Coral Mucus Is a Hot Spot for Viral Infections

ABSTRACTThere is increasing suspicion that viral communities play a pivotal role in maintaining coral health, yet their main ecological traits still remain poorly characterized. In this study, we examined the seasonal distribution and reproduction pathways of viruses inhabiting the mucus of the scleractiniansFungia repandaandAcropora formosacollected in Nha Trang Bay (Vietnam) during an 11-month survey. The strong coupling between epibiotic viral and bacterial abundance suggested that phages are dominant among coral-associated viral communities. Mucosal viruses also exhibited significant differences in their main features between the two coral species and were also remarkably contrasted with their planktonic counterparts. For example, their abundance (inferred from epifluorescence counts), lytic production rates (KCN incubations), and the proportion of lysogenic cells (mitomycin C inductions) were, respectively, 2.6-, 9.5-, and 2.2-fold higher in mucus than in the surrounding water. Both lytic and lysogenic indicators were tightly coupled with temperature and salinity, suggesting that the life strategy of viral epibionts is strongly dependent upon environmental circumstances. Finally, our results suggest that coral mucus may represent a highly favorable habitat for viral proliferation, promoting the development of both temperate and virulent phages. Here, we discuss how such an optimized viral arsenal could be crucial for coral viability by presumably forging complex links with both symbiotic and adjacent nonsymbiotic microorganisms.

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Analysis of composition and abundance of viral communities associated with coral \(\textit{Acropora formosa}\)

ACADEMIA JOURNAL OF BIOLOGY ◽

10.15625/2615-9023/15595 ◽

2021 ◽

Vol 43 (3) ◽

pp. 113-123

Author(s):

Doan Thi Nhung ◽

Bui Van Ngoc

Keyword(s):

Economic Development ◽

Coral Bleaching ◽

Coastal Communities ◽

Marine Animals ◽

Coral Mucus ◽

Bleached Coral ◽

The World ◽

Viral Communities ◽

Acropora Formosa ◽

Coral Health

Coral reefs harbor the extraordinary biodiversity and not only provide livelihoods for coastal communities but also play a crucial role in economic development generally. Unfortunately, they are in decline in Vietnam and around the world because mass coral bleaching events have become more common worldwide. However, little is discovered, about viruses that infect corals and their symbionts. Herein, we present metagenomic analyses of the viral communities in coral mucus associated with healthy and bleached coral Acropora formosa which was collected at Con Dao Island, Vietnam. Interestingly, the number of viral species in bleached specimens are higher than those in healthy status. Viruses similar to those that infect humans and some marine animals also appeared in the coral viral assemblage. The results indicated that the proportion of shared viruses were quite small, and represented extremely abundance. Among the phage identified, vibriophage and cyanophage were only presented in healthy and bleached coral, respectively. Therefore, coral-associated viruses could prospectively infect all constituents of the holobiont - coral, microalgal and microbial. Thus, we expect viruses to be illustrated prominently in the preservation and breakdown of coral health.

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Differential Patterns of Microbiota Recovery in Symbiotic and Aposymbiotic Corals following Antibiotic Disturbance

mSystems ◽

10.1128/msystems.01086-20 ◽

2021 ◽

Vol 6 (2) ◽

Author(s):

Shavonna M. Bent ◽

Carolyn A. Miller ◽

Koty H. Sharp ◽

Colleen M. Hansel ◽

Amy Apprill

Keyword(s):

Recovery Period ◽

Rrna Gene ◽

Initial State ◽

Microbial Composition ◽

Coral Mucus ◽

Content Type ◽

Coral Microbiome ◽

Algal Symbionts ◽

Astrangia Poculata ◽

Coral Health

ABSTRACT Microbial relationships are critical to coral health, and changes in microbiomes are often exhibited following environmental disturbance. However, the dynamics of coral-microbial composition and external factors that govern coral microbiome assembly and response to disturbance remain largely uncharacterized. Here, we investigated how antibiotic-induced disturbance affects the coral mucus microbiota in the facultatively symbiotic temperate coral Astrangia poculata, which occurs naturally with high (symbiotic) or low (aposymbiotic) densities of the endosymbiotic dinoflagellate Breviolum psygmophilum. We also explored how differences in the mucus microbiome of natural and disturbed A. poculata colonies affected levels of extracellular superoxide, a reactive oxygen species thought to have both beneficial and detrimental effects on coral health. Using a bacterial and archaeal small-subunit (SSU) rRNA gene sequencing approach, we found that antibiotic exposure significantly altered the composition of the mucus microbiota but that it did not influence superoxide levels, suggesting that superoxide production in A. poculata is not influenced by the mucus microbiota. In antibiotic-treated A. poculata exposed to ambient seawater, mucus microbiota recovered to its initial state within 2 weeks following exposure, and six bacterial taxa played a prominent role in this reassembly. Microbial composition among symbiotic colonies was more similar throughout the 2-week recovery period than that among aposymbiotic colonies, whose microbiota exhibited significantly more interindividual variability after antibiotic treatment and during recovery. This work suggests that the A. poculata mucus microbiome can rapidly reestablish itself and that the presence of B. psygmophilum, perhaps by supplying nutrients, photosynthate, or other signaling molecules, exerts influence on this process. IMPORTANCE Corals are animals whose health is often maintained by symbiotic microalgae and other microorganisms, yet they are highly susceptible to environmental-related disturbances. Here, we used a known disruptor, antibiotics, to understand how the coral mucus microbial community reassembles itself following disturbance. We show that the Astrangia poculata microbiome can recover from this disturbance and that individuals with algal symbionts reestablish their microbiomes in a more consistent manner compared to corals lacking symbionts. This work is important because it suggests that this coral may be able to recover its mucus microbiome following disturbance, it identifies specific microbes that may be important to reassembly, and it demonstrates that algal symbionts may play a previously undocumented role in microbial recovery and resilience to environmental change.

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Specificity of Associations between Bacteria and the Coral Pocillopora meandrina during Early Development

Applied and Environmental Microbiology ◽

10.1128/aem.01232-12 ◽

2012 ◽

Vol 78 (20) ◽

pp. 7467-7475 ◽

Cited By ~ 33

Author(s):

Amy Apprill ◽

Heather Q. Marlow ◽

Mark Q. Martindale ◽

Michael S. Rappé

Keyword(s):

Small Subunit ◽

Rrna Genes ◽

Polymorphism Analysis ◽

Roseobacter Clade ◽

Small Subunit Rrna ◽

Content Type ◽

Sterile Seawater ◽

Show Evidence ◽

Coral Health

ABSTRACTRelationships between corals and specific bacterial associates are thought to play an important role in coral health. In this study, the specificity of bacteria associating with the coralPocillopora meandrinawas investigated by exposing coral embryos to various strains of cultured marine bacteria, sterile seawater, or raw seawater and examining the identity, density, and location of incorporated cells. The isolates utilized in this experiment included members of the Roseobacter and SAR11 clades of theAlphaproteobacteria, aPseudoalteromonasspecies of theGammaproteobacteria, and aSynechococcusspecies of theCyanobacteriaphylum. Based on terminal restriction fragment length polymorphism analysis of small-subunit rRNA genes, similarities in bacterial communities associated with 170-h-old planulae were observed regardless of treatment, suggesting that bacteria may have been externally associated from the outset of the experiment. Microscopic examination ofP. meandrinaplanulae by fluorescencein situhybridization with bacterial and Roseobacter clade-specific oligonucleotide probes revealed differences in the densities and locations of planulae-associated cells. Planulae exposed to either raw seawater or strains ofPseudoalteromonasand Roseobacter harbored the highest densities of internally associated cells, of which 20 to 100% belonged to the Roseobacter clade. Planulae exposed to sterile seawater or strains of the SAR11 clade andSynechococcusdid not show evidence of prominent bacterial associations. Additional analysis of the raw-seawater-exposed planulae via electron microscopy confirmed the presence of internally associated prokaryotic cells, as well as virus-like particles. These results suggest that the availability of specific microorganisms may be an important factor in the establishment of coral-bacterial relationships.

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Molecular Identification and Antifungal Susceptibility of Yeast Isolates Causing Fungemia Collected in a Population-Based Study in Spain in 2010 and 2011

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.02155-13 ◽

2013 ◽

Vol 58 (3) ◽

pp. 1529-1537 ◽

Cited By ~ 82

Author(s):

Jesús Guinea ◽

Óscar Zaragoza ◽

Pilar Escribano ◽

Estrella Martín-Mazuelos ◽

Javier Pemán ◽

...

Keyword(s):

Hot Spot ◽

Antifungal Susceptibility ◽

Point Mutations ◽

Population Based ◽

Candida Guilliermondii ◽

Population Based Study ◽

Content Type ◽

Candida Lusitaniae ◽

Species Specific

ABSTRACTWe report the molecular identifications and antifungal susceptibilities of the isolates causing fungemia collected in the CANDIPOP population-based study conducted in 29 Spanish hospitals. A total of 781 isolates (from 767 patients, 14 of them having mixed fungemia) were collected. The species found most frequently wereCandida albicans(44.6%),Candida parapsilosis(24.5%),Candida glabrata(13.2%),Candida tropicalis(7.6%),Candida krusei(1.9%),Candida guilliermondii(1.7%), andCandida lusitaniae(1.3%). OtherCandidaand non-Candidaspecies accounted for approximately 5% of the isolates. The presence of cryptic species was low. Compared to findings of previous studies conducted in Spain, the frequency ofC. glabratahas increased. Antifungal susceptibility testing was performed by using EUCAST and CLSI M27-A3 reference procedures; the two methods were comparable. The rate of fluconazole-susceptible isolates was 80%, which appears to be a decrease compared to findings of previous studies, explained mainly by the higher frequency ofC. glabrata. Using the species-specific breakpoints and epidemiological cutoff values, the rate of voriconazole and posaconazolein vitroresistance was low (<2%). In the case ofC. tropicalis, using the EUCAST procedure, the rate of azole resistance was around 20%. There was a correlation between the previous use of azoles and the presence of fluconazole-resistant isolates. Resistance to echinocandins was very rare (2%), and resistance to amphotericin B also was very uncommon. The sequencing of the hot spot (HS) regions fromFKS1orFKS2genes in echinocandin-resistant isolates revealed previously described point mutations. The decrease in the susceptibility to fluconazole in Spanish isolates should be closely monitored in future studies.

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A perspective on embracing emerging technologies research for organizational behavior

Organization Management Journal ◽

10.1108/omj-10-2020-1063 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Jestine Philip

Keyword(s):

Organizational Behavior ◽

Emerging Technologies ◽

Analytical Techniques ◽

Organizational Level ◽

Tight Coupling ◽

Content Type ◽

Individual Level ◽

Theoretical Perspectives ◽

Tightly Coupled ◽

Oriented Research

Purpose Emerging technologies are capable of enhancing organizational- and individual-level outcomes. The organizational behavior (OB) field is beginning to pursue opportunities for researching emerging technologies. This study aims to describe a framework consisting of white, black and grey boxes to demonstrate the tight coupling of phenomena and paradigms in the field and discusses deconstructing OB’s white box to encourage data-driven phenomena to coexist in the spatial framework. Design/methodology/approach A scoping literature review was conducted to offer a preliminary assessment of technology-oriented research currently occurring in OB. Findings The literature search revealed two findings. First, the number of published papers on emerging technologies in top management journals has been increasing at a steady pace. Second, various theoretical perspectives at the micro- and macro- organizational level have been used so far for conducting technology-oriented research. Originality/value By conducting a scoping review of emerging technologies research in OB literature, this paper reveals a conceptual black box relating to technology-oriented research. The essay advocates for loosening OB’s tightly coupled white box to incorporate emerging technologies both as a phenomenon and as data analytical techniques.

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Characterization of Mutations Conferring Extensive Drug Resistance to Mycobacterium tuberculosis Isolates in Pakistan

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.05101-11 ◽

2011 ◽

Vol 55 (12) ◽

pp. 5654-5659 ◽

Cited By ~ 31

Author(s):

Asho Ali ◽

Rumina Hasan ◽

Kauser Jabeen ◽

Nusrat Jabeen ◽

Ejaz Qadeer ◽

...

Keyword(s):

Drug Resistance ◽

Mycobacterium Tuberculosis ◽

Hot Spot ◽

East African ◽

Content Type ◽

Diagnostic Assays ◽

Asian Strain ◽

Central Asian ◽

Extensive Drug Resistance ◽

Detection Of Mutations

ABSTRACTThe increasing incidence of extensively drug-resistant (XDR)Mycobacterium tuberculosisin high-tuberculosis-burden countries further highlights the need for improved rapid diagnostic assays. An increasing incidence of XDRM. tuberculosisstrains in Pakistan has been reported, but drug resistance-associated mutations in these strains have not been evaluated previously. We sequenced the “hot-spot” regions ofrpoB,katG,inhA,ahpC,gyrA,gyrB, andrrsgenes in 50 XDRM. tuberculosisstrains. It was observed that 2% of rifampin, 6% of isoniazid, 24% of fluoroquinolone, and 32% of aminoglycoside/capreomycin resistance in XDRM. tuberculosisstrains would be undetected if only these common hot-spot regions were tested. The frequencies of resistance-conferring mutations were found to be comparable among all XDRM. tuberculosisstrain families present, including the Central Asian Strain, Beijing, and East African Indian genogroups and the Unique isolates. Additional genetic loci need to be tested for detection of mutations conferring fluoroquinolone, aminoglycoside, and capreomycin resistance in order to improve molecular diagnosis of regional XDRM. tuberculosisstrains.

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Influence of Chemotaxis and Swimming Patterns on the Virulence of the Coral PathogenVibrio coralliilyticus

Journal of Bacteriology ◽

10.1128/jb.00791-17 ◽

2018 ◽

Vol 200 (15) ◽

Cited By ~ 6

Author(s):

Blake Ushijima ◽

Claudia C. Häse

Keyword(s):

Type Strain ◽

Wild Type Strain ◽

Bacterial Colonization ◽

Valuable Insight ◽

Wild Type ◽

Coral Mucus ◽

Content Type ◽

Swimming Pattern ◽

Vibrio Coralliilyticus ◽

Insight Into

ABSTRACTChemotaxis, the directed movement toward or away from a chemical signal, can be essential to bacterial pathogens for locating hosts or avoiding hostile environments. The coral pathogenVibrio coralliilyticuschemotaxes toward coral mucus; however, chemotaxis has not been experimentally demonstrated to be important for virulence. To further examine this, in-frame mutations were constructed in genes predicted to be important forV. coralliilyticuschemotaxis. MostVibriogenomes contain multiple homologs of various chemotaxis-related genes, and two paralogs of each forcheB,cheR, andcheAwere identified. Based on single mutant analyses, the paralogscheB2,cheR2, andcheA1were essential for chemotaxis in laboratory assays. As predicted, the ΔcheA1and ΔcheR2strains had a smooth-swimming pattern, while the ΔcheB2strain displayed a zigzag pattern when observed under light microscopy. However, these mutants, unlike the parent strain, were unable to chemotax toward the known attractants coral mucus, dimethylsulfoniopropionate, andN-acetyl-d-glucosamine. The ΔcheB2strain and an aflagellate ΔfliG1strain were avirulent to coral, while the ΔcheA1and ΔcheR2strains were hypervirulent (90 to 100% infection within 14 h on average) compared to the wild-type strain (66% infection within 36 h on average). Additionally, the ΔcheA1and ΔcheR2strains appeared to better colonize coral fragments than the wild-type strain. These results suggest that although chemotaxis may be involved with infection (the ΔcheB2strain was avirulent), a smooth-swimming phenotype is important for bacterial colonization and infection. This study provides valuable insight into understandingV. coralliilyticuspathogenesis and how this pathogen may be transmitted between hosts.IMPORTANCECorals are responsible for creating the immense structures that are essential to reef ecosystems; unfortunately, pathogens like the bacteriumVibrio coralliilyticuscan cause fatal infections of reef-building coral species. However, compared to related human pathogens, the mechanisms by whichV. coralliilyticusinitiates infections and locates new coral hosts are poorly understood. This study investigated the effects of chemotaxis, the directional swimming in response to chemical signals, and bacterial swimming patterns on infection of the coralMontipora capitata. Infection experiments with different mutant strains suggested that a smooth-swimming pattern resulted in hypervirulence. These results demonstrate that the role of chemotaxis in coral infection may not be as straightforward as previously hypothesized and provide valuable insight intoV. coralliilyticuspathogenesis.

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Extending the Definition of the GyrB Quinolone Resistance-Determining Region in Mycobacterium tuberculosis DNA Gyrase for Assessing Fluoroquinolone Resistance in M. tuberculosis

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.06272-11 ◽

2012 ◽

Vol 56 (4) ◽

pp. 1990-1996 ◽

Cited By ~ 40

Author(s):

Alix Pantel ◽

Stéphanie Petrella ◽

Nicolas Veziris ◽

Florence Brossier ◽

Sylvaine Bastian ◽

...

Keyword(s):

Mycobacterium Tuberculosis ◽

Hot Spot ◽

Dna Gyrase ◽

Quinolone Resistance ◽

Fluoroquinolone Resistance ◽

Wild Type ◽

Content Type ◽

Highly Active ◽

Definition Of

ABSTRACTFluoroquinolone (FQ) resistance is emerging inMycobacterium tuberculosis. The main mechanism of FQ resistance is amino acid substitution within the quinolone resistance-determining region (QRDR) of the GyrA subunit of DNA gyrase, the sole FQ target inM. tuberculosis. However, substitutions in GyrB whose implication in FQ resistance is unknown are increasingly being reported. The present study clarified the role of four GyrB substitutions identified inM. tuberculosisclinical strains, two located in the QRDR (D500A and N538T) and two outside the QRDR (T539P and E540V), in FQ resistance. We measured FQ MICs and also DNA gyrase inhibition by FQs in order to unequivocally clarify the role of these mutations in FQ resistance. Wild-type GyrA, wild-type GyrB, and mutant GyrB subunits produced from engineeredgyrBalleles by mutagenesis were overexpressed inEscherichia coli, purified to homogeneity, and used to reconstitute highly active gyrase complexes. MICs and DNA gyrase inhibition were determined for moxifloxacin, gatifloxacin, ofloxacin, levofloxacin, and enoxacin. All these substitutions are clearly implicated in FQ resistance, underlining the presence of a hot spot region housing most of the GyrB substitutions implicated in FQ resistance (residues NTE, 538 to 540). These findings help us to refine the definition of GyrB QRDR, which is extended to positions 500 to 540.

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Molecular Analysis of Resistance and Detection of Non-Wild-Type Strains Using Etest Epidemiological Cutoff Values for Amphotericin B and Echinocandins for Bloodstream Candida Infections from a Tertiary Hospital in Qatar

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00214-18 ◽

2018 ◽

Vol 62 (9) ◽

Cited By ~ 4

Author(s):

Saad J. Taj-Aldeen ◽

Husam Salah ◽

Winder B. Perez ◽

Muna Almaslamani ◽

Mary Motyl ◽

...

Keyword(s):

Amphotericin B ◽

Hot Spot ◽

Antifungal Susceptibility ◽

Tertiary Hospital ◽

Wild Type ◽

Content Type ◽

Cutoff Values ◽

Echinocandin Resistance ◽

Candida Infections ◽

Type Strains

ABSTRACT A total of 301 Candida bloodstream isolates collected from 289 patients over 5 years at a tertiary hospital in Qatar were evaluated. Out of all Candida infections, 53% were diagnosed in patients admitted to the intensive care units. Steady increases in non-albicans Candida species were reported from 2009 to 2014 (30.2% for Candida albicans versus 69.8% for the other Candida species). Etest antifungal susceptibility testing was performed on all recovered clinical isolates to determine echinocandin (micafungin and anidulafungin) and amphotericin B susceptibilities and assess non-wild-type (non-WT) strains (strains for which MICs were above the epidemiological cutoff values). DNA sequence analysis was performed on all isolates to assess the presence of FKS mutations, which confer echinocandin resistance in Candida species. A total of 3.9% of isolates (12/301) among strains of C. albicans and C. orthopsilosis contained FKS hot spot mutations, including heterozygous mutations in FKS1. For C. tropicalis, the Etest appeared to overestimate strains non-WT for micafungin, anidulafungin, and amphotericin B, as 14%, 11%, and 35% of strains, respectively, had values above the epidemiological cutoff value. However, no FKS mutations were identified in this species. For all other species, micafungin best reported the echinocandin non-WT strains relative to the FKS genotype, as anidulafungin tended to overestimate non-wild-type strains. Besides C. tropicalis, few strains were classified as non-WT for amphotericin B.

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Transcriptional response of Wolbachia-transinfected Aedes aegypti mosquito cells to dengue virus at early stages of infection

Journal of General Virology ◽

10.1099/jgv.0.001694 ◽

2022 ◽

Vol 103 (1) ◽

Author(s):

Michael Leitner ◽

Kayvan Etebari ◽

Sassan Asgari

Keyword(s):

Aedes Aegypti ◽

Dengue Virus ◽

Viral Infections ◽

Transcriptional Response ◽

Denv Infection ◽

Content Type ◽

Public Health Burden ◽

Immune Genes ◽

Link Type ◽

Early Stages

Mosquito-borne flaviviruses are responsible for viral infections and represent a considerable public health burden. Aedes aegypti is the principal vector of dengue virus (DENV), therefore understanding the intrinsic virus–host interactions is vital, particularly in the presence of the endosymbiont Wolbachia, which blocks virus replication in mosquitoes. Here, we examined the transcriptional response of Wolbachia -transinfected Ae. aegypti Aag2 cells to DENV infection. We identified differentially expressed immune genes that play a key role in the activation of anti-viral defence such as the Toll and immune deficiency pathways. Further, genes encoding cytosine and N6-adenosine methyltransferases and SUMOylation, involved in post-transcriptional modifications, an antioxidant enzyme, and heat-shock response were up-regulated at the early stages of DENV infection and are reported here for the first time. Additionally, several long non-coding RNAs were among the differentially regulated genes. Our results provide insight into Wolbachia -transinfected Ae. aegypti’s initial virus recognition and transcriptional response to DENV infection.

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