What makes a cyanobacterial bloom disappear? A review of the abiotic and biotic cyanobacterial bloom loss factors.

Cyanobacterial blooms present substantial challenges to managers and threaten ecological and public health. Although the majority of cyanobacterial bloom research and management focuses on factors that control bloom initiation, duration, toxicity, and geographical extent, relatively little research focuses on the role of loss processes in blooms and how these processes are regulated. Here, we define a loss process in terms of population dynamics as any process that removes cells from a population, thereby decelerating or reducing the development and extent of blooms. We review abiotic (e.g., hydraulic flushing and oxidative stress/UV light) and biotic factors (e.g., allelopathic compounds, infections, grazing, and resting cells/programmed cell death) known to govern bloom loss. We found that the dominant loss processes depend on several system specific factors including cyanobacterial genera-specific traits, in situ physicochemical conditions, and the microbial, phytoplankton, and consumer community composition. We also address loss processes in the context of bloom management and discuss perspectives and challenges in predicting how a changing climate may directly and indirectly affect loss processes on blooms. A deeper understanding of bloom loss processes and their underlying mechanisms may help to mitigate the negative consequences of cyanobacterial blooms and improve current management strategies.

An investigation into the use of riverine mesocosms to analyse the effect of flow velocity and recipient textiles on forensic fibre persistence studies.

Textile fibre evidence can provide important activity level information in criminal cases. To date, very few studies have investigated fibre persistence on fabrics exposed to aquatic conditions, even though items of evidence and victim's bodies can regularly be found in aquatic environments. This lack of research on whether fibres (and other trace evidence) persist on evidence submerged in water, has shown to impact practice as it is reported that crime scene examiners do not attempt to recover this evidence, due to the belief that it would not be present. The dynamic nature of aquatic environments mean that the studies are difficult to conduct in situ and variables, such as water flow rate are not possible to control and thought to be difficult to monitor. To address these challenges, artificial streams (also known as mesocosms) were employed in this study to investigate the persistence rate of polyester fibres on different fabric types (Woollen/nylon mix carpet, 100% polyester fleece, and 95% polyester/5% elastane sports vest) for a four week exposure time (1, 8, 24, 48, 120, 168, 264, 336, 504 and 672 hrs). The effect of water flow rate on the persistence of fibres was investigated by conducting the experiment with two flow velocities; 'high' (∼2.75 L/s) or 'low' (∼0.7 L/s). Significant differences between textile type were seen at 504 hrs under low flow conditions and 8, 24, 168 and 264 hrs under high flow conditions. When comparing flow velocities, a significant difference was seen at 1 hr exposure for the fleece textile only, indicating that the two flow rates used in this study do not significantly affect fibre persistence. Initial loss rates were highest for the first hour of submergence for the carpet, fleece and sports vest. Fibre persistence rates were highest on the carpet, followed by fleece and then sports vest. Persistence rates remained mostly constant after 24 hrs for all textiles but with redistribution of fibres between textiles being seen after this exposure time. The use of artificial flumes in this study provided a balance between realistic experimentation and a controlled study; key experimental variables could be continously and safely monitored. This study provides the first fibre persistence data in river type environments and proposes a new method for testing persistence in aquatic environments. This approach is not limited to fibres evidence and could be employed for other evidence such as glass, pollen, fingerprints and DNA.

Plastic debris in lakes and reservoirs.

Plastic debris is thought to be widespread in freshwater ecosystems globally1. However, a lack of comprehensive and comparable data makes rigorous assessment of its distribution challenging2,3. Here we present a standardized cross-national survey that assesses the abundance and type of plastic debris (>250 µm) in freshwater ecosystems. We sample surface waters of 38 lakes and reservoirs, distributed across gradients of geographical position and limnological attributes, with the aim to identify factors associated with an increased observation of plastics. We find plastic debris in all studied lakes and reservoirs, suggesting that these ecosystems play a key role in the plastic-pollution cycle. Our results indicate that two types of lakes are particularly vulnerable to plastic contamination: lakes and reservoirs in densely populated and urbanized areas and large lakes and reservoirs with elevated deposition areas, long water-retention times and high levels of anthropogenic influence. Plastic concentrations vary widely among lakes; in the most polluted, concentrations reach or even exceed those reported in the subtropical oceanic gyres, marine areas collecting large amounts of debris4. Our findings highlight the importance of including lakes and reservoirs when addressing plastic pollution, in the context of pollution management and for the continued provision of lake ecosystem services.

Monitoring contaminants of emerging concern in aquatic systems through the lens of citizen science.

Global urbanization trends have led to the widespread increasing occurrence of contaminants of emerging concern (CECs) such as pharmaceuticals, personal care products, pesticides, and micro- and nano-plastics in aquatic systems. Even at low concentrations, these contaminants pose a threat to aquatic ecosystems. To better understand the effects of CECs on aquatic ecosystems, it is important to measure concentrations of these contaminants present in these systems. Currently, there is an imbalance in CEC monitoring, with more attention to some categories of CECs, and a lack of data about environmental concentrations of other types of CECs. Citizen science is a potential tool for improving CEC monitoring and to establish their environmental concentrations. However, incorporating citizen participation in the monitoring of CECs poses some challenges and questions. In this literature review, we explore the landscape of citizen science and community science projects which monitor different groups of CECs in freshwater and marine ecosystems. We also identify the benefits and drawbacks of using citizen science to monitor CECs to provide recommendations for sampling and analytical methods. Our results highlight an existing disparity in frequency of monitoring different groups of CECs with implementing citizen science. Specifically, volunteer participation in microplastic monitoring programs is higher than volunteer participation in pharmaceutical, pesticide, and personal care product programs. These differences, however, do not necessarily imply that fewer sampling and analytical methods are available. Finally, our proposed roadmap provides guidance on which methods can be used to improve monitoring of all groups of CECs through citizen science.

Nocardia neocaledoniensis as Rare Cause of Spondylodiscitis.

Nocardia neocaledoniensis is a rare species of Nocardia bacteria, identified in 2004 in hypermagnesian ultramafic soil of New Caledonia. Culture of this opportunistic pathogen from spinal biopsy samples confirmed N. neocaledoniensis spondylodiscitis in an immunocompromised man. Isolation of this unusual species from spinal biopsy samples illustrates its underappreciated ability to cause invasive infection.

Identification of Streptomyces spp. in a Clinical Sample: Always Contamination? Results of a French Retrospective Study.

Background: Streptomyces are environmental gram-positive bacilli that can cause ubiquitous mycetoma and, more rarely, invasive infections. We describe the clinical relevance of Streptomyces spp. identified in human samples and characteristics of patients with invasive Streptomyces infections. Methods: We conducted a retrospective (2006-2017) study of Streptomyces isolates identified in clinical samples in French microbiology laboratories. Streptomyces genus was confirmed by a specific 16S rRNA polymerase chain reaction, and antibiotic susceptibility testing was performed by disk diffusion and trimethoprim-sulfamethoxazole minimum inhibitory concentration (E-test) if resistance was suspected. Patient characteristics, treatments, and outcomes were collected. Invasive infection was defined as a positive culture from a sterile site with signs of infection but without cutaneous inoculation. Results: Of 137 Streptomyces isolates, all were susceptible to amikacin (113/113) and linezolid (112/112), and 92.9% to imipenem (105/113). Using disk diffusion, 50.9% (57/112) of isolates were susceptible to trimethoprim-sulfamethoxazole, but most of the apparently resistant isolates (25/36, 69.4%) tested by E-test were ultimately classified as susceptible. Clinical data were obtained for 63/137 (45.9%) isolates: 30 (47.6%) invasive infections, 8 (12.7%) primary cutaneous infections, 22 (34.9%) contaminations, 3 (4.7%) respiratory colonization. Patients with invasive infection were more frequently receiving corticosteroids than patients without invasive infection (11/30, 36.7%, vs 2/25, 8.0%; P = .03), and at 6-month follow-up, 14 of them were cured, 3 had relapsed, 4 were dead, and 9 were lost to follow-up. Conclusions: Half of the clinical samples that grew Streptomyces were from patients with invasive infection. In that case, antimicrobial therapy should include 1 or 2 antibiotics among linezolid, amikacin, or imipenem.

Prognosis and factors associated with disseminated nocardiosis: a ten-year multicenter study.

OBJECTIVES: Nocardiosis is a rare opportunistic infection that is frequently associated with dissemination (i.e. involvement of several body sites). Identifying the factors associated with Nocardia spp. dissemination may help improving the management of patients with nocardiosis. METHODS: This 10-year (2010-2020) retrospective multicenter cohort study included adult patients with Nocardia-confirmed infections. The first objective was to determine the factors associated with disseminated nocardiosis. The secondary endpoints were to determine and compare the management and the 12-month overall mortality in patients with localized and disseminated nocardiosis. Univariate and multivariate logistic regression analyses were used. RESULTS: Nocardia spp. infection was confirmed in 110 patients, of whom 38 (34.5%) had disseminated nocardiosis. In univariate analysis, the factors associated with dissemination were immunosuppressive conditions: having an auto-immune disease and receiving high-dose corticosteroid (31.5% vs 8.3%, P = 0.003 and 52.6% vs 26.3%, P = 0.007, respectively). Absolute lymphocyte count <1 G/L at diagnosis was the only biomarker associated with dissemination (57.2% vs 26.3%, P = 0.007). Nocardia farcinica was not only the most frequent species identified in patient specimens (n = 22, 20%) but was also associated with a higher rate of dissemination (36.8% vs 11.1%, P = 0.002). Multivariate analysis confirmed the association between auto-immune diseases, lymphopenia, N. farcinica species and the higher rate of dissemination. Even though patients with disseminated nocardiosis were treated longer and more often with an antibiotic combination therapy, their 12-month overall mortality was significantly higher than that of patients with localized nocardiosis (36.8% vs 18%). CONCLUSIONS: Dissemination of Nocardia spp. is favoured by auto-immune diseases, lymphopenia, and infection with N. farcinica.

Comparison of Actinobacteria communities from human-impacted and pristine karst caves.

Actinobacteria are important cave inhabitants, but knowledge of how anthropization and anthropization-related visual marks affect this community on cave walls is lacking. We compared Actinobacteria communities among four French limestone caves (Mouflon, Reille, Rouffignac, and Lascaux) ranging from pristine to anthropized, and within Lascaux Cave between marked (wall visual marks) and unmarked areas in different rooms (Sas-1, Passage, Apse, and Diaclase). In addition to the 16S rRNA gene marker, 441 bp fragments of the hsp65 gene were used and an hsp65-related taxonomic database was constructed for the identification of Actinobacteria to the species level by Illumina-MiSeq analysis. The hsp65 marker revealed higher resolution for species and higher richness (99% operational taxonomic units cutoff) versus the 16S rRNA gene; however, more taxa were identified at higher taxonomic ranks. Actinobacteria communities varied between Mouflon and Reille caves (both pristine), and Rouffignac and Lascaux (both anthropized). Rouffignac displayed high diversity of Nocardia, suggesting human inputs, and Lascaux exhibited high Mycobacterium relative abundance, whereas Gaiellales were typical in pristine caves and the Diaclase (least affected area of Lascaux Cave). Within Lascaux, Pseudonocardiaceae dominated on unmarked walls and Streptomycetaceae (especially Streptomyces mirabilis) on marked walls, indicating a possible role in mark formation. A new taxonomic database  was developed. Although not all Actinobacteria species were represented, the use of the hsp65 marker enabled species-level variations of the Actinobacteria community to be documented based on the extent of anthropogenic pressure. This approach proved effective when comparing different limestone caves or specific conditions within one cave.

Spatial and temporal variability and sources of dissolved trace elements in the Sava River (Slovenia, Croatia).

The spatial and temporal variability of dissolved trace elements (Al, As, Ba, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, Pb, Sb, Sr, Ti, U, V and Zn) in the upper and middle reaches of the Sava River during two campaigns (2007/2008 and 2017/2018) was examined. The study also included important tributaries and wastewater effluents. No crucial change in metal concentrations in the Sava River water between the two sampling periods was detected. Elements Co, Cr, Cu, Fe, Sb and Zn had higher concentrations at several sites in the first period, whereas Ba, Cd and Pb in the second period. The influence of wastewater discharges proved to be negligible. The highest levels of potentially toxic metals (Cd, Cr, Cu, Sb, V and Zn) were found downstream of the industrial town of Sisak. Concentration-discharge relationship of dissolved elements showed a chemostatic behaviour for As, Cr, Cu, Sr and V and chemodynamic behaviour for all other elements. The UNMIX model, used to identify and quantify metal sources, indicated that soil weathering was the main source of most elements (Al, As, Ba, Co, Cu, Fe, Li, Ni, Sb, Sr and V), with an anthropogenic contribution for Cd, Mo, Pb, Ti and Zn, while Mn and U were associated with colloid formation. The Sava River was defined as moderately polluted regarding metals, whose water quality meets environmental quality standards (EQS). These results may help to better understand the behaviour of dissolved metals in rivers under anthropogenic pressure and to control pollution in the Sava River Basin.

Microalgae colonization of different microplastic polymers in experimental mesocosms across an environmental gradient.

A variety of organisms can colonize microplastic surfaces through biofouling processes. Heterotrophic bacteria tend to be the focus of plastisphere research; however, the presence of epiplastic microalgae within the biofilm has been repeatedly documented. Despite the relevance of biofouling in determining the fate and effects of microplastics in aquatic systems, data about this process are still scarce, especially for freshwater ecosystems. Here, our goal was to evaluate the biomass development and species composition of biofilms on different plastic polymers and to investigate whether plastic substrates exert a strong enough selection to drive species sorting, overcoming other niche-defining factors. We added microplastic pellets of high-density polyethylene (HDPE), polyethylene terephthalate (PET), and a mix of the two polymers in 15 lentic mesocosms in five different locations of the Iberian Peninsula, and after one month, we evaluated species composition and biomass of microalgae developed on plastic surfaces. Our results, based on 45 samples, showed that colonization of plastic surfaces occurred in a range of lentic ecosystems covering a wide geographical gradient and different environmental conditions (e.g., nutrient concentration, conductivity, macrophyte coverage). We highlighted that total biomass differed based on the polymer considered, with higher biomass developed on PET substrate compared to HDPE. Microplastics supported the growth of a rich and diversified community of microalgae (242 species), with some cosmopolite species. However, we did not observe species-specificity in the colonization of the different plastic polymers. Local species pool and nutrient concentration rather than polymeric composition seemed to be the determinant factor defying the community diversity. Regardless of specific environmental conditions, we showed that many species could coexist on the surface of relatively small plastic items, highlighting how microplastics may have considerable carrying capacity, with possible consequences on the wider ecological context.

Raman Spectroscopy for the Analysis of Microplastics in Aquatic Systems.

Raman spectroscopy is gaining ground in the analysis of microplastics, especially due to its high spatial resolution that allows the investigation of small plastic particles, whose numeric abundance is argued to be particularly relevant in aquatic systems. Here, we aimed at outlining the status of Raman analysis of microplastics from aquatic systems, highlighting the advantages and the drawbacks of this technique and critically presenting tools and ways to effectively employ this instrument and to improve the spectra obtained and their interpretation. In particular, we summarized procedural information for the use of Raman spectroscopy, and we discussed issues linked to fluorescence interference and the analysis of weathered polymers, which may complicate the interpretation of Raman signatures. In this context, a deep understanding of the different plastic polymers and their Raman peaks and chemical fingerprints is fundamental to avoid misidentification. Therefore, we provided a catalog with detailed information about peaks of most common plastic polymers, and this represents, to the best of our knowledge, the first comprehensive resource that systematically synthesized plastic Raman peaks. Additionally, we focused on plastic additives, which are contained in the majority of plastics. These compounds are often intense in Raman scattering and may partly or completely overlie the actual material types, resulting in the identification of additives alone or misidentification issue. For these reasons, we also presented a new R package "RamanMP" that includes a database of 356 spectra (325 of which are additives). This will help to foster the use of this technique, which is becoming especially relevant in microplastic analysis.

Microbial risk assessment of Nocardia cyriacigeorgica in polluted environments, case of urban rainfall water.

Urban Infiltration Basins (UIBs) are used to manage urban runoff transfers and feed aquifers. These UIBs can accumulate urban pollutants and favor the growth of potentially pathogenic biological agents as Nocardia. OBJECTIVES: To assess the spatio-temporal dynamics of pathogenic Nocardia in UIBs and to stablish phylogenetic relationships between clinical and UIB N. cyriacigeorgica strains. To assess pathogenicity associated with environmental N. cyriacigeorgica using an animal model, and to identify genetic elements that may be associated to its virulence. METHODS: A well-characterized UIB in terms of chemical pollutants from Lyon area was used in this study during a whole year. Cultural and Next-Generation-Sequencing methods were used for Nocardia detection and typing. Clinical and environmental isolates phylogenetic relationships and virulences were compared with Multilocus-Sequence-Analysis study together with a murine model. RESULTS: In autumn, N. cyriacigeorgica and N. nova were the pathogenic most prevalent species in the UIB. The complex N. abscessus/asiatica was also detected together with some other non-pathogenic species. The presence of pathogenic Nocardia was positively correlated to metallic trace elements. Up to 1.0 × 103 CFU/g sediment of N. cyriacigeorgica and 6 OTUs splited in two different phylogroups were retrieved and were close to clinical strains. The EML446 tested UIB isolate showed significant infectivity in mice with pulmonary damages similar to clinical clone (GUH-2). CONCLUSION: Hsp65 marker-based metabarcoding approach allowed detecting N. cyriacigeogica as the most abundant Nocardia pathogenic species in a UIB. Metal trace elements-polluted environments can be reservoirs of pathogenic Nocardia which may have a similar virulence to clinical strains.

Overlapping redox zones control arsenic pollution in Pleistocene multi-layer aquifers, the Po Plain (Italy).

Understanding the factors that control As concentrations in groundwater is vital for supplying safe groundwater in regions with As-polluted aquifers. Despite much research, mainly addressing Holocene aquifers hosting young (<100 yrs) groundwater, the source, transport, and fate of As in Pleistocene aquifers with fossil (>12,000 yrs) groundwaters are not yet fully understood and so are assessed here through an evaluation of the redox properties of the system in a type locality, the Po Plain (Italy). Analyses of redox-sensitive species and major ions on 22 groundwater samples from the Pleistocene arsenic-affected aquifer in the Po Plain shows that groundwater concentrations of As are controlled by the simultaneous operation of several terminal electron accepters. Organic matter, present as peat, is abundant in the aquifer, allowing groundwater to reach a quasi-steady-state of highly reducing conditions close to thermodynamic equilibrium. In this system, simultaneous reduction of Fe-oxide and sulfate results in low concentrations of As (median 7 µg/L) whereas As reaches higher concentrations (median of 82 µg/L) during simultaneous methanogenesis and Fe-reduction. The position of well-screens is an additional controlling factor on groundwater As: short screens that overlap confining aquitards generate higher As concentrations than long screens placed away from them. A conceptual model for groundwater As, applicable worldwide in other Pleistocene aquifers with reducible Fe-oxides and abundant organic matter is proposed: As may have two concentration peaks, the first after prolonged Fe-oxide reduction and until sulfate reduction takes place, the second during simultaneous Fe-reduction and methanogenesis.

A critical review of interactions between microplastics, microalgae and aquatic ecosystem function.

With the widespread occurrence of microplastics in aquatic ecosystems having been firmly established, the focus of research has shifted towards the assessments of their influence on ecosystem functions and food webs. This includes interactions between microplastics and microalgae, as fundamental components at the base of aquatic food webs and pivotal organisms in a wide range of ecosystem functions. In this review, we present the current state of knowledge on microalgae-microplastic interactions and summarize the potential effect on their respective fate. Microplastics can and do interact with microalgae and the available literature has suggested that the epiplastic community of microalgae differs consistently from the surrounding aquatic communities; however, it is still not clear whether this different colonization is linked to the composition of the surface or more to the availability of a "hard" substrate on which organisms can attach and grow. Further studies are needed to understand to what extent the properties of different plastic materials and different environmental factors may affect the growth of microalgae on plastic debris. Biofouling may alter microplastic properties, especially increasing their density, consequently affecting the vertical fluxes of plastics. Moreover, microplastics may have toxic effects on microalgae, which could be physical or related to chemical interactions with plasticizers or other chemicals associated with plastics, with consequences for algal growth, photosynthetic activity, and morphology. Microplastics seems to have the potential to affect not only the quality (e.g., fatty acids and lipids composition, food dilution effect) but also the quantity of algal production, both positively and negatively. This may have consequences for energy fluxes, which may propagate throughout the whole food web and alter aquatic productivity. Even though experimental results have indicated reciprocal impacts between plastics and microalgae, it is currently difficult to predict how these impacts may manifest themselves at the ecosystem level. Therefore, further studies are needed to address this important topic.

Invasive Nocardiosis: Disease Presentation, Diagnosis and Treatment - Old Questions, New Answers?

Nocardia spp. is an environmental filamentous Gram-positive bacterium that may cause infections in humans and, despite recent progress, many challenges remain regarding the management of nocardiosis. This review aims at describing most recently published data regarding the diagnosis, treatment and follow-up of patients with invasive nocardiosis. As nocardiosis mainly affects patients with cell-mediated immunity defects, a comprehensive workup is mandatory in case of invasive nocardiosis occurring in "apparently healthy patients". Indeed, invasive nocardiosis might reveal an unknown primary immunodeficiency or the presence of anti-GM-CSF autoantibodies. Even if the diagnosis of nocardiosis mostly relies on direct examination and bacterial culture, a genus-specific PCR may be used for the detection of Nocardia, when directly performed on a clinical sample. Brain imaging should always be performed, even in the absence of neurological symptoms. Cotrimoxazole (trimethoprim/sulfamethoxazole), linezolid, parenteral cephalosporins, carbapenems and amikacin may be used as initial antibiotics to treat nocardiosis. Cotrimoxazole or linezolid can be used as monotherapy in selected patients without brain involvement. Although treatment duration has historically been set to at least 6 months in the absence of central nervous system involvement, shorter durations (<120 days) seem to be associated with a favourable outcome.

Nocardiosis Associated with Primary Immunodeficiencies (Nocar-DIP): an International Retrospective Study and Literature Review.

PURPOSE: Nocardiosis is a life-threatening infectious disease. We aimed at describing nocardiosis in patients with primary immunodeficiency diseases (PID). METHODS: This international retrospective cohort included patients with PID and nocardiosis diagnosed and/or published from Jan 1, 2000, to Dec 31, 2016. To identify nocardiosis cases, we analyzed PID databases from the French National Reference Center for PID (Paris, France) and the National Institute of Health (NIH, United States of America) and we performed a literature review on PubMed. RESULTS: Forty-nine cases of nocardiosis associated with PID were included: median age at diagnosis of nocardiosis was 19 (0-56) years and most cases were observed among chronic granulomatous disease (CGD) patients (87.8%). Median time from symptoms to diagnosis of Nocardia infection was 20 (2-257) days. Most frequent clinical nocardiosis presentation was pneumonia (86.7%). Twelve-month mortality rate was 4.2%, and 11.9% of patients experienced a possible recurrence of infection. Nocardiosis more frequently led to the diagnosis of PID among non-CGD patients than in CGD patients. Non-CGD patients experienced more cerebral nocardiosis and more disseminated infections, but mortality and recurrence rates were similar. Highest incidences of nocardiosis among PID cohorts were observed among CGD patients (0.0057 and 0.0044 cases/patient-year in the USA and in France, respectively), followed by IL-12p40 deficiency. CONCLUSIONS: Among 49 cases of nocardiosis associated with PID, most patients had CGD and lung involvement. Both mortality and recurrence rates were low.

Nocardia takedensis: a newly recognized pathogen responsible for skin and soft tissue infections.

Nocardia takedensis was first isolated in 2005, from soil in Japan. We report here two cases of lymphangitis in France (2012-2017) caused by N. takedensis both occurring after skin injury while gardening, which enabled its inoculation. The two patients were immunocompromised and successfully treated by an antimicrobial agent active on the isolated strain, trimethoprim-sulfamethoxazole and amoxicillin-clavulanic acid for patient one and patient two, respectively. Our study along with previous ones supports the idea of a newly recognized cutaneous opportunistic pathogen and reinforces the recommendation of using gloves during soil exposure for immunocompromised patients. Lastly, according to data found in the literature, we would recommend trimethoprim-sulfamethoxazole as an efficient empirical antibiotic therapy in case of cutaneous infection caused by N. takedensis.

Metal oxide nanoparticles for the decontamination of toxic chemical and biological compounds.

For several years, the international context is deeply affected by the use of chemical and biological weapons. The use of CBRN (Chemical Biological Radiological Nuclear) threat agents from military stockpiles or biological civilian industry demonstrate the critical need to improve capabilities of decontamination for civilians and military. Physical decontamination systems that operate only by adsorption and displacement such as Fuller's Earth, have the drawback of not neutralizing hazardous agents, giving place to cross contaminations. Consequently, the development of a formulation based on metal oxide nanoparticles attracts considerable interest, since they offer physicochemical properties that allow them to both adsorb and degrade toxic compounds. Thus, the aim of this study is to found metal oxide nanoparticles with a versatile activity on both chemical and biological toxic agents. Therefore, several metal oxides such as MgO, TiO2, CeO2, ZnO and ZrO2 were characterized and their decontamination kinetics of less-toxic surrogate of VX, paraoxon, were studied in vitro. To determine the antimicrobial activity of these nanoparticles, simulants of biological terrorist threat were used by performing a 3-hours decontamination kinetics. This proof-of-concept study showed that MgO is the only one that exhibits both chemical and antibacterial actions but without sporicidal activity.

Actinomycetoma Caused by Actinomadura mexicana, A Neglected Entity in the Caribbean.

Mycetoma is a chronic infection that is slow to develop and heal. It can be caused by fungi (eumycetoma) or bacteria (actinomycetoma). We describe a case of actinomycetoma caused by Actinomadura mexicana in the Caribbean region.

Genome Sequences of Three Nocardia cyriacigeorgica Strains and One Nocardia asteroides Strain.

We report four draft genome sequences of Nocardia spp. The strains are the Nocardia cyriacigeorgica DSM 44484 pathogenic type strain; two environmental isolates, Nocardia cyriacigeorgica EML446 and EML1456; and the Nocardia asteroides ATCC 19247 nonpathogenic type strain, with estimated genome sizes of 6.3 to 6.8 Mb. The study of these isolates will provide insight into physiology, evolution, and pathogenicity of Nocardia spp.