Dataset Information

Ultra-small microorganisms in the polyextreme conditions of the Dallol volcano, Northern Afar, Ethiopia.

ABSTRACT: The Dallol geothermal area in the northern part of the Danakil Depression (up to 124-155 meter below sea level) is deemed one of the most extreme environments on Earth. The area is notable for being part of the Afar Depression, an incipient seafloor-spreading center located at the triple junction, between Nubian, Somali and Arabian plates, and for hosting environments at the very edge of natural physical-chemical extremities. The northern part of the Danakil Depression is dominated by the Assale salt plain (an accumulation of marine evaporite deposits) and hosts the Dallol volcano. Here, the interaction between the evaporitic deposit and the volcanisms have created the unique Dallol hot springs, which are highly acidic (pH?~?0) and saline (saturation) with maximum temperatures ranging between 90 and 109?°C. Here we report for the first time evidence of life existing with these hot springs using a combination of morphological and molecular analyses. Ultra-small structures are shown to be entombed within mineral deposits, which are identified as members of the Order Nanohaloarchaea. The results from this study suggest the microorganisms can survive, and potential live, within this extreme environment, which has implications for understanding the limits of habitability on Earth and on (early) Mars.

SUBMITTER: Gomez F

PROVIDER: S-EPMC6536532 | biostudies-literature | 2019 May

REPOSITORIES: biostudies-literature

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Ultra-small microorganisms in the polyextreme conditions of the Dallol volcano, Northern Afar, Ethiopia.

Gómez Felipe F Cavalazzi Barbara B Rodríguez Nuria N Amils Ricardo R Ori Gian Gabriele GG Olsson-Francis Karen K Escudero Cristina C Martínez Jose M JM Miruts Hagos H

Scientific reports 20190527 1

The Dallol geothermal area in the northern part of the Danakil Depression (up to 124-155 meter below sea level) is deemed one of the most extreme environments on Earth. The area is notable for being part of the Afar Depression, an incipient seafloor-spreading center located at the triple junction, between Nubian, Somali and Arabian plates, and for hosting environments at the very edge of natural physical-chemical extremities. The northern part of the Danakil Depression is dominated by the Assale ...[more]

PMID: 31133675

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Project description:BackgroundUse of modern contraceptive methods reduces the risk of unwanted pregnancy, and is influenced by individual-level factors. Willingness to use modern contraceptive methods maybe a useful metric when considering health outcomes as it could predict health behaviors. Therefore, the current study aimed to assess the willingness of women to use modern contraceptives in Afar pastoralist communities.MethodsA community-based cross-sectional study was conducted from May 1 to 30, 2016. Three hundred forty-five women of childbearing age (15-49 years) were systematically sampled with proportionate allocation from seven randomly selected kebeles (neighborhoods) in Aballa District of Afar Region, Ethiopia. All women meeting the inclusion criteria in each selected household were interviewed at home using a semi-structured questionnaire. Construct validity was assured using factor analysis. A combination of individual behavioral models were applied in order to measure willingness to use modern contraceptive methods. Multiple logistic regressions were utilized to identify factors associated with willingness to use contraceptive at P-value of less than 0.05.ResultsThree hundred twenty-two women participated in the study, for a response rate of 93.3%. The mean age of respondents was 27 (±6) years. About one-third (N = 106, 32.9%) of the participants reported that they were willing to use modern contraceptives. Orthodox Christians (AOR = 4.22, 95% CI 1.94-8.92), women aged 19 or older at first marriage (AOR = 2.89, 95% CI 1.16-7.23), and women who had never experienced a stillbirth (AOR = 3.85, 95%CI 1.37-10.78) were more likely to report being willing to use modern contraceptives. Additionally, perceived severity of an unwanted pregnancy (AOR = 1.71, 95% CI 1.57-1.93) and perceived self-efficacy to use contraceptives (AOR = 1.26, 95% CI 1.17-1.65) were positively associated with the willingness. Women who had never had an abortion were less likely to express willingness to use modern contraceptives (AOR = 0.41, 95% CI 0.19-0.92) and perceived importance of cultural and religious norms (AOR = 0.85, 95% CI 0.62-0.90) was also negatively associated with willingness.ConclusionsThe majority of women in this study were not willing to use modern contraceptive methods. A previous pregnancy outcome of stillbirth was associated with reduced willingness, while a prior abortion was associated with increased willingness. Perceived severity of unwanted pregnancy and higher self-efficacy surrounding contraceptive use were strong predictors of increased willingness to use contraceptives. Religious and cultural norms also appear to influence perception towards modern contraception. Thus, involvement of cultural and religious leaders and consideration of a woman's reproductive history are recommended when designing health education messages on contraception for Afar pastoralist women.

Project description:BackgroundAfrican animal trypanosomosis, transmitted cyclically by tsetse flies or mechanically by other biting flies, causes serious inflictions to livestock health. This study investigates the extent of non-tsetse transmitted animal trypanosomosis (NTTAT) by Trypanosoma (T.) evansi and T. vivax in domestic animals in the tsetse-free regions of Northern Ethiopia, Afar and Tigray.MethodsA cross sectional study was conducted on 754 dromedary camels, 493 cattle, 264 goats, 181 sheep, 84 donkeys, 25 horses and 10 mules. The microhaematocrit centrifugation technique was used as parasitological test. Plasma was collected for serodiagnosis with CATT/T.evansi and RoTat 1.2 immune trypanolysis (ITL) while buffy coat specimens were collected for molecular diagnosis with T. evansi type A specific RoTat 1.2 PCR, T. evansi type B specific EVAB PCR and T. vivax specific TvPRAC PCR.ResultsThe parasitological prevalence was 4.7% in Tigray and 2.7% in Afar and significantly higher (z = 2.53, p = 0.011) in cattle (7.3%) than in the other hosts. Seroprevalence in CATT/T.evansi was 24.6% in Tigray and 13.9% in Afar and was significantly higher (z = 9.39, p < 0.001) in cattle (37.3%) than in the other hosts. On the other hand, seroprevalence assessed by ITL was only 1.9% suggesting cross reaction of CATT/T.evansi with T. vivax or other trypanosome infections. Molecular prevalence of T. evansi type A was 8.0% in Tigray and in Afar and varied from 28.0% in horses to 2.2% in sheep. It was also significantly higher (p < 0.001) in camel (11.7%) than in cattle (6.1%), donkey (6%), goat (3.8%), and sheep (2.2%). Four camels were positive for T. evansi type B. Molecular prevalence of T. vivax was 3.0% and was similar in Tigray and Afar. It didn't differ significantly among the host species except that it was not detected in horses and mules.ConclusionsNTTAT caused by T. vivax and T. evansi, is an important threat to animal health in Tigray and Afar. For the first time, we confirm the presence of T. evansi type B in Ethiopian camels. Unexplained results obtained with the current diagnostic tests in bovines warrant particular efforts to isolate and characterise trypanosome strains that circulate in Northern Ethiopia.

Project description:Determining the precise limits of life in polyextreme environments is challenging. Studies along gradients of polyextreme conditions in the Dallol proto-volcano area (Danakil salt desert, Ethiopia) showed the occurrence of archaea-dominated communities (up to 99%) in several hypersaline systems but strongly suggested that life did not thrive in the hyperacidic (pH ∼0), hypersaline (∼35% [wt/vol],) and sometimes hot (up to 108°C) ponds of the Dallol dome. However, it was recently claimed that archaea flourish in these brines based on the detection of one Nanohaloarchaeotas 16S rRNA gene and fluorescent in situ hybridization (FISH) experiments with archaea-specific probes. Here, we characterized the diversity of microorganisms in aerosols over Dallol, and we show that, in addition to typical bacteria from soil/dust, they transport halophilic archaea likely originating from neighboring hypersaline ecosystems. We also show that cells and DNA from cultures and natural local halophilic communities are rapidly destroyed upon contact with Dallol brine. Furthermore, we confirm the widespread occurrence of mineral particles, including silica-based biomorphs, in Dallol brines. FISH experiments using appropriate controls show that DNA fluorescent probes and dyes unspecifically bind to mineral precipitates in Dallol brines; cellular morphologies were unambiguously observed only in nearby hypersaline ecosystems. Our results show that airborne cell dispersal and unspecific binding of fluorescent probes are confounding factors likely affecting previous inferences of archaea thriving in Dallol. They highlight the need for controls and the consideration of alternative abiotic explanations before safely drawing conclusions about the presence of life in polyextreme terrestrial or extraterrestrial systems. IMPORTANCE Determining the precise limits of life in polyextreme environments is challenging. Confounding factors such as exogenous contamination and the abiotic formation of structures resembling cells need to be considered before concluding on the unambiguous development of microbial life in low-biomass environments. Here, we explored how these factors can affect contrasting reports about microbial life thriving in the hypersaline and hyperacidic brines of the Dallol geothermal field (Danakil Depression, Ethiopia). We show not only that aerosols actively transport a wide diversity of prokaryotic and eukaryotic cells over Dallol but also that, upon contact with the chaotropic hyperacidic brine, cells and DNA are rapidly degraded. We also show the extant occurrence of mineral (mostly silica-based) biomorphs that unspecifically bind fluorescent probes and dyes. Our study highlights the need for controls and the consideration of alternative abiotic explanations before safely drawing conclusions on the presence of life in polyextreme terrestrial or extraterrestrial systems.

Project description:BackgroundTo effectively address the burden of postpartum depression (PPD), it is crucial to gain a comprehensive understanding of its magnitude and the factors associated with it in the pastoral and hot region of the Afar Region. This will help identify the progress made thus far and highlight areas that require further attention to accelerate efforts toward reducing the impact of PPD. Notably, no previous study has examined the prevalence and associated factors of PPD specifically in pastoral communities within Ethiopia, including the Afar Region. Accordingly, we investigated the prevalence and associated factors of PPD among postpartum women in the Afar Region, Northeast Ethiopia.MethodsAn institution-based cross-sectional study was conducted in the Awsi Rasu Zone of Afar Regional State from June to July 2021. The study employed a systematic random sampling method to select a total of 302 postpartum mothers who had visited the Expanded Program of Immunisation (EPI) clinics in public health facilities within the Awsi Rasu Zone of the Afar Region. The measurement of PPD was performed using the Edinburgh Postnatal Depression Scale (EPDS). Multivariable binary logistic regression modelling was used to investigate associations between sociodemographic, obstetric and health service, and psychosocial factors with PPD.ResultsThe overall prevalence of PPD was 37.4% with a 95% confidence interval (CI) from 32.0% to 43.0%. Postpartum women who attained high school education were associated with a lower odds of PPD compared to those who did not attain formal schooling (adjusted odds ratio [AOR] = 0.31; 95% CI: 0.12, 0.82). Postpartum women with a family history of mental illness (AOR = 2.34; 95% CI: 1.24, 4.41), those who had trouble in infant feeding (AOR = 4.26; 95% CI: 2.32, 7.83), and those who experienced intimate partner violence (AOR = 3.09; 95% CI: 1.58, 6.04) were positively associated with PPD.ConclusionThe results of our study revealed that the prevalence of PPD in the Awsi Rasu Zone of the Afar Region is higher than both the national and global averages. The findings also highlighted the need for targeted interventions addressing the needs of pastoral postpartum women who experience various stressors, such as feeding difficulties and intimate partner violence.

Project description:The remote Dallol Hot Springs, an active hydrothermal system in the volcanic region of Danakil (Ethiopia), is an interesting yet poorly studied polyextreme environment for investigating the limits of life. Here, we explored the presence of signs of life in five samples of sinter deposits at Dallol, by means of lipid biomarkers and stable isotope composition. The results reveal the existence of biological material with predominance of (presently or recently active) microbial sources, according to the relative abundance of low-over-high molecular weight moieties (n-alkanes, n-carboxylic acids, or n-alkanols), and the detection of diverse microbial-diagnostic compounds (i.e., monomethyl alkanes; C16:1 ?7, C18:1 ?9, C18:1 ?10, C18:2 ?6,9 and iso/anteiso C15 and C17 carboxylic acids; or short-chained dicarboxylic acids). The molecular lipid patterns at Dallol suggest a microbial community largely composed of thermophilic members of the Aquificae, Thermotogae, Chroroflexi, or Proteobacteria phyla, as well as microbial consortia of phototrophs (e.g., Cyanobacteria-Chloroflexi) in lower-temperature and higher-pH niches. Autotrophic sources most likely using the Calvin cycle, together with the acetyl coenzyme A (CoA) pathway, were inferred from the depleted bulk ?13C ratios (-25.9/-22.6‰), while sulfate-reducing bacteria were considered according to enriched sulfate (7.3/11.7‰) and total sulfur (20.5/8.2‰) ?34S ratios. The abundance of functionalized hydrocarbons (i.e., n-carboxylic acids and n-alkanols) and the distinct even-over-odd predominance/preference on the typically odd n-alkanes (CPIalkanes ? 1) pointed to active or recent microbial metabolisms. This study documents the detection of biosignatures in the polyextreme environment of Dallol and raises the possibility of finding life or its remnants in other remote locations on Earth, where the harsh environmental conditions would lead to expect otherwise. These findings are relevant for understanding the limits of life and have implications for searching for hypothetical life vestiges in extreme environments beyond Earth.

Dataset Information

Ultra-small microorganisms in the polyextreme conditions of the Dallol volcano, Northern Afar, Ethiopia.

Publications

Ultra-small microorganisms in the polyextreme conditions of the Dallol volcano, Northern Afar, Ethiopia.

Similar Datasets

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