Plastiome: Plastisphere-enriched mobile resistome in aquatic environments.

Aquatic microplastics (MPs) act as reservoirs for microbial communities, fostering the formation of a mobile resistome encompassing diverse antibiotic (ARGs) and biocide/metal resistance genes (BMRGs), and mobile genetic elements (MGEs). This collective genetic repertoire, referred to as the "plastiome," can potentially perpetuate environmental antimicrobial resistance (AMR). Our study examining two Japanese rivers near Tokyo revealed that waterborne MPs are primarily composed of polyethylene and polypropylene fibers and sheets of diverse origin. Clinically important genera like Exiguobacterium and Eubacterium were notably enriched on MPs. Metagenomic analysis uncovered a 3.46-fold higher enrichment of ARGs on MPs than those in water, with multidrug resistance genes (MDRGs) and BMRGs prevailing, particularly within MPs. Specific ARG and BMRG subtypes linked to resistance to vancomycin, beta-lactams, biocides, arsenic, and mercury showed selective enrichment on MPs. Network analysis revealed intense associations between host genera with ARGs, BMRGs, and MGEs on MPs, emphasizing their role in coselection. In contrast, river water exhibited weaker associations. This study underscores the complex interactions shaping the mobile plastiome in aquatic environments and emphasizes the global imperative for research to comprehend and effectively control AMR within the One Health framework.

Detection of benzotriazole UV stabilizers in the blubber of marine mammals by gas chromatography-high resolution mass spectrometry (GC-HRMS).

Benzotriazole UV stabilizers (BUVSs), such as UV-328 and UV-327, were identified in the blubbers of finless porpoises (Neophocaena phocaenoides) collected from the Ariake Sea, western Japan, by gas chromatography-high resolution mass spectrometry (GC-HRMS). The mean concentrations and standard deviations of UV-328 and UV-327 in five blubber samples were 38 ± 28 ng g(-1) (lipid wt) and 19 ± 19 ng g(-1), respectively. The bioconcentration factor (BCF) of UV-327 between water and finless porpoises was estimated to be 33 300, which is approximately one order of magnitude higher than that found for small fish inhabiting the same regions. The BCF of UV-327 in finless porpoises was similar to that of persistent organochlorine pesticide, hexachlorocyclohexane (HCH: 37 000) in marine mammals from the western North Pacific Ocean. These results suggest that BUVSs appear to be persistent and bioaccumulative in the aquatic food chain. Further investigations on temporal trends, and regional and global monitoring of BUVSs are needed to understand their environmental profiles and potential risks to wildlife and human.

Profiles of polychlorinated biphenyl congeners, organochlorine pesticides, and butyltins in southern sea otters and their prey.

Concentrations of organochlorine pesticides, polychlorinated biphenyl (PCB) congeners, and butyltins were measured in sea otters and selected prey species (invertebrates) collected from the California (USA) coast. Polychlorinated biphenyls, DDTs (sum of p,p'-dichlorodiphenyldichloroethylene [p,p'-DDE], p,p'-dichlorodiphenyldichloroethane [p,p'-DDD], and p,p'-DDT), and butyltins were the major contaminants found in sea otters and their prey. Lipid-normalized concentrations of PCBs and DDT in sea otter livers were 60- and 240-fold greater than those found in the prey. Great biomagnification of PCBs and DDT in sea otters is suggested to result from their high per-capita intake of diet compared with those of other marine mammals. Profiles of PCB congeners in sea otters and prey species suggest a great capacity of sea otters to biotransform lower-chlorinated congeners. Sea otters seem to possess a greater ability than cetaceans to metabolize PCBs. The 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents of non- and mono-ortho PCBs in sea otters and certain prey species were at or above the theoretical threshold for toxic effects.

Accumulation patterns of polychlorinated biphenyl congeners and organochlorine pesticides in Steller's sea eagles and white-tailed sea eagles, threatened species, in Hokkaido, Japan.

Polychlorinated biphenyls (PCBs), including coplanar congeners, hexachlorocyclohexane isomers, chlordane-related compounds, and hexachlorobenzene, were found in the breast muscle of Steller's sea eagles (SSE) and white-tailed sea eagles (WSE) threatened species, collected in Hokkaido, Japan, during the two years from 1998 to 1999. Both PCBs and DDTs were the most notable compounds, with concentrations one to two orders of magnitude higher than the other compounds, that is, from 120 to 39,000 and from 68 to 15,000 ng/g wet weight, respectively. Non-ortho (International Union of Pure and Applied Chemistry [IUPAC] 77, 126, and 169) and mono-ortho (IUPAC 105, 118, and 156)-substituted coplanar PCB congeners amounted to 9.2 to 740 pg/g of 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalents derived from the World Health Organization, Paris, France (WHO), toxic equivalent factors. The atmospheric PCBs and DDTs in eastern Siberian cities, such as Khabarovsk and Magadan, have been reported to be much higher than Hokkaido and the North Pacific. Thus, we speculated that the eagles might have been contaminated in these areas, where they spend most of the year except winter, which they spend in eastern Siberia. Adult eagles accumulated more PCBs and DDTs than younger ones. The patterns of PCB congeners were also found to change, depending on the age of the eagle examined; adult eagles showed relatively higher proportions of highly chlorinated PCBs thanjuvenile eagles did. This difference would be related to the efficiency of the excretion and the metabolism of each PCB congener in the eagles.