We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Combined effects of microplastics and antibiotic-resistant bacteria on Daphnia magna growth and expression of functional genes
AI summary Read the abstract
Researchers tested the combined effects of microplastics and antibiotic-resistant bacteria on tiny freshwater organisms called Daphnia magna. They found that polystyrene microplastics colonized with resistant Shigella bacteria were ingested and trapped in the organisms' intestines, causing changes in body size, reproduction, and gene expression. The study suggests that microplastics carrying antibiotic-resistant bacteria may pose amplified ecological risks to aquatic food chains.
Microplastics could act as vectors for the transport of harmful bacteria, such as pathogens and antibiotic resistance bacteria (ARB), but their combined effects have not been reported yet. Here, ARB Shigella flexneri with sulfonamides resistance and micro-polystyrene (micro-PS) were used to investigate their possible combined effects on the growth and expression of functional genes in Daphnia magna. Results showed that micro-PS colonized with S. flexneri were ingested by D. magna and blocked in their intestine after 24 h exposure. Changes were observed in the life history and morphology of D. magna, as well as the expression of functional genes in all treatments, but with no difference in the survival rate. We also determined the expression of six functional genes involved in energy and metabolism (arginine kinase, AK) and oxidative stress response (thioredoxin reductase, TRxR, catalase, CAT, and glutathione S-transferases, GSTs), as well as in growth, development and reproduction (vitellogenin, Vtg1 and ecdysone receptor, EcR). AK and Vtg1 did not show significant differences, however, EcR was down-regulated and the other three genes (TRxR, CAT, GSTs) were up-regulated in the combined-treated group. Antibiotic resistance gene (ARGs) sul1 was detected when exposed to micro-PS colonized with S. flexneri., suggesting that D. magna could acquire resistance genes through microplastic biofilms. These results indicated that MPs could act as a carrier of ARB to transfer ARGs into D. magna, and affect the life history, morphology, and the expression of related functional genes of D. magna, to adapt to the stress caused by MPs and ARB.
More Papers Like This
Combined Effects of Polystyrene Nanoplastics and Enrofloxacin on the Life Histories and Gut Microbiota of Daphnia magna
AI summary Read the abstract
Researchers exposed Daphnia magna to polystyrene nanoplastics and the antibiotic enrofloxacin alone and in combination, measuring life history traits and gut microbiota responses. Both stressors individually reduced survival and reproduction, and combined exposure altered the taxonomic composition and metabolic function of gut microbiota more than either contaminant alone.
Effects of microplastics on Daphnia-associated microbiomes in situ and in vitro
AI summary Read the abstract
This study investigated how microplastic exposure alters the microbiome associated with Daphnia in freshwater, finding shifts in bacterial community composition that may affect host health and ecological function. The results suggest that microplastics can indirectly harm zooplankton by disrupting their microbial symbionts.
Effects of microplastics on Daphnia -associated microbiomes in situ and in vitro
AI summary Read the abstract
Researchers examined how microplastics affect the microbiome of Daphnia, a keystone freshwater organism, through both field sampling and controlled laboratory experiments. Using DNA sequencing techniques, they found that microplastic exposure altered the composition of bacterial communities associated with Daphnia. The study suggests that microplastic pollution may disrupt the beneficial microbial relationships that support the health of important freshwater species.
Effect of microplastics on oxytetracycline trophic transfer: Immune, gut microbiota and antibiotic resistance gene responses
AI summary Read the abstract
When polypropylene microplastics and the antibiotic oxytetracycline were present together in water, the microplastics acted as carriers that increased antibiotic buildup in shrimp and fish through the food chain. This combination caused more gut and liver damage, weakened immune defenses, and promoted the spread of antibiotic-resistant bacteria. The findings highlight that microplastics can make antibiotic pollution worse by helping resistant genes move up the food chain.
Abundance and characteristics of microplastics in market bivalves from South Korea
AI summary Read the abstract
Researchers investigated the effects of polystyrene microplastics on the freshwater cladoceran Daphnia magna, a key species in aquatic food webs. They found that microplastic exposure impaired reproduction, reduced growth, and caused oxidative stress even at relatively low concentrations. The study highlights that these tiny plastic particles can harm small freshwater organisms that play a critical role in maintaining healthy aquatic ecosystems.
Research digests by email
When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.