Genomics study in the Caribbean, Sargasso Seas represents the first vibrio assembled from plastic waste — ScienceDaily

Featured Sponsor

Store	Link	Sample Product
UK Artful Impressions	Premiere Etsy Store

Since 2011, Sargassum, free-living populations of brown macroalgae, have been expanding rapidly in the Sargasso Sea and other parts of the open ocean, such as the Great Atlantic Sargassum Belt, including frequent and unremarkable kelp buildup events. precedents on the beaches. Plastic marine debris, first found in the surface waters of the Sargasso Sea, has become a global concern and is known to persist decades longer than natural substrates in the marine environment.

Little is currently known about the ecological relationship of vibrios to sargassum. In addition, genomic and metagenomic evidence is lacking as to whether vibrios colonizing plastic marine debris and sargassum could infect humans. As summer gets underway and efforts are made to find innovative solutions to reuse sargassum, could these substrates pose a triple threat to public health?

Researchers at Florida Atlantic University and collaborators fully sequenced the genomes of 16 Vibrio cultivars isolated from eel larvae, plastic marine debris, sargassum, and seawater samples collected in the Caribbean seas and sargassum from the North Atlantic Ocean. What they discovered is that Vibrio pathogens have the unique ability to “stick” to microplastics and that these microbes may be adapting to plastic.

“Plastic is a new element that has been introduced to marine environments and has only been around for about 50 years,” said Tracy Mincer, Ph.D., corresponding lead author and an assistant professor of biology at the Harbor Branch Institute of Oceanography at the FAU and Harriet L. Wilkes Honors College. “Our lab work showed that these Vibrio are extremely aggressive and can seek out and attach themselves to plastic in a matter of minutes. We also found that there are attachment factors that microbes use to attach themselves to plastics, and it’s the same type of mechanism that microbes use to attach themselves to plastics.” pathogens.”

The study, published in the journal Water Research, illustrates that open-sea vibrios represent a previously undescribed group of microbes, some representing potential new species, possessing a combination of pathogenic genes and low nutrient acquisition, reflecting their pelagic habitat and the substrates and hosts they colonize. Using the metagenome-assembled genome (MAG), this study represents the first Vibrio spp. genome assembled from plastic waste.

The study highlighted vertebrate pathogen genes closely related to cholera and bacterial strains unrelated to cholera. Cultivar phenotype tests confirmed rapid biofilm formation, hemolytic and lipophospholytic activities, consistent with pathogenic potential.

The researchers also found that genes for zonula occludens toxin, or “zot,” first described in Vibrio cholerae, which is a secreted toxin that increases intestinal permeability, were some of the most retained and selected genes in the vibrios they found. . These vibrios appear to be entering the intestine, getting stuck in the intestines and infecting that way.

“Another interesting thing that we discovered is a set of genes called ‘zot’ genes, which cause leaky gut syndrome,” Mincer said. “For example, if a fish eats a piece of plastic and becomes infected with this Vibrio, causing leaky gut and diarrhea, it will release waste nutrients like nitrogen and phosphate that could stimulate the growth of sargassum and other surrounding organisms.”

The findings show some Vibrio spp. in this environment they have an ‘omnivorous’ lifestyle that targets both plant and animal hosts in combination with the ability to persist under oligotrophic conditions. With increased interactions between humans, sargassum, and plastic marine debris, the associated microbial flora of these substrates could harbor potent opportunistic pathogens. Importantly, some culture-based data shows that stranded sargassum appears to harbor large numbers of Vibrio bacteria.

“I don’t think at this point anyone has really considered these microbes and their ability to cause infections,” Mincer said. “We really want to make the public aware of these associated risks. In particular, caution should be exercised regarding the harvesting and processing of sargassum biomass until the risks are further explored.”

Study co-authors represent the NIOZ Royal Netherlands Institute for Sea Research, the Japan Agency for Earth and Marine Sciences and Technologies, Ludwig Maximilian University of Munich, Germany, Emory University, the University of Amsterdam, and the Marine Biological Laboratory.

This research was supported by the National Science Foundation (NSF) (grant OCE-1155671 awarded to Mincer), FAU World Class Faculty and Scholar Program (awarded to Mincer), NSF (grant OCE-1155571 awarded to Linda A. Amaral-Zettler, Ph.D., Corresponding Author, NIOZ), NSF (Grant OCE-1155379 awarded to Erik R. Zettler, Ph.D., Co-Author, NIOZ), NSF TUES Grant (DUE-1043468 awarded to Linda Zettler and Erik Zettler).