Search

In this study, we report on the synthesis of silver nanoparticles (AgNPs) achieved by using three bacterial strains Rhodococcus, Brevundimonas and Bacillus as reducing and capping agents, newly isolated from a consortium associated with the Antarctic marine ciliate Euplotes focardii. After incubation of these bacteria with a 1 mM solution of AgNO3 at 22 °C, AgNPs were synthesized within 24 h. Unlike Rhodococcus and Bacillus, the reduction of Ag+ from AgNO3 into Ag0 has never been reported for a Brevundimonas strain. The maximum absorbances of these AgNPs in the UV-Vis spectra were in the range of 404 nm and 406 nm. EDAX spectra showed strong signals from the Ag atom and medium signals from C, N and O due to capping protein emissions. TEM analysis showed that the NPs were spherical and rod-shaped, with sizes in the range of 20 to 50 nm, and they were clustered, even though not in contact with one another. Besides aggregation, all the AgNPs showed significant antimicrobial activity. This biosynthesis may play a dual role: detoxification of AgNO3 and pathogen protection against both the bacterium and ciliate. Biosynthetic AgNPs also represent a promising alternative to conventional antibiotics against common nosocomial pathogens.

Background The scope of this work is to build a Machine Learning model able to predict patients risk to contract a multidrug resistant urinary tract infection (MDR UTI) after hospitalization. To achieve this goal, we used different popular Machine Learning tools. Moreover, we integrated an easy-to-use cloud platform, called DSaaS (Data Science as a Service), well suited for hospital structures, where healthcare operators might not have specific competences in using programming languages but still, they do need to analyze data as a continuous process. Moreover, DSaaS allows the validation of data analysis models based on supervised Machine Learning regression and classification algorithms. Results We used DSaaS on a real antibiotic stewardship dataset to make predictions about antibiotic resistance in the Clinical Pathology Operative Unit of the Principe di Piemonte Hospital in Senigallia, Marche, Italy. Data related to a total of 1486 hospitalized patients with nosocomial urinary tract infection (UTI). Sex, age, age class, ward and time period, were used to predict the onset of a MDR UTI. Machine Learning methods such as Catboost, Support Vector Machine and Neural Networks were utilized to build predictive models. Among the performance evaluators, already implemented in DSaaS, we used accuracy (ACC), area under receiver operating characteristic curve (AUC-ROC), area under Precision-Recall curve (AUC-PRC), F1 score, sensitivity (SEN), specificity and Matthews correlation coefficient (MCC). Catboost exhibited the best predictive results (MCC 0.909; SEN 0.904; F1 score 0.809; AUC-PRC 0.853, AUC-ROC 0.739; ACC 0.717) with the highest value in every metric. Conclusions the predictive model built with DSaaS may serve as a useful support tool for physicians treating hospitalized patients with a high risk to acquire MDR UTIs. We obtained these results using only five easy and fast predictors accessible for each patient hospitalization. In future, DSaaS will be enriched with more features like unsupervised Machine Learning techniques, streaming data analysis, distributed calculation and big data storage and management to allow researchers to perform a complete data analysis pipeline. The DSaaS prototype is available as a demo at the following address: https://dsaas-demo.shinyapps.io/Server/

This paper discusses the impact of a wet flat radome on the performance of a line replaceable unit active phased-array antenna developed for a dual-polarized phased-array weather radar. Water formations, such as film and droplets, were fully characterized over flat and curved radome surfaces using an analytical model as a function of the precipitation rate. Numerical simulations and experimental results validated the proposed analytical model. An active dual-polarized phased-array of $8\times 2$ elements was used to evaluate the degradation of the cross-polarization component as well as the mismatch and the phase of scanned antenna radiation patterns for vertical and horizontal polarizations. In addition, a radome panel of an $S$ -band weather radar (WSR-88D) was characterized in the far field using a single radio-frequency probe. It is demonstrated that even at the $S$ -band, the water formation on the radome affects both copolarization and cross-polarization components, degrading the overall performance of the dual-polarized radar system under rain conditions.

In the last decade, metal nanoparticles (NPs) have gained significant interest in the field of biotechnology due to their unique physiochemical properties and potential uses in a wide range of applications. Metal NP synthesis using microorganisms has emerged as an eco-friendly, clean, and viable strategy alternative to chemical and physical approaches. Herein, an original and efficient route for the microbial synthesis of copper NPs using bacterial strains newly isolated from an Antarctic consortium is described. UV-visible spectra of the NPs showed a maximum absorbance in the range of 380–385 nm. Transmission electron microscopy analysis showed that these NPs are all monodispersed, spherical in nature, and well segregated without any agglomeration and with an average size of 30 nm. X-ray powder diffraction showed a polycrystalline nature and face centered cubic lattice and revealed characteristic diffraction peaks indicating the formation of CuONPs. Fourier-transform infrared spectra confirmed the presence of capping proteins on the NP surface that act as stabilizers. All CuONPs manifested antimicrobial activity against various types of Gram-negative, Gram-positive bacteria, and fungi pathogen microorganisms including Escherichia coli, Staphylococcus aureus, and Candida albicans. The cost-effective and eco-friendly biosynthesis of these CuONPs make them particularly attractive in several application from nanotechnology to biomedical science.

Funder: Fondi di Ateneo per la Ricerca (FAR-UNICAM) 2014-2015, Funder: European Commission Marie Sklodowska-Curie Actions H2020 RISE Metable– 645693, We isolated a novel bacterial strain from a prokaryotic consortium associated to the psychrophilic marine ciliate Euplotes focardii, endemic of the Antarctic coastal seawater. The 16S rDNA sequencing and the phylogenetic analysis revealed the close evolutionary relationship to the Antarctic marine bacterium Marinomonas sp. BSw10506 and the sub antarctic Marinomonas polaris. We named this new strain Marinomonas sp. ef1. The optimal growth temperature in LB medium was 22 °C. Whole genome sequencing and analysis showed a reduced gene loss limited to regions encoding for transposases. Additionally, five genomic islands, e.g. DNA fragments that facilitate horizontal gene transfer phenomena, were identified. Two open reading frames predicted from the genomic islands coded for enzymes belonging to the Nitro-FMN-reductase superfamily. One of these, the putative NAD(P)H nitroreductase YfkO, has been reported to be involved in the bioreduction of silver (Ag) ions and the production of silver nanoparticles (AgNPs). After the Marinomonas sp. ef1 biomass incubation with 1 mM of AgNO3 at 22 °C, we obtained AgNPs within 24 h. The AgNPs were relatively small in size (50 nm) and had a strong antimicrobial activity against twelve common nosocomial pathogenic microorganisms including Staphylococcus aureus and two Candida strains. To our knowledge, this is the first report of AgNPs biosynthesis by a Marinomonas strain. This biosynthesis may play a dual role in detoxification from silver nitrate and protection from pathogens for the bacterium and potentially for the associated ciliate. Biosynthetic AgNPs also represent a promising alternative to conventional antibiotics against common pathogens.

In a passage of the Life of Nero (Suet. Ner. 47.2) concerning the emperor’s indecision over what to do after the revolt of the provincial armies, it can clearly be seen that there is an influence from an argumentative structure particular to a certain type of deliberative oratory, the suasoria triplex. This influence may be due simply to Suetonius’ familiarity with the declamatory exercises in vogue at the rhetorical schools, but some hints allow us to suppose the existence of a suasoria theme that took as its subject this very episode in the life of the emperor.

The synthesis of silver nanoparticles (AgNPs) by microorganisms recently gained a greater interest due to its potential to produce them in various sizes and morphologies. In this study, for AgNP biosynthesis, we used a new Pseudomonas strain isolated from a consortium associated with the Antarctic marine ciliate Euplotes focardii. After incubation of Pseudomonas cultures with 1 mM of AgNO3 at 22 °C, we obtained AgNPs within 24 h. Scanning electron (SEM) and transmission electron microscopy (TEM) revealed spherical polydispersed AgNPs in the size range of 20–70 nm. The average size was approximately 50 nm. Energy dispersive X-ray spectroscopy (EDS) showed the presence of a high intensity absorption peak at 3 keV, a distinctive property of nanocrystalline silver products. Fourier transform infrared (FTIR) spectroscopy found the presence of a high amount of AgNP-stabilizing proteins and other secondary metabolites. X-ray diffraction (XRD) revealed a face-centred cubic (fcc) diffraction spectrum with a crystalline nature. A comparative study between the chemically synthesized and Pseudomonas AgNPs revealed a higher antibacterial activity of the latter against common nosocomial pathogen microorganisms, including Escherichia coli, Staphylococcus aureus and Candida albicans. This study reports an efficient, rapid synthesis of stable AgNPs by a new Pseudomonas strain with high antimicrobial activity.

The concept and theory of a novel instrument to characterize the radio frequency performance of a radome under different conditions, including dirtiness, wetness, and varying temperature, was presented and discussed in Part I. The proposed concept estimates the transmittance through the radome using the reflected signal, directly measured, and an algorithm to evaluate the water absorption on the radome surface. In this second part of the paper, the proposed concept was employed to characterize the radome of an operative X-band weather radar in both dry and wet conditions.

This paper presents a unique instrument for characterizing the impact of wet radomes in radar systems. The proposed technique enables full radio frequency (RF) characterization of the radome, by evaluating its performance under a variety of conditions, including dirtiness, wetness, ice formation, and varying temperature, and providing a potential solution for future wet radome calibration methods. The reflections generated from the wet radome surface, measured from a high-resolution probe, are combined with an estimation of water absorption as a function of the precipitation rain rate, to calculate the attenuation introduced by the wet radome. This instrument is a cost-effective solution that can be integrated into an existing or new radar system.

Persae et Magi omnes qui Persicae regionis incolunt fines ignem praeferunt et omnibus elementis ignem putant debere praeponi. (Firm. Mat.Err. prof. rel.5.1)The Persians and all the Magi who dwell in the confines of the Persian land give their preference to fire and think it ought to be ranked above all the other elements.Iulius Firmicus Maternus was a Latin writer who lived in the fourth centurya.d. In the 340s, following his conversion to Christianity, he wrote theDe errore profanarum religionum, which has been preserved only in the tenth-century manuscript Vaticanus Palatinus Latinus 165. In this work he argues against the pagan cults, calling for the emperors to suppress them. The first sections are dedicated to the pagan worship of the natural elements: objects of a cult are water among the Egyptians, earth among the Phrygians, air among the Assyrians. The chapter we are dealing with, the fifth, is dedicated to fire, a central element of the Zoroastrian religion. Greek and Roman writers, pagans and Christians alike, were aware of this, and references to some sort of fire-cult among Persians are numerous in literature and are found as early as Herodotus (1.131, 3.16). Just like Firmicus Maternus, some authors also state that the Magi worship fire as a god or divine element and that they conduct fire-related rituals. In Greek and Latin authors there is a view that the Magi, these specialists of the rituals of the Persian religion, were originally a Median tribe. As shown by the passages of Ammianus and Basil, such knowledge was also available to Firmicus Maternus’ contemporaries, and there do not appear to be particular differences in the way in which Greek and Latin authors viewed the Magi in Achaemenid and Sassanid times. Regrettably, one cannot know for certain which of these sources Firmicus Maternus knew.

the scholion to Lucan, “Bellum Civile” 8, 618 that is found in the “Adnotationes super Lucanum” is at first sight pointless, but it becomes immediately meaningful if we accept the idea that the scholiast commented the text by systematically comparing it with Livy’s narrative on those same events. This approach casts a new light on how these ancient commentators read Lucan and can be also useful to solve exegetical issues.

In Italy, there are limited studies on the molecular epidemiology of Clostridium difficile, possibly due to insufficient laboratory diagnostic capacity, low awareness and lack of high-quality surveillance systems. The aim of this study was to evaluate the diffusion of C. difficile in a tertiary care hospital and to genotype all the collected strains in order for hospital staff to take corrective action. All specimens were subjected to a CDI diagnostic algorithm. This included highly specific toxin PCRs and multilocus sequence typing (MLST) to obtain clear, unequivocal genotypization. During a three-year study period, as part of routine C. difficile testing, 711 stool samples were collected from 522 patients to detect the presence of toxigenic genes. After testing, 106 different samples were identified as toxigenic. The proportions of non-toxigenic and toxigenic isolates were respectively 8.7% (62/711) and 14.9% (106/711). The most infection findings in wards for toxigenic strains were in Internal Medicine (56), followed by Neurology (11) and Gastroenterology (11). Three novel sequence types (STs) were found. The two most prevalent STs in wards were clade 1 ST-378 (40) and clade 1 ST-379 (33). Other healthcare-acquired strains were clade 4 ST-37 (11) and clade 5 ST-11 (7). Two STs, namely clade 3 ST-5 (10) and clade 1 ST-380 (5), were isolated among external patients. To prevent an increase in outbreak probability, an active surveillance programme combined with proper hand hygiene, environmental cleaning and contact precautions should be implemented.

The aim of this retrospective study is to evaluate the reliability and robustness of six glucose meters for point-of-care testing in our wards using a brand-new protocol. During a 30-days study period a total of 50 diabetes patients were subjected to venous blood sampling and glucose meter blood analysis. The results of six glucose meters were compared with our laboratory reference assay. GlucoMen Plus (Menarini) with the 82% of acceptable results was the most robust glucose meter. Even if the Passing-Bablok analysis demonstrates the presence of constant systematic errors and the Bland-Altman test highlighted a possible overestimation, the surveillance error grid analysis showed that this glucose meter can be used safely. We proved that portable glucose meters are not always reliable in routinely clinical settings.

EM-X is a mixed consortium of beneficial microorganisms of natural occurrence (lactic bacteria, yeast and photosynthetic bacteria). The aim of this study is to evaluate the antimicrobial activity in-vitro of EM-X to the principal pathogens isolated in clinical settings and to understand if it could be a suitable adjuvant to synthetic antibiotics. According the World Health Organization we performed antimicrobial assays to the main pathogens usually found in hospital wards. After antimicrobial testing, EM-X has been shown to be most effective at a concentration of 40 mg/ml four time concentrated than the commercial original solution (10 mg/ml). The EM-X antimicrobial action, although effective against bacteria, has proved to be ineffective against the candida genus. This active range of concentration (mg/ml) may prove a very weak action of EM, but further investigations will be done to separate the active substances form the inactive ones in this complex mixture.

A novel instrument to characterize the effect of wet radomes in radar systems is presented. The focus of this research is enabling full characterization of radome performance under a variety of conditions including cleanliness, dirtiness, and wetness, and to provide a potential solution for wet radome characterization. The proposed method consists of using a low profile instrument that can be easily integrated into an existing or new radar system. A low profile dielectric antenna connected to the reflectometer employs the time domain gating (TDG) analysis, which is used to minimize the impact of undesirable reflections. The concept was validated with on-field experiments.

non, si Cambysae redeant et flumina Croesi,dicat ‘De nostro surge, poeta, toro’. In these two lines Propertius is proud to say that his puella would not dismiss him for the fabulous treasures of some dives amator. The problem is caused by the interpretation of Cambysae as given in all the manuscripts; it is difficult to understand both as a genitive singular and as a nominative plural. This form of the genitive is not, in fact, recorded before Apul. Fl. 15.12, and the concurrent form Cambysis is even less common. Moreover, the Persian king Cambyses was not an example of opulence in Antiquity like the Lydian king Croesus, but of cruelty. The only passages where he is linked with the idea of richness are Apul. Mun. 26.13–15: Cambyses et Xerxes et Darius potentissimi reges fuerunt. Horum praepotentiam, quam ex opibus collegerant, lenocinium vitae effecerat celsiorem, and (indirectly) Juv. 14.328–31: Si nondum implevi gremium, si panditur ultra, | nec Croesi fortuna umquam nec Persica regna | sufficient animo nec divitiae Narcissi, | indulsit Caesar cui Claudius omnia, cuius | paruit imperiis uxorem occidere iussus, where we find apparently the same connection between Persian royalty and Croesus' richness that we read in Propertius' line.

This report describes a case of meningitis caused by Listeria monocytogenes in a stem cell transplant recipient on immunosuppressive therapy for cutaneous chronic graft-versus host disease. A 59-year-old woman had undergone allogeneic stem cell transplantation (from a matched unrelated donor) 13 months previously for chronic lymphocytic leukemia. She was on regular hematologic follow-up. Though her previous malignancy has been in remission, she was immunosuppressed due to the pharmacological treatment. We describe a meningitis caused by a typical food-borne pathogen, dangerous in patients with impaired cell-mediated immunity. Moreover the bacterium had a multidrug resistance, a rare characteristic in clinical listeriosis. Rapid diagnosis and treatment are key factors in these cases. We chose ampicillin and rifampicin that allowed a complete resolution of the clinical manifestations.

We report the characterization of the bacterial consortium associated to Euplotes focardii, a strictly psychrophilic marine ciliate that was maintained in laboratory cultures at 4 °C after its first isolation from Terra Nova Bay, in Antarctica. By Illumina genome analyser, we obtained 11,179 contigs of potential prokaryotic origin and classified them according to the NCBI’s prokaryotic attributes table. The majority of these sequences correspond to either Bacteroidetes (16 %) or Proteobacteria (78 %). The latter were dominated by gamma- (39 %, including sequences related to the pathogenic genus Francisella), and alpha-proteobacterial (30 %) sequences. Analysis of the Pfam domain family and Gene Ontology term variation revealed that the most frequent terms that appear unique to this consortium correspond to proteins involved in “transmembrane transporter activity” and “oxidoreductase activity”. Furthermore, we identified genes that encode for enzymes involved in the catabolism of complex substance for energy reserves. We also characterized members of the transposase and integrase superfamilies, whose role in bacterial evolution is well documented, as well as putative antifreeze proteins. Antibiotic treatments of E. focardii cultures delayed the cell division of the ciliate. To conclude, our results indicate that this consortium is largely represented by bacteria derived from the original Antarctic sample and may contribute to the survival of E. focardii in laboratory condition. Furthermore, our results suggest that these bacteria may have a more general role in E. focardii survival in its natural cold and oxidative environment. Electronic supplementary material The online version of this article (doi:10.1007/s00248-015-0568-9) contains supplementary material, which is available to authorized users.

Biological systems show impressive adaptations at extreme environments. In extreme environments, directional selection pressure mechanisms acting upon mutational events often produce functional and structural innovations. Examples are the antifreeze proteins in Antarctic fish and their lack of hemoglobin, and the thermostable properties of TAQ polymerase from thermophilic organisms. During the past decade, more than 4000 organisms have been part of genome-sequencing projects. This has enabled the retrieval of information about evolutionary relationships among all living organisms, and has increased the understanding of complex phenomena, such as evolution, adaptation, and ecology. Bioinformatics tools have allowed us to perform genome annotation, cross-comparison, and to understand the metabolic potential of living organisms. In the last few years, research in bioinformatics has started to migrate from the analysis of genomic sequences and structural biology problems to the analysis of genotype-phenotype mapping. We believe that the analysis of multi-omic information, particularly metabolic and transcriptomic data of organisms living in extreme environments, could provide important and general insights into the how natural selection in an ecosystem shapes the molecular constituents. Here we present a review of methods with the aim to bridge the gap between theoretical models, bioinformatics analysis and experimental settings. The amount of data suggests that bioinformatics could be used to investigate whether the adaptation is generated by interesting molecular inventions. We therefore review and discuss the methodology and tools to approach this challenge.

The aim of this retrospective study was to highlight the differences in antibiotic resistance between Hospital-acquired and Community-acquired urinary tract infections (UTIs). Antimicrobial UTIs resistance data were collected from March 2011 to March 2018. Uropathogens were identified from 41,715 patients using routine laboratory methods. Differences in antibiotic resistance between Hospital and Community (non-hospitalized) patients were statistically validated. Odds ratio (OR) and p-values was used to determine whether a particular exposure (hospitalization) was a risk factor for a particular outcome (higher antibiotic resistance). We reported a general increase of unnecessary urine cultures in both community and hospital patients. The most representative microorganism isolated from Community (58.2%) and Hospital (47.6%) was E. coli. UTIs causative bacteria in hospitalized patients was more than twice as resistant to Trimetoprim/sulphamethoxazole (OR 2.26) and Imipenem (OR 2.56), for Gram-positive and Gram-negative, respectively, than in Community patients. Nitrofurantoin was the only agent without differences in resistance rate between community and hospital UTIs. Therefore, physicians could use it as a definitive therapy for uncomplicated cystitis and as a prophylactic agent for recurrent uncomplicated cystitis. With this work we provided a general protocol applicable by physicians to select the most suitable, if necessary, UTIs empiric treatment.