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1.
Cryobiology ; 114: 104855, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38301952

RESUMO

The Symbiodinium genus is ancestral among other Symbiodiniaceae lineages with species that are both symbiotic and free living. Changes in marine ecosystems threaten their existence and crucial ecological roles. Cryopreservation offers an avenue for their long-term storage for future habitat restoration after coral bleaching. In our previous study we demonstrated that high salinity treatments of Symbiodiniaceae isolates led to changes in their fatty acid (FA) profiles and higher cell viabilities after cryopreservation. In this study, we investigated the role of increased salinity on FA production and the genes involved in FA biosynthesis and degradation pathways during the cryopreservation of Symbiodinium pilosum. Overall, there was a twofold increase in mass of FAs produced by S. pilosum after being cultured in medium with increased salinity (54 parts per thousand; ppt). Dimethyl sulfoxide (Me2SO) led to a ninefold increase of FAs in standard salinity (SS) treatment, compared to a fivefold increase in increased salinity (IS) treatments. The mass of the FA classes returned to baseline during recovery. Transcriptomic analyses showed an acyl carrier protein gene was significantly upregulated after Me2SO treatment in the SS cultures. Cytochrome P450 reductase genes were significantly down regulated after Me2SO addition in SS treatment preventing FA degradation. These changes in the expression of FA biosynthesis and degradation genes contributed to more FAs in SS treated isolates. Understanding how increased salinity changes FA production and the roles of specific genes in regulating FA pathways will help improve current freezing protocols for Symbiodiniaceae and other marine microalgae.


Assuntos
Antozoários , Dinoflagellida , Animais , Dimetil Sulfóxido/farmacologia , Criopreservação/métodos , Ácidos Graxos , Salinidade , Ecossistema , Antozoários/fisiologia , Dinoflagellida/genética
2.
Mar Drugs ; 22(3)2024 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-38535460

RESUMO

The genus Gambierdiscus produces an array of bioactive hydrophilic and lipophilic secondary metabolites that range in mode of action and toxicity. In this study, the metabolite fingerprint was mapped for thirteen Gambierdiscus, five Coolia and two Fukuyoa species (34 isolates) by assessing the production of 56 characterised secondary metabolites. Gambierdiscus polynesiensis was the only species to produce Pacific-ciguatoxin-3B (P-CTX3B), P-CTX3C, iso-P-CTX3B/C, P-CTX4A, P-CTX4B and iso-P-CTX4A/B. G. australes produced maitotoxin-1 (MTX-1) and MTX-5, G. cheloniae produced MTX-6 and G. honu produced MTX-7. Ubiquitous production of 44-methylgambierone was observed amongst all the Gambierdiscus isolates, with nine species also producing gambierone. Additional gambierone analogues, including anhydrogambierone (tentatively described herein), were also detected in all Gambierdiscus species, two Coolia and two Fukuyoa species. Gambieroxide was detected in G. lewisii and G. pacificus and gambieric acid A was detected in ten Gambierdiscus species, with G. australes (CAWD381) being the only isolate to produce gambieric acids A-D. This study has demonstrated that the isolates tested to date produce the known CTXs or MTXs, but not both, and highlighted several species that produced 'unknown' compounds displaying characteristics of cyclic polyethers, which will be the focus of future compound discovery efforts.


Assuntos
Ciguatoxinas , Dinoflagellida , Éteres , Sorogrupo
3.
Epilepsia ; 64(2): 386-395, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36318046

RESUMO

OBJECTIVE: The objectives of this study were to assess the accuracy of parental seizure detection in infants with antenatally diagnosed tuberous sclerosis complex (TSC), and to document the total seizure burden (clinical and subclinical) in those patients who met criteria for prolonged electroencephalography (EEG) recording. METHODS: Consecutive infants at a single institution with antenatally diagnosed TSC who met criteria for prolonged video-EEG (vEEG) were recruited to this study. The vEEG data were reviewed and when a seizure was identified on EEG, the video and audio recording was assessed for evidence of clinical seizure and, if present, whether there was evidence of parent seizure identification. RESULTS: Nine infants were enrolled, for whom 674 focal seizures were identified in eight of nine patients across 24 prolonged vEEG recordings, with vEEG total duration of 634 h 49 min (average seizure frequency of 1 focal seizure/h). Only 220 of 674 (32.6%) were clinical seizures, 395 of 674 (58.6%) were subclinical seizures, and 59 of 674 seizures could not be classified. Only 63 of 220 clinical seizures (28.6%) were identified by parents, with 157 of 220 (71.4%) not identified. Thirty clusters of epileptic spasms were detected in one patient. At least one clinical epileptic spasm occurred in 2 of 30 clusters (6.7%), 24 of 30 clusters of epileptic spasms (80%) were electrographic only, and classification was uncertain for 4 of 30 clusters (13.3%). No clinical epileptic spasms were detected by parents. Clinical seizure frequency was significantly underestimated by parents for all patients. SIGNIFICANCE: This study demonstrates that in infants with TSC who met criteria for prolonged vEEG, (1) parents significantly under recognize total clinical seizure count, (2) parents fail to identify epileptic spasms, and (3) seizure frequency is high. This highlights that epilepsy treatment decisions should not be based solely on parental clinical seizure identification. Prolonged vEEG monitoring may have an important role in the routine epilepsy care of infants with TSC, as demonstrating undetected high clinical seizure frequency may allow improved epilepsy management decisions.


Assuntos
Epilepsia , Espasmos Infantis , Esclerose Tuberosa , Humanos , Lactente , Esclerose Tuberosa/complicações , Esclerose Tuberosa/diagnóstico , Epilepsia/diagnóstico , Eletroencefalografia , Espasmos Infantis/diagnóstico , Espasmos Infantis/etiologia , Convulsões/diagnóstico , Convulsões/etiologia , Espasmo
4.
J Med Internet Res ; 25: e46701, 2023 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-37656506

RESUMO

BACKGROUND: Molecular point-of-care (POC) testing for Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), and Trichomonas vaginalis (TV) has been available in regional and remote primary health services in Australia as part of a decentralized POC testing program since 2016 and for SARS-CoV-2 from 2020. As there was no suitable existing connectivity infrastructure to capture and deliver POC test results to a range of end users, a new system needed to be established. OBJECTIVE: The aim of the study is to design, implement, and optimize a connectivity system to meet clinical management, analytical quality management, and public health surveillance needs. METHODS: We used commercially available e-messaging technology coupled with adapted proprietary software to integrate a decentralized molecular POC testing platform (GeneXpert) in primary health services and interface with end-user databases. This connectivity infrastructure was designed to overcome key barriers to the implementation, integration, and monitoring of these large multijurisdictional infectious disease POC testing networks. Test result messages were tailored to meet end-user needs. Using centrally captured deidentified data, we evaluated the time to receipt of test results and completeness of accompanying demographic data. RESULTS: From January 2016 to April 2020, we operationalized the system at 31 health services across 4 jurisdictions and integrated with 5 different patient management systems to support the real-time delivery of 29,356 CT/NG and TV test results to designated recipients (patient management system and local clinical and central program databases). In 2019, 12,105 CT/NG and TV results were delivered, and the median time to receipt of results was 3.2 (IQR 2.2-4.6) hours, inclusive of test runtime. From May 2020 to August 2022, we optimized the system to support rapid scale-up of SARS-CoV-2 testing (105 services; 6 jurisdictions; 71,823 tests) and additional sexually transmissible infection testing (16,232 tests), including the electronic disease-specific notifications to jurisdictional health departments and alerts for connectivity disruption and positive results. In 2022, 19,355 results were delivered with an overall median transmission time of 2.3 (IQR 1.4-3.1) hours, 2.2 (IQR 1.2-2.3) hours for SARS-CoV-2 (n=16,066), 3.0 (IQR 2.0-4.0) hours for CT/NG (n=1843), and 2.6 (IQR 1.5-3.8) hours for TV (n=1446). Demographic data (age, sex, and ethnicity) were completed for 99.5% of test results in 2022. CONCLUSIONS: This innovative connectivity system designed to meet end-user needs has proven to be sustainable, flexible, and scalable. It represents the first such system in Australia established independent of traditional pathology providers to support POC testing in geographically dispersed remote primary health services. The system has been optimized to deliver real-time test results and has proven critical for clinical, public health, and quality management. The system has significantly supported equitable access to rapid diagnostics for infectious diseases across Australia, and its design is suitable for onboarding other POC tests and testing platforms in the future.


Assuntos
COVID-19 , Doenças Transmissíveis , Humanos , COVID-19/diagnóstico , Teste para COVID-19 , SARS-CoV-2 , Testes Imediatos , Serviços de Saúde
5.
Med J Aust ; 217(3): 149-154, 2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-35820664

RESUMO

OBJECTIVES: To compare the usability and acceptability of oral fluid- and blood-based HIV self-test kits among men who have sex with men in Australia. DESIGN: Randomised crossover trial. SETTING, PARTICIPANTS: Gay, bisexual, and other men aged 18 years or older who have sex with men, who attended two metropolitan sexual health clinics in Sydney and Melbourne, 7 January - 10 December 2019. MAIN OUTCOME MEASURES: Ease of use of HIV self-test kits; preferred HIV self-test type; difficulties encountered during HIV self-testing. RESULTS: 170 men were recruited (median age, 34 years; interquartile range, 29-43 years); 144 identified as gay (85%), 96 were born outside Australia (57%). Participants were more likely to report the oral fluid HIV self-test was easy to use than the blood-based self-test (oral fluid, 99%; blood, 86%; odds ratio [OR], 3.0; 95% confidence interval [CI], 1.4-6.6). The oral fluid test was preferred by 98 participants (58%; 95% CI, 50-65%), the blood-based test by 69 (41%; 95% CI, 33-48%). Difficulties with the oral fluid test kit identified by observing nurses included problems placing the buffer solution into the stand (40 of 170 participants, 24%) and not swabbing both gums (23 of 169, 14%); difficulties with the blood-based test kit included problems filling the device test channel (69 of 170, 41%) and squeezing the finger firmly enough to generate a blood drop (42 of 170, 25%). No participant received an invalid result with the oral fluid self-test; two of 162 participants (1%) received invalid results with the blood self-test. After adjusting for age, education level, and ethnic background, characteristics associated with higher odds of using HIV self-testing in the future were overseas birth (adjusted OR, 3.07; 95% CI, 1.42-6.64), and self-evaluated ease of use and confidence in using the kits. CONCLUSION: It is important to provide options for obtaining both oral fluid- and blood-based HIV self-tests. The usability and acceptability of both kits were high, but the ease of use and perceived accuracy influenced test kit preference.


Assuntos
Infecções por HIV , Minorias Sexuais e de Gênero , Adulto , Estudos Cross-Over , Infecções por HIV/diagnóstico , Homossexualidade Masculina , Humanos , Masculino , Autoteste
6.
J Phycol ; 58(3): 465-486, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35234279

RESUMO

The taxonomy of the extant dinoflagellate genus Gonyaulax is challenging since its thecate morphology is rather conservative. In contrast, cysts of Gonyaulax are varied in morphology and have been related with the fossil-based genera Spiniferites and Impagidinium. To better understand the systematics of Gonyaulax species, we performed germination experiments on cysts that can be identified as S. ristingensis, an unidentified Spiniferites with petaloid processes here described as Spiniferites pseudodelicatus sp. nov. and Impagidinium variaseptum from Chinese and Portuguese waters. Despite marked differences in cyst morphology, motile cells of S. pseudodelicatus and I. variaseptum are indistinguishable from Gonyaulax baltica. Motile cells hatched from S. ristingensis are morphologically similar to G. baltica as well but differ in the presence of one pronounced antapical spine. Three new species, Gonyaulax amoyensis (cyst equivalent S. pseudodelicatus), Gonyaulax bohaiensis (cyst equivalent I. variaseptum), and Gonyaulax portimonensis (cyst equivalent S. ristingensis), were erected. In addition, a new ribotype (B) of G. baltica was reported from South Korea and a bloom of G. baltica ribotype B is reported from New Zealand. Molecular phylogeny based on LSU and SSU rRNA gene sequences revealed that Gonyaulax species with minute or short antapical spines formed a well-resolved clade, whereas species with two pronounced antapical spines or lack of antapical spines formed the sister clade. Six strains of four above species were examined for yessotoxin production by liquid chromatography coupled with tandem mass spectrometry, and very low concentrations of yessotoxin were detected for one G. bohaiensis strain.


Assuntos
Dinoflagellida , Cromatografia Líquida , Dinoflagellida/genética , Filogenia , República da Coreia , Espectrometria de Massas em Tandem
7.
BMC Public Health ; 21(1): 2048, 2021 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-34753433

RESUMO

BACKGROUND: HIV self-testing was proved as an effective tool for increasing testing frequency in gay and bisexual men at high risk of infection. Questions remain about understanding why HIVST encouraged testing and how such success can be translated to programmatic implementation. METHODS: We conducted a qualitative investigation of how FORTH participants experienced and perceived HIVST. Stratified sampling was used to recruit gay and bisexual men participating in the FORTH HIVST intervention to take part in interviews, focusing on infrequent testers and those who had received inaccurate HIVST results. RESULTS: Our analysis identified several prominent themes organized into two overarching domains from the 15 interviews: (i) aspects of HIVST contributing to HIV testing frequency, and (ii) sustaining HIVST into the future. Participants also believed that their use of HIVST in the future would depend on the test kit's reliability, particularly when compared with highly reliable clinic-based testing. CONCLUSION: HIVST increases the frequency of HIV testing among gay and bisexual men due, in part, to the practical, psychological, and social benefits it offers. To capitalize fully on these benefits, however, strategies to ensure the availability of highly reliable HIVST are required to sustain benefits beyond the confines of a structured research study.


Assuntos
Infecções por HIV , Minorias Sexuais e de Gênero , Infecções por HIV/diagnóstico , Infecções por HIV/epidemiologia , Teste de HIV , Humanos , Masculino , Reprodutibilidade dos Testes , Autoteste
8.
Mar Drugs ; 19(1)2021 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-33450969

RESUMO

Most marine biotoxins are produced by microalgae. The neurotoxin tetrodotoxin (TTX) has been reported in many seafood species worldwide but its source is unknown, making accumulation and depuration studies in shellfish difficult. Tetrodotoxin is a water-soluble toxin and cannot be directly ingested by shellfish. In the present study, a method was developed which involved binding TTX to solid particles of humic acid and encapsulating them in agar-gelatin capsules. A controlled quantity of TTX-containing microcapsules (size range 20-280 µm) was fed to Paphies australis, a bivalve known to accumulate TTX in the wild. The TTX-containing microcapsules were fed to P. australis every second day for 13 days. Ten P. australis (including five controls fed non-toxic microalgae) were harvested after 7 days and ten after 13 days. Paphies australis accumulated TTX, reaching concentrations of up to 103 µg kg-1 by day 13, exceeding the European Food Safety Authority recommended concentration of 44 µg kg-1 in shellfish. This novel method will allow future studies to explore the effects, accumulation and depuration rates of TTX in different animals and document how it is transferred through food webs.


Assuntos
Bivalves/efeitos dos fármacos , Bivalves/metabolismo , Composição de Medicamentos/métodos , Sistemas de Liberação de Medicamentos/métodos , Tetrodotoxina/administração & dosagem , Tetrodotoxina/metabolismo , Animais , Espectrometria de Massas em Tandem/métodos
9.
Value Health ; 23(7): 870-879, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32762988

RESUMO

OBJECTIVES: Human immunodeficiency virus self-testing (HIVST) is a promising approach to improve HIV testing coverage. We aimed to understand HIV testing preferences of men who have sex with men (MSM) to optimize HIVST implementation. METHODS: Discrete choice experiments (DCEs) were conducted among HIV-negative MSM living in Australia and aged ≥18 years. Men completed 1 of 2 DCEs: DCETest for preferred qualities of HIV testing (price, speed, window period, test type, and collector of specimen) and DCEKits for preferred qualities of HIVST kits (price, location of access, packaging, and usage instructions). Latent class conditional logit regression was used to explore similarities (or "classes") in preference behavior. RESULTS: Overall, the study recruited 1606 men: 62% born in Australia, who had an average age of 36.0 years (SD 11.7), and a self-reported median of 4 (interquartile range 2-8) sexual partners in the last 6 months. The respondents to DCETest was described by 4 classes: "prefer shorter window period" (36%), "prefer self-testing" (27%), "prefer highly accurate tests" (22%), and "prefer low prices" (15%). Respondents to DCEKits were described by 4 classes: "prefer low prices" (48%), "prefer retail access (from pharmacy or online stores)" (29%), "prefer access at sex venues" (15%), and "prefer to buy from healthcare staff" (12%). Preferences varied by when someone migrated to Australia, age, frequency of testing, and number of sexual partners. CONCLUSION: A subset of MSM, particularly infrequent testers, value access to HIVST. Expanding access to HIVST kits through online portals and pharmacies and at sex venues should be considered.


Assuntos
Comportamento de Escolha , Infecções por HIV/diagnóstico , Programas de Rastreamento/métodos , Minorias Sexuais e de Gênero/estatística & dados numéricos , Adulto , Austrália , Homossexualidade Masculina , Humanos , Masculino , Pessoa de Meia-Idade , Preferência do Paciente , Kit de Reagentes para Diagnóstico/estatística & dados numéricos , Autocuidado/psicologia , Parceiros Sexuais , Adulto Jovem
10.
Sex Health ; 17(2): 198-199, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32164820

RESUMO

Rates of sexually transmissible infections (STIs) in remote central Australian Aboriginal communities have been persistently high for over two decades, yet risk factors for STIs in these communities are not well understood. This qualitative study explored behavioural and contextual risk factors for STIs in young Aboriginal people in central Australia. The study identified that casual relationships between young people are common and that there is a strong association between travel, alcohol and casual sex, highlighting the ongoing need for comprehensive sexual health programs that are tailored to the specific social, cultural and interpersonal circumstances of young people in this setting.


Assuntos
Havaiano Nativo ou Outro Ilhéu do Pacífico , Infecções Sexualmente Transmissíveis/etnologia , Infecções Sexualmente Transmissíveis/epidemiologia , Adolescente , Feminino , Humanos , Masculino , Pesquisa Qualitativa , Fatores de Risco , Adulto Jovem
11.
J Phycol ; 55(3): 565-577, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30635909

RESUMO

Environmental variables such as temperature, salinity, and irradiance are significant drivers of microalgal growth and distribution. Therefore, understanding how these variables influence fitness of potentially toxic microalgal species is particularly important. In this study, strains of the potentially harmful epibenthic dinoflagellate species Coolia palmyrensis, C. malayensis, and C. tropicalis were isolated from coastal shallow water habitats on the east coast of Australia and identified using the D1-D3 region of the large subunit (LSU) ribosomal DNA (rDNA). To determine the environmental niche of each taxon, growth was measured across a gradient of temperature (15-30°C), salinity (20-38), and irradiance (10-200 µmol photons · m-2  · s-1 ). Specific growth rates of Coolia tropicalis were highest under warm temperatures (27°C), low salinities (ca. 23), and intermediate irradiance levels (150 µmol photons · m-2  · s-1 ), while C. malayensis showed the highest growth at moderate temperatures (24°C) and irradiance levels (150 µmol photons · m-2  · s-1 ) and growth rates were consistent across the range of salinity levels tested (20-38). Coolia palmyrensis had the highest growth rate of all species tested and favored moderate temperatures (24°C), oceanic salinity (35), and high irradiance (>200 µmol photons · m-2  · s-1 ). This is the first study to characterize the environmental niche of species from the benthic harmful algal bloom genus Coolia and provides important information to help define species distributions and inform risk management.


Assuntos
Dinoflagellida , Austrália , DNA Ribossômico , Proliferação Nociva de Algas , Salinidade
12.
Fam Pract ; 35(5): 626-632, 2018 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-29608672

RESUMO

Background: Chlamydia is the most common notifiable sexually transmissible infection in Australia. Left untreated, it can develop into pelvic inflammatory disease and infertility. The majority of notifications come from general practice and it is ideally situated to test young Australians. Objectives: The Australian Chlamydia Control Effectiveness Pilot (ACCEPt) was a multifaceted intervention that aimed to reduce chlamydia prevalence by increasing testing in 16- to 29-year-olds attending general practice. GPs were interviewed to describe the effectiveness of the ACCEPt intervention in integrating chlamydia testing into routine practice using Normalization Process Theory (NPT). Methods: GPs were purposively selected based on age, gender, geographic location and size of practice at baseline and midpoint. Interview data were analysed regarding the intervention components and results were interpreted using NPT. Results: A total of 44 GPs at baseline and 24 at midpoint were interviewed. Most GPs reported offering a test based on age at midpoint versus offering a test based on symptoms or patient request at baseline. Quarterly feedback was the most significant ACCEPt component for facilitating a chlamydia test. Conclusions: The ACCEPt intervention has been able to moderately normalize chlamydia testing among GPs, although the components had varying levels of effectiveness. NPT can demonstrate the effective implementation of an intervention in general practice and has been valuable in understanding which components are essential and which components can be improved upon.


Assuntos
Atitude do Pessoal de Saúde , Infecções por Chlamydia/diagnóstico , Medicina Geral , Clínicos Gerais , Padrões de Prática Médica , Adulto , Austrália , Chlamydia/isolamento & purificação , Feminino , Medicina Geral/métodos , Humanos , Masculino , Programas de Rastreamento , Pessoa de Meia-Idade , Inquéritos e Questionários
13.
Sex Transm Dis ; 44(7): 417-422, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28608791

RESUMO

BACKGROUND: Repeat chlamydia detection after treatment is common, and there is concern that treatment failure may be a cause. METHODS: Within a randomized trial, we established a prospective cohort of 600 participants with anogenital chlamydia diagnoses (200 each of women, heterosexual men, and men who have sex with men [MSM]). Participants were invited for repeat testing at 3 months and to complete a behavioral survey at 4 months. Positive samples were analyzed for organism DNA load and genovar. We estimated repeat chlamydia positivity, reinfection and treatment failure rates, and investigated the biological and behavioral factors associated with a repeat positive test. RESULTS: A total of 290 participants (100 women, 89 heterosexual men, 101 MSM) were retested at 1 to 4 months, with 43 repeat positives, including 26 classed as reinfection and 9 as treatment failures. Comparing MSM with heterosexual men and women combined, repeat positivity was higher (20.8% vs 11.6%, P = 0.04), and treatment failure was higher (6.9% vs 1.1%, P = 0.01), but there was no difference in reinfection rates (11.9% vs 7.4%, P = 0.21). Among MSM, the odds of repeat positivity increased by 90% with each additional log organism load in the original specimen (baseline) (adjusted odds ratio, 1.9; 95% confidence interval, 1.1-3.2). Among heterosexuals, the odds of repeat positivity decreased by 10% with each additional week delay in being retested for chlamydia (adjusted odds ratio, 0.9; 95% confidence interval, 0.8-0.9). CONCLUSIONS: Positive retests were more common among MSM than heterosexuals. Treatment failure was more common in MSM with rectal chlamydia, reinforcing concerns about azithromycin treatment failure.


Assuntos
Infecções por Chlamydia/diagnóstico , Infecções por Chlamydia/psicologia , Chlamydia trachomatis/efeitos dos fármacos , Heterossexualidade/psicologia , Homossexualidade Masculina/psicologia , Cooperação do Paciente , Adulto , Antibacterianos/uso terapêutico , Austrália/epidemiologia , Azitromicina/uso terapêutico , Infecções por Chlamydia/tratamento farmacológico , Feminino , Seguimentos , Doenças dos Genitais Femininos/diagnóstico , Doenças dos Genitais Femininos/tratamento farmacológico , Doenças dos Genitais Femininos/psicologia , Doenças dos Genitais Masculinos/diagnóstico , Doenças dos Genitais Masculinos/tratamento farmacológico , Doenças dos Genitais Masculinos/psicologia , Humanos , Masculino , Programas de Rastreamento/métodos , Estudos Prospectivos , Doenças Retais/diagnóstico , Doenças Retais/tratamento farmacológico , Doenças Retais/psicologia , Recidiva , Falha de Tratamento , Adulto Jovem
14.
J Eukaryot Microbiol ; 64(5): 691-706, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28211202

RESUMO

Gambierdiscus, a benthic dinoflagellate, produces ciguatoxins that cause the human illness Ciguatera. Ciguatoxins are polyether ladder compounds that have a polyketide origin, indicating that polyketide synthases (PKS) are involved in their production. We sequenced transcriptomes of Gambierdiscus excentricus and Gambierdiscus polynesiensis and found 264 contigs encoding single domain ketoacyl synthases (KS; G. excentricus: 106, G. polynesiensis: 143) and ketoreductases (KR; G. excentricus: 7, G. polynesiensis: 8) with sequence similarity to type I PKSs, as reported in other dinoflagellates. In addition, 24 contigs (G. excentricus: 3, G. polynesiensis: 21) encoding multiple PKS domains (forming typical type I PKSs modules) were found. The proposed structure produced by one of these megasynthases resembles a partial carbon backbone of a polyether ladder compound. Seventeen contigs encoding single domain KS, KR, s-malonyltransacylase, dehydratase and enoyl reductase with sequence similarity to type II fatty acid synthases (FAS) in plants were found. Type I PKS and type II FAS genes were distinguished based on the arrangement of domains on the contigs and their sequence similarity and phylogenetic clustering with known PKS/FAS genes in other organisms. This differentiation of PKS and FAS pathways in Gambierdiscus is important, as it will facilitate approaches to investigating toxin biosynthesis pathways in dinoflagellates.


Assuntos
Ciguatoxinas/metabolismo , Dinoflagellida/enzimologia , Perfilação da Expressão Gênica/métodos , Policetídeo Sintases/genética , Análise de Sequência de DNA/métodos , Sequência de Aminoácidos , Vias Biossintéticas , Dinoflagellida/genética , Dinoflagellida/metabolismo , Ácido Graxo Sintases/genética , Ácido Graxo Sintases/metabolismo , Ácidos Graxos/metabolismo , Regulação Enzimológica da Expressão Gênica , Modelos Moleculares , Filogenia , Policetídeo Sintases/química , Policetídeo Sintases/metabolismo , Proteínas de Protozoários/química , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , Homologia de Sequência de Aminoácidos
15.
Mar Drugs ; 15(8)2017 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-28767092

RESUMO

Ciguatera Fish Poisoning (CFP) is increasing across the Pacific and the distribution of the causative dinoflagellates appears to be expanding. Subtle differences in thecal plate morphology are used to distinguish dinoflagellate species, which are difficult to determine using light microscopy. For these reasons we sought to develop a Quantitative PCR assay that would detect all species from both Gambierdiscus and Fukuyoa genera in order to rapidly screen environmental samples for potentially toxic species. Additionally, a specific assay for F. paulensis was developed as this species is of concern in New Zealand coastal waters. Using the assays we analyzed 31 samples from three locations around New Zealand and the Kingdom of Tonga. Fourteen samples in total were positive for Gambierdiscus/Fukuyoa and two samples were also positive using the F. paulensis assay. Samples from the Kermadec Islands were further characterized using high-throughput sequencing metabarcoding. The majority of reads corresponded to Gambierdiscus species with three species identified at all sites (G. australes, G. honu and G. polynesiensis). This is the first confirmed identification of G. polynesiensis, a known ciguatoxin producer, in New Zealand waters. Other known toxin-producing genera were also detected, included Alexandrium, Amphidinium, Azadinium, Dinophysis, Ostreopsis, and Prorocentrum.


Assuntos
Ciguatera , Dinoflagellida/genética , Animais , Bioensaio , Dinoflagellida/classificação , Meio Ambiente , Toxinas Marinhas , Nova Zelândia , Oceanos e Mares , Filogenia , Reação em Cadeia da Polimerase
16.
Mar Drugs ; 15(7)2017 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-28696400

RESUMO

Species in the genus Gambierdiscus produce ciguatoxins (CTXs) and/or maitotoxins (MTXs), which may cause ciguatera fish poisoning (CFP) in humans if contaminated fish are consumed. Species of Gambierdiscus have previously been isolated from macroalgae at Rangitahua (Raoul Island and North Meyer Islands, northern Kermadec Islands), and the opportunity was taken to sample for Gambierdiscus at the more southerly Macauley Island during an expedition in 2016. Gambierdiscus cells were isolated, cultured, and DNA extracted and sequenced to determine the species present. Bulk cultures were tested for CTXs and MTXs by liquid chromatography-mass spectrometry (LC-MS/MS). The species isolated were G. australes, which produced MTX-1 (ranging from 3 to 36 pg/cell), and G. polynesiensis, which produced neither MTX-1 nor, unusually, any known CTXs. Isolates of both species produced putative MTX-3. The risk of fish, particularly herbivorous fish, causing CFP in the Zealandia and Kermadec Islands region is real, although in mainland New Zealand the risk is currently low. Both Gambierdiscus and Fukuyoa have been recorded in the sub-tropical northern region of New Zealand, and so the risk may increase with warming seas and shift in the distribution of Gambierdiscus species.


Assuntos
Ciguatera/etiologia , Ciguatoxinas/toxicidade , Dinoflagellida/genética , Dinoflagellida/isolamento & purificação , Peixes/parasitologia , Animais , Ilhas , Nova Zelândia , Espectrometria de Massas em Tandem
17.
BMC Infect Dis ; 15: 561, 2015 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-26653203

RESUMO

BACKGROUND: Gay and bisexual men (GBM) are a major risk group for HIV acquisition, yet the majority of higher-risk GBM test for HIV less often than recommended (3-6 monthly). HIV self-testing has the potential to increase testing frequency and improve awareness of personal HIV status. HIV self-tests have been approved in some countries, however there are concerns whether self-testing would increase HIV testing frequency enough to compensate for the reduced sensitivity of self-tests in early infection. We describe here a randomised controlled trial to assess the effectiveness of self-testing in increasing HIV testing frequency among higher-risk GBM, and its acceptability. METHODS/DESIGN: Participants are higher-risk HIV negative GBM (>5 partners or condomless anal intercourse in previous 3 months; n = 350), including 50 GBM who tested for HIV over two years ago or never tested before ('infrequent-testers'). Participants are recruited from sexual health clinics and community-based organisations, and randomised 1:1 to either self-testing or standard-care (routine clinic-based testing) arms. The trial employs a wait-list control design: participants in the standard-care arm switch to self-testing arm in the second year, and gain access to self-test kits. Participants in the self-testing arm receive four oral-fluid self-test kits at enrolment, with additional kits provided on request. Demographics, sexual behaviour and HIV testing preferences are collected at baseline, and the frequency and pattern of HIV and sexually transmissible infection (STI) testing is collected via online 3-monthly questionnaires. The acceptability of self-testing is assessed at 12 months via an online questionnaire and in-depth interviews. A 24-h telephone support is provided, with expedited follow-up of those with reactive self-test results. The primary outcome is HIV testing frequency (mean number of HIV tests per person) over 12 months, and the secondary outcomes are: mean number of STI tests (chlamydia, gonorrhoea, syphilis) per person; reasons for HIV testing; and acceptability of HIV self-testing. DISCUSSION: This is the first trial to evaluate the use of self-testing among GBM in Australia, and the first internationally among infrequent testers. The study will provide evidence on whether self-testing increases HIV testing frequency, and its acceptability among GBM. The findings will improve our understanding of self-testing patterns, and whether GBM supplement or replace their existing testing routine. TRIAL REGISTRATION: Australian and New Zealand Clinical Trial Registration number: ACTRN12613001236785 , registered on November 12, 2013.


Assuntos
Bissexualidade , Infecções por HIV/diagnóstico , Homossexualidade , Adulto , Austrália , Seguimentos , Linhas Diretas , Humanos , Entrevistas como Assunto , Masculino , Programas de Rastreamento , Nova Zelândia , Testes Sorológicos , Infecções Sexualmente Transmissíveis/diagnóstico , Inquéritos e Questionários
18.
Mutagenesis ; 29(4): 241-9, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24737269

RESUMO

This study investigated the levels of DNA strand breaks and formamidopyrimidine DNA glycosylase (FPG) sensitive sites, as assessed by the comet assay, in peripheral blood mononuclear cells (PBMC) from healthy women from five different countries in Europe. The laboratory in each country (referred to as 'centre') collected and cryopreserved PBMC samples from three donors, using a standardised cell isolation protocol. The samples were analysed in 13 different laboratories for DNA damage, which is measured by the comet assay. The study aim was to assess variation in DNA damage in PBMC samples that were collected in the same way and processed using the same blood isolation procedure. The inter-laboratory variation was the prominent contributor to the overall variation. The inter-laboratory coefficient of variation decreased for both DNA strand breaks (from 68 to 26%) and FPG sensitive sites (from 57 to 12%) by standardisation of the primary comet assay endpoint with calibration curve samples. The level of DNA strand breaks in the samples from two of the centres (0.56-0.61 lesions/10(6) bp) was significantly higher compared with the other three centres (0.41-0.45 lesions/10(6) bp). In contrast, there was no difference between the levels of FPG sensitive sites in PBMC samples from healthy donors in the different centres (0.41-0.52 lesion/10(6) bp).


Assuntos
Separação Celular/métodos , Dano ao DNA , Laboratórios , Leucócitos Mononucleares/metabolismo , Adulto , Calibragem , Ensaio Cometa , Quebras de DNA de Cadeia Dupla , DNA-Formamidopirimidina Glicosilase/metabolismo , Feminino , Humanos , Pessoa de Meia-Idade , Testes de Mutagenicidade , Análise de Regressão
19.
BMC Infect Dis ; 14: 584, 2014 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-25409698

RESUMO

BACKGROUND: Female general practitioners (GPs) have higher chlamydia testing rates than male GPs, yet it is unclear whether this is due to lack of knowledge among male GPs or because female GPs consult and test more female patients. METHODS: GPs completed a survey about their demographic details and knowledge about genital chlamydia. Chlamydia testing and consultation data for patients aged 16-29 years were extracted from the medical records software for each GP and linked to their survey responses. Chi-square tests were used to determine differences in a GP's knowledge and demographics. Two multivariable models that adjusted for the gender of the patient were used to investigate associations between a GP and their chlamydia testing rates - Model 1 included GPs' characteristics such as age and gender, Model 2 excluded these characteristics to specifically examine any associations with knowledge. RESULTS: Female GPs were more likely than male GPs to know when to re-test a patient after a negative chlamydia test (18.8% versus 9.7%, p = 0.01), the correct symptoms suggestive of PID (80.5% versus 67.8%, p = 0.01) and the correct tests for diagnosing PID (57.1% versus 42.6%, p = 0.01). Female GPs tested 6.5% of patients, while male GPs tested 2.2% (p < 0.01). Model 1 found factors associated with chlamydia testing were being a female GP (OR = 2.5, 95% CI: 1.9, 3.3) and working in a metropolitan clinic (OR = 3.2; 95% CI: 2.4, 4.3). Model 2 showed that chlamydia testing increased as knowledge of testing guidelines improved (3-5 correct answers - AOR = 2.0, 95% CI: 1.0, 4.2; 6+ correct answers - AOR = 2.9, 95% CI: 1.4, 6.2). CONCLUSIONS: Higher rates of chlamydia testing are strongly associated with GPs who are female, based in a metropolitan clinic and among those with more knowledge of the recommended guidelines. Improving chlamydia knowledge among male GPs may increase chlamydia testing.


Assuntos
Infecções por Chlamydia/diagnóstico , Programas de Rastreamento/estatística & dados numéricos , Adulto , Austrália , Estudos Transversais , Medicina de Família e Comunidade , Feminino , Clínicos Gerais , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Padrões de Prática Médica/estatística & dados numéricos , Inquéritos e Questionários
20.
BMC Infect Dis ; 14: 223, 2014 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-24758169

RESUMO

BACKGROUND: Repeat infection with Chlamydia trachomatis is common and increases the risk of sequelae in women and HIV seroconversion in men who have sex with men (MSM). Despite guidelines recommending chlamydia retesting three months after treatment, retesting rates are low. We are conducting the first randomised controlled trial to assess the effectiveness of home collection combined with short message service (SMS) reminders on chlamydia retesting and reinfection rates in three risk groups. METHODS/DESIGN: The REACT (retest after Chlamydia trachomatis) trial involves 600 patients diagnosed with chlamydia: 200 MSM, 200 women and 200 heterosexual men recruited from two Australian sexual health clinics where SMS reminders for retesting are routine practice. Participants will be randomised to the home group (3-month SMS reminder and home-collection) or the clinic group (3-month SMS reminder to return to the clinic). Participants in the home group will be given the choice of attending the clinic if they prefer. The mailed home-collection kit includes a self-collected vaginal swab (women), UriSWAB (Copan) for urine collection (heterosexual men), and UriSWAB plus rectal swab (MSM). The primary outcome is the retest rate at 1-4 months after a chlamydia diagnosis, and the secondary outcomes are: the repeat positive test rate; the reinfection rate; the acceptability of home testing with SMS reminders; and the cost effectiveness of home testing. Sexual behaviour data collected via an online survey at 4-5 months, and genotyping of repeat infections, will be used to discriminate reinfections from treatment failures. The trial will be conducted over two years. An intention to treat analysis will be conducted. DISCUSSION: This study will provide evidence about the effectiveness of home-collection combined with SMS reminders on chlamydia retesting, repeat infection and reinfection rates in three risk groups. The trial will determine client acceptability and cost effectiveness of this strategy. TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Registry ACTRN12611000968976.


Assuntos
Infecções por Chlamydia/diagnóstico , Chlamydia trachomatis/isolamento & purificação , Programas de Rastreamento/economia , Adolescente , Adulto , Austrália , Infecções por Chlamydia/economia , Infecções por Chlamydia/microbiologia , Análise Custo-Benefício , Coleta de Dados , Feminino , Humanos , Masculino , Nova Zelândia , Comportamento Sexual , Adulto Jovem
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