Investigating microbial size classes associated with the transmission of stony coral tissue loss disease (SCTLD)

Bibliographic Details
Title: Investigating microbial size classes associated with the transmission of stony coral tissue loss disease (SCTLD)
Authors: James S. Evans, Valerie J. Paul, Blake Ushijima, Kelly A. Pitts, Christina A. Kellogg
Source: PeerJ, Vol 11, p e15836 (2023)
Publisher Information: PeerJ Inc., 2023.
Publication Year: 2023
Collection: LCC:Medicine
LCC:Biology (General)
Subject Terms: Coral, 16S, Disease, Microbes, Bacteria, SCTLD, Medicine, Biology (General), QH301-705.5
More Details: Effective treatment and prevention of any disease necessitates knowledge of the causative agent, yet the causative agents of most coral diseases remain unknown, in part due to the difficulty of distinguishing the pathogenic microbe(s) among the complex microbial backdrop of coral hosts. Stony coral tissue loss disease (SCTLD) is a particularly destructive disease of unknown etiology, capable of transmitting through the water column and killing entire colonies within a matter of weeks. Here we used a previously described method to (i) isolate diseased and apparently healthy coral colonies within individual mesocosms containing filtered seawater with low microbial background levels; (ii) incubate for several days to enrich the water with coral-shed microbes; (iii) use tangential-flow filtration to concentrate the microbial community in the mesocosm water; and then (iv) filter the resulting concentrate through a sequential series of different pore-sized filters. To investigate the size class of microorganism(s) associated with SCTLD transmission, we used 0.8 µm pore size filters to capture microeukaryotes and expelled zooxanthellae, 0.22 µm pore size filters to capture bacteria and large viruses, and 0.025 µm pore size filters to capture smaller viruses. In an attempt to further refine which size fraction(s) contained the transmissible element of SCTLD, we then applied these filters to healthy “receiver” coral fragments and monitored them for the onset of SCTLD signs over three separate experimental runs. However, several factors outside of our control confounded the transmission results, rendering them inconclusive. As the bulk of prior studies of SCTLD in coral tissues have primarily investigated the associated bacterial community, we chose to characterize the prokaryotic community associated with all mesocosm 0.22 µm pore size filters using Illumina sequencing of the V4 region of the 16S rRNA gene. We identified overlaps with prior SCTLD studies, including the presence of numerous previously identified SCTLD bioindicators within our mesocosms. The identification in our mesocosms of specific bacterial amplicon sequence variants that also appear across prior studies spanning different collection years, geographic regions, source material, and coral species, suggests that bacteria may play some role in the disease.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 2167-8359
Relation: https://peerj.com/articles/15836.pdf; https://peerj.com/articles/15836/; https://doaj.org/toc/2167-8359
DOI: 10.7717/peerj.15836
Access URL: https://doaj.org/article/211b7ce730ef4f63bf3fd9c660844f60
Accession Number: edsdoj.211b7ce730ef4f63bf3fd9c660844f60
Database: Directory of Open Access Journals
More Details
ISSN:21678359
DOI:10.7717/peerj.15836
Published in:PeerJ
Language:English