We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Differential effects of two prevalent environmental pollutants on host-pathogen dynamics
Summary
Freshwater amphibian hosts were exposed to microplastics and glyphosate herbicide individually and in combination to assess effects on infection dynamics with a fungal pathogen, finding that pollutant exposure altered disease outcomes in complex ways depending on dose and combination. The study highlights that understanding real-world infection risk requires accounting for multiple co-occurring environmental stressors.
Chemical pollutants are a major factor implicated in freshwater habitat degradation and species loss. Microplastics and glyphosate-based herbicides are prevalent pollutants with known detrimental effects on animal welfare but our understanding of their impacts on infection dynamics are limited. Within freshwater vertebrates, glyphosate formulations reduce fish tolerance to infections, but the effects of microplastic consumption on disease tolerance have thus far not been assessed. Here, we investigated how microplastic (polypropylene) and the commercial glyphosate-based herbicide, Roundup®, impact fish tolerance to infectious disease and mortality utilising a model fish host-pathogen system. For uninfected fish, microplastic and Roundup had contrasting impacts on mortality as individual stressors, with microplastic increasing and Roundup decreasing mortality compared with control fish not exposed to pollutants. Concerningly, microplastic and Roundup combined had a strong interactive reversal effect by significantly increasing host mortality for uninfected fish (73% mortality). For infected fish, the individual stressors also had contrasting effects on mortality, with microplastic consumption not significantly affecting mortality and Roundup increasing mortality to 55%. When combined, these two pollutants had a moderate interactive synergistic effect on mortality levels of infected fish (53% mortality). Both microplastic and Roundup individually had significant and contrasting impacts on pathogen metrics with microplastic consumption resulting in fish maintaining infections for significantly longer and Roundup significantly reducing pathogen burdens. When combined, the two pollutants had a largely additive effect in reducing pathogen burdens. This study is the first to reveal that microplastic and Roundup individually and interactively impact host-pathogen dynamics and can prove fatal to fish.
Sign in to start a discussion.
More Papers Like This
Combined effect and mechanism of microplastic with different particle sizes and levofloxacin on developing Rana nigromaculata: Insights from thyroid axis regulation and immune system
Researchers exposed developing frogs to a combination of microplastics of different sizes and the antibiotic levofloxacin at environmentally relevant levels. They found that the combination disrupted thyroid hormone regulation and immune system function more severely than either pollutant alone. The study suggests that microplastics and pharmaceutical contaminants together may pose compounding risks to amphibian development and health.
Trophically Transmitted Parasites and Their Responses to Microbial Pathogens and Consumed Plastic Contaminants
Researchers reviewed how trophically transmitted parasites respond to stressors including microplastic contaminants and microbial pathogens, finding that plastic exposure can disrupt host-parasite dynamics by altering host microbiomes and immune responses. The interactions add complexity to understanding parasite infection success in polluted environments.
Multi stress system: Microplastics in freshwater and their effects on host microbiota
This study examined how combined exposure to microplastics and organic chemical pollutants affects freshwater organisms through a multi-stress approach, focusing on gut microbiome changes as an indicator. Microplastic exposure in combination with other pollutants altered microbiome composition more than either stressor alone, with potential consequences for host fitness and disease resistance.
Direct and indirect ecological impacts of microplastic fibers on host-parasite and host-microbiota interactions
Researchers experimentally tested how polyester microplastic fibers of two sizes affect trematode parasite infection rates and gut microbiome composition in leopard frog tadpoles. Microplastic fibers altered both host-parasite dynamics and microbiota structure in size-dependent ways, demonstrating that plastic fiber pollution has cascading effects on freshwater ecological interactions.
Effect of emerging pollutants on the gut microbiota of freshwater animals: Focusing on microplastics and pesticides
This review examines how microplastics and pesticides, two pollutants commonly found together in freshwater, each disrupt the gut bacteria of fish and other aquatic animals, and their combined presence can make the effects worse. Changes in gut bacteria caused by these pollutants can impair metabolism, immunity, and overall health of aquatic organisms, with potential consequences for the food chain.