Bacterial Reductionism: Host Thiols Enhance Virulence

Intracellular bacteria exploit host cytosolic signals to upregulate virulence genes. In this issue of Cell Host & Microbe, Wong et al. (2015) show that Burkholderia pseudomallei senses host cytosolic glutathione, a low-molecular-weight thiol, through the membrane-bound histidine sensor kinase VirA, highlighting the importance of inter-kingdom signaling in bacterial pathogenesis

Diagnóstico ambiental do segmento urbano do Rio Palmeirinha no município de Cruz Machado, PR

Orientador : Alessandro C. AngeloMonografia (especialização) - Universidade Federal do Paraná, Setor de Ciências Agrárias, Curso de Especialização em MBA em Gestão AmbientalInclui referênciasResumo : A supressão da mata ciliar ocasionada pelo crescimento urbano desordenado e pelo interesse de uso da terra para agricultura e criação de animais ao longo do rio Palmeirinha no município de Cruz Machado, no Paraná, vem gerando vários impactos importantes. Por meio de diagnóstico ambiental foi possível observar a qualidade fitossanitária dos fragmentos de mata ciliar existentes ao longo do curso d’ água no seu perímetro urbano. O presente trabalho identificou também vários impactos gerados diretamente ao corpo hídrico causando a degradação da qualidade da água e o assoreamento de sua calha. O inventário florístico nos demostrou com seus resultados que os fragmentos florestais ainda possuem em sua maioria árvores nativas, por esta razão propôs-se que seja feita um controle das espécies exóticas nestes fragmentos assim como uma fiscalização mais efetiva dos órgãos competentes as ligações de esgoto e cumprimentos da preservação das áreas de APP. Palavras-chave: Mata ciliar, diagnóstico ambiental, inventário florístico, impactos

Recurrent urinary tract infections in healthy and nonpregnant women

AbstractRecurrent urinary tract infections (RUTI) are prevalent and pose significant clinical challenges. Although the term RUTI has long been vaguely defined, a consensus definition has emerged in recent years. The exact etiology behind RUTI remains under debate, with valid arguments for both ascending reinfections as well as persistent infection inside the bladder. These persistent infections exist in the form of quiescent intracellular reservoirs in the mouse model and may represent a novel concept to explain UTI recurrence in humans. Manageable risk factors such as behavioral patterns alongside nonmanageable risk factors including genetic susceptibility are growing fields of investigation. Acute UTI have been studied through two model bacterial strains: Escherichia coli UTI89 and CFT073. However, the clinical relevance to RUTI of these two strains has not been firmly established. Current treatment strategies for RUTI are limited and remain dominated by antibiotic usage despite variable efficacy. The majority of studies in humans have focused on younger groups of women with little information available about the postmenopausal population despite a heightened risk of RUTI in this age group

Gut colonization by Proteobacteria alters host metabolism and modulates cocaine neurobehavioral responses

Gut-microbiota membership is associated with diverse neuropsychological outcomes, including substance use disorders (SUDs). Here, we use mice colonized with Citrobacter rodentium or the human γ-Proteobacteria commensal Escherichia coli HS as a model to examine the mechanistic interactions between gut microbes and host responses to cocaine. We find that cocaine exposure increases intestinal norepinephrine levels that are sensed through the bacterial adrenergic receptor QseC to promote intestinal colonization of γ-Proteobacteria. Colonized mice show enhanced host cocaine-induced behaviors. The neuroactive metabolite glycine, a bacterial nitrogen source, is depleted in the gut and cerebrospinal fluid of colonized mice. Systemic glycine repletion reversed, and γ-Proteobacteria mutated for glycine uptake did not alter the host response to cocaine. γ-Proteobacteria modulated glycine levels are linked to cocaine-induced transcriptional plasticity in the nucleus accumbens through glutamatergic transmission. The mechanism outline here could potentially be exploited to modulate reward-related brain circuits that contribute to SUDs.Fil: Cuesta, Santiago. University of Texas. Southwestern Medical Center; Estados UnidosFil: Burdisso, Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Segev, Amir. University Of Texas Southwestern Medical School,; Estados Unidos. University of Texas; Estados UnidosFil: Kourrich, Saïd. Université du Québec a Montreal; CanadáFil: Sperandio, Vanessa. University of Texas. Southwestern Medical Center; Estados Unido

The Gut Commensal Bacteroides thetaiotaomicron Exacerbates Enteric Infection through Modification of the Metabolic Landscape

SummaryThe enteric pathogen enterohemorrhagic Escherichia coli (EHEC) causes severe diarrhea, but the influence of the gut microbiota on EHEC infection is largely unknown. A predominant member of the microbiota, Bacteroides thetaiotaomicron (Bt), is resident at EHEC attachment sites. We show that Bt enhances EHEC virulence gene expression through the transcription factor Cra, which is functionally sensitive to sugar concentrations. This enhanced virulence accompanies increased formation of attaching and effacing (AE) lesions requisite for EHEC colonization. Infection with Citrobacter rodentium, a natural mouse pathogen homologous to EHEC, in Bt-reconstituted mice results in increased gut permeability along with exacerbated host pathology and mortality compared to mice deplete of microflora. Bt modifies the metabolite environment at infection sites, increasing metabolites involved in gluconeogenesis, with stark increases in succinate, which can be sensed by Cra. Our findings suggest that microbiota composition affects disease outcome and may explain links between microbiota composition and disease susceptibility

AS DIMENSÕES DOS PRODUTOS INTELIGENTES: UM ESTUDO EXPLORATÓRIO A PARTIR DA PERCEPÇÃO DOS USUÁRIOS DE SMARTPHONES

RESUMOO presente trabalho teve como objetivo explorar a percepção das dimensões-chave percebidas pelos usuários de produtos inteligentes que são: autonomia, capacidade de aprender, reatividade, capacidade de cooperação, interação humana e personalidade. Para tanto, foi realizada uma pesquisa qualitativa, por meio de 15 entrevistas em profundidade utilizando questionário semiestruturado. Para análise de conteúdo das entrevistas em profundidade foi utilizado software Nvivo Plus. A análise de cluster revelou a relação entre as dimensões habilidade para cooperar e interação humana, bem como a dimensão autonomia com habilidade para aprender. Como principais resultados, pode-se afirmar que este trabalho resultou em maior entendimento da percepção das seis dimensões-chave bem como sua relação, frequência e importância para os usuários. Além disso, identificou-se três dimensões adicionais: segurança, desempenho e status, sendo a dimensão status um resultado da percepção integrada de todas as outras dimensões.Palavras-chave: Produtos Inteligentes. Smartphone. iPhone. Dimensões-chave dos produtos inteligentes.ABSTRACTThe present work aimed to explore the perception of key dimensions perceived by users of smart products that are: autonomy, ability to learn, reactivity, capacity for cooperation, human interaction and personality. For that, a qualitative research was carried out, through 15 interviews in depth using semi-structured questionnaire. NVivo® software was used for in-depth interview content analysis. Cluster analysis revealed the relationship between the dimensions of ability to cooperate and human interaction, as well as the dimension of autonomy with ability to learn. As main results, it can be affirmed that this work resulted in a greater understanding of the perception of the six key dimensions as well as their relation, frequency and importance for the users. In addition, three additional dimensions were identified: security, performance, and status; the status dimension being a result of the integrated perception of all other dimensions.Keywords: Smart products. Smartphone. iPhone. Smart products key-dimensions

Fucose Sensing Regulates Bacterial Intestinal Colonization

The mammalian gastrointestinal (GI) tract provides a complex and competitive environment for the microbiota1. Successful colonization by pathogens depends on scavenging nutrients, sensing chemical signals, competing with the resident bacteria, and precisely regulating expression of virulence genes2. The GI pathogen enterohemorrhagic E.coli (EHEC) relies on inter-kingdom chemical sensing systems to regulate virulence gene expression3–4. Here we show that these systems control the expression of a novel two-component signal transduction system, named FusKR, where FusK is the histidine sensor kinase (HK), and FusR the response regulator (RR). FusK senses fucose and controls expression of virulence and metabolic genes. This fucose-sensing system is required for robust EHEC colonization of the mammalian intestine. Fucose is highly abundant in the intestine5. Bacteroides thetaiotaomicron (B.theta) produces multiple fucosidases that cleave fucose from host glycans, resulting in high fucose availability in the gut lumen6. During growth in mucin, B.theta contributes to EHEC virulence by cleaving fucose from mucin, thereby activating the FusKR signaling cascade, modulating EHEC’s virulence gene expression. Our findings suggest that EHEC uses fucose, a host-derived signal made available by the microbiota, to modulate EHEC pathogenicity and metabolism

Phage inhibit pathogen dissemination by targeting bacterial migrants in a chronic infection model

The microbial communities inhabiting chronic infections are often composed of spatially organized micrometer-sized, highly dense aggregates. It has recently been hypothesized that aggregates are responsible for the high tolerance of chronic infections to host immune functions and antimicrobial therapies. Little is currently known regarding the mechanisms controlling aggregate formation and antimicrobial tolerance primarily because of the lack of robust, biologically relevant experimental systems that promote natural aggregate formation. Here, we developed an in vitro model based on chronic Pseudomonas aeruginosa infection of the cystic fibrosis (CF) lung. This model utilizes a synthetic sputum medium that readily promotes the formation of P. aeruginosa aggregates with sizes similar to those observed in human CF lung tissue. Using high-resolution imaging, we exploited this model to elucidate the life history of P. aeruginosa and the mechanisms that this bacterium utilizes to tolerate antimicrobials, specifically, bacteriophage. In the early stages of growth in synthetic sputum, planktonic cells form aggregates that increase in size over time by expansion. In later growth, migrant cells disperse from aggregates and colonize new areas, seeding new aggregates. When added simultaneously with phage, P. aeruginosa was readily killed and aggregates were unable to form. When added after initial aggregate formation, phage were unable to eliminate all of the aggregates because of exopolysaccharide production; however, seeding of new aggregates by dispersed migrants was inhibited. We propose a model in which aggregates provide a mechanism that allows P. aeruginosa to tolerate phage therapy during chronic infection without the need for genetic mutation

Odontomas are associated with impacted permanent teeth in orthodontic patients

Odontomas are the most frequent odontogenic tumors in the oral cavity and can result in failure of eruption of permanent teeth or be associated with impacted teeth. The present study evaluated the prevalence of complex and compound odontomas in non-syndromic patients prior to the onset of orthodontic treatment. Panoramic radiographs of 4,267 non-syndromic patients were evaluated; 22 cases were included being 54.5% complex and 45.4% compound odontomas. The sample was composed predominantly by White males with mean age of 14.5 years. Complex odontomas were commonly found in the maxilla (83.3%) while compound type was mostly located on mandible (60%), presenting a significant association (P=0.027). Moreover, odontomas were significantly associated with impacted teeth (P<0.0001). The most frequently odontoma-associated impacted teeth were lower canines, followed by upper central incisors and upper canines, while impacted teeth with no odontoma were predominantly upper canines, lower second premolars and upper second premolars. Compound and complex odontomas showed mean size of 10.5 and 7.25 mm, respectively, presenting significant association between lesion size and odontoma type (P=0.021). Odontomas affected mainly White male patients with mean age of 14.5 years, being the complex type commonly found in the maxilla and the compound type mostly located on mandible. Furthermore, odontomas were significantly associated with impacted teeth, affecting mainly lower canines. Early diagnosis and correct treatment are essential to avoid any complications, such as prolonged retention of primary teeth and delayed eruption of permanent teeth

Genotypic profile and antimicrobial resistance of avian pathogenic Escherichia coli

Avian pathogenic Escherichia coli (APEC) is responsible for several anatomopathological conditions in poultry, which cause great damage to the poultry sector. This study aimed to evaluate the pathogenicity of E. coli strains isolated from broiler chickens and to perform in vitro tests on strains classified as APEC to identify their capacity to form biofilms and sensitivity to antimicrobials routinely used in the poultry breeding process. Sixty E. coli poultry isolated were used in this study. The real-time Polymerase Chain Reaction (PCR) test identified that 100% of the isolates had the hlyF and ompT genes, 98.3% the iroN and iss genes, and 83.33% the iutA gene, being all the evaluated strains classified as APEC. In the in vitro evaluations regarding the formation and characterization of biofilms, the APEC samples were characterized as 71.66% weakly biofilm-forming. The antibiotic sensitivity test showed that the highest resistance percentages were found in the molecules of oxytetracycline, with 33%, and doxycycline, with 31.66%, but about 58,33% of the samples had a profile of multi-resistance to antimicrobials. Further studies are needed to better characterize APEC virulence genes and multi-drug resistance, given their impact on poultry health/production and potential risk to human health