteria would carry a given resistance gene. This level varied quite a bit between different resistance genes, however, but not so much between environmental types (except for in human and animal feces, where some resistance genes were clearly more abundant, most prominently tetracycline resistance genes). What was more striking was that there was a clear difference between environments impacted or likely impacted by human activities, as opposed to more pristine environments with little to none human impact. Some resistance genes, such as tetA, tetG, blaTEM and blaCTX-M, showed very marked differences between these impacted and non-impacted environments, making them great markers of human-activity-associated resistance.
Our final recommendations with regards to monitoring include:
- Include the intI1, sul1, blaTEM, blaCTX-M and qnrS genes in environmental monitoring, along with a selection of tetracycline resistance genes, including either tetA or tetG.
- Other potential target genes could be sul3, vanA, tetH, aadA2, floR, ereA and mexF, which are abundant in some environments, but are not often included in qPCR studies of environmental AMR
- If a gene deviates from the expected 10-5 to 10-3 interval, this warrants further investigation of the causes.
- Maximum acceptable levels need to be determined not only taking relative abundances of genes into account, but also risks to human health as well as the numbers of bacteria in a given volume of sample into account (5,6) and transmission routes to humans (7)
- The different standards of reporting DNA abundances constituted a complicating factor for this study. Both abundances of resistance genes relative to the 16S rRNA gene and to the sample volume or weight should be reported.
- The absence of clear trends of increases or decreases in resistance gene abundances over time indicates a need for more systematic time series data in a variety of environments.
Our results also highlighted the scarcity of resistance gene data from parts of the world, particularly from Africa and South America, and underscores the need for a concerted effort to quantify typical background levels of resistance in the environment more broadly to enable efficient environmental surveillance schemes akin to those that exist in clinical and veterinary settings.
I encourage anyone with an interesting these topics to at least skim the full papers [Monitoring overview paper here, Normal qPCR resistance abundances here]. These will be great resources and I am very proud of them both. I would really like to thank the entire EMBARK team and our collaborators in CORNELIA, WastPAN and in other organisations. I would also like to thank Anna for her hard work on collecting and analysing the qPCR data for around two years. It has been a long ride, and I think we are both happy, proud and a bit relieved to finally see this paper published!
- Bengtsson-Palme J, Abramova A, Berendonk TU, Coelho LP, Forslund SK, Gschwind R, Heikinheimo A, Jarquin-Diaz VH, Khan AA, Klümper U, Löber U, Nekoro M, Osińska AD, Ugarcina Perovic S, Pitkänen T, Rødland EK, Ruppé E, Wasteson Y, Wester AL, Zahra R: Towards monitoring of antimicrobial resistance in the environment: For what reasons, how to implement it, and what are the data needs? Environment International, 108089 (2023). doi: 10.1016/j.envint.2023.108089
- Inda-Díaz JS, Lund D, Parras-Moltó M, Johnning A, Bengtsson-Palme J, Kristiansson E: Latent antibiotic resistance genes are abundant, diverse, and mobile in human, animal, and environmental microbiomes. Microbiome, 11, 44 (2023). doi: 10.1186/s40168-023-01479-0
- Abramova A, Berendonk TU, Bengtsson-Palme J: A global baseline for qPCR-determined antimicrobial resistance gene prevalence across environments. Environment International, 178, 108084 (2023). doi: 10.1016/j.envint.2023.108084
- Ebmeyer S, Kristiansson E, Larsson DGJ: A framework for identifying the recent origins of mobile antibiotic resistance genes. Communications Biology, 4 (2021). doi:10.1038/s42003-020-01545-5
- Larsson DGJ, Andremont A, Bengtsson-Palme J, Brandt KK, de Roda Husman AM, Fagerstedt P, Fick J, Flach C-F, Gaze WH, Kuroda M, Kvint K, Laxminarayan R, Manaia CM, Nielsen KM, Ploy M-C, Segovia C, Simonet P, Smalla K, Snape J, Topp E, van Hengel A, Verner-Jeffreys DW, Virta MPJ, Wellington EM, Wernersson A-S: Critical knowledge gaps and research needs related to the environmental dimensions of antibiotic resistance. Environment International, 117, 132–138 (2018). doi: 10.1016/j.envint.2018.04.041
- Pruden A, Larsson DGJ, Amézquita A, Collignon P, Brandt KK, Graham DW, et al. Management options for reducing the release of antibiotics and antibiotic resistance genes to the environment. Environmental Health Perspectives, 121, 878–885 (2013). doi:10.1289/ehp.1206446
- Bengtsson-Palme J, Kristiansson E, Larsson DGJ: Environmental factors influencing the development and spread of antibiotic resistance. FEMS Microbiology Reviews, 42, 1, 68–80 (2018). doi: 10.1093/femsre/fux053
Not only did we release the most recent episode of the lab’s podcast this weekend. Today, the episode of The AMR Studio where I’m interviewed by Eva Garmendia of the Uppsala Antibiotic Center was put online. We talk mostly about antibiotic resistance in the environment and the role that the EMBARK program can play in mitigating environmental resistance. I think it’s a nice listen (recorded in the beautiful world pre-covid-19). Find it where you find podcasts (e.g. Apple or Spotify).
I am very happy to announce today (on the European Antibiotic Awareness Day), that the EMBARK project that I am coordinator for got funded by JPIAMR with almost 1.4 million Euros over three years!
The primary goal of EMBARK is to establish a baseline for how common resistance is in the environment and what resistance types that can be expected where. That background data will then underpin efforts to standardize different methods for resistance surveillance and identify high-priority targets that should be used for efficient monitoring. In addition, EMBARK will develop and evaluate methods to detect new resistance factors and thereby provide an early-warning system for emerging resistance threats.
EMBARK is an international collaboration funded by JPIAMR. The consortium consists of myself, Thomas Berendonk (TU-Dresden, Germany), Luis Pedro Coelho (Fudan University, China), Sofia Forslund (ECRC Max-Delbrück-Centrum für Molekulare Medizin, Germany), Etienne Ruppé (INSERM, France) and Rabaab Zahra (Quaid-i-Azam University, Pakistan).
EMBARK has a website where the protocols and data generated during the project will be released. Follow our progress towards better monitoring of antimicrobial resistance in the environment here and on the EMBARK Twitter account: @EMBARK_JPIAMR!