Carly Ching

Antimicrobial resistance (AMR) is a major threat to global health and resistant bacterial populations have been observed to develop and spread in and around wastewater. However, in vitro studies on AMR development are typically conducted in ideal rich media conditions, which can differ in composition and nutrient density from wastewater. In this study, we compare the growth and AMR development of E. coli in a synthetic wastewater recipe to autoclaved wastewater samples from the Massachusetts Water Resources Authority (MWRA). We found that synthetic wastewater and real wastewater samples both supported less bacterial growth compared to LB broth and had similar susceptibility profiles to antibiotic pressure from Doxycycline, Ciprofloxacin and Streptomycin. More importantly, unlike in LB broth, AMR development over time during continuous passaging under subinhibitory antibiotic pressure in pH‐adjusted synthetic wastewater was similar in fold change to real wastewater samples. Thus, we suggest that synthetic wastewater is a more accurate predictor of both E. coli growth and antibiotic resistance development in wastewater systems than standard nutrient broths such as LB. The validation of synthetic wastewater as a better proxy for real wastewater will allow for further recapitulation of the wastewater environment in future in vitro studies of AMR in these conditions.

Background: Antibiotic use in food-producing animals can drive antimicrobial resistance (AMR). Communication is a central strategy to promote behavioral change. As such, there is a need to determine from whom and where farmers receive information about antibiotic use. We aim to identify communication pathways that influence farmers’ antibiotic use in food-producing animals and understand the barriers and facilitators for using these information sources. Methods: PRISMA Extension for Scoping Reviews guidelines were followed. PubMed, CAB Abstracts, ProQuest Social Science Premium Collection, and PsycINFO were searched for primary peer-reviewed studies published from 2000 to April 10 ^th , 2025, in any language. We sought studies from any country, that state from whom or where farmers or farm workers get information about antibiotic use. Title and abstract, full text screening and data charting were performed by two reviewers. One researcher inductively coded points of influence, barriers and facilitators, which were thematically combined through discussion. Quantitative and qualitative analyses were then performed. Results: Our search retrieved 5925 records. After abstract review, 140 records met the inclusion criteria. After review of full texts, 75 papers were included for data charting. Overall, we identify a complex network of 25 stakeholders, all of whom can exert influence. The most mentioned actors across eligible studies were veterinarians (86.7%), followed by peers (49.3%). The major barriers to advice were access/availability (48.6%) and cost (45.9%), and the major facilitators were trust (41.7%), followed by access/availability (33.3%). Differences in mechanics and impact on antibiotic use, along with recommendations from the literature, were also summarized Conclusions: Our results suggest that knowledge and awareness about appropriate antibiotic use and AMR must permeate multiple layers of actors with differing interests. We suggest potential strategies to address barriers, including ways to reduce costs, increase access and build trust.

Antimicrobial resistance (AMR) is a One Health policy issue, which connects humans, animals and the environment. Antibiotics and AMR impact ecosystems, yet microbes (which are also part of ecosystems) are often overlooked in biodiversity strategies. This perspective examines the limited integration of AMR-related topics in current biodiversity strategies and discusses barriers and recommendations for inclusion. Documents reviewed include the Kunming-Montreal Global Biodiversity Framework and seven different biodiversity strategies from various regions.

Refugee settlements are often positioned around natural borders, which often have a heightened danger of environmental hazards. Here, we aim to better understand why settlements are in environmentally vulnerable land and what social and physical factors contribute to this phenomenon. To do this, we present a holistic narrative that maps climate threats among displaced populations in Cox’s Bazar district, Bangladesh, while contextualizing environmental vulnerability by incorporating historical and social constraints. Using ArcGIS, an online mapping program, we illustrate the overlap between different climatic events and how these vulnerabilities compound and intensify one another. We also discuss the history of natural migration and settlement pertaining to the physical landscape and the sociopolitical reasons refugees remain in environmentally vulnerable areas. Overall, we find an emerging trend that may be broadly applicable to instances of forced displacement; physical settlement locations near international borders demarcated by landforms may be more vulnerable to the effects of climate change and extreme climate events. However, physical, social, and political reasons often cement these locations. Recommendations include enhancing the resilience of refugee camps through infrastructure improvements, sustainable land management, and reforestation efforts, which would benefit both the environment and local and refugee communities.

Background: Indiscriminate use of antimicrobials in food-producing animals is a critical driver of antimicrobial resistance (AMR). However, pushback from stakeholders on policies and regulations on antimicrobial use in food-producing animals remains. One important strategy to promote behavioural change is effective communication. Framing, or how issues are constructed to relate to specific interests, is a mechanism to guide sentiment, including of political stakeholders and end-users. Methods: Through a sector-specific approach, we used a combination of inductive and deductive coding to quantitatively determine how risk and rationale for action were framed within portions of policy documents and reports from international organizations focused on food-producing animals and AMR. We also qualitatively examined the frames and language used within the documents, to identify specific narratives used, as well as gaps and opportunities to improve communication for end-user support and political legitimacy. Results: We found that while similar motivational frames are used throughout, they were distributed differently and utilized different narratives. The most frequently used motivational frame, on average, was ‘Human Health’ (20.9% of all frames used) with ‘Animal Health and Welfare’ and ‘Food Production and Security’ second and third, respectively (18.2% and 14.5%). Self-interest frames specific to the farmer or farm worker were rarely used. Conclusions: Specific recommendations include increasing self-interest frames, ensuring accessibility of messaging and considering underlying assumptions. Overall, our findings can improve framing and language to improve resonance on policies surrounding antimicrobial use in food-producing animals. This work provides a framework to systematically analyse framing in documents to compare different sectors or regions.

Acinetobacter baumannii is an opportunistic pathogen causing several infections that are increasingly difficult to treat due to its ability to rapidly gain antibiotic resistances. These resistances can arise due to mutations through the activity of error‐prone DNA polymerases, such as DNA polymerase V (DNA Pol V) in response to DNA damage. The regulation of the DNA damage response (DDR) in A. baumannii is not completely understood; the regulation of genes encoding multiple copies of DNA Pol V is not fully characterized. Through genome‐wide mutagenesis, we have identified a novel TetR‐like family regulator of the umuDC and umuC genes, which we have named Error‐prone polymerase regulator (EppR). We have found that EppR represses the expression of the genes encoding DNA Pol V and itself through direct binding to an EppR motif in their promoters. Lastly, we show that EppR also regulates UmuDAb, previously identified as a regulator of genes encoding DNA Pol V. These two gene products are functionally required to ensure regulation of the expression of the two umuDC, the two umuC genes as well as the regulators umuDAb and eppR genes. With these results, we propose a model in which multiple transcription factors regulate the expression of all these genes.

Changing climate may contribute to increased antimicrobial resistance (AMR), particularly in wastewater which acts as a reservoir for resistant bacteria. Here, we determined how applying climate dependencies to our previously published model, rooted in theory, impacts computational simulations of AMR in wastewater. We found AMR levels were reduced at lower temperatures but increased with lower precipitation. The impact of precipitation on AMR was more pronounced at higher temperatures compared to lower temperatures. To validate our model, we investigated associations between total AMR gene abundance in wastewater from the Global Sewage Surveillance project and mean temperature and rainfall values extracted from European Centre for Medium-Range Weather Forcasts Reanalysis v5 (ERA5) reanalysis. We observed similar trends between the simulations and observations. Observations and simulations from our study can inform experiments to determine causal relationships as well as help identify other key drivers. We also discuss study challenges given the complex nature of AMR in the environment.

Acinetobacter baumannii is an opportunistic pathogen causing several infections that are increasingly difficult to treat due to its ability to rapidly gain antibiotic resistances. These resistances can arise due to mutations during the DNA damage response (DDR), through the activity of error-prone DNA polymerases, such as DNA polymerase V (DNA Pol V). Currently, the DDR in A. baumannii is not well understood and the regulation of genes encoding multiple copies of DNA Pol V is not fully characterized. Through genome wide mutagenesis, we have identified a novel TetR-like family regulator of genes that encode DNA Pol V, which we have named E rror- p rone p olymerase r egulator, EppR. We have found that EppR represses the expression of the genes encoding DNA Pol V and itself through direct binding to a conserved EppR motif in their promoters. Lastly, we show that EppR also regulates UmuDAb, previously identified as a regulator of genes encoding DNA Pol V. These two gene products are functionally required to ensure regulation of expression of genes encoding DNA Pol Vs and umuDAb . With these results, we propose a co-repressor model for the regulation of genes encoding DNA Pol V and umuDAb .

Objectives Identifying key barriers to accessing quality-assured and affordable antimicrobials among forcibly displaced persons in Uganda, Yemen and Colombia and investigating their (1) utilisation patterns of antibiotics, (2) knowledge about antimicrobial resistance (AMR) and (3) perception of the quality of antimicrobials received. Design Pilot cross-sectional survey. Setting Data were collected from five health facilities in the Kiryandongo refugee settlement (Bweyale, Uganda), three camps for internally displaced persons (IDPs) in the Dar Sad district (Aden, Yemen) and a district with a high population of Venezuelan migrants (Kennedy district, Bogotá, Colombia). Data collection took place between February and May 2021. The three countries were selected due to their high number of displaced people in their respective continents. Participants South Sudanese refugees in Uganda, IDPs in Yemen and Venezuelan migrants in Colombia. Outcome measure The most common barriers to access to quality-assured and affordable antimicrobials. Results A total of 136 participants were enrolled in this study. Obtaining antimicrobials through informal pathways, either without a doctor’s prescription or through family and friends, was common in Yemen (27/50, 54.0%) and Colombia (34/50, 68.0%). In Yemen and Uganda, respondents used antibiotics to treat (58/86, 67.4%) and prevent (39/86, 45.3%) a cold. Knowledge of AMR was generally low (24/136, 17.6%). Barriers to access included financial constraints in Colombia and Uganda, prescription requirements in Yemen and Colombia, and non-availability of drugs in Uganda and Yemen. Conclusion Our multicentred research identified common barriers to accessing quality antimicrobials among refugees/IDPs/migrants and common use of informal pathways. The results suggest that knowledge gaps about AMR may lead to potential misuse of antimicrobials. Due to the study’s small sample size and use of non-probability sampling, the results should be interpreted with caution, and larger-scale assessments on this topic are needed. Future interventions designed for similar humanitarian settings should consider the interlinked barriers identified.

The aim of this paper is to explore and assess various strategies for monitoring antimicrobial consumption (AMC) in animals, within the context of the One Health approach. Recent studies have shed light on the limited surveillance and data collection for AMC in animals. Using the United States Center for Disease Control and Prevention Policy Analytical Framework, we assess global, national, and farm-level surveillance strategies on public health impact and feasibility using evidence from primary, secondary, and grey literature. From this, we identify key policy mechanisms that support the adoption of surveillance while providing specific recommendations. We find that a global strategy, though valuable for benchmarking and policy guidance, faces participation and data visibility challenges. National-level surveillance offers direct inputs into national action plans but struggles with data uniformity and comparability. Farm-level surveillance, while resource-intensive, provides the most granular data for informing specific interventions. We advocate for a multi-faceted approach to AMC surveillance, emphasizing that legal mandates and financial incentives are crucial for encouraging surveillance participation, along with international cooperation for enhancing participation and data quality. Drawing parallels with public reporting challenges in other sectors can provide valuable lessons on how to address data collection, analysis, and reporting barriers.