RESUMO
BACKGROUND: Schoolteachers are often the first to respond when a student presents with a mental health issue in the classroom. This places a burden on schools that impacts school staff, healthcare workers and teachers. More broadly, it places a responsibility on the education system to address students' mental health. This study examines Australian teachers' classroom experiences and the training areas identified by teachers as necessary to manage these issues. METHOD: Interviews were undertaken with 18 in-service teachers between 2020 and 2021 from Catholic, Independent and Public schools. Data were gathered via multiple interviews and analysed using thematic content analysis. RESULTS: The major mental health issues identified by teachers related to mental disorders, depression, anxiety, and a complex range of negative emotional states. Teachers requested training in child and adolescent mental health, counselling skills, early detection and intervention, and training skills to manage the complex relationship with parents and external health and community personnel. Teachers also reported the need to access mental health resources, support and training, which were differentially accessed along socioeconomic status and postcodes. CONCLUSION: The data show that teachers are often placed as first responders when a student has a mental health issue but feel inadequately trained to manage these issues in the classroom. We identified mental health issues presenting in Australian classrooms and documented critical features of mental-health training asked for by teachers in order to address those issues. Given the increasing demands on teachers to address the mental health of children and adolescents, we argue that an urgent review of mental health training for teachers is needed.
Assuntos
Socorristas , Transtornos Mentais , Adolescente , Criança , Humanos , Saúde Mental , Austrália , AnsiedadeRESUMO
The World Health Organisation defines health in terms of wellbeing, and wellbeing has become both a construct and a measure of impact in early intervention and prevention programs in schools. In Australia, schools report on their wellbeing initiatives and there is a plethora of government-funded wellbeing programs already in place in schools. However, education systems and stakeholders worldwide are facing significant challenges with mixed evaluation results of program impact and intervention effect. To better support students, schools, school-based healthcare workers, and community, it is important to know about the effectiveness of school-based programs; yet in the last decade, there has been no national appraisal of these programs in Australia. This systematic review aims to report on the effectiveness of Australian school-based wellbeing programs through a search of 13 databases. Out of 2888 articles, 29 met inclusion criteria. The results found that seventeen interventions comprising 80% of the total number of participants reported no statistically significant intervention effect on wellbeing outcomes. We argue that supporting wellbeing through robust program intervention is important as wellbeing presents both an indication of later onset of more serious mental health issues, and an opportunity for early intervention to break the trajectory leading to full disorder.
Assuntos
Instituições Acadêmicas , Estudantes , Humanos , Austrália , Estudantes/psicologia , Intervenção Educacional Precoce , Avaliação de Programas e Projetos de SaúdeRESUMO
Ostreid herpes virus causes serious disease in the Pacific oyster (Crassostrea gigas), but not in the Sydney Rock Oyster (Saccostrea glomerata). To investigate differences in disease progression, we injected oysters with double stranded RNA (dsRNA). dsRNA is known to mimic viral infection, and can evoke immune responses when Toll-like receptors detect the dsRNA, leading to the production of type 1 interferon and inflammation cytokines. The uptake and processing of dsRNA was tracked in gill and mantle tissue of Crassostrea gigas and Saccostrea glomerata after injection of fluorochrome labelled poly (I:C) dsRNA. The two species showed significant differences in tissue uptake and clearance, and differences in immune responses confirmed by real time PCR. These results showed that S. glomerata was more efficient in processing dsRNA than C. gigas, and that the gill tissue is an important site of dsRNA processing and response.
Assuntos
Crassostrea/genética , Brânquias/fisiologia , Infecções por Herpesviridae/imunologia , Herpesviridae/imunologia , Processamento Pós-Transcricional do RNA , RNA de Cadeia Dupla/metabolismo , Animais , Crassostrea/virologia , Suscetibilidade a Doenças , Imunidade Inata , Interferon Tipo I/metabolismo , Poli I-C/imunologia , Especificidade da EspécieRESUMO
Viral diseases are a significant cause of mortality and morbidity in oysters, resulting in significant economic losses. We investigated the proteomic responses of these two species of oysters to generic double-stranded RNAs (poly I:C and poly A:U). Analysis of proteomic data using isobaric tags for relative and absolute quantitaion (iTRAQ) indicated that there were significant differences in the proteomic responses of the two oyster species resulting from this treatment. Gene ontology analysis showed that several biological processes, cellular components, and molecular function were unique to the different data sets. For example, a number of proteins implicated in the TLR signaling pathway were associated with the Saccostrea glomerata data set but were absent in the Crassostra gigas data set. These results suggest that the differences in the proteomic responses to dsRNA may underpin the biological differences in viral susceptibility. Molecular targets previously shown to be expressed in C. gigas in response to OsHV1 infections were not present in our proteomic data sets, although they were present in the RNA extracted from the very same tissues. Taken together, our data indicate that there are substantial disparities between transcriptomic and proteomic responses to dsRNA challenge, and a comprehensive account of the oysters' biological responses to these treatments must take into account that disparity.
Assuntos
Ostreidae/virologia , Proteoma/efeitos dos fármacos , RNA de Cadeia Dupla/farmacologia , Viroses/patologia , Animais , Suscetibilidade a Doenças , Ontologia Genética , Poli A-U/farmacologia , Poli I-C/farmacologia , Proteômica/métodos , TranscriptomaRESUMO
Many microarray and suppression subtractive hybridization (SSH) studies have analyzed the effects of environmental stress on gene transcription in marine species. However, there have been no unifying analyses of these data to identify common stress response pathways. To address this shortfall, we conducted a meta-analysis of 14 studies that investigated the effects of different environmental stressors on gene expression in oysters. The stressors tested included chemical contamination, hypoxia and infection, as well as extremes of temperature, pH and turbidity. We found that the expression of over 400 genes in a range of oyster species changed significantly after exposure to environmental stress. A repeating pattern was evident in these transcriptional responses, regardless of the type of stress applied. Many of the genes that responded to environmental stress encoded proteins involved in translation and protein processing (including molecular chaperones), the mitochondrial electron transport chain, anti-oxidant activity and the cytoskeleton. In light of these findings, we put forward a consensus model of sub-cellular stress responses in oysters.
Assuntos
Meio Ambiente , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Ostreidae/genética , Ostreidae/fisiologia , Estresse Fisiológico/genética , Técnicas de Hibridização Subtrativa/métodos , Transcrição Gênica , Animais , Ostreidae/metabolismoRESUMO
In the current study, we tested the effects of common environmental contaminants (the metals zinc and lead) on gene expression in Sydney rock oysters (Saccrostrea glomerata). Oysters were exposed to a range of metal concentrations under controlled laboratory conditions. The expression of 14 putative stress response genes was then measured using quantitative, real-time (q) PCR. The expression of all 14 genes was significantly affected (p < 0.05 vs. nonexposed controls) by at least one of the metals, and by at least one dose of metal. For 5 of the 14 target genes (actin, calmodulin, superoxide dismutase, topoisomerase I, and tubulin) the alteration of expression relative to controls was highest at intermediate (rather than high) doses of metals. Such responses may reflect adaptive (acclimation) reactions in gene expression at low to intermediate doses of contaminants, followed by a decline in expression resulting from exposure at higher doses. The data are discussed in terms of the intracellular pathways affected by metal contamination, and the relevance of such gene expression data to environmental biomonitoring.
Assuntos
Metais/toxicidade , Ostreidae/efeitos dos fármacos , Transcriptoma/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Cloretos/toxicidade , Monitoramento Ambiental , Chumbo/toxicidade , Metais/química , Ostreidae/genética , Ostreidae/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Poluentes Químicos da Água/química , Compostos de Zinco/toxicidadeRESUMO
This study characterizes the highly variable He185/333 genes, transcripts and proteins in coelomocytes of the sea urchin, Heliocidaris erythrogramma. Originally discovered in the purple sea urchin, Strongylocentrotus purpuratus, the products of this gene family participate in the anti-pathogen defenses of the host animals. Full-length He185/333 genes and transcripts are identified. Complete open reading frames of He185/333 homologues are analyzed as to their element structure, single nucleotide polymorphisms, indels and sequence repeats and are subjected to diversification analyses. The sequence elements that compose He185/333 are different to those identified for Sp185/333. Differences between Sp185/333 and He185/333 genes are also evident in the complexity of the sequences of the introns. He185/333 proteins show a diverse range of molecular weights on Western blots. The observed sizes and pIs of the proteins differ from predicted values, suggesting post-translational modifications and oligomerization. Immunofluorescence microscopy shows that He185/333 proteins are mainly located on the surface of coelomocyte subpopulations. Our data demonstrate that He185/333 bears the same substantial characteristics as their S. purpuratus homologues. However, we also identify several unique characteristics of He185/333 (such as novel element patterns, sequence repeats, distribution of positively-selected codons and introns), suggesting species-specific adaptations. All sequences in this publication have been submitted to Genbank (accession numbers JQ780171-JQ780321) and are listed in table S1.
Assuntos
Genes MHC da Classe II , Família Multigênica , Ouriços-do-Mar/genética , Animais , Sequência de Bases , Variação Genética , Íntrons/genética , Ouriços-do-Mar/imunologia , Alinhamento de Sequência , Especificidade da EspécieRESUMO
Sydney rock oysters (Saccostrea glomerata) were exposed to environmental stressors at contaminated field sites or in a controlled laboratory setting. RNA seq transcriptome data were generated for the gill and digestive gland using Roche's 454 pyrosequencing technology. 28,685 contigs were de novo assembled which encoded 11,671 different protein products. The data will act as a reference for future studies in ecology, immunology and environmental toxicology.
Assuntos
Meio Ambiente , Ostreidae/genética , Estresse Fisiológico/genética , Transcriptoma , Animais , Sequência de Bases , Primers do DNA/genética , Perfilação da Expressão Gênica , Brânquias/metabolismo , Sequenciamento de Nucleotídeos em Larga Escala , Dados de Sequência Molecular , Ostreidae/fisiologia , Análise de Sequência de RNA , Estresse Fisiológico/fisiologiaRESUMO
Environmental contamination by metals is a serious threat to the biological sustainability of coastal ecosystems. Our current understanding of the potential biological effects of metals in these ecosystems is limited. This study tested the transcriptional expression of immune- and stress-response genes in Sydney Rock oysters (Saccostrea glomerata). Oysters were exposed to four metals (cadmium, copper, lead and zinc) commonly associated with anthropogenic pollution in coastal waterways. Seven target genes (superoxide dismutase, ferritin, ficolin, defensin, HSP70, HSP90 and metallothionein) were selected. Quantitative (real-time) PCR analyses of the transcript expression of these genes showed that each of the different metals elicited unique transcriptional profiles. Significant changes in transcription were found for 18 of the 28 combinations tested (4 metals × 7 genes). Of these, 16 reflected down-regulation of gene transcription. HSP90 was the only gene significantly up-regulated by metal contamination (cadmium and zinc only), while defensin expression was significantly down-regulated by exposure to all four metals. This inhibition could have a significant negative effect on the oyster immune system, promoting susceptibility to opportunistic infections and disease.
Assuntos
Monitoramento Ambiental/métodos , Regulação da Expressão Gênica/efeitos dos fármacos , Metais/toxicidade , Ostreidae , Poluentes Químicos da Água/toxicidade , Animais , Regulação para Baixo , Expressão Gênica/efeitos dos fármacos , Proteínas de Choque Térmico HSP90/genética , Sistema Imunitário/efeitos dos fármacos , Sistema Imunitário/fisiologia , Estresse Fisiológico/fisiologia , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo , Regulação para CimaRESUMO
The purple sea urchin has a complex immune system that is likely mediated by gene expression in coelomocytes (blood cells). A broad array of potential immune receptors and immune response proteins has been deduced from their gene models. Here we use shotgun mass spectrometry to describe 307 proteins with possible immune function in sea urchins including proteins involved in the complement pathway and numerous SRCRs. The relative abundance of dual oxidase 1, ceruloplasmin, ferritin and transferrin suggests the production of reactive oxygen species in coelomocytes and the sequestration of iron. Proteins such as selectin, cadherin, talin, galectin, amassin and the Von Willebrand factor may be involved in generating a strong clotting reaction. Cell signaling proteins include a guanine nucleotide binding protein, the Rho GDP dissociation factor, calcium storage molecules and a variety of lipoproteins. However, based on this dataset, the expression of TLRs, NLRs and fibrinogen domain containing proteins in coelomic fluid and coelomocytes could not be verified.
Assuntos
Células Sanguíneas/metabolismo , Proteômica/métodos , Strongylocentrotus purpuratus/metabolismo , Animais , Coagulação Sanguínea , Cálcio/metabolismo , Ceruloplasmina/metabolismo , Proteínas do Sistema Complemento/metabolismo , Ferritinas/metabolismo , Proteínas de Ligação ao GTP/metabolismo , Ferro/metabolismo , Espectrometria de Massas , NADPH Oxidases/metabolismo , Receptores Depuradores/metabolismo , Transdução de Sinais , Transferrina/metabolismoRESUMO
Research into marsupial adaptive immunity during ontogeny has been hampered by the lack of antibodies that react to marsupial immunological cell populations. In this study, newly synthesised polyclonal antibodies to the T cell marker, CD8, have been developed and used to investigate the ontogeny and distribution of this T cell population in the tammar wallaby. Immunohistochemical analysis indicated that the distribution of the CD8 lymphocytes in the lymphoid tissues of tammar neonates during the first 144 days of pouch life was similar to that of the eutherian mammals. However, CD8α(+) lymphocytes were observed in the intestines of tammar neonates prior to their first appearance in the cervical thymus, an observation that has not been found in eutherians. A dual labelling immunohistochemical approach was used for the indirect demonstration of CD4 and enabled the simultaneous detection in the tammar wallaby tissues of the two major T-lymphocyte populations, CD4 and CD8 that are associated with adaptive immunity. As in eutherian mammals, CD4(+) cells were the predominant T cell lymphocyte subset observed in the spleen while in the nodal tissues, an age-related decrease in the CD4(+)/CD8(+) ratio was noted. These antibodies provide a new immunological tool to study the role of T cell subsets in marsupial immunity and disease pathogenesis studies.
Assuntos
Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Tecido Linfoide/citologia , Macropodidae/crescimento & desenvolvimento , Imunidade Adaptativa/fisiologia , Animais , Animais Recém-Nascidos , Anticorpos/química , Especificidade de Anticorpos , Cabras , Imuno-Histoquímica , Intestinos/citologia , Intestinos/crescimento & desenvolvimento , Linfonodos/citologia , Linfonodos/crescimento & desenvolvimento , Tecido Linfoide/crescimento & desenvolvimento , Macropodidae/imunologia , Baço/citologia , Baço/crescimento & desenvolvimento , Timo/citologia , Timo/crescimento & desenvolvimentoRESUMO
This study used proteomics to assess the impacts of metal contamination in the field on Sydney Rock oysters. Oysters were transplanted into Lake Macquarie, NSW, for two weeks in both 2009 and 2010. Two-dimensional electrophoresis identified changes in protein expression profiles of oyster haemolymph between control and metal contaminated sites. There were unique protein expression profiles for each field trial. Principal components analysis attributed these differences in oyster proteomes to the different combinations and concentrations of metals and other environmental variables present during the three field trials. Identification of differentially expressed proteins showed that proteins associated with cytoskeletal activity and stress responses were the most commonly affected biological functions in the Sydney Rock oyster. Overall, the data show that proteomics combined with multivariate analysis has the potential to link the effects of contaminants with biological consequences.
Assuntos
Monitoramento Ambiental/métodos , Metais/toxicidade , Proteoma/metabolismo , Poluentes Químicos da Água/toxicidade , Animais , Hemolinfa/metabolismo , Lagos , Metais/análise , Metais/metabolismo , New South Wales , Ostreidae/efeitos dos fármacos , Ostreidae/metabolismo , Proteômica , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/metabolismoRESUMO
Genome sequences and high diversity cDNA arrays have provided a detailed molecular understanding of immune responses in a number of invertebrates, including sea urchins. However, complementary analyses have not been undertaken at the level of proteins. Here, we use shotgun proteomics to describe changes in the abundance of proteins from coelomocytes of sea urchins after immunological challenge and wounding. The relative abundance of 345 reproducibly identified proteins were measured 6, 24 and 48 h after injection. Significant changes in the relative abundance of 188 proteins were detected. These included pathogen-binding proteins, such as the complement component C3 and scavenger receptor cysteine rich proteins, as well as proteins responsible for cytoskeletal remodeling, endocytosis and intracellular signaling. An initial systemic reaction to wounding was followed by a more specific response to immunological challenge involving proteins such as apolipophorin, dual oxidase, fibrocystin L, aminopeptidase N and α-2-macroglobulin.
Assuntos
Anthocidaris/citologia , Anthocidaris/imunologia , Proteômica , Animais , Anthocidaris/genética , Imunidade Celular , Espectrometria de Massas , Proteínas/análise , Proteínas/genética , Fatores de TempoRESUMO
In the current study we examined the effects of metal contamination on the protein complement of Sydney Rock oysters. Saccostrea glomerata were exposed for 4 days to three environmentally relevant concentrations (100 µg/l, 50 µg/l and 5 µg/l) of cadmium, copper, lead and zinc. Protein abundances in oyster haemolymph from metal-exposed oysters were compared to those from non-exposed controls using two-dimensional electrophoresis to display differentially expressed proteins. Differentially expressed proteins were subsequently identified using tandem mass spectrometry (LC-MS/MS), to assign their putative biological functions. Unique sets of differentially expressed proteins were affected by each metal, in addition to proteins that were affected by more than one metal. The proteins identified included some that are commonly associated with environmental monitoring, such as HSP 70, and other novel proteins not previously considered as candidates for molecular biomonitoring. The most common biological functions of proteins were associated with stress response, cytoskeletal activity and protein synthesis.
Assuntos
Biomarcadores/análise , Monitoramento Ambiental/métodos , Metais Pesados/toxicidade , Ostreidae/efeitos dos fármacos , Proteômica , Poluentes Químicos da Água/toxicidade , Animais , Regulação da Expressão Gênica/efeitos dos fármacos , Metais Pesados/análise , Poluentes Químicos da Água/análiseRESUMO
BACKGROUND: Late stage Ovarian Cancer is essentially incurable primarily due to late diagnosis and its inherent heterogeneity. Single agent treatments are inadequate and generally lead to severe side effects at therapeutic doses. It is crucial to develop clinically relevant novel combination regimens involving synergistic modalities that target a wider repertoire of cells and lead to lowered individual doses. Stemming from this premise, this is the first report of two- and three-way synergies between Adenovirus-mediated Purine Nucleoside Phosphorylase based gene directed enzyme prodrug therapy (PNP-GDEPT), docetaxel and/or carboplatin in multidrug-resistant ovarian cancer cells. METHODS: The effects of PNP-GDEPT on different cellular processes were determined using Shotgun Proteomics analyses. The in vitro cell growth inhibition in differentially treated drug resistant human ovarian cancer cell lines was established using a cell-viability assay. The extent of synergy, additivity, or antagonism between treatments was evaluated using CalcuSyn statistical analyses. The involvement of apoptosis and implicated proteins in effects of different treatments was established using flow cytometry based detection of M30 (an early marker of apoptosis), cell cycle analyses and finally western blot based analyses. RESULTS: Efficacy of the trimodal treatment was significantly greater than that achieved with bimodal- or individual treatments with potential for 10-50 fold dose reduction compared to that required for individual treatments. Of note was the marked enhancement in apoptosis that specifically accompanied the combinations that included PNP-GDEPT and accordingly correlated with a shift in the expression of anti- and pro-apoptotic proteins. PNP-GDEPT mediated enhancement of apoptosis was reinforced by cell cycle analyses. Proteomic analyses of PNP-GDEPT treated cells indicated a dowregulation of proteins involved in oncogenesis or cancer drug resistance in treated cells with accompanying upregulation of apoptotic- and tumour- suppressor proteins. CONCLUSION: Inclusion of PNP-GDEPT in regular chemotherapy regimens can lead to significant enhancement of the cancer cell susceptibility to the combined treatment. Overall, these data will underpin the development of regimens that can benefit patients with late stage ovarian cancer leading to significantly improved efficacy and increased quality of life.
Assuntos
Adenoviridae/genética , Antineoplásicos/farmacologia , Resistencia a Medicamentos Antineoplásicos , Terapia Genética , Vetores Genéticos , Neoplasias Ovarianas/terapia , Purina-Núcleosídeo Fosforilase/genética , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Efeito Espectador , Carboplatina/farmacologia , Carboplatina/uso terapêutico , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Docetaxel , Sinergismo Farmacológico , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Humanos , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/genética , Pró-Fármacos/metabolismo , Proteômica , Purina-Núcleosídeo Fosforilase/metabolismo , Taxoides/farmacologia , Taxoides/uso terapêutico , Transdução GenéticaRESUMO
The current study uses proteomics to assess the effects of metal contamination on Sydney Rock oyster haemolymph. Saccostrea glomerata were exposed in aquaria for four days to three environmentally relevant metals (copper, lead or zinc). Oyster haemolymph proteins from metal-exposed oysters were then compared to haemolymph from non-exposed controls using 2-dimensional electrophoresis to identify proteins that differed significantly in intensity. These proteins were then subjected to tandem mass spectrometry so that putative protein identities could be assigned. The data suggest that there are unique protein expression profiles for each metal. Exposure to 100 µg/l of copper, lead or zinc yielded a total of 25 differentially expressed proteins. However, only one of these protein spots exhibited altered intensities in response to all three metals. Eighteen of the 25 spots were significantly affected by just one of the three metals. Differentially expressed proteins were assigned to five different categories of biological function. Proteins affecting shell properties were the most common functional group accounting for 34% of the identified proteins. Cytoskeletal activities and metabolism/stress responses each accounted for a further 25% of the proteins.
Assuntos
Hemolinfa/metabolismo , Metais/metabolismo , Ostreidae/metabolismo , Proteoma/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Monitoramento Ambiental , Metais/toxicidade , New South Wales , Ostreidae/efeitos dos fármacos , Proteômica , Poluentes Químicos da Água/toxicidadeRESUMO
The 185/333 proteins of sea urchins represent a family of highly variable immune response molecules with unknown functions. In this study, we show that 185/333 proteins are expressed by three cell types: amoebocytes, colourless spherule cells and gut-associated amoebocytes. A sub-population of amoebocytes express 185/333 proteins on the membranes of vesicles emanating from the trans-Golgi and which later fuse with the plasma membranes of the cells. The previously uncharacterized gut-associated amoebocytes also show a high level of 185/333 protein expression on their internal vesicles and plasma membranes. Colourless spherule cells contain 185/333 proteins within large spherules (specialized intracellular vesicles). In the presence of bacteria and yeast, the ultrastucture of colourless spherule cells changes and 185/333 proteins disappear. In contrast, 185/333 proteins were not found in the phagosomes of coelomocytes. The 185/333-positive gut amoebocytes were often associated with anuclear bodies, which appeared to incorporate material of microbial origin that was surrounded by 185/333 proteins. The association between 185/333 proteins on gut amoebocytes and anuclear bodies suggests that these proteins may be involved in the phagocytosis of microbes in the gut epithelium.
Assuntos
Anthocidaris/imunologia , Proteínas de Membrana/imunologia , Proteínas de Membrana/metabolismo , Animais , Anthocidaris/metabolismo , Anthocidaris/ultraestrutura , Membrana Celular/imunologia , Vesículas Citoplasmáticas/imunologia , Vesículas Citoplasmáticas/ultraestrutura , Sistema Digestório/imunologia , Sistema Digestório/metabolismo , Mucosa Intestinal/imunologia , Mucosa Intestinal/ultraestrutura , Fagócitos/imunologia , Fagócitos/metabolismo , FagocitoseRESUMO
Echinoderms evolved early in the deuterostome lineage, and as such constitute model organisms for comparative physiology and immunology. The sea urchin genome sequence (Strongylocentrotus purpuratus) revealed a complex repertoire of genes with similarities to the immune response genes of other species. To complement these genomic data, we investigated the responses of sea urchins to the injection of bacteria using a comparative proteomics approach on a closely related species. In the sea urchin, Heliocidaris erythrogramma, the relative abundance of many proteins was altered in response to the injection of both bacteria and saline, suggesting their involvement in wounding responses, while others were differentially altered in response to bacteria only. The identities of 15 proteins that differed in relative abundance were determined by mass spectrometry. These proteins revealed a significant modification in energy metabolism in coelomocytes towards the consumption of glutamate and the production of NADPH after injection, as well as an increased concentration of cell signalling molecules, such as heterotrimeric guanine nucleotide-binding protein. The injection of bacteria specifically increased the abundance of apextrin and calreticulin, suggesting that these two proteins are involved in the sequestration or inactivation of bacteria.
Assuntos
Calreticulina/metabolismo , Proteínas/metabolismo , Proteômica , Ouriços-do-Mar/imunologia , Ouriços-do-Mar/microbiologia , Vibrio/imunologia , Animais , Anticorpos Antibacterianos/metabolismo , Ouriços-do-Mar/metabolismo , Vibrio/patogenicidade , Vibrioses/prevenção & controleRESUMO
Relatively little is known about the microbial ecology of biofilm communities or the diversity of antimicrobial molecules that they produce to regulate these communities. This study tested whether the production of antimicrobial activity in biofilm cultures is enhanced towards competing bacteria found in those biofilms. First, the production of antimicrobial activity of marine bacteria grown in biofilms was tested. Fourteen of the 105 marine isolates tested were found to produce antimicrobial factors when grown in biofilms. The antimicrobial activity produced by these isolates in biofilms was more potent and inhibited a broader range of target bacteria grown in biofilms compared to shaken liquid cultures. In a separate experiment, we found that cultivation in biofilms containing produced metabolites from an 'inducer' bacterium stimulated the production of antimicrobial molecules by 'producer' bacteria that were active against the 'inducer' bacterium. Overall, the study suggests that surface attached marine bacteria can target their antimicrobial activity towards competing bacteria in biofilms.
Assuntos
Antibacterianos/metabolismo , Bactérias/metabolismo , Biofilmes , Água do Mar/microbiologia , Bactérias/crescimento & desenvolvimento , Bactérias/isolamento & purificação , Fenômenos Fisiológicos Bacterianos , Testes de Sensibilidade MicrobianaRESUMO
This study assessed the effects of mechanical agitation, hypo-saline conditions, and exposure to the air on the Akoya pearl oyster, Pinctada imbricata, focusing specifically on the immunological activity of haemocytes. Both phagocytosis and phenoloxidase activity decreased significantly when oysters were exposed to all three stressors. Transient decreases were also evident in total haemocyte counts after mechanical stress and exposure to air, while significant increases in total haemocyte counts were evident after exposure to low salinity. Acid phosphatase activity increased significantly when oysters were exposed to air. The frequency of granulocytes in the haemolymph increased significantly when oysters were stressed by hypo-saline conditions, whilst the relative frequency of granulocytes did not differ significantly after mechanical agitation or exposure to air. The total protein content of haemolymph increased significantly when oysters were stressed by mechanical agitation and low salinity. These results suggest that fluctuations in environmental conditions affect circulating haemocytes and their cytochemistry, and that the different immunological parameters tested were influenced uniquely according to the type of stressor.