Detection of the Diadema antillarum scuticociliatosis Philaster clade and associated microorganisms in museum specimens from 1965 to 2015
Museum specimens provide a crucial window into historical biodiversity, allowing researchers to investigate long-term host-microbe interactions and pathogen dynamics. This study examined Diadema antillarum specimens collected between 1965 and 2015 for the presence of causative agent of recent D. antillarum mass mortality events, the Diadema antillarum scuticociliatosis Philaster-clade (DaScPc). Specimens (n = 102) spanning this time period, were assessed for DaScPc by PCR amplification of the 18S and 28S rRNA genes. Additionally, prokaryotic 16S rRNA gene amplicon sequencing was used to explore shifts in the microbial community across time in relation to collection time, specimen storage facility, and presence of DaScPc. Successful recovery of DaScPc 18S and 28S rRNA sequences from the museum specimens across most time points showed that DaScPc or a close relative was associated with grossly normal D. antillarum between 1965 and 2015. It is unclear whether this taxon represents a commensal organism, which became antagonistic, or a parasite that caused low level disease at the time of collection, is still unknown. 16S rRNA gene amplicon analyses of spine and body wall samples indicated that composition of museum specimen bacteria and archaea are strongly influenced by storage facility, time of collection, and even DaScPc ocurrence. Despite the strong variation due to these properties bacterial genera associated contemporary and unpreserved grossly normal D. antillarum recovered in amplicon libraries.
Museum specimens provide a crucial window into historical biodiversity, allowing researchers to investigate long-term host-microbe interactions and pathogen dynamics. This study examined Diadema antillarum specimens collected between 1965 and 2015 for the presence of causative agent of recent D. antillarum mass mortality events, the Diadema antillarum scuticociliatosis Philaster-clade (DaScPc). Specimens (n = 102) spanning this time period, were assessed for DaScPc by PCR amplification of the 18S and 28S rRNA genes. Additionally, prokaryotic 16S rRNA gene amplicon sequencing was used to explore shifts in the microbial community across time in relation to collection time, specimen storage facility, and presence of DaScPc. Successful recovery of DaScPc 18S and 28S rRNA sequences from the museum specimens across most time points showed that DaScPc or a close relative was associated with grossly normal D. antillarum between 1965 and 2015. It is unclear whether this taxon represents a commensal organism, which became antagonistic, or a parasite that caused low level disease at the time of collection, is still unknown. 16S rRNA gene amplicon analyses of spine and body wall samples indicated that composition of museum specimen bacteria and archaea are strongly influenced by storage facility, time of collection, and even DaScPc ocurrence. Despite the strong variation due to these properties bacterial genera associated contemporary and unpreserved grossly normal D. antillarum recovered in amplicon libraries.
University of California San Diego Microbiome Initiative