ORCID Profile
0000-0001-6895-4677
Current Organisations
Cactus Communications Pvt Ltd
,
Universiti Sains Malaysia - Kampus Kesihatan
,
James Cook University
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Publisher: Wiley
Date: 12-11-2019
Abstract: Research into causative agents underlying coral disease have focused primarily on bacteria, whereas potential roles of viruses have been largely unaddressed. Bacteriophages may contribute to diseases through the lysogenic introduction of virulence genes into bacteria, or prevent diseases through lysis of bacterial pathogens. To identify candidate phages that may influence the pathogenicity of black band disease (BBD), communities of bacteria (16S rRNA) and T4-bacteriophages (gp23) were simultaneously profiled with licon sequencing among BBD-lesions and healthy-coral-tissue of Montipora hispida, as well as seawater (study site: the central Great Barrier Reef). Bacterial community compositions were distinct among BBD-lesions, healthy coral tissue and seawater s les, as observed in previous studies. Surprisingly, however, viral beta ersities based on both operational taxonomic unit (OTU)-compositions and overall viral community compositions of assigned taxa did not differ statistically between the BBD-lesions and healthy coral tissue. Nonetheless, relative abundances of three bacteriophage OTUs, affiliated to Cyanophage PRSM6 and Prochlorococcus phages P-SSM2, were significantly higher in BBD-lesions than in healthy tissue. These OTUs associated with BBD s les suggest the presence of bacteriophages that infect members of the cyanobacteria-dominated BBD community, and thus have potential roles in BBD pathogenicity.
Publisher: The Royal Society
Date: 06-05-2009
Abstract: Recurring summer outbreaks of black band disease (BBD) on an inshore reef in the central Great Barrier Reef (GBR) constitute the first recorded BBD epizootic in the region. In a 2.7 year study of 485 colonies of Montipora species, BBD affected up to 10 per cent of colonies in the assemblage. Mean maximum abundance of BBD reached 16±6 colonies per 100 m 2 ( n =3 quadrats, each 100 m 2 ) in summer, and decreased to 0–1 colony per 100 m 2 in winter. On average, BBD lesions caused 40 per cent tissue loss and 5 per cent of infections led to whole colony mortality. BBD reappearance on previously infected colonies and continuous tissue loss after the BBD signs had disappeared suggest that the disease impacts are of longer duration than indicated by the presence of characteristic signs. Rates of new infections and linear progression of lesions were both positively correlated with seasonal fluctuations in sea water temperatures and light, suggesting that seasonal increases in these environmental parameters promote virulence of the disease. Overall, the impacts of BBD are greater than previously reported on the GBR and likely to escalate with ocean warming.
Publisher: Wiley
Date: 18-01-2016
Abstract: Emerging infectious diseases are contributing to global declines in coral reef ecosystems, highlighting a growing need for aetiological knowledge to develop effective management strategies. In this review, we focus on black band disease (BBD), one of the most virulent diseases and the only polymicrobial disease so far known to affect corals. A multipartite microbial consortium dominated by Cyanobacteria, but also including sulfur-cycling bacteria, other bacterial groups and members of the Archaea and Eukarya, forms a sulfide-rich anaerobic mat that migrates across the surface of coral colonies, killing the underlying tissues. The polymicrobial nature of the disease challenges classic aetiological approaches to unravelling disease causation. Here, we synthesize current knowledge on the range of pathogens forming the microbial consortium with recent studies on the transmission, biogeochemistry and environmental drivers of BBD to develop a conceptual model of BBD pathogenesis. The model illustrates how the development of BBD virulence factors is linked to a cascade of microbial community shifts and associated functional roles that progressively develop the microbial consortium from comparatively benign cyanobacterial patches to virulent BBD lesions. This review showcases how an approach that integrates multiple key aspects of the disease provides insights essential to elucidating the aetiology of BBD.
Publisher: Wiley
Date: 22-04-2013
Abstract: This study investigated the ersity and quantitative shifts of sulfur-oxidizing bacteria (SOB) during the onset of black band disease (BBD) in corals using quantitative PCR (qPCR) and cloning approaches targeting the soxB gene, involved in sulfur oxidation. Four Montipora sp. coral colonies identified with lesions previously termed cyanobacterial patches (CP) (comprising microbial communities different from those of BBD lesions), was monitored in situ as CP developed into BBD. The overall abundance of SOB in both CP and BBD lesions were very low and near the detection limit of the qPCR assay, although consistently indicated that SOB populations decreased as the lesions transitioned from CP to BBD. Phylogenetic assessment of retrieved soxB genes showed that SOB in both CP and BBD lesions were dominated by one sequence type, representing > 70% of all soxB gene sequences and affiliated with members of the Rhodobacteraceae within the α-Proteobacteria. This study represents the first assessment targeting SOB within BBD lesions and clearly shows that SOB are not highly erse or abundant in this complex microbial mat. The lack of oxidation of reduced sulfur compounds by SOB likely aids the accumulation of high levels of sulfide at the base of the BBD mat, a compound contributing to the pathogenicity of BBD lesions.
Publisher: Wiley
Date: 24-09-2013
Abstract: Black band disease (BBD) is a microbial consortium that creates anoxic, sulfide-rich microenvironments and kills underlying coral tissues as it rapidly migrates across colonies. Although bacterial communities associated with BBD have been studied extensively, the presence and roles of archaea are unexplored. Using licon-pyrosequencing of 16S ribosomal RNA genes, we investigated the community structure of both archaea and bacteria within microbial lesions of BBD and the less-virulent precursor stage, 'cyanobacterial patches' (CP), affecting the coral Montipora hispida. We detected characteristic shifts in microbial communities during the development of BBD from CP, reflecting microenvironmental changes within lesions. Archaeal profiles in CP suggested a erse assemblage affiliated with the Thaumarchaeota and Euryarchaeota, similar to communities described for oxic marine environments. In contrast, a novel ribotype, distantly affiliated to the Euryarchaeota, dominated up to 94% of archaeal sequences retrieved from BBD. The physiological characteristics of this dominant archaeal ribotype are unknown because of the novelty of its 16S ribosomal RNA gene sequences however, their prominent associations with BBD lesions suggest the ability to thrive in the organic- and sulfide-rich anoxic microenvironment characteristic of BBD lesions. Discovery of this novel archaeal ribotype provides new insights into the microbial ecology and aetiology of BBD.
Publisher: Springer Science and Business Media LLC
Date: 30-10-2022
DOI: 10.1007/S10266-022-00762-0
Abstract: MicroRNAs (miRNAs) are short, 19-23 nucleotide non-coding RNA molecules that regulate gene expression by silencing or degrading the target mRNA gene. Since their discovery in the nineties of the last century, they have emerged as key inflammatory regulators. Inflammation induces the synthesis of various miRNAs that modulate the expression of multiple molecules involved in orchestrating the inflammatory response. This review aims to provide an insight into the role of miRNAs as potential biomarkers, mediators, and potential therapeutic targets of dental pulp inflammation. A literature search was conducted using the keywords biogenesis of microRNA, human dental pulp cells, pulpitis, and inflammation in PubMed and Scopus index databases for all the published articles dealing with the role of miRNAs in pulp inflammation in the last 10 years. According to the literature, there is a clear correlation between miRNAs and several physiological events, as well as their role as mediators of innate immune response and inflammation in dental pulp cells. Our narrative review stipulates that numerous miRNAs play a key role in modulating inflammation, delaying or enhancing cell repair, cell differentiation, and survival in dental pulp diseases. However, further studies are required for the validation of miRNAs as reliable biomarkers in dental pulp pathology and their targeted therapy.
Publisher: American Society for Microbiology
Date: 30-07-2020
DOI: 10.1128/MRA.00704-20
Publisher: Springer Science and Business Media LLC
Date: 09-02-2012
DOI: 10.1038/ISMEJ.2012.2
Publisher: Springer Science and Business Media LLC
Date: 02-09-2011
Publisher: Cold Spring Harbor Laboratory
Date: 28-04-2021
DOI: 10.1101/2021.04.28.441735
Abstract: Many animals are obligately associated with microbial symbionts that provide essential services such as nutrition or protection against predators. It is assumed that in such obligate associations fidelity between the host and its symbionts must be high to ensure the evolutionary success of the symbiosis. We show here that this is not the case in marine oligochaete worms, despite the fact that they are so dependent on their bacterial symbionts for their nutrition and waste recycling that they have lost their digestive and excretory systems. Our metagenomic analyses of 64 gutless oligochaete species from around the world revealed highly variable levels of fidelity not only across symbiont lineages, but also within symbiont clades. We hypothesize that in gutless oligochaetes, selection within host species for locally adapted and temporally stable symbiont communities leads to varying levels of symbiont fidelity and shuffles the composition of symbiont assemblages across geographic and evolutionary scales.
Publisher: Springer Science and Business Media LLC
Date: 10-04-2011
Publisher: Cold Spring Harbor Laboratory
Date: 11-09-2020
DOI: 10.1101/2020.09.11.282681
Abstract: The composition and ersity of animal microbiomes is shaped by a variety of factors, many of them interacting, such as host traits, the environment, and biogeography. Hybrid zones, in which the ranges of two host species meet and hybrids are found, provide natural experiments for determining the drivers of microbiome communities, but have not been well studied in marine environments. Here, we analysed the composition of the symbiont community in two deep-sea, Bathymodiolus mussel species along their known distribution range at hydrothermal vents on the Mid-Atlantic Ridge, with a focus on the hybrid zone where they interbreed. In-depth metagenomic analyses of the sulphur-oxidising symbionts of 30 mussels from the hybrid zone, at a resolution of single nucleotide polymorphism analyses of ∼2500 orthologous genes, revealed that parental and hybrid mussels have genetically indistinguishable symbionts. While host genetics does not appear to affect symbiont composition in these mussels, geographic location of the mussels on the Mid-Atlantic Ridge explained 45 % of symbiont genetic variability based on redundancy analyses. We hypothesize that geographic structuring of the free-living symbiont population plays a major role in driving the composition of the microbiome in these deep-sea mussels.
Publisher: American Society for Microbiology
Date: 16-04-2020
DOI: 10.1128/MRA.00276-20
Abstract: Here, we present high-quality metagenome-assembled genome sequences of two closely related deltaproteobacterial endosymbionts from the gutless marine worm Olavius algarvensis (Annelida). The first is an improved draft genome sequence of the previously described sulfate-reducing symbiont Delta1. The second is from a closely related, recently discovered symbiont of O. algarvensis .
Publisher: Cold Spring Harbor Laboratory
Date: 30-01-2021
DOI: 10.1101/2021.01.30.428904
Abstract: In obligate symbioses, partner fidelity plays a central role in maintaining the association over evolutionary time. Fidelity has been well studied in hosts with only a few symbionts, but little is known about how fidelity is maintained in obligate associations with multiple co-occurring symbionts. Here, we show that partner fidelity varies from strict to absent in a gutless marine annelid and its consortium of co-occurring symbionts that provide it with nutrition. We sequenced the metagenomes of 80 Olavius algarvensis in iduals from the Mediterranean, and compared host mitochondrial and symbiont phylogenies based on single nucleotide polymorphisms across genomes, using a low-coverage sequencing approach that has not yet been applied to microbial community analyses. Fidelity was strongest for the two chemoautotrophic, sulphur-oxidizing symbionts that dominated the microbial consortium in all host in iduals. In contrast, fidelity was only intermediate to absent in the sulphate-reducing and spirochaetal symbionts, which occurred in lower abundance and were not always present in all host in iduals. We propose that variable degrees of fidelity are advantageous for these hosts by allowing the faithful transmission of their nutritionally most important symbionts and flexibility in the acquisition of other symbionts that promote ecological plasticity in the acquisition of environmental resources.
Publisher: Springer Science and Business Media LLC
Date: 25-04-2016
Publisher: Oxford University Press (OUP)
Date: 30-03-2010
DOI: 10.1111/J.1574-6941.2010.00874.X
Abstract: Cyanobacterial toxins (i.e. microcystins) produced within the microbial mat of coral black band disease (BBD) have been implicated in disease pathogenicity. This study investigated the presence of toxins within BBD lesions and other cyanobacterial patch (CP) lesions, which, in some instances ( approximately 19%), facilitated the onset of BBD, from an outbreak site at Pelorus Island on the inshore, central Great Barrier Reef (GBR). Cyanobacterial species that dominated the biomass of CP and BBD lesions were cultivated and identified, based on morphology and 16S rRNA gene sequences, as Blennothrix- and Oscillatoria-affiliated species, respectively, and identical to cyanobacterial sequences retrieved from previous molecular studies from this site. The presence of the cyanotoxins microcystin, cylindrospermopsin, saxitoxin, nodularin and anatoxin and their respective gene operons in field s les of CP and BBD lesions and their respective culture isolations was tested using genetic (PCR-based screenings), chemical (HPLC-UV, FTICR-MS and LC/MS(n)) and biochemical (PP2A) methods. Cyanotoxins and cyanotoxin synthetase genes were not detected in any of the s les. Cyanobacterial species dominant within CP and BBD lesions were phylogenetically distinct from species previously shown to produce cyanotoxins and isolated from BBD lesions. The results from this study demonstrate that cyanobacterial toxins appear to play no role in the pathogenicity of CP and BBD at this site on the GBR.
Publisher: Springer Science and Business Media LLC
Date: 17-01-2017
DOI: 10.1038/SREP40455
Abstract: Coral disease outbreaks contribute to the ongoing degradation of reef ecosystems, however, microbial mechanisms underlying the onset and progression of most coral diseases are poorly understood. Black band disease (BBD) manifests as a cyanobacterial-dominated microbial mat that destroys coral tissues as it rapidly spreads over coral colonies. To elucidate BBD pathogenesis, we apply a comparative metagenomic and metatranscriptomic approach to identify taxonomic and functional changes within microbial lesions during in-situ development of BBD from a comparatively benign stage termed cyanobacterial patches. Results suggest that photosynthetic CO 2 -fixation in Cyanobacteria substantially enhances productivity of organic matter within the lesion during disease development. Photosynthates appear to subsequently promote sulfide-production by Deltaproteobacteria, facilitating the major virulence factor of BBD. Interestingly, our metagenome-enabled transcriptomic analysis reveals that BBD-associated cyanobacteria have a putative mechanism that enables them to adapt to higher levels of hydrogen sulfide within lesions, underpinning the pivotal roles of the dominant cyanobacterium within the polymicrobial lesions during the onset of BBD. The current study presents sequence-based evidence derived from whole microbial communities that unravel the mechanism of development and progression of BBD.
Publisher: Springer Science and Business Media LLC
Date: 24-09-2010
Abstract: Black band disease (BBD) consists of a mat-forming microbial consortium that migrates across coral colonies causing rapid tissue loss. Although BBD-associated microbial communities have been well characterized, little is known regarding how these complex bacterial consortia develop. This study analyzed successional changes in microbial communities leading to the development of BBD. Long-term monitoring of tagged corals throughout outbreaks of BBD in the central Great Barrier Reef documented cyanobacterium-infected lesions, herein termed cyanobacterial patch(es) (CP), which were macroscopically distinct from BBD and preceded the onset of BBD in 19% of the cases. Dominant cyanobacteria within CP lesions were morphologically distinct from ones dominating BBD lesions. Clone libraries and terminal restriction fragment length polymorphism analysis confirmed shifts within cyanobacterial assemblages, from Blennothrix sp.-affiliated sequences dominating CP lesions, to Oscillatoria sp.-affiliated sequences, similar to those retrieved from other BBD s les worldwide, dominating BBD lesions. Bacterial 16S ribosomal RNA clone libraries also showed shifts in bacterial ribotypes during transitions from CP to BBD, with Alphaproteobacteria-affiliated sequences dominant in CP libraries, whereas gammaproteobacterial and cyanobacterial ribotypes were more abundant in BBD clone libraries. Sequences affiliated with organisms identified in sulfur cycling were commonly retrieved from lesions showing characteristic field signs of BBD. As high sulfide concentrations have been implicated in BBD-mediated coral tissue degradation, proliferation of a microbial community actively involved in sulfur cycling potentially contributes to the higher progression rates found for BBD compared with CP lesions. Results show how microbial colonization of indistinct lesions may facilitate a common coral disease with proven ecological effects on coral populations.
Publisher: PeerJ
Date: 12-06-2017
DOI: 10.7717/PEERJ.3438
Abstract: Seawater temperature anomalies associated with warming climate have been linked to increases in coral disease outbreaks that have contributed to coral reef declines globally. However, little is known about how seasonal scale variations in environmental factors influence disease dynamics at the level of in idual coral colonies. In this study, we applied a multi-state Markov model (MSM) to investigate the dynamics of black band disease (BBD) developing from apparently healthy corals and/or a precursor-stage, termed ‘cyanobacterial patches’ (CP), in relation to seasonal variation in light and seawater temperature at two reef sites around Pelorus Island in the central sector of the Great Barrier Reef. The model predicted that the proportion of colonies transitioning from BBD to Healthy states within three months was approximately 57%, but 5.6% of BBD cases resulted in whole colony mortality. According to our modelling, healthy coral colonies were more susceptible to BBD during summer months when light levels were at their maxima and seawater temperatures were either rising or at their maxima. In contrast, CP mostly occurred during spring, when both light and seawater temperatures were rising. This suggests that environmental drivers for healthy coral colonies transitioning into a CP state are different from those driving transitions into BBD. Our model predicts that (1) the transition from healthy to CP state is best explained by increasing light, (2) the transition between Healthy to BBD occurs more frequently from early to late summer, (3) 20% of CP infected corals developed BBD, although light and temperature appeared to have limited impact on this state transition, and (4) the number of transitions from Healthy to BBD differed significantly between the two study sites, potentially reflecting differences in localised wave action regimes.
Publisher: Cold Spring Harbor Laboratory
Date: 17-10-2023
Publisher: Springer Science and Business Media LLC
Date: 08-08-2018
DOI: 10.1038/S41598-018-29608-Y
Abstract: Increases in the frequency of perturbations that drive coral community structure, such as severe thermal anomalies and high intensity storms, highlight the need to understand how coral communities recover following multiple disturbances. We describe the dynamics of cover and assemblage composition of corals on exposed inshore reefs in the Palm Islands, central Great Barrier Reef, over 19 years encapsulating major disturbance events such as the severe bleaching event in 1998 and Cyclone Yasi in 2011, along with other minor storm and heat stress events. Over this time, 47.8% of hard coral cover was lost, with a concomitant shift in coral assemblage composition due to taxon-specific rates of mortality during the disturbances, and asymmetric recovery in the aftermath thereof. High recruitment rates of some broadcast-spawning corals, particularly corymbose Acropora spp., even in the absence of adult colonies, indicate that a strong external larval supply replenished the stocks. Conversely, the time required for recovery of slow-growing coral morphologies and life histories was longer than the recurrence times of major disturbances. With interludes between bleaching and cyclones predicted to decrease, the probability of another severe disturbance event before coral cover and assemblage composition approximates historical levels suggests that reefs will continue to erode.
Publisher: Springer Science and Business Media LLC
Date: 20-02-2018
No related grants have been discovered for Yui Sato.