Search

Abstract Radar systems are a topic of great interest, especially due to their extensive range of applications and ability to operate in all weather conditions. Modern radars have high requirements such as its resolution, accuracy and robustness, depending on the application. Noise Radar Technology (NRT) has the upper hand when compared to conventional radar technology in several characteristics. Its robustness to jamming, low Mutual Interference and low probability of intercept are good examples of these advantages. However, its signal processing is more complex than that associated to a conventional radar. Artificial Intelligence (AI)‐based signal processing is getting increasing attention from the research community. However, there is yet not much research on these methods for noise radar signal processing. The aim of the authors is to provide general information regarding the research performed on radar systems using AI and draw conclusions about the future of AI in noise radar. The authors introduce the use of AI‐based algorithms for NRT and provide results for its use.

Introdução/Objetivo: Clostridioides Difficile (CDI) é um bacilo gram-positivo produtor de esporos e toxinas relacionado com desordens do trato gastrointestinal. Diarreia e colite pseudomembranosa são as principais manifestações clínicas que ocorrem pela produção das toxinas A, B e binária, e das enzimas hialuronidase e colagenase, que danificam o citoesqueleto da célula epitelial, causando a secreção de fluido e inflamação. CDI é uma grande ameaça à saúde. Em 2017, foram estimados 223.900 casos em pacientes hospitalizados e 12.800 mortes nos Estados Unidos. O objetivo do estudo foi avaliar a prevalência de CDI produtor de toxina e a prevalência da cepa hipervirulenta, relacionando com o local de internação e idade dos pacientes no Hospital de Clínicas de Porto Alegre (HCPA). Materiais e métodos: Estudo retrospectivo para análise da prevalência de CDI produtor de toxina. Foram utilizados os dados do sistema de informática laboratorial do período de janeiro a 30 de abril de 2023. O diagnóstico de CDI foi realizado através de uma testagem em duas etapas: primeiramente, as amostras foram submetidas a um imunoensaio fluorescente (ECO F GDH, ECO Diagnóstica) para a detecção da enzima Glutamato Desidrogenase (GDH). Amostras GDH positivas foram submetidas à técnica de qPCR (Xpert® C. difficile BT, Cepheid) para detecção dos genes que codificam as toxinas B (tcdB) e binária (cdt), assim como a deleção em tcdC que identifica a cepa hipervirulenta pertencente ao ribotipo 027 e resistente às fluoroquinolonas. Resultados: Foram investigadas 473 amostras de fezes de pacientes com diarreia clínica. Encontrou-se uma prevalência de CDI toxigênico em 12,4% (59/473), dos quais 5 pacientes testaram positivo para a cepa hipervirulenta. Apesar de ser relatada a idade avançada como fator de risco, 33% dos pacientes com CDI toxigênico estavam na faixa etária de 0 a 10 anos, enquanto que 27% tinham idade acima de 60 anos. 16,9% dos pacientes tinham de 18 a 30 anos e 22% tinham entre 31 e 59 anos. Quanto ao local da solicitação, observa-se uma predominância de testes da internação pediátrica (23,7%) e internação clínica (22%). Conclusão: A prevalência de CDI toxigênico foi de 12,4% nas amostras analisadas. Esses resultados mostram a importância da epidemiologia local para melhorar o tratamento e as medidas de controle de infecção. CDI é uma importante infecção nosocomial e incorre em tratamentos caros, isolamento do paciente e maior tempo de internação.

ABSTRACT Poor penetration through the outer membrane (OM) of Gram-negative bacteria is a major barrier of antibiotic development. While β-lactam antibiotics are commonly used against Klebsiella pneumoniae and Enterobacter cloacae, there are limited data on OM permeability especially in K. pneumoniae. Here, we developed a novel cassette assay, which can simultaneously quantify the OM permeability to five β-lactams in carbapenem-resistant K. pneumoniae and E. cloacae. Both clinical isolates harbored a blaKPC-2 and several other β-lactamases. The OM permeability of each antibiotic was studied separately (“discrete assay”) and simultaneously (“cassette assay”) by determining the degradation of extracellular β-lactam concentrations via multiplex liquid chromatography-tandem mass spectrometry analyses. Our K. pneumoniae isolate was polymyxin resistant, whereas the E. cloacae was polymyxin susceptible. Imipenem penetrated the OM at least 7-fold faster than meropenem for both isolates. Imipenem penetrated E. cloacae at least 258-fold faster and K. pneumoniae 150-fold faster compared to aztreonam, cefepime, and ceftazidime. For our β-lactams, OM permeability was substantially higher in the E. cloacae compared to the K. pneumoniae isolate (except for aztreonam). This correlated with a higher OmpC porin production in E. cloacae, as determined by proteomics. The cassette and discrete assays showed comparable results, suggesting limited or no competition during influx through OM porins. This cassette assay allowed us, for the first time, to efficiently quantify the OM permeability of multiple β-lactams in carbapenem-resistant K. pneumoniae and E. cloacae. Characterizing the OM permeability presents a critical contribution to combating the antimicrobial resistance crisis and enables us to rationally optimize the use of β-lactam antibiotics. IMPORTANCE Antimicrobial resistance is causing a global human health crisis and is affecting all antibiotic classes. While β-lactams have been commonly used against susceptible isolates of Klebsiella pneumoniae and Enterobacter cloacae, carbapenem-resistant isolates are spreading worldwide and pose substantial clinical challenges. Rapid penetration of β-lactams leads to high drug concentrations at their periplasmic target sites, allowing β-lactams to more completely inactivate their target receptors. Despite this, there are limited tangible data on the permeability of β-lactams through the outer membranes of many Gram-negative pathogens. This study presents a novel, cassette assay, which can simultaneously characterize the permeability of five β-lactams in multidrug-resistant clinical isolates. We show that carbapenems, and especially imipenem, penetrate the outer membrane of K. pneumoniae and E. cloacae substantially faster than noncarbapenem β-lactams. The ability to efficiently characterize the outer membrane permeability is critical to optimize the use of β-lactams and combat carbapenem-resistant isolates.

Abstract Background Between November 2013 and June 2014, 56 cases of bacteremia (15 deaths) associated with the use of Total Parenteral Nutrition (TPN) and/or calcium gluconate (CG) were reported in four Brazilian states. Methods We analyzed 73 bacterial isolates from four states: 45 from blood, 25 from TPN and three from CG, originally identified as Acinetobacter baumannii, Rhizobium radiobacter, Pantoea sp. or Enterobacteriaceae using molecular methods. Results The first two bacterial species were confirmed while the third group of species could not be identified using standard identification protocols. These isolates were subsequently identified by Multi-Locus Sequence Analysis as Phytobacter diazotrophicus, a species related to strains from similar outbreaks in the United States in the 1970’s. Within each species, TPN and blood isolates proved to be clonal, whereas the R. radiobacter isolates retrieved from CG were found to be unrelated. Conclusion This is the first report of a three-species outbreak caused by TPN contaminated with A. baumannii, R. radiobacter and P. diazotrophicus. The concomitant presence of clonal A. baumannii and P. diazotrophicus isolates in several TPN and blood samples, as well as the case of one patient, where all three different species were isolated simultaneously, suggest that the outbreak may be ascribed to a discrete contamination of TPN. In addition, this study highlights the clinical relevance of P. diazotrophicus, which has been involved in outbreaks in the past, but was often misidentified as P. agglomerans.

Objectives: To determine the prevalence of class A extended spectrum β-lactamases (ESBL)-producing Escherichia coli and Klebsiella spp., and to investigate clonality among ESBL-producing isolates of nosocomial and community infections. Methods: The study involved 354 nosocomial infections samples and 992 community infections samples, obtained between 2003 and 2006 at Caxias do Sul, RS. The detection of ESBL was performed by the disk-diffusion test. Presence of blaCTX-M, blaSHV and blaTEM β-lactamase genes was evaluated by PCR, and genomic typing was determined by pulsed-field gel electrophoresis analysis. Results: Higher frequency of ESBL-producing isolates were detected among nosocomial samples of E. coli (6.7%) and Klebsiella (43.7%), than those obtained from community infections (0.4% and 2.6%). blaTEM and blaCTX were the most prevalent ESBL gene families in both E. coli and Klebsiella isolates. Different pulsotypes were obtained among ESBL-producing E. coli and 11 clones for Klebsiella spp., which occurred over the years and in different hospital wards. Among ESBL-producing K. pneumoniae, 74.3% transferred ESBL genes by conjugation and exhibited concomitant decreased aminoglycosides susceptibility. Conclusion: ESBL-producing E. coli, and especially K. pneumoniae are essentially a nosocomial problem, and their dissemination to the community is relatively limited. The great genetic variability observed among ESBL-producing bacteria indicates polyclonal spread and high transference of ESBL genes between bacteria in the hospital environment. This information is of paramount importance for nosocomial infection control. Keywords: β-lactamases, polymerase chain reaction, bacterial typing techniques

Quarenta canídeos selvagens foram capturados por "live trap" nos municípios de Pedro Osório e Pelotas, sul do estado do Rio Grande do Sul e transportados para o Laboratório de Parasitologia da Universidade Federal de Pelotas. Após serem necropsiados, segmentos do intestino, respiratório, urinário e fígado foram separados e examinados. Os crânios dos animais foram usados para identificação taxonômica. Dos 40 animais capturados, 22 (55%) foram Pseudalopex gymnocercus e 18 (45%) Cerdocyon thous. Os nematóides mais prevalentes foram: Ancylostoma caninum (45,4 em P. gymnocercus e 22,2% em C. thous), Molineus felineus (9,9 em P. gymnocercus e 5,6% em C. thous), Strongyloides sp. (22,7 em P. gymnocercus e 16,7% em C. thous), Trichuris sp. (13,6 em P. gymnocercus e 11,1% em C. thous), e Capillaria hepatica (13,6 em P. gymnocercus e 5,5 % em C. thous). Os trematódeos observados foram: Alaria alata (50,0% em C. thous e 36,4 em P. gymnocercus), e Asthemia heterolecithodes em 5,6% dos C. thous. Cestóides foram identificados como Spirometra sp. (61,1% em C. thous e 54,5 em P. gymnocercus), Diphyllobothriidae (81,8 em P. gymnocercus e 77,8% em C. thous), e Acantocephala do gênero Centrorhynchus foi observado somente em 5,6% dos C. thous. Estes resultados indicaram a helmintofauna de canídeos selvagens nas áreas estudadas.Forty wild canids were captured by live trap at Municipalities of Pedro Osorio and Pelotas in Southern of the State of Rio Grande do Sul and they were transported to the Parasitology Laboratory at the Universidade Federal de Pelotas. After they were posted, segments of intestinal, respiratory and urinary tracts and liver were separated and examined. Animal skulls were used for taxonomic identification. Of forty wild animals trapped, 22 (55%) were Pseudalopex gymnocercus and 22 (55%) Cerdocyon thous. The most prevalent nematodes were: Ancylostoma caninum (45.4 in P. gymnocercus and 22.2% in C. thous), Molineus felineus (9.9 in P. gymnocercus and 5.6% in C. thous), Strongyloides sp. (22.7 in P. gymnocercus and 16.7% in C. thous), Trichuris sp. (13.6 in P. gymnocercus and 11.1% in C. thous), and Capillaria hepatica (13.6 in P. gymnocercus and 5.5 % in C. thous). The trematodes observed were: Alaria alata (36.4 in P. gymnocercus and 50.0% in C. thous), and Asthemia heterolecithodes in 5.6% C. thous. Cestodes were identified as Spirometra sp. (61.1 % in C. thous and 54.5 in P. gymnocercus), Diphyllobothriidae, (81.8 in P. gymnocercus and 77.8 % in C. thous) and an Acantocephala of the genus Centrorhynchus was also observed in 5.6% of C. thous only. These results indicated the helminths fauna in wild canids from the studied area.

Some tests were carried out in this work with the aim of evaluating a partial replacement of fat in the raw batter of ham pâté by using bovine blood constituents, such as globin (GL), plasma (PL) or 1:1 globin and plasma (GP). Plasma was separated from red cells by blood centrifugation, and globin was extracted by the carboxymethylcellulose method. The salt-soluble protein content (SSP) and the binding properties including water holding capacity (WHC) and raw batter stability (RBS) were estimated. The results indicated that among the 3 treatments studied, the use of globin showed to be a little more advantageous for the quality of the raw batter of ham pâté, since its incorporation as fat replacer led to an increase in RBS but no change of SSP was observed.

Radar systems are a topic of great interest, especially due to their extensive range of applications and ability to operate in all weather conditions. Modern radars have high requirements such as its resolution, accuracy and robustness, depending on the application. Noise Radar Technology (NRT) has the upper hand when compared to conventional radar technology in several characteristics. Its robustness to jamming, low Mutual Interference and low probability of intercept are good examples of these advantages. However, its signal processing is more complex than that associated to a conventional radar. Artificial Intelligence (AI)‐based signal processing is getting increasing attention from the research community. However, there is yet not much research on these methods for noise radar signal processing. The aim of the authors is to provide general information regarding the research performed on radar systems using AI and draw conclusions about the future of AI in noise radar. The authors introduce the use of AI‐based algorithms for NRT and provide results for its use. [ABSTRACT FROM AUTHOR]

OBJECTIVES: To determine the prevalence of class A extended spectrum β-lactamases (ESBL)-producing Escherichia coli and Klebsiella spp., and to investigate clonality among ESBL-producing isolates of nosocomial and community infections. METHODS: The study involved 354 nosocomial infections samples and 992 community infections samples, obtained between 2003 and 2006 at Caxias do Sul, RS. The detection of ESBL was performed by the disk-diffusion test. Presence of blaCTX-M, blaSHV and blaTEM β-lactamase genes was evaluated by PCR, and genomic typing was determined by pulsed-field gel electrophoresis analysis. RESULTS: Higher frequency of ESBL-producing isolates were detected among nosocomial samples of E. coli (6.7%) and Klebsiella (43.7%), than those obtained from community infections (0.4% and 2.6%). blaTEM and blaCTX were the most prevalent ESBL gene families in both E. coli and Klebsiella isolates. Different pulsotypes were obtained among ESBL-producing E. coli and 11 clones for Klebsiella spp., which occurred over the years and in different hospital wards. Among ESBL-producing K. pneumoniae, 74.3% transferred ESBL genes by conjugation and exhibited concomitant decreased aminoglycosides susceptibility. CONCLUSION: ESBL-producing E. coli, and especially K. pneumoniae are essentially a nosocomial problem, and their dissemination to the community is relatively limited. The great genetic variability observed among ESBL-producing bacteria indicates polyclonal spread and high transference of ESBL genes between bacteria in the hospital environment. This information is of paramount importance for nosocomial infection control.

Over the last decade, Acinetobacter baumannii resistant to carbapenems has emerged in many medical centres and has been commonly associated with high morbimortality. In Brazil, this resistance is mainly attributed to the spread of OXA-23-producing clones and, to a lesser extent, to OXA-143-producing clones. Here, we describe, for the first time, two OXA-72-producing A. baumannii isolates in southern Brazil to a broad spectrum of antibiotics, except polymyxin B and tigecycline. Molecular typing by multilocus sequence typing (MLST) demonstrated that both OXA-72-producing isolates belong to a new sequence type (ST), ST730, which was recently identified in OXA-23-producing A. baumannii isolates in São Paulo, Brazil. We demonstrate that the two A. baumannii ST730 isolates carrying blaOXA-72share a common ancestral origin with the blaOXA-23producers in Brazil. This observation reinforces the importance of strain-typing methods in order to clarify the dynamics of the emergence of new clones in a geographic region.

Background: In this study, we designed a novel genetic circuit sensitive to Cd2+, Zn2+ and Pb2+ by mimicking the CadA/CadR operon system mediated heavy metal homeostasis mechanism of Pseudomonas aeruginosa. The regular DNA motifs on natural operon were reconfigured and coupled with the enhanced Green Fluorescent Protein (eGFP) reporter to develop a novel basic NOT type logic gate CadA/CadR-eGFP to respond metal ions mentioned above. A Genetically Engineered Microbial (GEM)-based biosensor (E.coli-BL21:pJET1.2-CadA/CadR-eGFP) was developed by cloning the chemically synthesised CadA/CadR-eGFP gene circuit into pJET1.2-plasmid and transforming into Escherichia coli (E. coli)-BL21 bacterial cells. Results: The GEM-based biosensor cells indicated the reporter gene expression in the presence of Cd2+, Zn2+ and Pb2+ either singly or in combination. Further, the same biosensor cells calibrated for fluorescent intensity against heavy metal concentration generated linear graphs for Cd2+, Zn2+ and Pb2+ with the R2 values of 0.9809, 0.9761 and 0.9758, respectively as compared to non-specific metals, Fe3+ (0.0373), AsO43− (0.3825) and Ni2+ (0.8498) making our biosensor suitable for the detection of low concentration of the former metal ions in the range of 1–6 ppb. Furthermore, the GEM based biosensor cells were growing naturally within the concentration range of heavy metals, at 37 °C and optimum pH = 7.0 in the medium, resembling the characteristics of wildtype E.coli. Conclusion: Finally, the novel GEM based biosensor cells developed in this study can be applied for detection of targeted heavy metals in low concentration ranges (1–6 ppb) at normal bacterial physiological conditions. [ABSTRACT FROM AUTHOR]

This essay is part of a collection of short essays solicited from authors around the globe who teach religion courses at the college level (not for professional religious training). They are published together with an introduction in "Teaching Theology and Religion" 18:3 (July 2015). The authors were asked to provide a brief overview of the curriculum, student learning goals, and pedagogical techniques employed in their courses.

Introduction: Novel beta-lactam/beta-lactamase inhibitor (BIBLI) combinations are commercially available and have been used for treating carbapenem-resistant Klebsiella pneumoniae (CRKP) infections. Continuous surveillance of susceptibility profiles and resistance mechanism identification are necessary to monitor the evolution of resistance within these agents. Objective: The purpose of this study was to evaluate the susceptibility rates of ceftazidime/avibactam, imipenem/relebactam and meropenem/vaborbactam in CRKP isolated from patients with bloodstream infections who underwent screening for a randomized clinical trial in Brazil. Methods: Minimum inhibitory concentrations (MICs) were determined for meropenem, ceftazidime/avibactam, imipenem/relebactam and meropenem/vaborbactam using the gradient diffusion strip method. Carbapenemase genes were detected by multiplex real-time polymerase chain reaction. Klebsiella pneumoniae carbapenemase (KPC)-producing isolates showing resistance to any BLBLI and New Delhi Metallo-beta-lactamase (NDM)-producing isolates with susceptibility to any BLBLI isolates were further submitted for whole-genome sequencing. Results: From a total of 69 CRKP isolates, 39 were positive for blaKPC, 19 for blaNDM and 11 for blaKPC and blaNDM. KPC-producing isolates demonstrated susceptibility rates above 94 % for all BLBLIs. Two isolates with resistance to meropenem/vaborbactam demonstrated a Gly and Asp duplication at the porin OmpK36 as well as a truncated OmpK35. All NDM-producing isolates, including KPC and NDM coproducers, demonstrated susceptibility rates to ceftazidime/avibactam, imipenem/relebactam and meropenem/vaborbactam of 0 %, 9.1–21.1 % and 9.1–26.3 %, respectively. Five NDM-producing isolates that presented susceptibility to BLBLIs also had porin alterations Conclusions: This study showed that, although high susceptibility rates to BLBLIs were found, KPC-2 isolates were able to demonstrate resistance probably as a result of porin mutations. Additionally, NDM-1 isolates showed susceptibility to BLBLIs in vitro.

Abstract Background Bronchiectasis is a condition characterized by abnormal and irreversible bronchial dilation resulting from lung tissue damage and can be categorized into two main groups: cystic fibrosis (CF) and non-CF bronchiectasis (NCFB). Both diseases are marked by recurrent infections, inflammatory exacerbations, and lung damage. Given that infections are the primary drivers of disease progression, characterization of the respiratory microbiome can shed light on compositional alterations and susceptibility to antimicrobial drugs in these cases compared to healthy individuals. Methods To assess the microbiota in the two studied diseases, 35 subjects were recruited, comprising 10 NCFB and 13 CF patients and 12 healthy individuals. Nasopharyngeal swabs and induced sputum were collected, and total DNA was extracted. The DNA was then sequenced by the shotgun method and evaluated using the SqueezeMeta pipeline and R. Results We observed reduced species diversity in both disease cohorts, along with distinct microbial compositions and profiles of antimicrobial resistance genes, compared to healthy individuals. The nasopharynx exhibited a consistent microbiota composition across all cohorts. Enrichment of members of the Burkholderiaceae family and an increased Firmicutes/Bacteroidetes ratio in the CF cohort emerged as key distinguishing factors compared to NCFB group. Staphylococcus aureus and Prevotella shahii also presented differential abundance in the CF and NCFB cohorts, respectively, in the lower respiratory tract. Considering antimicrobial resistance, a high number of genes related to antibiotic efflux were detected in both disease groups, which correlated with the patient’s clinical data. Conclusions Bronchiectasis is associated with reduced microbial diversity and a shift in microbial and resistome composition compared to healthy subjects. Despite some similarities, CF and NCFB present significant differences in microbiome composition and antimicrobial resistance profiles, suggesting the need for customized management strategies for each disease.