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Echinoderms from Azores islands: An unexpected source of antibiotic resistant Enterococcus spp. and Escherichia coli isolates
2013
Marinho, Catarina | Silva, Nuno | Pombo, Sofia | Santos, Tiago | Monteiro, Ricardo | Gonçalves, Alexandre | Micael, Joana | Rodrigues, Pedro | Costa, Ana Cristina | Igrejas, Gilberto | Poeta, Patrícia
The prevalence of antibiotic resistance and the implicated mechanisms of resistance were evaluated in Enterococcus spp. and Escherichia coli, isolated from a total of 250 faecal samples of echinoderms collected from Azorean waters (Portugal). A total of 144 enterococci (120 Enterococcus faecium, 14 E. hirae, 8 E. faecalis, 2 E. gallinarum) and 10 E. coli were recovered. High percentages of resistance in enterococci were found for erythromycin, ampicillin, tetracyclin and ciprofloxacin. The erm(A) or erm(B), tet(M) and/or tet(L), vat(D), aac(6′)-aph(2″) and aph(3′)-IIIa genes were found in isolates resistant to erythromycin, tetracycline, quinupristin/dalfopristin, high-level gentamicin and high-level kanamycin, respectively. Resistance in E. coli isolates was detected for streptomycin, amikacin, tetracycline and tobramycin. The aadA gene was found in streptomycin-resistant isolates and tet(A)+tet(B) genes in tetracycline-resistant isolates. The data recovered are essential to improve knowledge about the dissemination of resistant strains through marine ecosystems and the possible implications involved in transferring these resistances either to other animals or to humans.
Afficher plus [+] Moins [-]Seasonal variation of metal contamination in the barnacles Pollicipes pollicipes in northwest coast of Portugal show clear correlation with levels in the surrounding water
2013
Reis, Pedro A. | Salgado, María Antonia | Vasconcelos, Vitor
The concentrations of metals were determined in northwest (NW) coast of Portugal seawaters and soft tissues of goose barnacles Pollicipes pollicipes. P. pollicipes can be used for monitoring metal contamination in these coastal seawaters, because there were significant correlations (p<0.05) for all metals between soft tissues and seawaters during the four seasons. Metal concentrations in seawaters and P. pollicipes had significant (p<0.05) spatial and seasonal variations and mean log BAFs for Fe and Cd were higher than for Cr, Cu, Mn and Zn. Regarding the metal concentrations obtained in the coastal seawaters, all NW coast of Portugal should be classified as “Class IV – Bad”, except two locations (location 7 at Summer and location 10 at Winter), which should be classified as “Class III – Moderate”. However, considering the metal concentrations bioaccumulated in P. pollicipes, all locations should be classified as “Class III – Remarkably Polluted” during all seasons of 2011.
Afficher plus [+] Moins [-]Artificial radionuclides 90Sr and 241Am in the sediments of the Baltic Sea: Total and spatial inventories and some temporal trends
2013
Hutri, Kaisa-Leena | Mattila, Jukka | Ikäheimonen, Tarja Tuulikki | Vartti, Vesa-Pekka
The Baltic Sea was contaminated by radioactivity following global nuclear fallout and later by the Chernobyl accident. Despite the decrease of radioactivity caused by radioactive decay, radionuclides have a prolonged residence time in the water of the Baltic Sea due to slow water exchange and relatively rapid sedimentation. Very little is known about the amounts or spatial differences of 90Sr and 241Am in the Baltic Sea sediments. In this study, 20 sediment cores taken around the Baltic Sea were investigated to estimate inventories of these radionuclides. The rough results show that the Chernobyl fallout added the amount of 90Sr in the same areas where the increase of 137Cs can be detected, whereas this is not the case for 241Am which is more evenly distributed in the sea bottom. In addition, local differences occur in the concentrations. These results are an important amendment to the radioactivity baseline of the Baltic Sea.
Afficher plus [+] Moins [-]Characterization of mercury in atmospheric particulate matter in the southeast coastal cities of China
2013
Xu, Lingling | Chen, Jinsheng | Niu, Zhenchuan | Yin, Liqian | Chen, Yanting
Although present in a low concentration in the atmosphere, mercury in particulate matter (PHg) plays an important role in the biogeochemical process of mercury. In this study, the mercury concentrations in three size fractions of airborne particulate matters collected from 14 sites (12 urban sites, 1 rural site and 1 remote site) in the southeast coastal cities of China during different seasons in 2010–2011 were investigated. Most of PHg (46.8–71.9%) was concentrated in the finer particles, i.e. PM2.5 (particulate matter ≤2.5 µm in aerodynamic diameter). The average mercury concentrations in PM2.5 were 141.2±128.1 (range of 7.6–956.5), 37.0±19.2 (5.6–89.4), and 24.0±14.6 (3.2– 59.9) pg m–3 at urban, rural, and remote sites during the whole sampling period, respectively. The PHg concentrations were almost at the same level in spring, autumn, and winter, approximately two times of that in summer. PHg concentrations in the atmosphere displayed a significant spatial variation with far higher values in urban areas than those at rural and remote sites. The dry deposition fluxes of total PHg estimated by a theoretical model were 38.3, 47.7, and 58.7 µg m–2 y–1 at Ji’an (JA), Jimei (JM), and Longwen (LW), respectively. The backward air trajectory analysis revealed that the atmospheric PHg concentrations were mainly influenced by air masses from ocean sources that diluted PHg in summer and on contrary from continental sources in other seasons.
Afficher plus [+] Moins [-]Levels and spatial distribution of perfluorinated compounds (PFCs) in superficial sediments from the marine reserves of the Tuscan Archipelago National Park (Italy)
2013
Perra, Guido | Focardi, Silvano Ettore | Guerranti, Cristiana
Surface sediments from marine reserves of the Tuscan Archipelago National Park (Italy), including remote islands not directly affected by anthropogenic influences, were analyzed for two dominant perfluorinated compounds (PFCs), namely perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA), using LC–ESI-MS/MS. The concentrations of PFOS were low, with medians ranging from 0.25 to 1.50ng/g dry wt, whereas PFOA was always below the detection limit of 0.1ng/g dry wt. The present paper can be considered a baseline study useful in future environmental monitoring programs.
Afficher plus [+] Moins [-]Critical research needs for identifying future changes in Gulf coral reef ecosystems
2013
Feary, David A. | Burt, John A. | Bauman, Andrew G. | Al Hazeem, Shaker | Abdel-Moati, Mohamed A. | Al-Khalifa, Khalifa A. | Anderson, Donald M. | Amos, Carl | Baker, Andrew | Bartholomew, Aaron | Bento, Rita | Cavalcante, Geórgenes H. | Chen, Chaolun Allen | Coles, Steve L. | Dab, Koosha | Fowler, Ashley M. | George, David | Grandcourt, E. M. | Hill, Ross | John, D. M. | Jones, David A. | Keshavmurthy, Shashank | Mahmoud, Huda | Moradi Och Tapeh, Mahdi | Mostafavi, Pargol Ghavam | Naser, Humood | Pichon, Michel | Purkis, Samuel J. | Riegl, Bernhard | Samimi-Namin, Kaveh | Sheppard, Charles | Vajed Samiei, Jahangir | Voolstra, Christian R. | Wiedenmann, Joerg
Expert opinion was assessed to identify current knowledge gaps in determining future changes in Arabian/Persian Gulf (thereafter ‘Gulf’) coral reefs. Thirty-one participants submitted 71 research questions that were peer-assessed in terms of scientific importance (i.e., filled a knowledge gap and was a research priority) and efficiency in resource use (i.e., was highly feasible and ecologically broad). Ten research questions, in six major research areas, were highly important for both understanding Gulf coral reef ecosystems and also an efficient use of limited research resources. These questions mirrored global evaluations of the importance of understanding and evaluating biodiversity, determining the potential impacts of climate change, the role of anthropogenic impacts in structuring coral reef communities, and economically evaluating coral reef communities. These questions provide guidance for future research on coral reef ecosystems within the Gulf, and enhance the potential for assessment and management of future changes in this globally significant region.
Afficher plus [+] Moins [-]An integrated microfluidic device in marine microalgae culture for toxicity screening application
2013
Zheng, Guoxia | Wang, Yunhua | Wang, Zumin | Zhong, Weiliang | Wang, Hu | Li, Yajie
Algal assay using marine microalgae has emerged as an important method to evaluate the toxicity of chemicals, which is currently undertaken using conventional culture and additional detection of physiological cellular endpoints. While effective, this approach can be labor-intensive and thus could benefit from a more streamlined, integrated approach. Microfluidics offers a way to accomplish this goal. Here, we demonstrate a microfluidic device which consists of a concentration gradient generator (CGG), diffusible culturing module and power-free valve system. It allows the processes of chemical liquid dilution and diffusion, micro-scale microalgal culture (in batch or chemostatic conditions), cell stimulation and on-lined screening to be integrated into a single device. Using the device, marine microalgae were successfully cultured and stressed on-chip. The simple assay provides multi-biological response measurements of cell division rate, autofluorescence and esterase activity. This work showed promising in developing a microfluidic platform for toxicity screening based on marine microalgal culture.
Afficher plus [+] Moins [-]Urban breakwaters as reef fish habitat in the Persian Gulf
2013
Burt, John A. | Feary, David A. | Cavalcante, Georgenes | Bauman, Andrew G. | Usseglio, Paolo
Breakwaters and related structures dominate near-shore environments in many Persian Gulf countries, but little is known of their ecology. To examine the influence of wave exposure on fish communities we surveyed exposed and sheltered breakwaters seasonally over 2years and compared these with natural reef assemblages. Species richness and adult, juvenile, and total abundance were generally comparable among the three habitat types each season. However, differences in multivariate community structure indicated that each habitat contained a distinct assemblage, with strongest difference between sheltered breakwaters and the exposed natural reef. All communities were characterized by marked seasonality; abundance and richness were generally higher in the warmer seasons (summer, fall) than during cooler periods (winter, spring), and there were related seasonal changes in community structure, particularly on the natural reef. Results indicate that breakwaters are important fish habitats, but that breakwater communities vary with wave exposure and are distinct from natural reefs.
Afficher plus [+] Moins [-]Recruitment of marine biota onto hard and soft artificially created subtidal habitats in Sabah Al-Ahmad Sea City, Kuwait
2013
Jones, David A. | Nithyanandan, Manickam
Remediation of coastal habitats from impacts such as dredging and excavation in Gulf coastal waters is hampered by a lack of information on natural recolonisation rates and recruitment patterns of subtidal biota. For soft substrate habitats recovery information is only available for severely polluted sites where recovery takes many years (Jones et al., 2008).Construction of the Sabah Al-Ahmad Sea City provides a unique opportunity to follow benthic recruitment and community development on a range of artificially created benthic habitats over time. The three phases completed were each flooded by the sea separately and annual ecological surveys allow comparison of colonisation patterns and community development rates over time.Species diversity similar to that seen in comparable natural open sea habitats is reached within 2–5years for mixed sand/rock biota, but longer (2–6years) for sand biota. Biotic abundance exceeds open sea levels within 1–2years due to settlement of opportunistic species. Coral recruitment occurred within 3years. Present data provides a reference point for recovery rates into none polluted benthic habitats for the Gulf.
Afficher plus [+] Moins [-]Impact of milk fish farming in the tropics on potentially pathogenic vibrios
2013
Reichardt, W.T. | Reyes, J.M. | Pueblos, M.J. | Lluisma, A.O.
Ratios of sucrose-negative to sucrose-positive vibrios on TCBS agar (suc−/suc+) indicate the abundance of potential human pathogenic non-cholera vibrios in coastal mariculture environments of the Lingayen Gulf (Philippines. In guts of adult maricultured milkfish (Chanos chanos) of suc− vibrios reached extreme peak values ranging between 2 and 545millionperg wet weight. Suc− vibrios outnumbered suc+ vibrios in anoxic sediments, too, and were rarely predominant in coastal waters or in oxidized sediments. Suc−/suc+ ratios in sediments increased toward the mariculture areas with distance from the open sea at decreasing redox potentials. There is circumstantial evidence that suc− vibrios can be dispersed from mariculture areas to adjacent environments including coral reefs. An immediate human health risk by pathogenic Vibrio species is discounted, since milkfish guts contained mainly members of the Enterovibrio group. A representative isolate of these contained proteolytic and other virulence factors, but no genes encoding toxins characteristic of clinical Vibrio species.
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