New treatment could replace antibiotic treatment and reduce risk of resistant pathogens
Researchers at the Smithsonian’s National Museum of Natural History are the first to treat and prevent stony coral tissue loss disease (SCTLD), a mysterious disease that has ravaged Florida’s coral reefs since 2014 and is rapidly spreading throughout the Caribbean. found effective bacterial probiotics.
Probiotic therapy, described in a paper published today in Communications Biology, is so far the only proven treatment for the disease, but the broad-spectrum antibiotic amoxicillin risks promoting antibiotic resistance. Offer an alternative to use. bacteria.
SCTLD afflicts at least 20 species of coral called hard corals. Hard corals provide essential habitat for a myriad of fish and marine animals of economic and intrinsic value, while also helping protect coastlines from storm damage. Since its discovery in Florida in 2014, cases of SCTLD have been confirmed in at least 20 countries. The exact cause of the disease remains unknown, but when corals become infected, colonies of polyps can die within weeks.
Valerie Paul, principal scientist at the Smithsonian Marine Station in Fort Pierce, Florida, and senior author of the study, said: “Biologic tissue sloughs off, leaving only a white calcium carbonate skeleton.”
Paul has studied coral reefs for decades, but decided to “go all out” with SCTLD in 2017 because it was so deadly, poorly understood, and She said it was because it spread so quickly.
While investigating how the disease spreads, Paul and a team including researchers from the University of Florida found that some pieces of giant coral (Montastraea cavernosa) rapidly developed lesions characteristic of SCTLD. I found it dead, but the other pieces didn’t get sick at all.
Although the exact cause of SCTLD is unknown, the efficacy of antibiotics as a treatment suggests that pathogenic bacteria are somehow involved in disease progression.
For this reason, the researchers collected samples of naturally occurring non-pathogenic bacteria present in pairs of disease-resistant large star coral fragments for further testing. Using these samples, the research team aimed to identify naturally occurring microbes protecting some large star corals from SCTLD.
First, the team tested the antimicrobial properties of 222 bacterial strains from disease-resistant corals using three harmful bacterial strains previously isolated from SCTLD-infected corals. Paul and Blake, lead authors of the study, assistant professors at the University of North Carolina at Wilmington and former fellows of George Burch at the Smithsonian Marine Station, and Blake his oxjima strains of his 83 strains with some antibacterial activity. One of his discoveries in particular stood out, his McH1-7.
The team next performed chemical and genetic analyzes to discover the compounds behind McH1-7’s antibiotic properties and the genes behind the production of those compounds. Finally, the researchers tested her McH1-7 using live giant coral fragments. These laboratory trials provided the final bit of conclusive evidence: McH1-7 halted or slowed disease progression in 68.2% of 22 infected coral fragments, and more significantly , it prevented the disease from spreading in all 12 transmission experiments. do.
Going forward, Paul said that if this probiotic is to be used on a large scale in the field, improved delivery mechanisms need to be worked on. , is basically wrapping the coral in a plastic bag, creating a small aquarium, and injecting it with useful bacteria. Paul said it remains to be seen if it will provide efficacy and preventive benefits.
That this newly identified probiotic could help struggling corals in Florida without the risk of inadvertently spawning antibiotic-resistant bacteria is an urgent need. This is good news for
“Between ocean acidification, coral bleaching, pollution and disease, there are many ways to kill corals,” Paul said. “We need to do everything we can to help them so they don’t disappear.”
Original: Newly discovered probiotics could protect Caribbean corals threatened by deadly, devastating disease
Than: || Smithsonian Institution || Smithsonian Institution University of Florida
