Vibrio cholerae El Tor strains linked to global cholera are homogeneous by pulsed-field gel electrophoresis

Vibrio cholerae O1 El Tor, causative agent of the ongoing seventh cholera pandemic, is native to the aquatic environment of the Ganges Delta, Bay of Bengal (GDBB). Recent studies traced pandemic strains to the GDBB and proposed global spread of cholera had occurred via intercontinental transmission. In the research presented here, Not I-digested genomic DNA extracted from V. cholerae O1 clinical and environmental strains isolated in Bangladesh during 2004 – 2014 was analyzed by pulsed-field gel electrophoresis (PFGE). Results of cluster analysis showed 94.67% of the V. cholerae isolates belonged to clade A and included the majority of clinical isolates of spatio-temporal origin and representing different cholera endemic foci. The rest of the strains were estuarine, all environmental isolates from Mathbaria, Bangladesh, and occurred as singletons, clustered in clades B and C, or in the small clades D and E. Cluster analysis of the Bangladeshi strains and including 157 El Tor strains from thirteen countries in Asia, Africa, and the Americas revealed 85% of the total set of isolates belonged to clade A, indicating all were related, yet did not form an homogeneous cluster. Overall, 15% of the global strains comprised multiple small clades or segregated as singletons. Three sub-clades could be discerned within the major clade A, reflecting distinct lineages of V. cholerae El Tor associated with cholera in Asia, Africa, and the Americas. The presence in Asia and the Americas of non-pandemic V. cholerae El Tor populations differing by PFGE and from strains associated with cholera globally suggests different ecotypes are resident in distant geographies.

Serine proteases profiles of Leishmania (Viannia) braziliensis clinical isolates with distinct susceptibilities to antimony

Glucantime (SbV) is the first-line treatment against American Tegumentary Leishmaniasis. Resistance cases to this drug have been reported and related to host characteristics and parasite phenotypes. In this study, 12 Leishmania (Viannia) braziliensis isolates from patients that presented clinical cure (Responders—R) and relapse or therapeutic failure (Non-responders—NR) after treatment with antimony, were analyzed. These parasites were assessed by in vitro susceptibility to SbIII and SbV, serine proteases activity measured with substrate (z-FR-AMC) and specific inhibitors (TLCK, AEBSF and PMSF). In vitro susceptibility of axenic amastigotes to SbIII showed a significant difference between R and NR groups. The protease assays showed that TLCK inhibited almost 100% of activity in both axenic amastigotes and promastigotes while AEBSF inhibited around 70%, and PMSF showed lower inhibition of some isolates. Principal component and clustering analysis performed with these data yielded one homogeneous cluster with only NR isolates and three heterogeneous clusters with R and NR isolates. Additionally, differential expression of subtilisins (LbrM.13.0860 and LbrM.28.2570) and TXNPx (LbrM.15.1080) was evaluated in promastigotes and axenic amastigotes from both groups. The results showed a higher expression of LbrM.13.0860 and LbrM.15.1080 genes in axenic amastigotes, while LbrM.28.2570 gene had the lowest expression in all isolates, regardless of the parasite form. The data presented here show a phenotypic heterogeneity among the parasites, suggesting that exploration of in vitro phenotypes based on SbIII and serine proteases profiles can aid in the characterization of L. (V.) braziliensis clinical isolates.

Serine Proteases Profiles of Leishmania (Viannia) Braziliensis Clinical Isolates With Distinct Susceptibilities to Antimony

Glucantime® (SbV) is the first-line treatment against leishmaniasis in South America. Its effectiveness has been associated with modulation of the parasite detoxification system that, in turn, is related to serine proteases such as subtilisins. In this study, 12 Leishmania (Viannia) braziliensis isolates from patients that presented clinical cure (Responders - R) and relapse or therapeutic failure (Non-responders - NR) were used. The parasites were assessed by in vitro susceptibility to SbIII and SbV, serine proteases activity – measured with z-FR-AMC as substrate and specific inhibitors – and expression of subtilisins and tryparedoxin-peroxidase (TXNPx). In vitro susceptibility of axenic amastigotes to SbIII showed a significant difference between R and NR groups. TLCK inhibited almost 100 % of activity in both axenic amastigotes and promastigotes while AEBSF inhibited around 70 %, and PMSF showed lower inhibition of specific isolates. Principal component and clustering analysis yielded one homogeneous cluster with only NR isolates and three heterogeneous clusters with R and NR isolates. Additionally, transcripts of subtilisins (LbrM.13.0860 and LbrM.28.2570) and TXNPx (LbrM.15.1080) were detected in promastigotes and axenic amastigotes from both groups. The data presented here show a phenotypic heterogeneity among the parasites, suggesting that exploration of in vitro phenotypes based on SbIII and serine proteases profiles can aid in the characterization of L. (V.) braziliensis clinical isolates.

Serine Proteases Profiles of Leishmania (Viannia) Braziliensis Clinical Isolates With Distinct Susceptibilities to Antimony

Background: Glucantime® (SbV) is considered the first-line treatment against American Tegumentary Leishmaniasis in South America, though increased parasite resistance towards it have been reported and hampered its effectiveness. In this context, subtilisins serine proteases have been related to parasites’ susceptibility to drugs such as SbV and derivatives, through modulation of the parasite detoxification system. However, little is known about parasites causing ATL and their distinct responses towards this treatment.Methods: The study was conducted using Leishmania (Viannia) braziliensis clinical isolates from patients that presented clinical cure or Responders (R) and relapse/therapeutic failure or Non-responders (NR). Twelve clinical isolates were used to assess their in vitro susceptibility to SbIII and SbV, serine proteases activity, and expression of subtilisins-like and tryparedoxin-peroxidase (TXNPx) transcripts. Results: SbIII was able to better distinguish axenic amastigotes from each clinical group. These isolates were also assessed for serine protease activity, using z-FR-AMC as substrate and detecting distinct enzyme profiles with specific inhibitors. TLCK inhibited almost 100% of activity in both promastigotes and axenic amastigotes while AEBSF inhibited around 70%. PMSF showed low inhibition of specific isolates (35%). Gathering all the quantitative data, we performed principal component analysis and then used the K-means algorithm to cluster the isolates. This analysis yielded one cluster with only one isolate (R isolate), one homogeneous cluster (NR isolates), and three heterogeneous clusters (R and NR isolates). Additionally, gene transcripts of subtilisins and TXNPx were detected in promastigotes and axenic amastigotes from both groups. Conclusions: Cluster analysis showed that there is a phenotypic heterogeneity among the isolates, however, exploration of in vitro phenotypes based on SbIII and serine proteases profiles can aid in the characterization and better understanding of L. (V.) braziliensis clinical isolates.

Genomic background of the Klebsiella pneumoniae NDM-1 outbreak in Poland, 2012–18

Objectives To characterize genomes of Klebsiella pneumoniae ST11 NDM-1 responsible for a countrywide outbreak in Poland and compare them phylogenetically with other Polish and international ST11 strains. Methods Seventy-one carbapenemase-producing K. pneumoniae ST11 isolates from Poland, including 66 representatives of the NDM-1 epidemic from 2012–18, were sequenced using Illumina MiSeq. Additionally, three outbreak isolates were also sequenced using MinION. The clonality and phylogenetic analysis was done by core-genome MLST and SNP approaches. Resistomes, virulomes, K/O antigens and plasmid replicons were screened for. The detailed plasmid analysis was based on full assemblies using Oxford Nanopore Technologies data. Results Chromosomes of the outbreak isolates formed an essentially homogeneous cluster (though accumulating SNPs gradually with time), differing remarkably from other Polish NDM-1/-5-, KPC-2- or OXA-48-producing K. pneumoniae ST11 strains. The cluster belonged to a clade with 72 additional isolates identified worldwide, including closely related NDM-1 producers from several countries, including organisms from Bulgaria and Greece. All these had KL24 and O2v1 antigens and the chromosomal yersiniabactin locus YbST230 residing in the ICEKp11 element. The specific blaNDM-1-carrying Tn125 transposon derivative, named Tn125A, was located in IncFII/pKPX-1- and/or IncR-like plasmids; however, the IncRs rearranged extensively during the outbreak, contributing to highly dynamic plasmid profiles and resistomes. Conclusions The K. pneumoniae ST11 NDM-1 genotype that has been expanding in Poland since 2012 is largely monoclonal and represents a novel international high-risk lineage that is also spreading in other countries.

Painting a portrait of the Galactic disc with its stellar clusters

Context. The large astrometric and photometric survey performed by the Gaia mission allows for a panoptic view of the Galactic disc and its stellar cluster population. Hundreds of stellar clusters were only discovered after the latest Gaia data release (DR2) and have yet to be characterised. Aims. Here we make use of the deep and homogeneous Gaia photometry down to G = 18 to estimate the distance, age, and interstellar reddening for about 2000 stellar clusters identified with Gaia DR2 astrometry. We use these objects to study the structure and evolution of the Galactic disc. Methods. We relied on a set of objects with well-determined parameters in the literature to train an artificial neural network to estimate parameters from the Gaia photometry of cluster members and their mean parallax. Results. We obtain reliable parameters for 1867 clusters. Our catalogue confirms the relative lack of old stellar clusters in the inner disc (with a few notable exceptions). We also quantify and discuss the variation of scale height with cluster age, and we detect the Galactic warp in the distribution of old clusters. Conclusions. This work results in a large and homogeneous cluster catalogue, allowing one to trace the structure of the disc out to distances of ∼4 kpc. However, the present sample is still unable to trace the outer spiral arm of the Milky Way, which indicates that the outer disc cluster census might still be incomplete.

A Pilot Study Assessing Attitudes toward Finance among Italian Business Students

Exploring ‘attitude toward finance’ as a factor predicting financial literacy is a new area of inquiry in academic literature. This study is a preliminary investigation of attitudes toward finance among a sample of students in higher education in Italy. It uses ten focus group discussions as data collecting method. Respondents are a total of 98 learners attending the Faculty of Business and Economics in a large University in  northern Italy, majoring in the areas of Finance, Accounting, or Marketing. The aim of this study is to assess the state of the art of the beliefs, feelings and self-perceptions of the target group regarding financial matters and practices, and to generate a questionnaire to measure attitudes toward finance in future quantitative studies. A Chi-Square analysis is used to analyse the collected data and determine if there are significant associations between students’ attitudes towards finance and characteristics like gender, level of study (first or second cycle degree) and faculty major. The research findings suggest that, even in a homogeneous cluster like our study population, the profile of attitude toward finance is not uniform. Overall, no significant differences are found between male and female students. Education level does not seem to significantly affect the construct either. However, the faculty major impacts on students’ attitude toward finance. Policy implications and suggestions for further work are discussed.

Adolescents’ Market Segmentation: Using CSI as a Tool

Purpose of this article: The study aims to examine the adolescents’ decision-making style and shopping orientation using consumer style inventory (CSI) as a segmentation tool. It proposes that adolescents’ decision-making styles are quite different from the adult consumers. Here, the researchers develop a typology that is based on the dimensions of CSI and its ability to predict the homogeneous cluster. Design/methodology/approach: The study is based on the clustering of adolescents on the basis of their decision-making styles. The study was carried out in India. A sample of 215 students has been taken. Factor analysis, cluster analysis which is followed by discriminant analysis, has been used in the study. Findings: The article provides a significant segmentation of adolescents’ market on the basis of their decision-making style. And at last in this article, we conclude that the adolescents have different decision-making styles than the adult consumers. Six out of eight dimensions of the Sproles and Kendall (1986) are relevant to the Indian adolescents. On the basis of these traits/styles, the adolescents are grouped into three different clusters, which are homogeneous and identifiable in nature. Originality/value: This article fulfils an identified need to study about the adolescents and how they have been clustered into different segments. The CSI is used as segmentation tool. This is the first study to segment the Indian adolescents market on the basis of their decision-making styles.

Structural and hidden properties of 1D point processes: A wavelet-based study

A one-dimensional (1D) point process, if considered as a random measure, can be represented by a sum, at most countable, of Delta Dirac measures concentrated at some random points. The integration with respect to the point process leads to the definition of the continuous wavelet transform of the process itself. As a possible choice of the mother wavelet, we propose the Mexican hat and the Morlet wavelet in order to implement the energy density of the process as a function of two wavelet parameters. Such mathematical tool works as a microscope to process an in-depth analysis of some classes of processes, in particular homogeneous, cluster, and locally scaled processes.