Study Reveals Species-Specific Microbial Changes in Corals with Stony Coral Tissue Loss Disease
Researchers analyzed microbial communities in three coral species with varying susceptibility to stony coral tissue loss disease (SCTLD), finding differential microbial shifts in highly susceptible species but not in moderately affected ones. The study examined healthy versus diseased tissue across Dendrogyra cylindrus, Pseudodiploria strigosa, and Orbicella faveolata collected from the Mexican Caribbean. These findings suggest that microbial community responses to SCTLD correlate with species-level disease susceptibility, potentially informing future disease management strategies.
A preprint study published on bioRxiv examined how microbial communities change within coral colonies affected by stony coral tissue loss disease (SCTLD), a pathology causing rapid tissue loss and high mortality across nearly 30 coral species. Researchers compared microbial profiles in healthy and diseased tissue from three species representing a gradient of disease susceptibility: two highly susceptible species (Dendrogyra cylindrus and Pseudodiploria strigosa) and one moderately affected species (Orbicella faveolata). Using 16S rRNA gene sequencing, the team found statistically significant microbial community differences between healthy and diseased tissue in the two highly susceptible species, but not in the moderately affected species. Notably, diseased tissue showed species-specific bacterial profiles, while healthy tissue across all three species shared common bacterial groups including Pirelullales, NB1-J, and SAR324. The researchers conclude that microbial community responses to SCTLD follow patterns consistent with each species' inherent susceptibility to the disease.
What's missing
The study does not discuss potential causative mechanisms—whether observed microbial shifts are drivers of disease susceptibility or consequences of tissue loss. Additionally, the preprint does not specify sample collection dates, environmental conditions during sampling, or whether results have undergone peer review prior to publication.
What different sources said
- bioRxivCenter
Within-colony microbial response of three species with different susceptibility to Stony Coral Tissue Loss Disease
Related
Gut Bacteria Enzyme Found to Break Down Heat-Processed Food Compounds, Producing Novel Biogenic Amines
Researchers have discovered that an enzyme in common gut bacteria can degrade N-epsilon-carboxymethyllysine (CML), a compound formed during thermal food processing, producing previously unknown biogenic amines. The enzyme, ornithine decarboxylase SpeC from enterobacteria, acts on CML and related modified lysine derivatives through a low-level 'underground' catalytic activity. This finding suggests a previously unrecognized communication axis between thermally processed dietary compounds and gut microbial physiology, with potential implications for host health.
Full-Length Gene Sequencing Reveals Two Distinct Bacterial Communities in Black-Legged Ticks Expanding Into Canada
Researchers used Oxford Nanopore full-length 16S rRNA gene sequencing to characterize the microbiome of Ixodes scapularis black-legged ticks collected in Nova Scotia, Canada, distinguishing between tick-adapted bacteria and environmentally acquired bacteria. The study comes as I. scapularis — the primary vector of Lyme disease — is rapidly expanding northward into Canada due to climate change. The findings suggest that environmentally derived bacteria in tick microbiomes are not mere contamination, which has implications for how tick microbiome data is collected and interpreted across surveillance studies.
Study Identifies Metabolic Link Between Cell Envelope Stress and Biofilm Formation in Bacteria
Researchers have discovered that the metabolite acetyl-CoA directly inhibits enzymes that degrade the bacterial signaling molecule c-di-GMP, connecting cell envelope biosynthesis stress to biofilm formation in Pseudomonas aeruginosa. The study found that sub-inhibitory concentrations of antibiotics targeting early peptidoglycan biosynthesis — but not other antibiotic classes — elevate c-di-GMP levels by reducing phosphodiesterase activity, with acetyl-CoA competing for the enzyme active site. Because the relevant enzyme domain is broadly conserved across bacterial species, this checkpoint mechanism may be widespread and could have implications for understanding antibiotic-induced biofilm responses.